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1.
J Oral Maxillofac Surg ; 76(8): 1719-1724, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29608904

ABSTRACT

After discectomy, interpositional implants (IPIs) are believed to provide temporomandibular joint stability and protect against degenerative joint space remodeling. Alloplastic IPIs gained popularity in the late 1970s because the practice showed early success without donor site morbidity. Unfortunately, these implants were subject to substantial fragmentation resulting in an exuberant foreign body giant cell response that progressively eroded adjacent structures. Most of these alloplastic implants were removed in the years following their recall by the US Food and Drug Administration in 1991, however some remained in circulation. This report describes a case of a failed Proplast/Teflon IPI 27 years after its placement. This case highlights the considerations for managing a patient with a Proplast/Teflon IPI and serves to remind providers that, although increasingly rare, these implants are still present and subject to delayed failure.


Subject(s)
Granuloma, Foreign-Body/etiology , Mandibular Prosthesis/adverse effects , Polytetrafluoroethylene/adverse effects , Proplast/adverse effects , Temporomandibular Joint Disorders/surgery , Cephalometry , Female , Giant Cells, Foreign-Body , Granuloma, Foreign-Body/diagnostic imaging , Humans , Middle Aged , Prosthesis Failure , Radiography, Panoramic , Tomography, X-Ray Computed
2.
J La State Med Soc ; 164(1): 31-2, 2012.
Article in English | MEDLINE | ID: mdl-22533111

ABSTRACT

Soft tissue reactions to materials in joint prostheses include discoloration, fibrosis, florid histiocytic reaction, and granulomatous inflammation with foreign body giant cell reaction. Clinical manifestations include pain and swelling. We report a case of temporomandibular joint Proplast-Teflon prosthesis, followed by the development of large cell lymphoma in the left parotid gland 10 years after joint replacement. While it is unclear whether the implant directly contributed to the development of lymphoma, this association has not been previously documented, prompting this report.


Subject(s)
Arthroplasty, Replacement , Joint Prosthesis/adverse effects , Lymphoma, Large B-Cell, Diffuse , Parotid Gland , Parotid Neoplasms , Proplast/adverse effects , Temporomandibular Joint/surgery , Arthroplasty, Replacement/adverse effects , Arthroplasty, Replacement/instrumentation , Arthroplasty, Replacement/methods , Equipment Failure Analysis , Humans , Lymphoma, Large B-Cell, Diffuse/pathology , Lymphoma, Large B-Cell, Diffuse/surgery , Male , Middle Aged , Parotid Gland/pathology , Parotid Gland/surgery , Parotid Neoplasms/etiology , Parotid Neoplasms/pathology , Parotid Neoplasms/surgery , Proplast/therapeutic use , Time , Treatment Outcome
3.
J Oral Maxillofac Surg ; 67(4): 788-96, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19304036

ABSTRACT

PURPOSE: Previous studies made only qualitative assessments of immune cell responses to temporomandibular joint (TMJ) implant wear debris. The aim of this study was to perform a quantitative comparison of inflammatory cell types in TMJ tissues with implant wear debris, TMJ tissues with a history of disc pathology without implant debris, and TMJ tissues from normal control subjects. MATERIALS AND METHODS: TMJ tissues were collected from the following 3 groups of subjects: 1) individuals with failed TMJ implants (implant group, n = 10), 2) patients with TMJ disc pathology but no history of implant placement (nonimplant surgery group, n = 10), and normal cadaveric tissues with no history of surgery (control group, n = 10). Tissue sections (5 microm) from all subjects were stained with hematoxylin-eosin, after which cell counts were done for 2 types of inflammatory cells: multinucleated giant cells and lymphocytes. Mean inflammatory cell counts from the 3 groups were compared by use of a 1-way analysis of variance procedure and Bonferroni adjustment to maintain an overall type I error rate of .05. RESULTS: Implant group tissues contained significantly more inflammatory cells than tissues from the nonimplant surgery and control groups (P < .0001). Multinucleated giant cells were only present in implant group tissues. Although the high number of multinucleated giant cells present in the implant group obscured a total count of lymphocytes for that group, lymphocyte cell counts were still significantly greater (P < .005) in implant group tissues than in tissues from the other 2 groups. CONCLUSIONS: Our data provide quantitative confirmation that the presence of Proplast-Teflon implant (Vitek, Houston, TX) wear debris is associated with a significant increase in the number of local multinucleated giant cells and lymphocytes.


Subject(s)
Biocompatible Materials/chemistry , Giant Cells/pathology , Joint Prosthesis , Lymphocytes/pathology , Temporomandibular Joint/immunology , Adult , Aged , Cadaver , Cell Count , Coloring Agents , Connective Tissue/immunology , Connective Tissue/pathology , Female , Fluorescent Dyes , Humans , Lymphocyte Count , Male , Middle Aged , Polytetrafluoroethylene/chemistry , Proplast/chemistry , Prosthesis Failure , Surface Properties , Temporomandibular Joint/pathology , Temporomandibular Joint Disc/immunology , Temporomandibular Joint Disc/surgery , Temporomandibular Joint Disorders/immunology , Temporomandibular Joint Disorders/surgery , Young Adult
4.
J Oral Maxillofac Surg ; 66(6): 1112-24, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18486775

ABSTRACT

PURPOSE: The purpose of this study was to perform a retrieval analysis of temporomandibular joint (TMJ) alloplastic interpositional implants and test possible correlation between implant failure features and patient clinical outcomes. In addition, we investigated the implants' surface and examined the foreign body reaction associated with different types of alloplastic materials. MATERIALS AND METHODS: Twelve implants (Proplast/Teflon [Vitek, Houston, TX] and Silastic [Dow Corning, Midland, MI]) were surgically removed from the patients' TMJs. Implant surface failure features (fracture length, perforation of the implants) were observed using stereomicroscopy and recorded for description of the failure mechanisms and to statistically compare with clinical outcomes. Patients' clinical data (pain symptoms and mandibular function) were collected and examined. Clinical outcomes were obtained relative to symptom severity (Symptom Severity Index [SSI]) and jaw function (modified Mandibular Function Impairment Questionnaire [mMFIQ]). Peri-implant soft tissues and implants were analyzed with light microscopy and stereo zoom microscopy. Electron microprobe analysis of implant fragments and peri-implant tissues was performed. RESULTS: The statistical results showed that only the presence of implant perforation was statistically associated with the SSI, specifically with the pain tolerability dimension. No statistical association was seen between any of the other implant failure predictors and the SSI and between the predictors and the mMFIQ. Stereo zoom microscopy suggested that Proplast/Teflon implants (n = 7) were susceptible to perforation, layer tearing, fracture and fiber extrusion. The Silastic implants (n = 3) revealed a possible center perforation with fracture lines towards the periphery and fiber extrusion. Teflon implant wear debris particles appear to trigger a multinucleated giant cell foreign body reaction. CONCLUSION: Facial pain was a significant correlate to perforation and breakdown of the alloplastic TMJ interpositional implants, and most likely was the reason for implant removal.


Subject(s)
Arthroplasty, Replacement/adverse effects , Device Removal , Prosthesis Failure , Temporomandibular Joint Disc , Temporomandibular Joint Disorders/surgery , Adult , Aged , Aged, 80 and over , Dimethylpolysiloxanes , Electron Probe Microanalysis , Facial Pain/etiology , Female , Foreign-Body Reaction/etiology , Humans , Male , Middle Aged , Pilot Projects , Proplast , Silicones , Surveys and Questionnaires , Temporomandibular Joint/pathology
5.
Int J Oral Maxillofac Surg ; 37(8): 763-7, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18375102

ABSTRACT

Multiple reports document that a foreign-body giant cell reaction forms around Proplast-Teflon temporomandibular joint (TMJ) implants. This results in destruction of surrounding bone and instability of the implants. This case presents a patient whose Proplast-Teflon TMJ implants became displaced into her middle cranial fossa. The staged reconstruction of this patient is described, including removal of the TMJ implants, reconstruction of the defect, concomitant orthodontic treatment and final reconstruction with TMJ Concepts. This process involved a multidisciplinary approach between several medical and dental specialties. At her 3-year follow up, the patient had a stable postoperative result.


Subject(s)
Arthroplasty, Replacement/adverse effects , Joint Prosthesis/adverse effects , Plastic Surgery Procedures/methods , Temporomandibular Joint Disorders/surgery , Temporomandibular Joint/surgery , Bone Transplantation , Female , Foreign-Body Reaction/etiology , Foreign-Body Reaction/surgery , Humans , Middle Aged , Polytetrafluoroethylene/adverse effects , Proplast/adverse effects , Prosthesis Failure , Pseudarthrosis/etiology , Pseudarthrosis/surgery , Range of Motion, Articular , Reoperation , Temporomandibular Joint Disorders/complications , Treatment Failure , Treatment Outcome
9.
Curr Opin Otolaryngol Head Neck Surg ; 14(4): 270-7, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16832185

ABSTRACT

PURPOSE OF REVIEW: This review examines implant materials currently used in rhinoplasty. In revision cases, the most desirable autogenous grafts from the septum are often unavailable in adequate quantities. The 'ideal' implant has strict requirements concerning biocompatibility, plasticity, stability of form, resistance to infection, and removability. RECENT FINDINGS: Silicone implants continue to be used in spite of frequent reports of rejection. In spite of its described absorption, conserved cartilage can help in preserving profiles. Increasingly, good results are being reported with porous polyethylene, although Proplast is sometimes used in its place. Despite the fact that AlloDerm is partially absorbed, it can still be useful. GoreTex is effective for smaller defects. Mersilene mesh is not absorbed and retains its stability of shape. 'Turkish Delight' (diced cartilage with a wrapping) seems to be absorbed when the wrapping is made of Surgicel, but a wrapping of autogenous fascia provides lasting results. SUMMARY: Several alloplastic materials do have a place in nasal surgery. Provided that the correct techniques are employed, side effects from their use are no greater than the complications resulting from the use of autogenous costal cartilage, with the intervention necessary for its harvesting.


Subject(s)
Biocompatible Materials/standards , Nasal Septum/surgery , Nose/surgery , Rhinoplasty , Bone Transplantation , Cartilage/transplantation , Collagen , Humans , Nasal Septum/transplantation , Polyethylene , Polyethylene Terephthalates , Polytetrafluoroethylene , Proplast , Silicones , Tissue Transplantation , Transplantation, Autologous
10.
Plast Reconstr Surg ; 116(5): 1502-16, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16217502

ABSTRACT

BACKGROUND: A retrospective evaluation of the authors' 32 years of experience in revision rhinoplasty is presented. The authors suggest that iatrogenic nasal deformities are studied under four groups on the basis of their location and the affected structures: lower third, middle third, upper third, and combined deformities. The authors also present the vertical columellar incision for insertion of alloplastic implants and cartilage grafts, a genuine approach avoiding contamination with the nasal flora. METHODS: A total of 182 cases were studied, as follows: lower third (n = 81), middle third (n = 65), upper third (n = 17), and combined (n = 19) deformities. The mean age of the patients was 40 years. RESULTS: Our follow-up was a minimum of 2 years, and some of the cases with Proplast implants have been followed for as long as 21 years. During this rather long follow-up, only two of the Proplast implants had to be removed (one because of an acute infection and the other because of a chronic infection causing extrusion after 5 years). CONCLUSIONS: The authors have always preferred to use autogenous cartilage grafts for tip deformities and Proplast implants for middle and upper third saddle nose deformities whenever necessary. Their long-term results with Proplast for more than 20 years show that alloplastic materials may be as reliable as autogenous implants if the surgical principles are met and the cases are carefully selected.


Subject(s)
Proplast/therapeutic use , Prostheses and Implants , Rhinoplasty/methods , Adolescent , Adult , Cartilage/transplantation , Female , Humans , Male , Middle Aged , Nasal Bone/surgery , Nasal Septum/surgery , Reoperation , Retrospective Studies , Rhinoplasty/trends , Transplantation, Autologous
11.
J Oral Maxillofac Surg ; 62(9): 1088-96, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15346359

ABSTRACT

PURPOSE: Total alloplastic temporomandibular joint (TMJ) reconstruction is often necessary because of the significant bony destruction resulting from failed Proplast-Teflon (Vitek, Houston, TX) and/or Silastic (Dow Corning, Arlington, TX) foreign body inflammatory reactions. Multiply operated and functionless, TMJ patients likewise have undergone total alloplastic reconstruction. Many of these patients were also exposed to failed TMJ implant materials. It was the purpose of this study to evaluate a population representative of both these groups of patients reconstructed with the Techmedica (now, TMJ Concepts, Ventura, CA) Total TMJ System to determine whether the long-term subjective and objective outcomes were affected by either the presence of the previously failed TMJ implant materials, the number of prior procedures, or both. PATIENTS AND METHODS: One hundred ninety-eight patients who had been implanted with 332 Techmedica System total joints between 1990 and 1994 where divided into 4 groups based on their prior exposure to failed TMJ implant materials: group I, Proplast-Teflon (82 patients, 135 joints); group II, Silastic (28 patients, 46 joints); group III, both Proplast-Teflon and Silastic (25 patients, 46 joints); and group IV, no prior exposure to Proplast-Teflon or Silastic (63 patients, 105 joints). The mean follow-up was 60.2 +/- 40.3 months (range, 2 to 120 months). To determine whether exposure to either or both failed implant materials affected the long-term subjective and objective outcome variables, the groups were compared statistically using multivariate mixed modeling with age, sex, number of prior operations, years with TMJ problem, prior implant type, and implant sides as independent variables, and the relevant baseline measure as covariates. RESULTS: For the subjective variables, patients exposed to Proplast-Teflon or Silastic had significantly higher mean pain scores long-term. The type of prior failed TMJ implant material was not statistically significant with regard to function. Patients exposed to Proplast-Teflon reported poorer diet consistency scores long-term. Objectively, patients with 5 or fewer prior TMJ surgeries exposed to neither failed implant or Silastic reported better long-term mean maximum interincisal opening than did those patients exposed to Proplast-Teflon or both failed materials. However, for patients with 6 or more prior TMJ surgeries, those exposed to Proplast-Teflon or both failed materials reported less decrease in mean maximum interincisal opening over time. CONCLUSION: These data confirm what has been observed clinically, that in the population studied, multiply operated patients previously exposed to failed Proplast-Teflon alone or both failed Proplast-Teflon and Silastic have poorer reported long-term outcomes with alloplastic reconstruction. However, the total alloplastic TMJ reconstruction devices used in this study remained functional.


Subject(s)
Arthroplasty, Replacement , Arthroplasty/adverse effects , Biocompatible Materials/adverse effects , Temporomandibular Joint Disorders/surgery , Adult , Age Factors , Aged , Cohort Studies , Diet , Dimethylpolysiloxanes/adverse effects , Facial Pain/surgery , Female , Follow-Up Studies , Foreign-Body Reaction/etiology , Humans , Joint Prosthesis , Longitudinal Studies , Male , Middle Aged , Proplast/adverse effects , Range of Motion, Articular/physiology , Sex Factors , Silicones/adverse effects , Treatment Outcome
12.
Int J Oral Maxillofac Surg ; 32(3): 268-74, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12767873

ABSTRACT

This prospective study evaluated the 5 to 8 year subjective and objective results of 42 consecutive patients who had TMJ reconstruction using the TMJ Concepts/Techmedica custom made total joint prosthesis. Criteria for use of the prosthesis included the following TMJ conditions: (1) multiply operated, (2) previous alloplastic implants, (3) osteoarthritis, (4) inflammatory or resorptive arthritis, (5) connective tissue or autoimmune disease, (6) ankylosis, and (7) absent or deformed structures. Thirty-eight of 42 patients (90%) with 69 TMJs reconstructed using the TMJ Concepts/Techmedica total joint prosthesis had appropriate data for inclusion in the study. The average age at surgery was 36 years and average follow-up was 73.5 months. The entire group and three subgroups were objectively evaluated for incisal opening, lateral excursions, and occlusal stability, while subjectively assessed for pain and jaw function. Paired t-test and comparison analyses were used to assess outcomes. For the group of 38 patients, there was statistically significant improvement in incisal opening (P=0.001), jaw function (P=0.001), and pain level (P=0.0001). Lateral excursion movements significantly decreased (P=0.04). The occlusion remained stable in all cases. Complications occurred in six patients. Comparison analysis of the three groups demonstrated significantly better outcomes for patients with fewer previous TMJ surgeries and without exposure to Proplast-Teflon or Silastic TMJ implants. This study demonstrated that the TMJ Concepts/Techmedica total joint prosthesis is a viable technique for TMJ reconstruction as a primary procedure and for patients with previous multiple TMJ surgeries and mutilated anatomy of the TMJ.


Subject(s)
Arthroplasty, Replacement/instrumentation , Joint Prosthesis , Oral Surgical Procedures , Temporomandibular Joint Disorders/surgery , Temporomandibular Joint/surgery , Adolescent , Adult , Chromium Alloys , Dimethylpolysiloxanes , Female , Follow-Up Studies , Humans , Male , Middle Aged , Polyethylene , Polytetrafluoroethylene , Proplast , Prosthesis Design , Reoperation , Silicones , Titanium
13.
J Oral Maxillofac Surg ; 60(12): 1389-99, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12464999

ABSTRACT

PURPOSE: An undetermined number of patients with temporomandibular joint (TMJ) symptoms have been treated with intra-articular disc implants composed of Teflon ethylene/propylene or Teflon polytetrafluoroethylene and aluminum oxide (Proplast-Teflon; Vitek, Houston, TX). These implants have shown the potential to fragment in situ resulting in nonbiodegradable particles that stimulate a giant cell reaction and lead to degeneration of local structures, pain, and limitation of mandibular opening. We examined the possible relationship between TMJ implants and persistent pain, responses to sensory stimuli, quality of life, and systemic immune dysfunction. PATIENTS AND METHODS: This case series (32 patients) were referred from university-based orofacial pain centers and private practices from across the United States. Laboratory and clinical assessments evaluated orofacial pain symptoms, neurologic function, clinical signs and symptoms of rheumatologic disease, physical function, systemic measures of immune function, and behavioral measures. RESULTS: We found that TMJ implant patients appeared to have altered sensitivity to sensory stimuli, a higher number of tender points with a diagnosis of fibromyalgia, increased self-report of chemical sensitivity, higher psychologic distress and significantly lower functional ability. Systemic illness or autoimmune disease was not evident in this series of TMJ implant patients. CONCLUSIONS: Significant problems were noted on clinical assessment of TMJ implant patients. This is a US government work. There are no restrictions on its use.


Subject(s)
Arthroplasty, Replacement/adverse effects , Facial Pain/etiology , Joint Prosthesis/adverse effects , Quality of Life , Temporomandibular Joint Disorders/surgery , Temporomandibular Joint/surgery , Adult , Analysis of Variance , Arthroplasty, Replacement/psychology , Autoimmune Diseases/etiology , Environmental Exposure , Female , Fibromyalgia/etiology , Humans , Immunophenotyping , Joint Prosthesis/psychology , Male , Middle Aged , Pain Measurement , Polytetrafluoroethylene/adverse effects , Proplast/adverse effects , Range of Motion, Articular , Statistics, Nonparametric , Temporomandibular Joint/immunology , Temporomandibular Joint/physiology , Temporomandibular Joint Disorders/psychology
14.
J Oral Maxillofac Surg ; 60(12): 1400-11; discussion 1411-2, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12465000

ABSTRACT

PURPOSE: The purpose of this study was to determine the long-term objective and subjective outcomes of temporomandibular joint (TMJ) implant surgery for the treatment of painful TMJ disc displacement using temporary Silastic (Dow Corning Corporation, Midland, MI), permanent Silastic, or Proplast (Vitek, Houston, TX) implants to replace the disc. These cases were compared with other cases of the same diagnosis treated with either nonsurgical rehabilitation or nonimplant surgery involving discectomy or disc repair procedures. MATERIALS AND METHODS: A cross-sectional study was conducted among 466 patients who received treatment for unilateral or bilateral TMJ disc displacement before January 1, 1990. The 5 treatment groups noted above were compared for long-term outcomes. Objective outcome measurements for jaw function were performed using a calibrated examiner and the Craniomandibular Index (CMI). Subjective (self-reported) outcomes were obtained relative to jaw function (Mandibular Function Impairment Questionnaire [MFIQ]), symptom severity (Symptom Severity Index [SSI]), and the impact of pain (Global Pain Impact [GPI] scale). RESULTS: The results, adjusted for gender, baseline tomogram score, and baseline symptom scores, showed that the nonsurgical rehabilitation group (n = 159) and the group having TMJ surgery without implants (n = 149) had statistically better results than the group who underwent surgery with a Proplast implant (n = 94). These between-group differences included both objective signs (CMI), and subjective reports of jaw function (MFIQ), symptom severity (SSI), and global pain impact (GPI). The MFIQ score associated with the nonsurgical rehabilitation group was also statistically better than for the Silastic implant groups, including both the temporary (n = 31) and permanent (n = 33) implants. Clinical differences between groups were slight. CONCLUSION: This study suggests that the use of interpositional disc implants in TMJ surgery is not associated with improved outcomes when compared with nonimplant surgery or nonsurgical rehabilitation.


Subject(s)
Arthroplasty, Replacement , Joint Prosthesis , Temporomandibular Joint Disc/surgery , Temporomandibular Joint Disorders/surgery , Adult , Arthroplasty, Replacement/adverse effects , Cross-Sectional Studies , Dimethylpolysiloxanes/adverse effects , Facial Pain/etiology , Female , Follow-Up Studies , Humans , Joint Dislocations/rehabilitation , Joint Dislocations/surgery , Joint Dislocations/therapy , Joint Prosthesis/adverse effects , Male , Mandible/physiology , Middle Aged , Pain Measurement , Physical Therapy Modalities , Proplast/adverse effects , Range of Motion, Articular , Silicones/adverse effects , Surveys and Questionnaires , Temporomandibular Joint Disorders/rehabilitation , Temporomandibular Joint Disorders/therapy , Treatment Outcome
15.
Minerva Chir ; 57(3): 283-7, 2002 Jun.
Article in English, Italian | MEDLINE | ID: mdl-12029221

ABSTRACT

BACKGROUND: Bone deficits of the midface can be observed following tumor surgery, facial traumas or malformations, and can determine aesthetic deformities requiring surgical corrections. The goal of this study is to illustrate the 23 years experience of the Maxillo-Facial Department of the "La Sapienza" University of Rome, in surgical correction of middle third bone loss for aesthetic improvement, and to compare postsurgical results from the use of biomaterials and homologous bone grafts. METHODS: From January 1977 to January 2000, 18 patients were surgically treated with bone grafts for bone deficit of the midface requiring aesthetic improvements, and 23 received biomaterial placement in the same district. A retrospective analysis regarding aesthetic improvements following corrective (reconstructive) surgery was carried out in order to compare long-term results obtained with bone grafts and biomaterials. RESULTS: Of the 19 implants of the zygomatic bone, 1 patient suffered from infection, observ-ed on the 8th day, following iliac bone graft in the maxillary area. Of the 32 prostheses, 7 became infected and in 1 case the material became exposed: Proplast(R) became infected 2 times, Gore-tex(R) 3 times and 1 time became exposed; 2 of the 24 Medpor(R) implants resulted in infection. The employment of bone graft obtained a good short term aesthetic result. Medpor(R) employment, was evaluated as an optimal aesthetic improvement. We cannot evaluate the results obtained with Gore-tex(R) and Proplast(R) because of the few cases treated. Anyway we consider unsatisfactory the corrections obtained with these 2 materials. CONCLUSIONS: Homologous bone grafts are still considered as the best choice when a further fixture positioning is planned for prosthetic rehabilitation of the alveolar ridge of the upper jaw or mandible. At the present time, some biomaterials are the definitive solution for restoring facial harmony in the 3 spatial dimensions.


Subject(s)
Biocompatible Materials , Bone Transplantation/methods , Facial Bones/surgery , Plastic Surgery Procedures/methods , Biocompatible Materials/adverse effects , Bone Transplantation/adverse effects , Facial Bones/pathology , Humans , Ilium/transplantation , Italy , Maxilla/surgery , Polyethylenes , Polytetrafluoroethylene , Proplast , Prosthesis-Related Infections/etiology , Plastic Surgery Procedures/adverse effects , Retrospective Studies , Transplantation, Homologous , Treatment Outcome , Zygoma/surgery
16.
Plant Cell Physiol ; 42(3): 251-63, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11266576

ABSTRACT

A temperature-sensitive, elongation-deficient mutant of Arabidopsis thaliana was isolated. At the non-permissive temperature of 31 degrees C, the mutation impaired tissue elongation; otherwise, tissue development was normal. Hypocotyl cells that had established cell walls at 21 degrees C under light-dark cycles ceased elongation and swelled when the mutant was shifted to 31 degrees C and darkness, indicating that the affected gene is essential for cell elongation. Analysis of the cell walls of mutant plants grown at 31 degrees C revealed that the cellulose content was reduced to 40% and the pectin content was increased to 162% of the corresponding values for the wild type grown at the same temperature. The increased amounts of pectin in the mutant were bound tightly to cellulose microfibrils. No change in the content of hemicellulose was apparent in the 31 degrees C-adapted mutant. Field emission-scanning electron microscopy suggested that the structure of cellulose bundles was affected by the mutation; X-ray diffraction, however, revealed no change in the crystallite size of cellulose microfibrils. The regeneration of cellulose microfibrils from naked mutant protoplasts was substantially delayed at 31 degrees C. The recessive mutation was mapped to chromosome V, and map-based cloning identified it as a single G-->A transition (resulting in a Gly(429)-->Arg substitution) in KORRIGAN, which encodes a putative membrane-bound endo-1,4-beta-glucanase. These results demonstrate that the product of this gene is required for cellulose synthesis.


Subject(s)
Arabidopsis/enzymology , Cellulase/physiology , Cellulose/biosynthesis , Membrane Proteins/physiology , Arabidopsis/genetics , Arabidopsis Proteins , Base Sequence , Cell Wall , Cellulase/genetics , Cellulase/metabolism , Chromosome Mapping , DNA, Plant , Genes, Plant , Membrane Proteins/genetics , Membrane Proteins/metabolism , Molecular Sequence Data , Mutagenesis , Polysaccharides , Proplast/metabolism , Temperature
18.
FEBS Lett ; 449(1): 57-60, 1999 Apr 16.
Article in English | MEDLINE | ID: mdl-10225428

ABSTRACT

Hyperpolarization of tobacco protoplasts is amongst the earliest auxin responses described. It has been proposed that the auxin-binding protein, ABP1, or a related protein could be involved in the first step of auxin perception at the plasma membrane. Using for the first time homologous conditions for interaction between the protein Nt-ERabp1 or a synthetic peptide corresponding to the C-terminus and tobacco protoplasts, we have demonstrated that both can induce the hyperpolarization response. The results show that Nt-ERabp1 or the C-terminal peptide alone activates the auxin pathway from the outer face of the plasma membrane.


Subject(s)
Indoleacetic Acids/metabolism , Plant Growth Regulators , Plant Proteins/metabolism , Receptors, Cell Surface/metabolism , Signal Transduction , Amino Acid Sequence , Molecular Sequence Data , Peptides/metabolism , Plants, Toxic , Proplast , Nicotiana , Zea mays
20.
J Oral Maxillofac Surg ; 57(4): 364-70; discussion 370-1, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10199486

ABSTRACT

PURPOSE: This study investigates the self-reported immune-related health status of patients exposed to Proplast-Teflon (P/T) temporomandibular joint (TMJ) implants, comparing their health status with a group of patients who were not exposed to any alloplastic TMJ implants. It also compares those whose implants were removed with those in whom they were retained. PATIENTS AND METHODS: Patients seen in a single oral and maxillofacial surgical practice completed a detailed self-report questionnaire about physical symptoms and disorders. Sixty-four had received P/T implants, and 22 were unexposed to any TMJ alloplastic implant. Of the P/T-exposed group, 44 had removed and 20 had retained implants. RESULTS: In general, P/T-exposed patients did not differ from unexposed patients in rates of reported immune-mediated and somatization-related conditions, allergies, or symptoms of environmental sensitivity. However, patients with removed P/T implants reported significantly more problems in all categories of conditions than those with retained P/T implants. This difference was no longer statistically significant after controlling for pain severity and sex. CONCLUSIONS: Although P/T-exposed patients do not report more systemic health conditions than similar patients who were unexposed to alloplastic jaw implants, those with removed implants report more conditions and are more likely to be seen in clinical practice. This may lead to a bias in the general perception regarding the systemic health status of P/T-exposed patients. In addition, effects may be secondary to high levels of pain and dysfunction among patients with removed implants, rather than implant exposure itself. Future prospective research is needed to identify factors associated with implant failure.


Subject(s)
Immune System Diseases/etiology , Joint Prosthesis/adverse effects , Polytetrafluoroethylene/adverse effects , Proplast/adverse effects , Temporomandibular Joint/surgery , Adult , Female , Foreign-Body Reaction/epidemiology , Foreign-Body Reaction/etiology , Humans , Hypersensitivity/epidemiology , Hypersensitivity/etiology , Immune System Diseases/epidemiology , Joint Prosthesis/statistics & numerical data , Logistic Models , Male , Middle Aged , Pain Measurement , Somatoform Disorders/epidemiology , Somatoform Disorders/etiology , Surveys and Questionnaires
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