bluuebunny/crossref_metadata_2025_split huggingface dataset:
Epidermal Growth Factor Signaling Mediated by Grb2 Associated Binder1 Is Required for the Spatiotemporally Regulated Proliferation of Olig2-Expressing Progenitors in the Embryonic Spinal Cord
Authors: Hayakawa-Yano Yoshika , Nishida Keigo , Fukami Shinichi , Gotoh Yukiko , Hirano Toshio , Nakagawa Toshiyuki , Shimazaki Takuya , Okano Hideyuki 
Published: March 2007

Abstract
Gab1 (Grb2 associated binder1) has been identified as an adaptor molecule downstream of many growth factors, including epidermal growth factor (EGF), fibroblast growth factor, and platelet-derived growth factor, which have been shown to play crucial roles as mitotic signals for a variety of neural progenitor cells, including stem cells, both in vitro and in vivo. Here, we show that Gab1 deficiency results in a reduction in the number of Olig2-positive (Olig2+) progenitor cells in the developing mouse spinal cord after embryonic day 12.5 (E12.5), when gliogenesis starts in the pMN domain where the EGF receptor (EGFR) is expressed predominantly. Our in vitro analysis further revealed that Gab1 is essential for EGF-dependent proliferation of Olig2+ progenitor cells derived from the E12.5 ventral and E14.5 dorsal but not ventral spinal cord, whereas Gab1 is always required for the activation of Akt1 but not of ERK1/2. Moreover, we found that the action of the Gab1/Akt pathway is context-dependent, since constitutively active Akt1 could rescue the proliferation defect only in the E12.5 spinal cord of the Gab1-deficient mouse in vitro. Finally, we demonstrated that EGFR-deficient mice and Gab1-deficient mice showed a similar reduction in the number of Olig2+ progenitor cells in the developing spinal cord. These findings indicate that EGFR-mediated signaling through Gab1/Akt contributes to the sufficient expansion of Olig2+ progenitor cells in a spatiotemporally regulated manner, which represents the origin of glial cells in the developing spinal cord.
Disclosure of potential conflicts of interest is found at the end of this article.
Bone Augmentation Techniques
Authors: McAllister Bradley S. , Haghighat Kamran 
Published: March 2007

Background: The advent of osseointegration and advances in biomaterials and techniques have contributed to increased application of dental implants in the restoration of partial and completely edentulous patients. Often, in these patients, soft and hard tissue defects result from a variety of causes, such as infection, trauma, and tooth loss. These create an anatomically less favorable foundation for ideal implant placement. For prosthetic‐driven dental implant therapy, reconstruction of the alveolar bone through a variety of regenerative surgical procedures has become predictable; it may be necessary prior to implant placement or simultaneously at the time of implant surgery to provide a restoration with a good long‐term prognosis. Regenerative procedures are used for socket preservation, sinus augmentation, and horizontal and vertical ridge augmentation.Methods: A broad overview of the published findings in the English literature related to various bone augmentation techniques is outlined. A comprehensive computer‐based search was performed using various databases that include Medline and PubMed. A total of 267 papers were considered, with non‐peer‐reviewed articles eliminated as much as possible.Results: The techniques for reconstruction of bony defects that are reviewed in this paper include the use of particulate bone grafts and bone graft substitutes, barrier membranes for guided bone regeneration, autogenous and allogenic block grafts, and the application of distraction osteogenesis.Conclusions: Many different techniques exist for effective bone augmentation. The approach is largely dependent on the extent of the defect and specific procedures to be performed for the implant reconstruction. It is most appropriate to use an evidenced‐based approach when a treatment plan is being developed for bone augmentation cases.
Polymorphisms Within the IL‐1 Gene Cluster: Effects on Cytokine Profiles in Peripheral Blood and Whole Blood Cell Cultures of Patients With Aggressive Periodontitis, Juvenile Idiopathic Arthritis, and Rheumatoid Arthritis
Authors: Havemose‐Poulsen Anne , Sørensen Lars Korsbæk , Bendtzen Klaus , Holmstrup Palle 
Published: March 2007

Background: Genetic polymorphisms of cytokines have been associated with the susceptibility, severity, and clinical outcome of inflammatory diseases, such as periodontitis and chronic arthritis. An important question to address is how interleukin (IL)‐1 polymorphisms affect the cytokine profiles of patients with such diseases.Methods: The study population consisted of Danish white adults, <3‐ years of age, who were diagnosed with localized aggressive periodontitis (LAgP, n = 18), generalized aggressive periodontitis (GAgP, n = 27), juvenile idiopathic arthritis (JIA, n = 10), and rheumatoid arthritis (RA, n = 23) and healthy individuals with no systemic or oral diseases (n = 25). Genotypes of IL‐1A−889, IL‐1A+4845, IL‐1B−511, and IL‐1B+3954 were determined by polymerase chain reaction (PCR)‐restriction fragment length polymorphism, and IL‐1RN variable number tandem repeat (VNTR) was detected by PCR amplification and fragment size analysis. Analysis of variance was used to evaluate the effects of IL‐1 genotypes on the levels of IL‐1α, ‐1β, ‐1 receptor antagonist, ‐6, and ‐10; tumor necrosis factor‐alpha (TNF‐α); and lymphotoxin‐α in peripheral blood (plasma) and in unstimulated and stimulated whole blood cell cultures from the same blood collection.Results: The frequencies of IL‐1 genotypes investigated did not differ significantly between diseased and control individuals. In LAgP patients, allele 2 of IL‐1RN VNTR was associated with significantly higher levels of IL‐1α, ‐6, and ‐10 and TNF‐α, whereas allele 2 of IL‐1B+39‐4 was associated with significantly lower levels of the same cytokines. In GAgP patients, a general lack of association was found. In JIA and RA patients, IL‐1RN VNTR also influenced the cytokine levels.Conclusions: IL‐1 genotypes were associated with cytokine levels in patients with aggressive periodontitis and chronic arthritis. No associations were observed in control individuals.
A Histologic and Histometric Assessment of the Influence of Nicotine on Alveolar Bone Loss in Rats
Authors: Bosco Alvaro Francisco , Bonfante Samara , de Almeida Juliano Milanezi , Luize Danielle Shima , Nagata Maria José Hitomi , Garcia Valdir Gouveia 
Published: March 2007

Background: Cigarette smoking has long been recognized as a risk factor for periodontal disease. The aim of this study was to perform quantitative and qualitative analyses of bone loss in the furcation region of periodontally healthy rats after daily systemic administration of nicotine or saline solution.Methods: Thirty adult male Wistar rats were assigned randomly to twice daily subcutaneous injections of saline solution (control, group C) or nicotine (group N). The animals were sacrificed at 37, 44, or 51 days after the first subcutaneous injection. The specimens were processed for serial histologic sections, and the area of bone loss in the furcation region of the second molar was analyzed histometrically.Results: Greater bone loss was detected in group N compared to group C on day 37 (16.36 ± 5.84 mm2 and 7.24 ± 2.66 mm2), day 44 (15.12 ± 4.57 mm2 and 7.76 ± 1.35 mm2), and day 51 (18.80 ± 3.71 mm2 and 8.74 ± 2.61 mm2), respectively (P <0.05). Extension of bone loss appeared greater in the furcation region of group N where a thinner trabeculae bone was found. After day 37, bone loss did not increase significantly.Conclusions: Daily systemic administration of nicotine resulted in significantly greater bone loss in the furcation region compared to saline solution. This indicated a close association between nicotine and periodontal morbidity in rats.
The Combined Genotypes of Stimulatory and Inhibitory Fcγ Receptors Associated With Systemic Lupus Erythematosus and Periodontitis in Japanese Adults
Authors: Kobayashi Tetsuo , Ito Satoshi , Yasuda Keiko , Kuroda Takeshi , Yamamoto Kouji , Sugita Noriko , Tai Hideaki , Narita Ichiei , Gejyo Fumitake , Yoshie Hiromasa 
Published: March 2007

Background: The pathobiology of systemic lupus erythematosus (SLE) is similar to that of periodontitis in that the immunoglobulin G Fc receptor (FcγR) and proinflammatory cytokines play an important role. Genetic variations of FcγR and interleukin (IL)‐1 are associated with susceptibility to both diseases. Therefore, we evaluated whether the combination of FcγR or IL‐1 polymorphic genes represents a common risk factor for SLE and periodontitis.Methods: The study population consisted of Japanese adults with SLE and periodontitis (SLE+P group; n = 46), SLE only (SLE group; n = 25), periodontitis only (P group; n = 58), and healthy individuals with no systemic or oral disease (H group; n = 44). Clinical periodontal condition was evaluated by measurement of probing depth, clinical attachment level, and alveolar bone loss. Genomic DNA was isolated from peripheral blood and analyzed for determination of FcγR genotypes (FcγRIIA, FcγRIIB, FcγRIIIA, and FcγRIIIB) and IL‐1 genotypes (IL‐1A +4845 and IL‐1B +3954) by allele‐specific polymerase chain reactions or DNA sequencing.Results: A significant overrepresentation of the R131 allele of stimulatory FcγRIIA and the 232T allele of inhibitory FcγRIIB was found in the SLE+P group compared to the H group (P = 0.01 and P = 0.0009, respectively). The combination of FcγRIIA‐R131 and FcγRIIB‐232T alleles yielded a strong association with SLE and periodontitis (SLE+P group versus P group: P = 0.01, odds ratio: 3.3; SLE+P group versus H group: P = 0.0009, odds ratio: 11.2). Furthermore, SLE patients with the combined FcγR risk alleles exhibited more severe periodontal tissue destruction compared to other SLE patients. The frequencies of IL‐1 polymorphic alleles were too low to assess the association with SLE or periodontitis.Conclusion: The combination of stimulatory FcγRIIA and inhibitory FcγRIIB genotypes may increase susceptibility to SLE and periodontitis in the Japanese population.
Influence of Photodynamic Therapy on the Development of Ligature‐Induced Periodontitis in Rats
Authors: de Almeida Juliano Milanezi , Theodoro Leticia Helena , Bosco Alvaro Francisco , Nagata Maria José Hitomi , Oshiiwa Marie , Garcia Valdir Gouveia 
Published: March 2007

Background: The purpose of this study was to evaluate, histologically and radiographically, the effect of photodynamic therapy on the progression of experimentally induced periodontal disease in rats.Methods: Ligatures were placed at the first mandibular molar in rats. The animals were divided into four groups: group 1 (C) received no treatment; group 2 was treated topically with methylene blue (MB; 100 μg/ml); group 3 was treated with low‐level laser therapy (LLLT); and group 4 was treated topically with methylene blue followed by LLLT (4.5 J/cm2) (photodynamic therapy; PDT). Rats were sacrificed 5, 15, or 30 days postoperatively. Standardized radiographs were taken to measure bone loss around the mesial root surface of the first molar. Data were analyzed statistically (analysis of variance and Tukey test; P <0.05). A scoring system was used to evaluate the connective tissue, periodontal ligament, and alveolar bone histologically. Data were analyzed statistically (Kruskal‐Wallis test; P <0.05).Results: Radiographic examination showed that there was significantly less bone loss in Group PDT compared to Group C at 5 and 15 days postoperatively. There was no significant difference in bone loss at 30 days. At 15 days, the histologic results showed significant differences in the extent of inflammatory reaction in the gingival tissue, with a greater extent of chronic inflammatory reaction in Group LLLT.Conclusion: PDT transiently reduced the periodontal tissue destruction.
Saliva From Subjects Harboring Actinobacillus actinomycetemcomitans Kills Streptococcus mutans In Vitro
Authors: Fine Daniel H. , Furgang David , Goldman Daniel 
Published: March 2007

Background: Previous research indicated that patients with localized aggressive periodontitis (LAgP) had minimal proximal decay. We speculated that differences in these two proximal dental diseases (LAgP and proximal decay) in LAgP could be due to the effect of saliva on the growth of key microorganisms related to these two infections. Carbon dioxide (CO2) is required for growth of Actinobacillus actinomycetemcomitans (Aa), the reputed cause of LAgP. Bicarbonate, a source of CO2, buffers acid production by Streptococcus mutans (Sm), a key organism associated with caries. The purpose of this study was to determine whether the saliva of LAgP patients and subjects with Aa had higher levels of bicarbonate, or an elevated pH, and/or reduced survival of Sm.Methods: Eleven Aa‐positive subjects (seven with LAgP) were matched with 11 Aa‐negative controls. A total of 5 ml saliva obtained from each subject was tested for CO2 levels, pH, and effects on survival of Aa and Sm. Saliva from 22 additional subjects was used for confirmatory data.Results: CO2 levels in the test group (Aa‐positive subjects) and controls (Aa‐negatives) were similar. No clinically relevant differences were found in salivary pH. However, saliva from the test group killed Sm by more than two logs (P <0.05). No effect was seen on Aa. The saliva from the Aa‐negative group killed Aa by two logs (P <0.05). No effect was seen on Sm.Conclusion: Aa‐positive subjects had a salivary factor that significantly reduced survival of Sm, which may help to explain the fact that this group typically has minimal proximal decay.
Bioactive Ceramic Filler in the Treatment of Severe Osseous Defects: 12‐Month Results
Authors: Dybvik Tore , Leknes Knut N. , Bøe Olav E. , Skavland Ragnfrid J. , Albandar Jasim M. 
Published: March 2007

Background: Bioactive ceramic fillers are synthetic materials for medical use with the potential to enhance bone formation. The purpose of this study was to evaluate the clinical effectiveness of a bioactive ceramic filler in the treatment of teeth with poor prognosis because of deep osseous defects and increased tooth mobility.Methods: Nineteen patients, 35 to 75 years of age, who presented with one proximal intrabony periodontal defect with vertical radiographic bone loss ≥3 mm were included. After initial therapy, defects were assigned randomly to a test (12 defects) or control (seven defects) procedure. Following flap reflection and root planing, test defects were filled with a bioactive ceramic filler. Mucoperiosteal flaps were replaced and sutured, and a periodontal dressing was applied. All patients received postoperative analgesics, rinsed twice daily with chlorhexidine, and were seen 2 weeks postoperatively for suture removal. Postoperative deplaquing and reinstruction in home care were performed at weekly intervals during the first month, and at 3, 6, and 12 months. At baseline and at 6 and 12 months, dental plaque, bleeding on probing (BOP), probing depth (PD), and probing attachment level (PAL) were assessed, and standardized radiographs were taken.Results: The test and control groups showed similar periodontal status at baseline, with no significant differences in clinical or radiographic parameters. Plaque and BOP showed a non‐significant deterioration over time. PD was reduced significantly in experimental and control sites following treatment (P <0.001), but there was no significant between‐group difference (P = 0.793). For PAL and radiographic bone levels, no overall within‐ or between‐group differences were detected.Conclusion: The use of bioactive ceramic filler in combination with open debridement provided no significant beneficial effect over open debridement alone in the treatment of teeth with deep intraosseous defects, severe bone loss, and hypermobility.
A New Treatment Strategy for Severe Arthrofibrosis of the Knee
Authors: Wang Jian-Hua , Zhao Jin-Zhong , He Yao-Hua 
Published: March 2007

BACKGROUND:
To reduce the morbidity of traditional quadricepsplasty for the treatment of severe arthrofibrosis of the knee, we instituted a treatment regimen consisting of an initial extra-articular mini-invasive quadricepsplasty and subsequent intra-articular arthroscopic lysis of adhesions during the same anesthesia session. The purpose of the present study was to determine the results of this technique.
METHODS:
From 1998 to 2001, twenty-two patients with severely arthrofibrotic knees were managed with this operative technique. The mean age of the patients at the time of the operation was thirty-seven years. After a mean duration of follow-up of forty-four months (minimum, twenty-four months), all patients were evaluated according to the criteria of Judet and The Hospital for Special Surgery knee-rating system.
RESULTS:
The average maximum degree of flexion increased from 27° preoperatively to 115° at the time of the most recent follow-up (p < 0.001). According to the criteria of Judet, the result was excellent for sixteen knees, good for five, and fair for one. The average Hospital for Special Surgery knee score improved from 74 points preoperatively to 94 points at the time of the most recent follow-up (p < 0.001). A superficial wound infection occurred in one patient. Only one patient had a persistent 15° extension lag.
CONCLUSIONS:
This mini-invasive operation for the severely arthrofibrotic knee can be used to increase the range of motion and enhance functional outcome.
Treatment of Primarily Ligamentous Lisfranc Joint Injuries: Primary Arthrodesis Compared with Open Reduction and Internal Fixation
Authors: Coetzee J. Chris , Ly Thuan V. 
Published: March 2007

BACKGROUND:
Open reduction and internal fixation is currently the accepted treatment for displaced Lisfranc joint injuries. However, even with anatomic reduction and stable internal fixation, treatment of these injuries does not have uniformly excellent outcomes. The objective of this study was to compare primary arthrodesis with open reduction and internal fixation for the treatment of primarily ligamentous Lisfranc joint injuries.
METHODS:
Forty-one patients with an isolated acute or subacute primarily ligamentous Lisfranc joint injury were enrolled in a prospective, randomized clinical trial comparing primary arthrodesis with traditional open reduction and internal fixation. The patients were followed for an average of 42.5 months. Evaluation was performed with clinical examination, radiography, the American Orthopaedic Foot and Ankle Society (AOFAS) Midfoot Scale, a visual analog pain scale, and a clinical questionnaire.
RESULTS:
Twenty patients were treated with open reduction and screw fixation, and twenty-one patients were treated with primary arthrodesis of the medial two or three rays. Anatomic initial reduction was obtained in eighteen of the twenty patients in the open-reductio group and twenty of the twenty-one in the arthrodesis group. At two years postoperatively, the mean AOFAS Midfoot score was 68.6 points in the open-reduction group and 88 points in the arthrodesis group (p < 0.005). Five patients in the open-reduction group had persistent pain with the development of deformity or osteoarthrosis, and they were eventually treated with arthrodesis. The patients who had been treated with a primary arthrodesis estimated that their postoperative level of activities was 92% of their preinjury level, whereas the open-reduction group estimated that their postoperative level was only 65% of their preoperative level (p < 0.005).
CONCLUSIONS:
A primary stable arthrodesis of the medial two or three rays appears to have a better short and medium-term outcome than open reduction and internal fixation of ligamentous Lisfranc joint injuries.
Proximal Femoral Allograft Treatment of Vancouver Type-B3 Periprosthetic Femoral Fractures After Total Hip Arthroplasty
Authors: Kellett Catherine F. , Boscainos Petros J. , Maury Anthony C. , Pressman Ari , Cayen Barry , Zalzal Paul , Backstein David , Gross Allan 
Published: March 2007

BACKGROUND:
Periprosthetic femoral fractures following total hip arthroplasty are becoming more prevalent. When a fracture occurs in a femur with substantial proximal bone deficiency, the surgical options for revision are limited. One option includes the use of a proximal femoral allograft.
METHODS:
We retrospectively assessed the results and complications of the use of a proximal femoral allograft to treat twenty-five Vancouver type-B3 periprosthetic fractures in twenty-four patients. The mean duration of follow-up was 5.1 years. Clinical results were graded with use of the Harris hip score. Radiographs were assessed for evidence of trochanteric union, host-allograft union, allograft resorption, and component loosening or fracture. Failure of the procedure was defined as the need for revision surgery requiring graft removal.
RESULTS:
The mean postoperative Harris hip score was 70.8. At the time of the final follow-up, twenty-one of the twenty-four patients reported no or mild pain and twenty-three patients were able to walk; fifteen required a walking aid. The greater trochanter united in seventeen of the twenty-five hips (68%), and osseous union of the allograft to the host femur occurred in twenty hips (80%). There was mild graft resorption in four hips and moderate graft resorption in two. Four (16%) of the twenty-five hips required repeat revision.
CONCLUSIONS:
The use of a proximal femoral allograft for the treatment of a Vancouver type-B3 periprosthetic femoral fracture can provide a satisfactory result in terms of pain relief and function at five years.