bluuebunny/crossref_metadata_2025 huggingface dataset:
Association between periodontal and peri‐implant conditions: a 10‐year prospective study
Authors: Karoussis Ioannis K. , Müller Samuel , Salvi Giovanni E. , Heitz‐mayfield Lisa J.A. , Brägger Urs , Lang Niklaus P.
Published: December 2004

Objectives: The aims of this study were to (1) compare prospectively the clinical and radiographic changes in periodontal and peri‐implant conditions, (2) investigate the association of changes in periodontal parameters and peri‐implant conditions over a mean observation period of 10 years (8–12 years) after implant installation, and (3) evaluate patient risk factors known to aggravate the periodontal conditions for their potential influence on the peri‐implant tissue status.

Materials and methods: Eighty‐nine partially edentulous patients with a mean age of 58.9 years (28–88 years) were examined at 1 and 10 years after implant placement. The patients contributed with 179 implants that were placed after comprehensive periodontal treatment and restored with crowns or fixed partial dentures. One hundred and seventy‐nine matching control teeth were chosen as controls. Also, the remaining teeth (n=1770) in the dentitions were evaluated. Data on smoking habits and general health aspects were collected at 1 and 10 years as well.

Results: At 10 years, statistically significant differences existed between implants and matching control teeth with regard to most of the clinical and radiographic parameters (P<0.01) with the exception of plaque index (PII) and recession. Multiple regression analyses were performed to associate combinations of periodontal diagnostic parameters to the peri‐implant conditions: probing attachment level (PAL) at implants at 10 years was associated with implant location, full‐mouth probing pocket depth (PPD) and full‐mouth PAL (P=0.0001, r2=0.36). PPD at implants at 10 years correlated to implant location, full‐mouth PPD and full‐mouth PAL (P<0.001, r2=0.47). Marginal bone level at implants at 10 years was significantly associated to smoking, general health condition, implant location, full‐mouth PAL and change over time in full‐mouth PPD (P<0.001, r2=0.39).

Conclusions: These results present evidence for the association between periodontal and peri‐implant conditions and the changes in these tissues over 10 years in partially edentulous patients.
Effect of GBR in combination with deproteinized bovine bone mineral and/or enamel matrix proteins on the healing of critical‐size defects
Authors: Donos Nikolaos , Lang Niklaus P. , Karoussis Ioannis K. , Bosshardt Dieter , Tonetti Maurizio , Kostopoulos Lambros
Published: December 2004

Objectives: To evaluate the effect of guided bone regeneration (GBR) in combination with or without deproteinized bovine bone mineral (DBBM) and/or an enamel matrix derivative (EMD) on the healing of critical‐size calvarial defects.

Material and methods: Forty rats were used. In all animals, a standardized critical‐size calvarial defect was created surgically. The animals were randomly allocated into 4 groups of 10 animals each. Group A: One calvarial defect was left untreated, while the galeal and the cerebral aspect of the contralateral defect were covered with a bioresorbable membrane (GBR). Group B: One calvarial defect was filled with EMD, while the contralateral defect was treated with GBR and EMD. Group C: One defect was filled with DBBM, while the contralateral defect was treated with combination of GBR and DBBM. Group D: One defect was filled with DBBM combined with EMD, while the contralateral defect was treated with combination of GBR, DBBM and EMD. The healing period was 4 months. Five specimens from each group were macerated and the length, the width and the vertical dimension (thickness) of the remaining defect were evaluated by a stereomicroscope. The remaining specimens in each group were analyzed histologically.

Results: The defects of the macerated specimens that were left untreated or were treated only by EMD, DBBM and combination of EMD and DBBM did not present predictably complete healing of the defects. All the defects where GBR was applied alone or combined with DBBM and/or EMD presented always complete healing (P<0.05). The combined use of GBR with EMD and/or DBBM did not offer any significant advantage above GBR alone in terms of healing of the length and the width of the defect. However, the vertical dimension of the defect was significantly higher (P<0.05) in the GBR‐treated specimens of Groups C and D. The histological analysis supported these findings.

Conclusion: The predictability of bone formation in critical‐size defects depends mainly on the presence or absence of barrier membranes (GBR). The combined use with deproteinized bovine bone mineral and/or enamel matrix proteins did not significantly enhance the potential for complete healing provided by the GBR procedure.
Growth‐associated protein‐43 immunoreactivity in human oral mucosa in dentate subjects, in edentulous patients and after implant‐anchored rehabilitation
Authors: Ramieri Guglielmo A. , Schierano Gianmario , Spada Maria Cristina , Giovando Maria Luisa , Verzè Laura , Preti Giulio
Published: December 2004

Abstract Objectives: This study investigates expression of the neural growth‐associated protein 43 (GAP‐43) in the oral mucosa of (A) normal dentate subjects, (B) edentulous patients rehabilitated with conventional denture and (C) those rehabilitated with mandibular implant‐retained overdentures (MIR‐OVD), in the long term. This study evaluates morphological changes in the distribution and representation of sensory terminations and corpuscles in the alveolar mucosa under the action of different masticatory or prosthetic loads, in the three clinical groups.

Material and methods: GAP‐43 immunoreactivity (‐ir) was compared with the distribution of nerves fibres in the mucosa, as visualised using anti‐protein gene product 9.5 (PGP 9.5), a general marker for peripheral nerves and terminals.

Results: GAP‐43‐ir was found to be highly expressed in the corium and submucosa in specimens from edentulous subjects wearing conventional denture and presenting a reduced number of PGP 9.5‐ir nerves in the mucosa, but not in specimens from control subjects or patients wearing MIR‐OVD, which on the contrary show a higher number of PGP 9.5‐ir mucosal sensory fibres.

Conclusion: As the mucosa under traditional denture has been shown to possess reduced innervation and the histological aspect of chronic overloading, these results may be considered indicative of a tentative induction to nerve re‐growth in the under‐innervated epithelium, or as a response to chronic inflammation. The detection of GAP‐43‐ir suggests that human oral mucosa presents signs of potential nerve plasticity also in the elderly, and that the type of rehabilitation and the condition of masticatory load transfer to the mucosa have important effects on the nerves underneath.
Grafting of deproteinized bone particles inhibits bone resorption after maxillary sinus floor elevation
Authors: Xu Hui , Shimizu Yoshinaka , Asai Sumito , Ooya Kiyoshi
Published: December 2004

Objectives: To evaluate the value of deproteinized bone particles on bone resorption in the augmented space after maxillary sinus floor elevation in rabbits.

Material and methods: A total of 20 rabbits underwent bilateral grafting, using blood clots (control group) and deproteinized bone particles (experimental group), and followed with histologic and histomorphometric analysis.

Results: Two weeks after grafting, the augmented space was almost completely obliterated by both newly formed bone and fibrous connective tissue in the control group. Some osteoclasts were found on the surface of newly formed bone, especially near the elevated sinus membrane. In the experimental group, newly formed bone was found along the elevated sinus membrane, the cortical wall of the augmented space, and the surface of deproteinized bone particles near the cortical wall. Some osteoclasts were found along the deproteinized bone particles and a few adhered to the surface of the newly formed bone. Eight to 10 weeks after implantation in the control group, most of the newly formed bone had been resorbed. In the experimental group, newly formed bone was found in most parts of the convex augmented space. Histomorphometrical analysis showed that the augmented height was significantly higher in the experimental group than in the control group at all evaluation times. Bone area was significantly higher in the experimental group than in the control group at 6, 8, and 10 weeks after implantation. The area of grafted deproteinized bone particles did not change significantly from 2 to 10 weeks.

Conclusion: Slowly resorbed deproteinized bone particles contribute to stable augmentation of the maxillary sinus floor by inhibiting bone resorption.
Effect of GBR and fixture installation on gingiva and bone levels at adjacent teeth
Authors: Van der zee Erwin , Oosterveld Paul , Van waas Marinus A.J.
Published: December 2004

Abstract: Guided bone regeneration (GBR) is frequently used in oral implantology. It is unclear to what extent GBR affects the periodontium of adjacent teeth. Therefore, the present study quantifies changes in the proximal gingiva and bone levels at these teeth in 30 patients. Staged surgery involved a standard GBR treatment, randomly using resorbable membranes with a bone substitute or non‐resorbable membranes with or without a bone substitute, followed by fixture installation at 6 months and abutment connection a further 6 months later. The data were sampled at each surgery and analysed using Manova. Twelve months after GBR, there was on average a small but statistically significant amount of proximal gingival recession (0.75 mm) and bone resorption (0.34 mm) observed, of which 50% was the result of GBR surgery. No significant differences were found between the different GBR treatment modalities. It is concluded that GBR treatment may have a small negative effect on the levels of the free gingival margin and alveolar bone at adjacent teeth, which is in most patients not clinically relevant.
Does excessive occlusal load affect osseointegration? An experimental study in the dog
Authors: Heitz‐Mayfield L. J. , Schmid B. , Weigel C. , Gerber S. , Bosshardt D. D. , Jönsson J. , Lang N. P. , Jönsson J.
Published: December 2004

Abstract Aim: The purpose of this study was to evaluate the effect of excessive occlusal load following placement of titanium implants in the presence of healthy peri‐implant mucosal tissues.

Materials and methods: Mandibular bilateral recipient sites in six Labrador dogs were established by extracting premolars and molars. After 3 months, two TPS (titanium plasma sprayed) implants and two SLA (sandblasted, large grit, acid etched) implants were placed on each side of the mandible in each dog. Three implants were lost in the initial healing phase, leaving 45 implants for evaluation. Following 6 months of healing, gold crowns were placed on implants on the test side of the mandible. The crowns were in supra‐occlusal contact with the opposing teeth in order to create excessive occlusal load. Implants on the control side were not loaded. Plaque control was performed throughout the experimental period. Clinical measurements and standardised radiographs were obtained at baseline and 1, 3 and 8 months after loading. At 8 months, the dogs were killed and histologic analyses were performed.

Results: At 8 months, all implants were osseointegrated. The mean probing depth was 2.5±0.3 and 2.6±0.3 mm at unloaded and loaded implants, respectively. Radiographically, the mean distance from the implant shoulder to the marginal bone level was 3.6±0.4 mm in the control group and 3.7±0.2 mm in the test group. Control and test groups were compared using paired non‐parametric analyses. There were no statistically significant changes for any of the parameters from baseline to 8 months in the loaded and unloaded implants. Histologic evaluation showed a mean mineralised bone‐to‐implant contact of 73% in the control implants and 74% in the test implants, with no statistically significant difference between test and control implants.

Conclusion: In the presence of peri‐implant mucosal health, a period of 8 months of excessive occlusal load on titanium implants did not result in loss of osseointegration or marginal bone loss when compared with non‐loaded implants.
The immediate rehabilitation by means of a ready‐made final fixed prosthesis in the edentulous mandible: a 1‐year follow‐up study on 50 consecutive patients
Authors: Van Steenberghe D. , Molly L. , Jacobs R. , Vandekerckhove B. , Quirynen M. , Naert I.
Published: December 2004

Abstract: Although a two‐stage procedure with symphyseal oral implants can lead to a long‐term (15 years) 99% cumulative survival rate, a one‐stage approach with immediate loading via prefabricated elements seems to offer a short‐term acceptable outcome with significantly lower costs. A series of 50 consecutive patients, not eliminated for any systemic or smoking condition, received at the department of periodontology three implants in the symphyseal area, connected by a very rigid horse shoe‐shaped titanium bar. A final screw retained prosthetic framework was placed on top of it at the department of prosthetic dentistry within 2 days after surgery (44) or after a delay, due to purely external factors, of up to 10 days (6). Forty‐five patients were followed for 1 year. In one patient, all three implants failed and another four patients were lost to follow‐up. The cumulative failure rates for implants and prostheses at 1 year were, respectively, 7.3% and 5%. The mean marginal bone loss at 1 year was 1.08 mm (SD: 1.62; range −5.68 to +2.55). This study shows that stable marginal bone levels can be maintained around immediately loaded implants in the lower jaw in an average patient population for at least 1 year. The survival rate is, however, lower than for a staged approach.
Chlorhexidine spray versus mouthwash in the control of dental plaque after implant surgery
Authors: Francetti Luca , Fabbro Massimo Del , Basso Matteo , Testori Tiziano , Taschieri Silvio , Weinstein Roberto
Published: December 2004

Background/purpose: This randomized clinical trial was aimed at comparing two different means of delivering chlorhexidine digluconate (CHX) for plaque control during the 2 weeks following implant surgery.

Materials and Methods: Twenty patients selected for implant therapy were randomly divided into two groups: 10 subjects used 15 ml of 0.12% CHX mouthrinse (control group) and 10 used 0.2% CHX spray (test group). Professional oral hygiene was carried out immediately before surgery. During the 14 days following surgery mechanical oral hygiene was performed only at the teeth not surgically involved. Plaque index (PI), stain index (SI), modified gingival index and taste alteration were assessed on the 7th and 14th day after surgery. The clinical parameters were evaluated at four tooth surfaces by a single examiner. Teeth proximal to surgical site and teeth not involved were statistically compared.

Results: In both groups, the PI increased similarly, with respect to the baseline, at days 7 and 14. There was no significant difference between the two groups at either time point. On the contrary, in the control group, the SI increased significantly when compared with baseline over the 14 days both at teeth nearest to surgical sites and at not‐involved sites. In the test group pigmentation was consistent only at teeth proximal to the surgical site. When considering not‐involved sites, tooth staining was significantly lower in the test with respect to the control group.

Conclusions: The present study indicates that the efficacy of CHX spray in the post‐surgical control of dental plaque is similar to that of CHX mouthwash. Tooth staining, however, is significantly lower in the spray group at sites not surgically involved. These effects might be related to the route of CHX delivery, as well as the total dose administered that was significantly lower in the spray group with respect to the rinse group.
Soft‐tissue wound healing following periodontal surgery and Emdogain® application
Authors: Hagenaars S. , Louwerse P. H. G. , Timmerman M. F. , Van der Velden U. , Van der Weijden G. A.
Published: December 2004

Objectives: The aim of the present study was to examine, by clinical means and as patient perception of post‐operative events, the effect of Emdogain® (enamel matrix derivative (EMD)) on the healing of soft‐tissue wounds following periodontal surgery in comparison to flap surgeries without application of EMD.

Material and Methods: For this study, 22 subjects (nine female and 13 male) who were scheduled for periodontal flap surgery were selected. The mean age for all patients was 49.9 (SD 8.7) years (range, 32–67). Six women and five men were assigned to the test group and three women and eight men were assigned to the control group. All subjects were scheduled, after re‐evaluation of the periodontal status 8 weeks after initial treatment, to undergo surgery of the soft tissues, because of existing of probing pocket depth (5 mm or more), on at least three teeth. At random, 11 patients were assigned to control treatment and 11 patients were placed in the test group. All underwent one periodontal flap surgery for the purpose of this study. A modified Widman flap was performed. Patients in the test group received an application of EMD underneath the mucoperiostal flaps and onto the exposed root surfaces. Clinical measurements were taken at four different points in time, at the time of surgery, 1, 4 and 8 weeks after surgery. All subjects filled out a questionnaire every day for the first 7 days following surgery to evaluate post‐operative complaints.

Results: Of all parameters evaluated none showed a significant difference between the control and EMD groups, except for gingival swelling at the 1‐week assessment, where the EMD group exhibited a higher swelling score. The questionnaire revealed that complaints of oozing of blood from the wound was twice more prevalent 1 day post‐surgery in the control (n=6) as in the EMD group (n=3).

Conclusion: This study shows that the early woundhealing of periodontal flap‐surgeries in those sites treated with Emdogain® is not different from control sites.
Dentine hypersensitivity: a randomised, double‐blind placebo‐controlled study of the efficacy of a fluoride‐sensitive teeth mouthrinse
Authors: Yates R. J. , Newcombe R. G. , Addy M.
Published: December 2004

Objectives: Potassium and fluoride salts have been used in the treatment of dentine hypersensitivity (DH). The primary aim of this study was to compare a fluoride‐containing mouthrinse product with a placebo rinse for the treatment of DH. A secondary aim was to compare effects on plaque index (PI) and gingivitis index (GI).

Material and Methods: The study was a double‐blind, randomised, two‐treatment parallel design involving 91 subjects with DH. At screening, an air evaporative stimulus (AES) was used for selection. Approximately 4 weeks later, at the baseline visit, DH was recorded, using a response‐based visual analogue scale (VAS) from upper and lower incisors, canines, premolars and first molars in response to AES and from two to six teeth in response to a cold water stimulus (CWS). PI and GI were also recorded. Subjects were then allocated the test or placebo rinse. On days 28 and 56, VAS scores were again recorded for AES and CWS, with PI and GI recorded at day 56.

Results: Both groups improved symptoms to day 28 and again to day 56. The majority of the data favoured the test rinse as more effective but there was no clear evidence for a statistically significant difference between test and placebo. PI at lingual sites approached significance for the test rinse.

Conclusions: The placebo response has again been shown to play a significant role in DH clinical trials and narrows the range over which to detect treatment differences. Study designs to minimise or prevent the placebo response in DH seem worthy of consideration.
Measuring inequalities in the distribution of dental caries
Authors: Antunes José Leopoldo Ferreira , Narvai Paulo Capel , Nugent Zoann Jane
Published: December 2004

Abstract – 

Objectives: To evaluate different measurements of prevalence and inequality in the distribution of dental caries as to their partial collinearity, and ability in expressing associations with the supply of fluoridated tap water, indices of socioeconomic status and provision of dental services.

Methods: The DMFT, the Significant Caries (SiC) Index, the proportions of children with high‐ (DMFT ≥ 4) and rampant‐ (DMFT ≥ 7) caries experience, caries‐free children (DMFT = 0), the Gini coefficient and the Dental Health Inequality Index (DHII) were the dental outcomes appraised in a sample comprising 18 718 oral examination records for 11‐ and 12‐year‐old schoolchildren in 131 towns of the state of São Paulo, Brazil. Spatial data analysis assessed the association between aggregate figures of dental indices and several covariates.

Results: The DMFT, the SiC Index and the proportions of children with high‐ and rampant‐caries experience presented strong linear associations (Pearsonrnear or higher than 0.95), and an analogous profile of correlation with indicators of socioeconomic status, dental services and access to fluoride tap water. The same was observed for the DHII, the Gini coefficient and the proportion of caries‐free children. These observations involve the perception of variables in each set as interchangeable tools for ecological studies assessing factors influencing, respectively, prevalence levels and inequality in the distribution of dental disease.

Conclusion: An improved characterization of the skewed distribution of caries experience demands the concurrent estimation of figures of prevalence and inequality in dental outcomes. This strategy may contribute to the design of socially appropriate programmes of oral health promotion.
Presence of somatic hypermutation and activation‐induced cytidine deaminase in acute lymphoblastic leukemia L2 with t(14;18)(q32;q21)
Authors: Hardianti Mardiah Suci , Tatsumi Eiji , Syampurnawati Meilani , Furuta Kaho , Suzuki Aya , Saigo Katsuyasu , Kawano Seiji , Takenokuchi Mariko , Kumagai Shunichi , Matsuo Yoshinobu , Koizumi Tamio , Takeuchi Makoto
Published: December 2004

Abstract:  Aim: Acute lymphoblastic leukemia (ALL) with L2 (FAB) morphology has rarely been reported to show t(14;18)(q32;q21). We aimed to delineate the stage at which this type of ALL is derived in B‐lineage differentiation. Methods: The somatic hypermutation (SHM) of the variable region of immunoglobulin heavy chain (IgVH) gene and the expression of terminal deoxynucleotidyl transferase (TdT), recombination‐activating gene 1 and 2 (RAG‐1 and ‐2), and activation‐induced cytidine deaminase (AID) were investigated in three cell lines and two fresh samples, including a pair of matched fresh and cell line cells. Results: TdT, RAG‐1, and RAG‐2 were variably expressed. AID was expressed in four of five samples. SHM of the IgVH gene was found in all samples with high average frequency (11.84%) comparable with that in follicular lymphoma. Ongoing mutation was seen in two fresh samples. Conclusion: As AID and SHM are generally regarded as properties exhibited by mature B cells, the presence of AID and SHM in this study seems to be incompatible with the general understanding of the early stage derivation of ALL in B‐lineage differentiation. The results here give some insight into the relationship between disease type (ALL or lymphoma) and derivation stage, the overlapping of the early stage phenotype and the mature genomic characteristics, and the probable relationship between the mechanism of the occurrence of t(14;18)(q32;q21) and the machinery causing SHM.
Analysis of serum soluble CD40 ligand (sCD40L) in the patients undergoing allogeneic stem cell transplantation: platelet is a major source of serum sCD40L
Authors: Nagasawa Masayuki , Zhu Yi , Isoda Takeshi , Tomizawa Daisuke , Itoh Sukeyuki , Kajiwara Michiko , Morio Tomohiro , Nonoyama Shigeaki , Shimizu Norio , Mizutani Shuki
Published: December 2004

Abstract:  CD40 ligand (CD40L) is expressed not only on activated T cells but also on activated platelets. A soluble CD40 ligand (sCD40L) is released from the activated T cells and platelets by ill‐defined proteolytic process in vitro. It has been reported that sCD40L is elevated in the serum of patients with systemic lupus erythematosus, unstable angina, essential thrombocythemia, and autoimmune thrombocytopenic purupura. However, source of sCD40L in vivo remains to be elucidated. We investigated the serial sCD40L in the serum in patients undergoing allogeneic stem cell transplantation and compared with the platelets number and soluble IL2R, which is a marker of activated T cells. The value of sCD40L was well correlated with platelet number or thrombopoiesis. In cases of severe graft vs. host disease with markedly increased sIL2R, sCD40L was not increased in vivo. These results indicate that sCD40L in vivo is released mainly from the platelets or in the process of platelet production but not from the activated T cells.
Thalidomide in combination with vincristine, epirubicin and dexamethasone (VED) for previously untreated patients with multiple myeloma
Authors: Schütt P. , Ebeling P. , Buttkereit U. , Brandhorst D. , Opalka B. , Hoiczyk M. , Flasshove M. , Hense J. , Bojko P. , Metz K. , Moritz T. , Seeber S. , Nowrousian M. R.
Published: December 2004

Abstract:  The present study aimed to evaluate the side‐effects and efficacy of thalidomide in combination with an anthracycline‐containing chemotherapy regimen in previously untreated myeloma patients. Thalidomide (400 mg/d) was combined with bolus injections of vincristine and epirubicin and oral dexamethasone (VED). Chemotherapy cycles were repeated every 3 wk until no further reduction in myeloma protein was observed, whereas the treatment with thalidomide was continued until disease progression. Thirty‐one patients were enrolled, 12 patients were exclusively treated with thalidomide in combination with VED and 19 patients additionally received high‐dose melphalan, for consolidation. Adverse events and response to therapy were assessed prior to treatment with high‐dose chemotherapy. Response to thalidomide combined with VED was complete remission in six patients (19%), partial remission in 19 patients (61%), stable disease in five patients (16%), and progressive disease in one patient (3.2%). Grade 3 and 4 adverse events consisted of leukocytopenia in 10 patients (32%), and thrombocytopenia and anemia in one patient each (3.2%). Neutropenic infections grade 3 and 4 occurred in seven (23%) and three patients (9.7%), respectively, including two patients (6.5%) who died from septic shock. Deep vein thrombosis occurred in eight patients (26%), constipation in 20 patients (65%), and polyneuropathy in 20 patients (65%). The probability of event‐free survival and overall survival in the whole group of patients at 36 months were 26 and 62%, respectively. In conclusion, the combination of thalidomide with VED appears to be highly effective in previously untreated patients with multiple myeloma, but it is associated with a high rate of thrombotic events, polyneuropathy, and neutropenic infections.
Detection of Chlamydophila pneumoniae in the bone marrow of two patients with unexplained chronic anaemia
Authors: Nebe C. Thomas , Rother Marion , Brechtel Ingrid , Costina Victor , Neumaier Michael , Zentgraf Hanswalter , Böcker Ulrich , Meyer Thomas F. , Szczepek Agnes J.
Published: December 2004

Abstract:  Anaemia of chronic disease (ACD) is a common finding involving iron deficiency and signs of inflammation. Here, we report on two patients with ACD where a persistent infection with Chlamydophila (Chlamydia) pneumoniae (CP) was detected in bone marrow (BM) biopsies. Infection was suspected by routine cytology and confirmed by immunofluorescence, electron microscopy, polymerase chain reaction (PCR) including different primer sets and laboratories and sequencing of the PCR product. This is a first report of chlamydial presence in the BM of anaemic patients. The cases are presented because persistent chlamydial infection may contribute more frequently to chronic refractory anaemia than previously suspected.
Bone marrow expression of vascular endothelial growth factor in myelofibrosis with myeloid metaplasia
Authors: Ho Ching‐Liang , Arora Brijesh , Hoyer James D. , Wellik Linda E. , Mesa Ruben A. , Tefferi Ayalew
Published: December 2004

Abstract:  The biologic relevance and prognostic impact of angiogenesis is being increasingly recognized in many solid tumors and hematologic malignancies including myelofibrosis with myeloid metaplasia (MMM). Many cytokines including vascular endothelial growth factor (VEGF) have been implicated for neoangiogenesis in MMM. However, the exact humoral basis remains to be elucidated. We examined the expression of VEGF by immunohistochemistry in a prospective cohort of 66 MMM patients, including six with cellular phase disease, and five normal controls. Contrary to most other hematologic malignancies, the distribution and intensity of staining for VEGF in bone marrow was similar between the MMM patients and controls. Interestingly, all six cellular phase patients displayed significantly increased VEGF expression. Thus, upregulation of angiogenic cytokines other than VEGF such as TGF‐β or loss of activity of an anti‐angiogenic cytokine might be the dominant pathway of endothelial activation in MMM. However, VEGF might contribute to the process in the early stages of the disease.
Growth factors and proliferation of cultured rat gingival cells in response to cyclosporin A
Authors: Yoshida Takumasa , Nagata Junji , Yamane Akira
Published: December 2004

Objective:  The prominent side‐effect of cyclosporin A, an immunosuppressive drug, in oral tissues is gingival outgrowth, although the exact mechanism underlying this side‐effect is unclear. The main purposes of the present study were to determine whether cyclosporin A induced the gingival outgrowth by promoting proliferation of gingival cells and whether growth factors such as transforming growth factor‐βs (TGF‐βs), fibroblast growth factor‐2 (FGF‐2), platelet‐derived growth factors (PDGFs), and insulin‐like growth factors (IGFs) are involved in the possible changes in the proliferation of gingival cells induced by cyclosporin A.

Methods:  Cells isolated from rat gingival tissues were cultured with cyclosporin A or IGF‐I for 3 days. The effects of cyclosporin A or IGF‐I on the proliferation of cultured rat gingival cells were analyzed with a CellTiter 96 proliferation assay kit. The mRNA expression levels for TGF‐βs, FGF‐2, PDGFs, IGFs, insulin‐like growth factor receptors (IGFRs), and insulin‐like growth factor binding proteins (IGFBPs) in the rat gingival cells treated with cyclosporin A were measured using competitive reverse transcription–polymerase chain reaction (RT–PCR).

Results:  Cyclosporin A induced 23–25% (p < 0.001) increases in the proliferation of rat gingival cells and approximately 130% (p < 0.05) and 60% (p < 0.05) elevations in the mRNA expression levels for TGF‐β1 and FGF‐2, respectively. On the other hand, exogenous IGF‐I induced 8–11% (p < 0.05) increases in the proliferation, but cyclosporin A induced 30–80% (p < 0.05–0.01) reductions in the mRNA expression levels for endogenous IGF‐I, IGFR1, IGFBP2, IGFBP3, IGFBP5, and IGFBP6.

Conclusions:  Cyclosporin A stimulates the proliferation of rat gingival cells. TGF‐β1 and FGF‐2 could be involved, but IGFs, IGFRs and IGFBPs could not be directly involved in this cyclosporin A induced‐stimulation of the gingival cell proliferation.
Efficiency of subgingival calculus removal with the Vector™‐system compared to ultrasonic scaling and hand instrumentation in vitro
Authors: Braun Andreas , Krause Felix , Frentzen Matthias , Jepsen Søren
Published: December 2004

Objective:  The recently introduced Vector™‐system (Duerr Dental, Bietigheim‐Bissingen, Germany) is recommended to be used in conjunction with different insert tips and irrigation fluids. The aim of the study was to assess subgingival calculus removal depending on the mode of operation and to compare the results to conventional methods for root debridement.

Methods:  Sixty extracted human teeth with calculus on the root surface were treated in an artificial periodontal pocket model using six methods: Vector™‐system with metal probe insert (VPP) or metal curette insert (VPC), both used with polishing fluid, Vector™‐system with metal probe insert (VAP) or metal curette insert (VAC), both used with abrasive fluid, EMS‐ultrasonic system (U) and hand instrument (Gracey curette). Photographs of the root surface were taken at intervals of 10 s and calculus removal was assessed using a surface analysis software until the root surfaces were cleaned completely. Analysis of variances (ANOVA) of the ranks with subsequent comparison of mean ranks and calculation of homogeneous groups (Scheffé) were used for statistical analysis.

Results:  Employing the hand instrument, highest efficiency could be observed (0.340 mm2/s). Calculus removal with the Vector™‐system and metal probe insert (VPP: 0.036 mm2/s; VAP: 0.067 mm2/s) was less effective (p < 0.05) than using the system with metal curette inserts (VPC: 0.122 mm2/s; VAC: 0.209 mm2/s). Employing the abrasive fluid, removal of deposits with the metal curette insert was as efficient as with the conventional ultrasonic system (U: 0.199 mm2/s, p > 0.05).

Conclusion:  The present in vitro study indicates that the efficiency of calculus removal with the Vector™‐system is significantly dependent on the selection of inserts and irrigation fluids.
Colocalization of the collagen‐binding proteoglycans decorin, biglycan, fibromodulin and lumican with different cells in human gingiva
Authors: Alimohamad H. , Habijanac T. , Larjava H. , Häkkinen L.
Published: December 2004

Background and objective:  Decorin, biglycan, fibromodulin and lumican are structurally related molecules that belong to the family of small leucine‐rich proteoglycans (SLRPs). These SLRPs are secreted extracellular matrix molecules that interact with type I collagen and regulate collagen fibrillogenesis. They may also modulate cell functions that are important in maintenance of connective tissue structure. The aim of this study was to localize decorin, biglycan, fibromodulin and lumican in human gingiva.

Methods:  Localization of decorin and its proform (prodecorin), biglycan, fibromodulin and lumican and mature and proform of type I collagen was studied by immunohistochemical staining of frozen tissue sections from healthy human attached gingiva. Double immunostaining with anti‐SLRP or anti‐type I procollagen antibodies and specific markers for different connective tissue cells was used to study association of these molecules with cells.

Results:  The mature and proforms of decorin and collagen and biglycan, fibromodulin and lumican showed distinct localization in the extracellular matrix, where they associated with type I collagen fiber bundles. Prodecorin also localized to the epithelial basement membrane zone. Fibroblasts, myofibroblasts, endothelial cells and pericytes showed immunoreactivity for procollagen, prodecorin, biglycan and fibromodulin, whereas lumican associated with fibroblasts and myofibroblasts only. Biglycan and fibromodulin were also associated with macrophages. Basal epithelial cells of the gingival epithelium showed immunoreactivity for biglycan, fibromodulin and lumican.

Conclusions:  Decorin, biglycan, fibromodulin and lumican associate with type I collagen and may collaborate to regulate collagen fibrillogenesis in human gingiva. Each of the SLRPs showed a distinct association with different connective tissue cells, suggesting that the cells produce these molecules and/or that the cells interact with them. Localization of biglycan, fibromodulin and lumican at the epithelial cells suggests novel functions for these SLRPs in human gingival epithelium.
Inhibition of Chemoattractant N‐Formyl Peptide Receptor Trafficking by Active Arrestins
Authors: Key T. Alexander , Vines Charlotte M. , Wagener Brant M. , Gurevich Vsevolod V. , Sklar Larry A. , Prossnitz Eric R.
Published: December 2004

Recent studies have highlighted the emergence of a class of G protein‐coupled receptors that are internalized in an arrestin‐independent manner. In addition to demonstrating that the N‐formyl peptide receptor belongs in this family, we have recently shown that recycling of the receptor requires the presence of arrestins. To further elucidate mechanisms of arrestin‐dependent regulation of G protein‐coupled receptor processing, we examined the effects of altering the receptor–arrestin complex on ternary complex formation and cellular trafficking of the N‐formyl peptide receptor by studying two active arrestin‐2 mutants (truncated arrestin‐2 [1–382], and arrestin‐2 I386A, V387A, F388A). Complexes between the N‐formyl peptide receptor and active arrestins exhibited higher affinity in vitro than the complex between the N‐formyl peptide receptor and wild‐type arrestin and furthermore were observed in vivo by colocalization studies using confocal microscopy. To assess the effects of these altered interactions on receptor trafficking, we demonstrated that active, but not wild‐type, arrestin expression retards N‐formyl peptide receptor internalization. Furthermore, expression of arrestin‐2 I386A/V387A/F388A but not arrestin‐2 [1–382] inhibited recycling of the N‐formyl peptide receptor, reflecting an expanded role for arrestins in G protein‐coupled receptor processing and trafficking. Whereas the extent of N‐formyl peptide receptor phosphorylation had no effect on the inhibition of internalization, N‐formyl peptide receptor recycling was restored when the receptor was only partially phosphorylated. These results indicate not only that a functional interaction between receptor and arrestin is required for recycling of certain G protein‐coupled receptors, such as the N‐formyl peptide receptor, but that the pattern of receptor phosphorylation further regulates this process.
Rab11 Promotes Docking and Fusion of Multivesicular Bodies in a Calcium‐Dependent Manner
Authors: Savina Ariel , Fader Claudio M. , Damiani María T. , Colombo María Isabel
Published: December 2004

Multivesicular bodies (MVBs) are membranous structures within 60–100 nm diameter vesicles accumulate. MVBs are generated after invagination and pinching off of the endosomal membrane in the lumen of the vacuole. In certain cell types, fusion of MVBs with the plasma membrane results in the release of the internal vesicles called exosomes. In this report we have examined how an increase in cytosolic calcium affects the development of MVBs and exosome release in K562 cells overexpressing GFP‐Rab11 wt or its mutants. In cells overexpressing the Rab11Q70 L mutant or Rab11 wt, an increase in the cytosolic calcium concentration induced by monensin caused a marked enlargement of the MVBs. This effect was abrogated by the membrane permeant calcium chelator BAPTA‐AM. We also examined the behavior of MVBs in living cells by time lapse confocal microscopy. Many MVBs, decorated by wt or Q70L mutant GFP‐Rab11, were docked and ready to fuse in the presence of a calcium chelator. This observation suggests that Rab11 is acting in the tethering/docking of MVBs to promote homotypic fusion, but that the final fusion reaction requires the presence of calcium. Additionally, a rise in intracellular calcium concentration enhanced exosome secretion in Rab11 wt overexpressing cells and reversed the inhibition of the mutants. The results suggest that both Rab11 and calcium are involved in the homotypic fusion of MVBs.
Survival of human periodontal ligament cells in media proposed for transport of avulsed teeth
Authors: Sigalas Emmanouil , Regan John D. , Kramer Phillip R. , Witherspoon David E. , Opperman Lynne A.
Published: December 2004

Abstract –  Many solutions have been examined as possible storage media for avulsed teeth. In this report, human periodontal ligament (PDL) cells were exposed for 1 h to culture medium, milk, Hanks Balanced Salt Solution (HBSS), Soft Wear, Opti Free, and Solo Care contact lens solutions, Gatorade®, and tap water, at room temperature and on ice. The number of viable cells was counted using the trypan blue exclusion technique, immediately after exposure (0 h) and at 24 and 48 h, to test the proliferative capacity of the cells after treatment. The results indicated that a significantly higher number of cells survived and proliferated when the exposures were performed at 0°C. Water had a detrimental effect on the cells, whereas culture medium and HBSS preserved significantly more viable cells than the other experimental solutions. Within the parameters of this study, it appears that HBSS is the optimal storage medium for avulsed teeth. Low‐fat milk could serve as an alternative if ice is available. Contact lens solutions or Gatorade® on ice could serve as short‐term (1 h) storage media if the other solutions are not readily available.
The influence of the sensor type on the measured impact absorption of mouthguard material
Authors: Takeda Tomotaka , Ishigami Keiichi , Jun Handa , Nakajima Kazunori , Shimada Atsushi , Ogawa Toru
Published: December 2004

Abstract –  Mouthguards have been tested for impact energy absorption using drop‐ball and/or pendulum devices. While all reports show efficiency of the mouthguard, the impact absorption abilities reported differ considerably. This difference has been attributed to differences of mouthguard material, design, and the impact force used. However, it is also possibly because of the difference in the sensors used in the experiments. The purpose of this study was to test three types of sensors and to assess which type was most appropriate for measurement of the impact absorption ability of mouthguards. A pendulum‐type testing equipment and steel ball, wooden bat, baseball, field‐hockey ball were used as the impact object. For all sensors or impact objects, the mouthguard decreased the impact forces. However, the absorption ability of the mouthguard varied according to the sensor or impact object. The absorbency values became smaller with the strain gauge, the accelerometer, and the load cell, respectively. With the steel ball as the impact object, 80.3% of impact absorption was measured with the strain gauge and the accelerometer but, only 62.1% with the load cell sensor. With the wooden bat, impact absorption was 76.3% with the strain gauge and 38.8% for the load cell. For the baseball ball, the absorption measurement decreased from 46.3% with the strain gauge to 4.36 with the load cell and for the field‐hockey ball, the decrease in measurement values were similar (23.6% with the strain gauge and 2.43% with the load cell). It is clear that the sensor plays an important role in the measurement values reported for absorbency of mouthguard materials and a standard sensor should be used for all experiments.
Optimal Profile Design for the Resonator Beam of an Ultrasonic Motor via Finite Element Modeling and Taguchi Methodology
Authors: Chao Paul C.-P. , Huang Jeng-Sheng , Chiu Chi-Wei
Published: December 2004

This study presents the optimal design for the resonator beam profile of a bimodal ultrasonic motor via finite element modeling and Taguchi experimental design method. General design goals of an ultrasonic motor are to maximize the output power while restraining the contact force in order to extend component lives. To achieve the aforementioned goals, based on recent studies, beam profile design could play an important role because geometric variants of profile lead to substantial changes in the output power of the motor and simultaneously affect the contact force significantly. To investigate the effect of various profiles on the performance of the ultrasonic motor, the dynamic equations of motion are first formulated by utilizing an extended Hamilton’s principle and the method of the Lagrange multiplier. The method of finite element modeling is meanwhile used to approximate the governing partial differential equations by a discrete, finite degree-of-freedom system. With the beam outer profile parametrized by cubic splines in terms of locations of two intercepts, the Taguchi experimental design method is finally applied based on the simulated dynamics of the derived finite system to distill generic design guidelines for beam profile of the ultrasonic motor. It is found that a general paraboliclike profile for beam outer shape is best suited for maximizing output power, while a vaselike profile leads to the worst performance.
Optimal Design and Implementation of an Omnidirectional Panel Speaker Array Using the Genetic Algorithm
Authors: Bai Mingsian R. , Kuo Jihting
Published: December 2004

A panel speaker array with omnidirectional radiation pattern is presented in this paper. Array signal-processing techniques are utilized to manipulate the sound beam electronically such that wide-angle radiation can be maintained over a large frequency range. In order to achieve this purpose without sacrificing the array efficiency, the genetic algorithm (GA) is employed in the design stage to calculate the optimal array coefficients. The GA proved to be an effective technique in searching for the array coefficients that maximize the efficiency with desired flatness of radiation pattern. In addition, a modified design is also proposed to further enhance the efficiency in the low frequency range. The resulting designs are implemented on a digital signal processor platform and experimentally verified by using a small 5×1 panel speaker array and a large 3×3 panel speaker array.
Assessment of Down-Hole Water Sink Technology for Controlling Water Inflow at Petroleum Wells
Authors: Wojtanowicz Andrew K. , Armenta Miguel
Published: December 2004

Water inflow to petroleum wells hampers production of oil or gas leading to early shut downs of the wells without sufficient recovery of hydrocarbons in place. Downhole water sink (DWS) is a completion/production technique for producing water-free hydrocarbons with minimum amount of water from reservoirs with bottom water drive and strong tendency to water coning. DWS eliminates water invasion to hydrocarbon production by employing hydrodynamic mechanism of coning control in situ at the oil-water or gas-water contact. The mechanism is based upon a localized water drainage generated by another well completion (downhole water sink) installed in the aquifer beneath the oil/water or gas/water contact. The paper summarizes the development and state-of-the-art of DWS technology. Presented are results from theoretical studies, physical and numerical experiments, and field projects to date. It is demonstrated that DWS could increase recovery and control water production in vertical and horizontal oil wells—with natural flow, downhole pumps or gas lift, and in the gas wells producing from low-pressure tight gas reservoirs. To date, DWS has been used in reservoirs with bottom water. Moreover, in principle, the technology might also be used in the dipping reservoir structures with encroaching side-water.