Infectious Diseases Society of America.

Fragile X syndrome (FXS) is the leading inherited form of intellectual disability and autism spectrum disorder, and patients can present with severe behavioural alterations, including hyperactivity, impulsivity and anxiety, in addition to poor language development and seizures. FXS is a trinucleotide repeat disorder, in which >200 repeats of the CGG motif in FMR1 leads to silencing of the gene and the consequent loss of its product, fragile X mental retardation 1 protein (FMRP). FMRP has a central role in gene expression and regulates the translation of potentially hundreds of mRNAs, many of which are involved in the development and maintenance of neuronal synaptic connections. Indeed, disturbances in neuroplasticity is a key finding in FXS animal models, and an imbalance in inhibitory and excitatory neuronal circuits is believed to underlie many of the clinical manifestations of this disorder. Our knowledge of the proteins that are regulated by FMRP is rapidly growing, and this has led to the identification of multiple targets for therapeutic intervention, some of which have already moved into clinical trials or clinical practice.

Fragile X syndrome

Purpose: The aim of this prospective clinical study was to assess the risk factors associated with failure of mini-implants used for orthodontic anchorage. Materials and Methods: A total of 140 miniimplants in 44 patients, including 48 miniplates and 92 freestanding miniscrews, were examined in the study. A variety of orthodontic loads were applied. The majority of implants were placed in the posterior maxilla (104/140), and the next most common location was the posterior mandible (34/140). Results: A cumulative survival rate of 89% (125/140) was found by Kaplan-Meier analysis. There was no significant difference in the survival rate between miniplates and freestanding miniscrews, but miniplates were used in more hazardous situations. The Cox proportional-hazards regression model identified anatomic location and peri-implant soft tissue character as 2 independent prognostic indicators. The estimated relative risk of implant failure in the posterior mandible was 1.101 (95% confidence interval, 0.942 to 1.301; P = .046). The risk ratio of failure for implants surrounded by nonkeratinized mucosa was 1.117 (95% confidence interval, 0.899 to 1.405; P = .026). Discussion and Conclusion: The results confirmed the effectiveness of orthodontic mini-implants, but in certain situations adjustment of the treatment plan or modifications in the technique of implant placement may lead to improved success rates. INT J ORAL MAXILLOFAC IMPLANTS 2004;19:100‐106

A Prospective Study of the Risk Factors Associated with Failure of Mini-implants Used for Orthodontic Anchorage

Normal and tumor-derived myoepithelial cells differ in their ability to interact with luminal breast epithelial cells for polarity and basement membrane deposition Thorarinn Gudjonsson 1 , Lone Ronnov-Jessen 2 , Rene Villadsen1, Fritz Rank 3 , Mina J. Bissell 4 and Ole William Petersen 1,* Structural Cell Biology Unit, Institute of Medical Anatomy, The Panum Institute, DK-2200 Copenhagen N, Denmark Zoophysiological Laboratory, The August Krogh Institute, DK-2100 Copenhagen O, Denmark Department of Pathology, Rigshospitalet, DK-2100 Copenhagen O, Denmark Life Sciences Division, Berkeley National Laboratory, Berkeley, CA 94720, USA Author for correspondence (e-mail: o.w.petersen@mai.ku.dk) LBNL/DOE funding & contract number: DE-AC02-05CH11231

Normal and tumor-derived myoepithelial cells differ in their ability to interact withluminal breast epithelial cells for polarity and basement membrane deposition

Biomineralization is a dynamic, complex, lifelong process by which living organisms control precipitations of inorganic nanocrystals within organic matrices to form unique hybrid biological tissues, for example, enamel, dentin, cementum, and bone. Understanding the process of mineral deposition is important for the development of treatments for mineralization-related diseases and also for the innovation and development of scaffolds. This review provides a thorough overview of the up-to-date information on the theories describing the possible mechanisms and the factors implicated as agonists and antagonists of mineralization. Then, the role of calcium and phosphate ions in the maintenance of teeth and bone health is described. Throughout the life, teeth and bone are at risk of demineralization, with particular emphasis on teeth, due to their anatomical arrangement and location. Teeth are exposed to food, drink, and the microbiota of the mouth; therefore, they have developed a high resistance to localized demineralization that is unmatched by bone. The mechanisms by which demineralization-remineralization process occurs in both teeth and bone and the new therapies/technologies that reverse demineralization or boost remineralization are also scrupulously discussed. Technologies discussed include composites with nano- and micron-sized inorganic minerals that can mimic mechanical properties of the tooth and bone in addition to promoting more natural repair of surrounding tissues. Turning these new technologies to products and practices would improve health care worldwide.

/pdf/demineralization-remineralization-dynamics-in-teeth-and-bone-4qz7fpfvch.pdf

Demineralization–remineralization dynamics in teeth and bone

The aim of this study was to evaluate if the presence of periodontal infections (PI) is associated with community-acquired pneumonia (CAP) in a group of patients admitted to a hospital. A total of 140 patients were enrolled in this case–control study, with 70 patients having CAP (case group) and the other 70 patients diagnosed with other systemic diseases (control group). A periodontal examination was carried out to assess pocket probing depth (PPD), clinical attachment loss (CAL), bleeding on probing (BOP), and presence of bacterial plaque (BP). CAL and BOP showed higher scores in the case group over the control group. They were, respectively, 3.16 ± 2.43 mm and 0.33 ± 0.24 % for the case group, and 1.99 ± 2.23 mm and 0.25 ± 0.24 % for the control group (p < 0.05). High scores for BP were observed in both groups (case: 97.1 %; control: 98.6 %, p = 1.0000). Chronic periodontitis (CP) was more frequent in patients with CAP (case: 61.4 %; control: 41.4 %). The presence of moderate or severe CP increased the risk for CAP [odds ratio (OR) = 4.4, 95 % confidence interval (CI) = 1.4–13.8], even when adjusted for age, ethnicity, gender, and smoking. Moderate and severe chronic periodontitis were associated with CAP in this study.

Periodontal infections and community-acquired pneumonia: a case–control study

Aggregatibacter actinomycetemcomitans biofilm can be inactivated by methylene blue-mediated photodynamic therapy

Dentin matrix protein 1 (DMP1) is an acidic phosphoprotein that plays an important role in mineralized tissue formation by initiation of nucleation and modulation of mineral phase morphology The purpose of the present study was to examine the immunoexpression of DMP1 in tooth germs of 7 human fetuses at different gestational ages (14, 16, 19, 20, 21, 23 and 24 weeks) comparing with completed tooth formation erupted teeth The results showed the presence of DMP1 in the dental lamina, as well as in the cells of the external epithelium, stellate reticulum and stratum intermedium of the enamel organ However, in the internal dental epithelium, cervical loop region and dental papilla some cells have not labeled for DMP1 In the crown stage, DMP1 was expressed in the ameloblast and odontoblast layer, as well as in the dentinal tubules of coronal dentin near the odontoblast area Erupted teeth with complete tooth formation exhibited immunolabeling for DMP1 only in the dentinal tubules mainly close to the dental pulp No staining was observed in the enamel, predentin or dental pulp matrix DMP1 is present in all developing dental structures (dental lamina, enamel organ, dental papilla) presenting few immunoexpression variations, with no staining in mineralized enamel and dentin

/pdf/dentin-matrix-protein-1-dmp1-expression-in-developing-human-57nt97948f.pdf

Dentin matrix protein 1 (DMP1) expression in developing human teeth

Strontium ranelate (SR) is the first generation of a new class of medication for osteoporosis, which is capable of inducing bone formation and, to a certain extent, inhibiting bone resorption. The aim of this study was to evaluate the in vitro effects of SR on osteoblastic cell cultures. MC3TE-E1 cells were seeded in 24-well plates at a density of 2×10(4) cells/well and exposed to SR at 0.05, 0.1, and 0.5mM. The following parameters were assayed: 1) Cell proliferation by hemocytometer counting after 24, 48 and 72h, 2) Cell viability by MTT assay after 24, 48 and 72h, 3) Type I Collagen and Osteopontin (OPN) quantification by Western Blotting, ELISA, and Real Time PCR after 48h, 3) Immunolocalization of fibronectin (FN) by epifluorescence, and 4) matrix mineralization by Alizarin Red staining after 14days. After 24, 48 and 72h, the cell proliferation and viability were not affected by SR at 0.05 and 0.1mM (p>0.05). However, cell cultures exposed to SR at 0.5mM exhibited a decrease in both cell proliferation and cell viability in all time points assayed (p<0.05). High levels of protein and mRNA for Type I Collagen and OPN were detected in cultures exposed to SR, particularly at 0.5mM (p<0.05). SR allowed the expression of FN in osteoblastic cell cultures as observed by epifluorescence analysis. The mineralized bone-like nodule formation was affected in a concentration-dependent manner by SR, with large bone-like nodules being detected in osteoblastic cell cultures exposed to SR at 0.5mM. In conclusion, these results suggest that SR can accelerate acquisition of the osteoblastic phenotype, which explains, at least in part, the rebalancing of bone turnover in favor of bone formation.

Strontium ranelate increases osteoblast activity.

Aim To compare the expression of extracellular matrix (ECM) components in human pulpal and gingival fibroblasts in vitro.



Methodology  Cultured dental pulp fibroblasts and gingival mucosa fibroblasts were used. Tenascin (TN), fibronectin (FN), type I (col I) and III collagen (col III) and osteonectin (ONEC) were detected by immunofluorescence. Main morphological characteristics were also analysed by light microscopy (LM) and transmission electron microscopy.



Results  The results revealed different expression patterns of the proteins. TN and ONEC were only immunoexpressed by pulpal fibroblast cells, suggesting a role of these glycoproteins in formation of mineralized tissues. FN and col I were present in the cytoplasms of both cell types. No expression of col III was detected. Different morphological characteristics were visualized under LM, in which pulpal fibroblasts were spindle-shaped with a wide cytoplasm, while gingival fibroblast cells exhibited stellate/pyramidal configuration, with rounded nuclei. However, ultrastructurally, both cell lineages showed very well developed rough endoplasmatic reticulum and Golgi complex.



Conclusions  Due to the immunodetection of TN and ONEC on pulpal fibroblasts, the present findings demonstrated that a pulpal fibroblast cell is similar to an osteoblastic cell rather than an undifferentiated mesenchymal cell, such as a gingival fibroblast cell. Functional differences between the two cell lines may then be suggested.

Elizabeth Ferreira Martinez

Papers

Periodontal infections and community-acquired pneumonia: a case–control study

Aggregatibacter actinomycetemcomitans biofilm can be inactivated by methylene blue-mediated photodynamic therapy

Dentin matrix protein 1 (DMP1) expression in developing human teeth

Strontium ranelate increases osteoblast activity.

In vitro immunoexpression of extracellular matrix proteins in dental pulpal and gingival human fibroblasts.