SH3BP2-encoding exons involved in cherubism are not associated with central giant cell granuloma

Central giant cell granuloma (CGCG) is a benign lesion with unpredictable biological behaviour ranging from a slow-growing asymptomatic swelling to an aggressive lesion associated with pain, bone and root resorption and also tooth displacement. The aetiology of the disease is unclear with controversies in the literature on whether it is mainly of reactional, inflammatory, infectious, neoplasic or genetic origin. To test the hypothesis that mutations in the SH3BP2 gene, as the principal cause of cherubism, are also responsible for, or at least associated with, giant cell lesions, 30 patients with CGCG were recruited for this study and subjected to analysis of germ line and/or somatic alterations. In the blood samples of nine patients, one codon alteration in exon 4 was found, but this alteration did not lead to changes at the amino acid level. In conclusion, if a primary genetic defect is the cause for CGCG it is either located in SH3BP2 gene exons not yet related to cherubism or in a different gene.

Agenesis of maxillary lateral incisors and associated dental anomalies

Introduction: The objectives of this study were to evaluate the prevalence of dental anomalies in patients with agenesis of maxillary lateral incisors and to compare the findings with the prevalence of these anomalies in the general population. Methods: A sample of 126 patients, aged 7 to 35 years, with agenesis of at least 1 maxillary lateral incisor was selected. Panoramic and periapical radiographs and dental casts were used to analyze other associated dental anomalies, including agenesis of other permanent teeth, ectopia of unerupted permanent teeth, microdontia of maxillary lateral incisors, and supernumerary teeth. The occurrence of these anomalies was compared with prevalence data previously reported for the general population. Statistical testing was performed with the chi-square test (P<0.05) and the odds ratio. Results: Patients with maxillary lateral incisor agenesis had a significantly increased prevalence rate of permanent tooth agenesis (18.2%), excluding the third molars. The occurrence of third-molar agenesis in a subgroup aged 14 years or older (n = 76) was 35.5%. The frequencies of maxillary second premolar agenesis (10.3%), mandibular second premolar agenesis (7.9%), microdontia of maxillary lateral incisors (38.8%), and distoangulation of mandibular second premolars (3.9%) were significantly increased in our sample compared with the general population. In a subgroup of patients aged 10 years or older (n = 115), the prevalence of palatally displaced canines was elevated (5.2%). The prevalences of mesioangulation of mandibular second molars and supernumerary teeth were not higher in the sample. Conclusions: Permanent tooth agenesis, maxillary lateral incisor microdontia, palatally displaced canines, and distoangulation of mandibular second premolars are frequently associated with maxillary lateral incisor agenesis, providing additional evidence of a genetic interrelationship in the causes of these dental anomalies. (Am J Orthod Dentofacial Orthop 2010;137:732.e1-732.e6)

Osteointegration of Autogenous Bone Graft Associated With Osteoblastic Cells Under Treatment With Caffeine

Purpose: The present study investigated osteointegration of autogenous bone (AB) from calvaria graft associated with osteoblastic cells (OC) in bone defects in rats subjected to daily administration of caffeine. Materials and Methods: Male rats received daily intraperitoneal injection of 1.5% caffeine (0.2 mL/100 g body weight) or saline solution for 30 days. Then they were anesthetized, submitted to the extraction of the upper right incisor, and implanted with AB only and AB + OC. The animals were killed on 7th, 21st, and 42nd days after surgery, and their maxilla were processed for obtaining semiserial sections (5 mu m) stained with hematoxylin and eosin. Through image analysis system, the bone volume and the quality of graft in adjacent areas were estimated. Results: The results showed that in caffeine treatment, the AB + OC graft showed no foreign body and acute inflammatory reactions inside the defect when compared to AB. The histometric results revealed that the association AB + OC produced significant increase (10%-15%) in bone volume in later experimental period (42 days) when compared with saline solution group (P <= 0.01). Conclusions: It was concluded that the association of AB from calvaria + OC demonstrated progressive osteointegration and accelerated the repair of bone defects in animals treated with daily caffeine. (Implant Dent 2011;20:369-373)

Functional polymorphisms in the promoter of the matrix metalloproteinase-9 (MMP-9) gene are not linked with significant plasma MMP-9 variations in healthy subjects

Background: Matrix metalloproteinase-9 (MMP-9) is involved in the degradation of the extracellular matrix during physiological and pathological processes. Two functional polymorphisms [C(-1562)T and microsatellite (CA)(13-25)] in the promoter region of the MMP-9 gene have been associated with several diseases. The aim of this study was to examine whether these MMP-9 polymorphisms and haplotypes are linked with plasma MMP-9 variations in healthy subjects. Methods: We studied 177 healthy male white volunteers (age range 20-55 years) who were non-smokers and not taking any medication. Genomic DNA was extracted from whole blood and genotypes for the C(-1562)T and the microsatellite (CA)(n) polymorphisms were determined. MMP-9 levels were measured in plasma samples by gelatin zymography. Results: The frequency of the alleles C and T for the C(-1562)T polymorphism were 90% and 10%, respectively. The frequency of the alleles with less than 21 CA repeats Q and with 21 repeats or higher (H) were 47% and 53%, respectively. We found no differences in plasma MMP-9 levels among the genotype groups or among different haplotypes (all p > 0.05). Conclusions: These findings suggest that functional polymorphisms in the promoter of the MMP-9 gene are not linked with significant plasma MMP-9 variations in healthy subjects.

Metalloproteinase inhibition protects against cardiomyocyte injury during experimental acute pulmonary thromboembolism

Objectives: Up-regulated matrix metalloproteinases may be involved in the development of cardiomyocyte injury and the degradation of troponin associated with acute pulmonary thromboembolism. We examined whether pretreatment with doxycycline (a nonspecific matrix metalloproteinase inhibitor) protects against cardiomyocyte injury associated with acute pulmonary thromboembolism. Design: Controlled animal study. Setting: University research laboratory. Subjects: Mongrel dogs. Interventions: Anesthetized animals received doxycycline (10 mg/kg intravenously) or saline and acute pulmonary thromboembolism was induced with autologous blood clots injected into the right atrium. Control animals received doxycycline (or saline). Measurements and Main Results: Hemodynamic measurements were performed, and acute pulmonary thromboembolism increased baseline mean pulmonary arterial pressure and pulmonary vascular resistance by approximately 160% and 362%, respectively (both p<.05), 120 mins after acute pulmonary thromboembolism. Pretreatment with doxycycline attenuated these increases (to 125% and 232%, respectively; both p<.05). Although acute pulmonary thromboembolism tended to increase the right ventricle maximum rate of isovolumic pressure development and the maximum rate of isovolumic pressure decay, doxycycline produced no effects on these parameters. Gelatin zymograms of right ventricle showed that acute pulmonary thromboembolism marginally increased matrix metalloproteinase-9 (but not matrix metalloproteinase-2) levels in the right ventricle. A fluorometric assay to assess net matrix metalloproteinase activities showed that acute pulmonary thromboembolism increased matrix metalloproteinase activities in the right ventricle by >100% (p<.05), and this finding was confirmed by in situ zymography of the right ventricle. Doxycycline attenuated acute pulmonary thromboembolism-induced increases in right ventricle matrix metalloproteinase activities. Acute pulmonary thromboembolism induced neutrophil accumulation in the right ventricle, as estimated by myeloperoxidase activity, and doxycycline blunted this effect (p<.05). Serum cardiac troponin I concentrations, which reflect cardiomyocyte injury, increased after acute pulmonary thromboembolism, and this increase was attenuated by pretreatment with doxycycline (p<.05). Conclusions: We found evidence supporting the idea that acute pulmonary thromboembolism is associated with increased matrix metalloproteinase activities in the right ventricle, which may lead to degradation of sarcomeric proteins, including cardiac troponin I. Inhibition of matrix metalloproteinases may be an effective therapeutic intervention in the management of acute pulmonary thromboembolism. (Crit Care Med 2011; 39: 349-356)

Osteoinductivity potential of rhBMP-2 associated with two carriers in different dosages

The objective of this study was to evaluate bone formation after application of different doses of recombinant human bone morphogenetic protein-2 (rhBMP-2) combined with monoolein or poloxamer gels, in critical bone defects of rats. Forty-five Wistar rats were divided into nine treatment groups with five animals each: I: application of 1 A mu g rhBMP-2 + monoolein; II: 3 A mu g rhBMP-2 + monoolein; III: 7 A mu g rhBMP-2 + monoolein; IV: 1 A mu g rhBMP-2 + poloxamer; V: 3 A mu g rhBMP-2 + poloxamer; VI: 7 A mu g rhBMP-2 + poloxamer; VII: monoolein only; VIII: poloxamer only; and IX: critical bone defect only. A critical-sized defect of 6 mm diameter was produced in the left parietal bone and it was filled with gels of the above mentioned treatments. After 2 weeks, the calvarial bones were removed for histological processing. Bone formation in the groups that received poloxamer gel and rhBMP-2 was not significantly different from the control group (IX). Groups receiving monoolein and rhBMP-2 (1 and 3 A mu g) and those that received only the carriers (VII and VIII) had less bone formation in relation to the control. The association of rhBMP-2 to both poloxamer and monoolein did not exhibit any significant differentiation in bone formation in comparison with the control group.

Determination of para-Chloroaniline and Reactive Oxygen Species in Chlorhexidine and Chlorhexidine Associated with Calcium Hydroxide

The aim of this study was to determine whether para-chloroaniline (PCA) and/or reactive oxygen species (ROS) are generated by chlorhexidine (CHX) alone or after CHX is mixed with calcium hydroxide at different time points. Mass spectrometry was performed to detect PCA in samples of 0.2% CHX and Ca(OH)2 mixed with 0.2% CHX. High-performance liquid chromatography was used to confirm the presence of CHX in the mixture with Ca(OH)2. The samples were analyzed immediately after mixing and after 7 and 14 days. During the intervals of the experiment, the samples were maintained at 36.5 degrees C and 95% relative humidity. PCA was detected in the 0.2% CHX solution after 14 days. The mixture of CHX with Ca(CH)2 liberated ROS at all time points, but no traces of CHX were present in the mixture as a result of immediate degradation of the CHX. (J Endod 2008;34:1508-1514)