Bradykinin,a new potential mediator of inflammation-induced bone resorption

The effect of bradykinin and desArg⁹-bradykinin on bone was studied in cultures of calvarial bones taken from 6–7-day-old mice. Bradykinin, at and above a 3-nM concentration, caused a dose-dependent stimulation of bone mineral mobilization and matrix degradation. Bradykinin-stimulated resorption was inhibited by calcitonin, an increased concentration of phosphate in the culture medium, hydrocortisone, dexamethasone, indomethacin, meclofenamic acid, naproxen, and 5,8,11,14-eicosatetraenoic acid. The results suggest that bradykinin stimulates osteoclast-mediated bone resorption by a process that is dependent on endogenous prostaglandin production. The stimulatory effect of bradykinin, but not of parathyroid hormone and prostaglandin E₂, was potentiated by the angiotensin-converting enzyme inhibitor, BPP_5a. Treatment with carboxypeptidase B did not affect the capacity of the peptide to stimulated ⁴⁵Ca release. DesArg⁹-bradykinin (1 m̈mole/liter) stimulated ⁴⁵Ca release to the same degree as did bradykinin. Bradykinin (3 m̈M) did not affect the degradation of cartilage proteoglycans, as assessed by the release of ³⁵S-sulfate from prelabeled calf articular cartilage in organ culture. These findings suggest that generation of bradykinin in inflammatory lesions of rheumatoid arthritis and periodontitis may contribute to the bone resorptive process seen in the joints and alveolar bone; however, bradykinin does not directly activate chondrocytes into a catabolic state.     

Childhood, neonatal, and stillborn pemphigus vulgaris

BACKGROUND: Childhood, neonatal, and stillborn cases of pemphigus vulgaris were reviewed. METHODS: From an examination of the pemphigus vulgaris literature, 46 childhood cases, nine neonatal cases, and three stillborn cases were found and investigated. RESULTS: In the childhood cases, the ratio between the sexes is approximately the same. The mean age of onset is 12 years, with only 11 children being 10 years of age or younger. Some children were treated with adjuvants to corticosteroids, most of them with azathioprine. While only one childhood case has been reported as fatal, the long-term prognosis and the relationship of early treatment and outcome are unknown. Neonatal prognosis, however, is excellent. Both neonatal and stillborn cases are probably the result of transplacental transmission of maternal antibodies. The connection between maternal antibody titer and fetal mortality is unknown. All stillborn cases reviewed died during the eight month of gestation. Immunosuppressive treatment probably affects fetal survival. In women with an active disease, who have had the disease, or who are monozygotic siblings to such patients, the possibility of the fetus developing the disease must be considered. CONCLUSIONS: It is essential that physicians be aware of the existence of childhood pemphigus vulgaris in order to make an early diagnosis and to avoid treatment delay. More childhood case reports are needed to obtain better information on optimal treatment, and authors should be encouraged to report the follow-up of their cases.     

The Regulatory Process for Dental Devices: a Researcher''s View

Comments from the three previous speakers ranged from moderate satisfaction to strong dissatisfaction with the regulatory process. Three different types of research are identified that seem to predict the ease of compliance with the 510(k) process. No one expressed satisfaction with the PMA application. It seems that current evaluation procedures inhibit the developing and marketing of new devices, but foster only enhancements to existing devices. The development of new evaluation methods is advocated to provide fast, inexpensive, but rigorous assessment of the clinical safety and treatment value of new devices.     

Conventional and Modified Veneered Zirconia vs. Metalloceramic: Fatigue and Finite Element Analysis

Purpose: The purpose of this study was to test the hypothesis that all-ceramic crown core-veneer system reliability is improved by modifying the core design and as a result is comparable in reliability to metal-ceramic retainers (MCR). Finite element analysis (FEA) was performed to verify maximum principal stress distribution in the systems. Materials and Methods: A first lower molar full crown preparation was modeled by reducing the height of proximal walls by 1.5 mm and occlusal surface by 2.0 mm. The CAD-based preparation was replicated and positioned in a dental articulator for specimen fabrication. Conventional (0.5 mm uniform thickness) and modified (2.5 mm height, 1 mm thickness at the lingual extending to proximals) zirconia (Y-TZP) core designs were produced with 1.5 mm veneer porcelain. MCR controls were fabricated following conventional design. All crowns were resin cemented to 30-day aged composite dies, aged 14 days in water and either single-loaded to failure or step-stress fatigue tested. The loads were positioned either on the mesiobuccal or mesiolingual cusp (n = 21 for each ceramic system and cusp). Probability Weibull and use level probability curves were calculated. Crack evolution was followed, and postmortem specimens were analyzed and compared to clinical failures. Results: Compared to conventional and MCRs, increased levels of stress were observed in the core region for the modified Y-TZP core design. The reliability was higher in the Y-TZP-lingual-modified group at 100,000 cycles and 200 N, but not significantly different from the MCR-mesiolingual group. The MCR-distobuccal group showed the highest reliability. Fracture modes for Y-TZP groups were veneer chipping not exposing the core for the conventional design groups, and exposing the veneer-core interface for the modified group. MCR fractures were mostly chipping combined with metal coping exposure. Conclusions: FEA showed higher levels of stress for both Y-TZP core designs and veneer layers compared to MCR. Core design modification resulted in fatigue reliability response of Y-TZP comparable to MCR at 100,000 cycles and 200 N. Fracture modes observed matched with clinical scenarios.     

Clinical and laboratory characteristics of focal laryngeal dystonia: Study of 110 cases

Spastic dysphonia is a syndrome often, producing a strain-strangle voice. We have previously classified most of these patients as having focal laryngeal dystonia, a disorder of central motor processing. In a study of 1,280 cases of dystonia registered at the Dystonia Clinical Research Center at the Columbia-Presbyterian Medical Center, we found 110 patients who had vocal cord involvement. These patients had historical information evaluated for age of onset (mean 34.6 years), duration of symptoms (mean 13.8 years), sex (1.4:1 female to male) family history (positive in 23%), and primary (66%) and secondary (34%) etiology; neurological evaluation for other dystonic involvement (25% with segmental cranial involvement, 23% with generalized dystonia) or tremor (irregular 23%, regular 6% on EMG). Treatment options were evaluated and included speech therapy, psychotherapy, biofeedback (with limited success), systemic medication (limited success except in abductor cases), nerve section (with late failure rate), and the use of botulinum toxin (improvement in all 34 injected patients).     

The double-inlay technique: a new concept and improvement in design

Gold and ceramic have long been used in prosthetic dentistry. In the posterior region, it is possible to use both materials with the double-inlay technique to add the strength of metal to the esthetics of ceramic. The problem, however, remains the volume of tooth reduction required to avoid ceramic fracture. This article describes a modification of the double-inlay technique that makes use of a pin system. This modified technique permits good retention while avoiding excessive tooth reduction.     

Gadoteridol in multiple sclerosis patients: A comparison of single and triple dose with immediate vs. delayed imaging

Enhancement of lesions in multiple sclerosis (MS) has been investigated using standard and high doses of gadolinium. The purposes of this study are to compare the relative merits of single and triple dose as well as examine the merits of delayed triple-dose images in a large group of patients. Thirty-seven patients with multiple sclerosis underwent contrast enhanced brain magnetic resonance imaging (MRI). After noncontrast images, a single dose (0.1 mmol/kg) of gadoteridol was administered. Subsequently, axial T1-weighted images were obtained immediately after administration, and again after a delay of approximately 20 minutes. After an additional 0.2-mmol/kg dose was administered, to provide a total cumulative dose of 0.3 mmol/kg of gadoteridol, immediate and delayed axial T1-weighted image sequences were repeated. The contrast-noise ratio (C/N) was calculated for each identified, enhancing lesion in each series. Furthermore, blinded readings were performed to determine the lesion detection rate. Of the forty definite lesions that underwent all four sequences, triple-dose delayed images exhibited the highest contrast-noise ratio in a significantly larger number of lesions (p < 0.0001). Triple-dose immediate and delayed scans resulted in significantly higher contrast-noise ratios (6.47 and 9.99, respectively) when compared with those of the single dose scans (3.4 for immediate scans and 5.24 for delayed) (p < 0.01). The lesion detection rate was highest for triple dose delayed (95%), followed by triple-dose immediate (83%), single-dose delayed (68%) and finally, single-dose immediate scans (43%). Triple-dose immediate was noted to have a significantly increased (p < 0.0002) lesion detection rate with respect to the standard-dose immediate scans and standard-dose delayed scans (p < 0.02). In four lesions (10% of the total number of lesions), detection occurred only with the triple-dose delayed image sequence. Triple-dose 0.3 mmol/kg gadolinium with delayed imaging resulted in the highest lesion conspicuity and the highest lesion identification rate. There was a trend of progressively increasing detection rates from single-dose immediate scans to triple-dose delayed scans. Triple-dose delayed scans resulted in significantly higher (p < 2 × 10⁻⁸) contrast noise ratios than all other sequences of this study.     

Programmatic effectiveness of a university-based implant training program: long-term, patient-centered outcomes

The University of Kentucky College of Dentistry established a formal implant program in 1999. The program utilizes a single system (Straumann) and a team concept in which implants are placed by residents in period ontology or oral and maxillofacial surgery and restored by predoctoral dental students. The program features stringent patient inclusion and exclusion criteria, incremental structured learning experiences, formal standardized protocols, and hands-on preclinical learning experiences. The use of a single system simplified training protocols and inventory requirements. Complete and partially edentulous patients requiring single and multiple implants are eligible for the program, although maxillary anterior sites are excluded. There is a formal quality assurance program to assess patient-centered outcomes. The current report includes data for patients who had implants placed in the period from January 2000 through December 2002. During that period, 192 patients received dental implants, of which 116 patients (248 implants) were available for analysis. The mean follow-up was 7.05 years (median = 7.32 years). The implant survival rate was 98.4%, while the success rate was 93.15%. Success was determined by the absence of pain or mobility, as well as self-reported patient satisfaction with function, appearance, and surgical experience.