Allogenic human serum,a clinical grade serum supplement for promoting human periodontal ligament stem cell expansion

Exposing human periodontal ligament stem cells (hPDLSCs) to animal proteins during cell expansion would compromise quality and safety of the hPDLSCs for clinical applications. The current study aimed to evaluate the replacement of animal‐based serum by human serum for the expansion of hPDLSCs. hPDLSCs were cultured in culture media supplemented with four types of serums: Group A: fetal bovine serum (FBS); Group B: allogeneic human male AB serum (HS); Group C: in‐house autologous (Auto‐HS); and Group D: in‐house allogeneic human serums (Allo‐HS). Exhibitions of mesenchymal stem cell characteristics of hPDLSCs were examined. Then, growth and osteogenic (OS) differentiation potential of hPDLSCs in FBS and HS at passages 5 and 15 were compared to investigate the effects of serum supplements on growth and expansion stability of the expanded hPDLSCs. After that, growth and OS differentiation of hPDLSCs in Auto‐ and Allo‐HS were investigated. Flow cytometrical analyses, functional differentiations, cell growth kinetic, cytogenetic analysis, alkaline phosphatase and calcium content assays, and oil red O and von Kossa staining were performed. Results showed that at passage 5, HS promoted growth and OS differentiation of hPDLSCs and extensive cell expansion, decreased growth and differentiation potential of the expanded hPDLSCs, particularly in HS. Growth and OS differentiation of hPDLSCs in Auto‐HS and Allo‐HS were not different. In summary, allogeneic human serum could be a replacement to FBS for hPDLSC expansion. In vitro cell expansion of hPDLSCs should be minimal to ensure optimal cell quality. Copyright © 2016 John Wiley & Sons, Ltd.     

Atypical avian influenza (H5N1)

We report the first case of avian influenza in a patient with fever and diarrhea but no respiratory symptoms. Avian influenza should be included in the differential diagnosis for patients with predominantly gastrointestinal symptoms, particularly if they have a history of exposure to poultry.     

Proportion of deproteinized bovine bone and autogenous bone affects bone formation in the treatment of calvarial defects in rabbits

This study assessed new bone formation generated using three different proportions of autogenous bone (AB) and deproteinized bovine bone (DBB). Thirty bicortical skull defects were prepared in 15 rabbits, divided into 3 groups: Group 1, critical size defect (CSD) versus AB as controls; Group 2, DBB versus a composite of AB and DBB using a proportion of 1:1; and Group 3, a composite of AB and DBB using a proportion of 1:2 versus a proportion of 1:4. After 8 weeks, radiographic evaluation was assessed using densitometry and new bone formation by histomorphometry. The mean optical density of the CSD (0.108 ± 0.238) and AB (0.352 ± 0.161) groups differed significantly from the DBB group (1.044 ± 0.093) and the groups using a proportion of 1:1 (0.905 ± 0.078), 1:2 (0.865 ± 0.294) and 1:4 (0.867 ± 0.304). Histomorphometry revealed a higher percentage of new bone in the AB group (30.223 ± 16.722) than in the groups using proportions of 1:2 (22.639 ± 5.659), 1:1 (20.929 ± 6.169), 1:4 (9.621 ± 2.400), DBB (14.441 ± 2.742) and CSD (10.645 ± 8.868), respectively. The 1:2 group had significantly higher bone content than the 1:4 group. The proportions of 1:1 and 1:2 resulted in greater bone formation than the proportion of 1:4, DBB and CSD.     

Fabrication and characterization of novel nano hydroxyapatite/β-tricalcium phosphate scaffolds in three different composition ratios

The biphasic calcium phosphate (BCP) concept was introduced to overcome disadvantages of single phase biomaterials. Different composition ratios of BCP bioceramics have been studied, yet controversies regarding the effects of ratio on biomaterial behavior still exist. In this study, BCP scaffolds were prepared from nano hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) that were synthesized via a solid state reaction. Three different composition ratios of pure BCP and collagen-based BCP scaffolds (%HA/%β-TCP; 30/70, 40/60, and 50/50) were produced using a polymeric sponge method. Physical and mechanical properties of all materials and scaffolds were investigated. SEM showed overall distribution of both macropores (80-200 μm) and micropores (0.5-2 μm) with high interconnected porosities. Total porosity of pure BCP (90% ± 3%) was found to be higher than collagen-based BCP (85% ± 2%). It was observed that following sintering process, dimensional shrinkage of large scaffolds (39% ± 4%) was lower than small ones (42% ± 5%) and scaffolds with high HA ratios (50%) experienced higher dimensional changes than those with higher β-TCP (70%) ratios (45% ± 3% and 36% ± 1%, respectively). Compressive strength of both groups was less than 0.1 MPa and collagen coating had almost no influence on mechanical behavior. Further studies may improve the physical properties of these scaffolds and investigate their exact biological behaviors.     

Growth and differentiation of mouse osteoblasts on chitosan-collagen sponges

The aim of this study was to investigate the effects of collagen on the microstructure and biocompatibility of chitosan-collagen composite sponges fabricated by a freezing and drying technique. The study was categorized into four groups: Group I: collagen; Group II: chitosan; Group III: 1:1 (by wt) chitosan-collagen and Group IV: 1:2 (by wt) chitosan-collagen sponges. A mouse osteoblast cell line, MC3T3-E1, was cultivated on the sponges in a mineralized culture medium for 21 days. Microstructure of scaffolds and growth of cells on the sponges were examined using scanning electron and confocal laser scanning electron microscopes. Pore size was analysed from scanning electron microscope images using Image-Pro Plus image analysis software. Cell viability (MTT assay), alkaline phosphatase activity and levels of osteocalcin and calcium were monitored every 3 days and on days 15 and 21, respectively. It was found that the sponges were porous with average pore sizes of 80-100 microm. A combination of chitosan and collagen matrixes created a well defined porous microstructure and biocompatible scaffolds. Chitosan-collagen composite sponges promoted growth and differentiation of osteoblasts into the mature stage. To optimize application of the composite sponges in bone regeneration, the fabrication process must be improved to increase the pore size of the scaffolds.     

Two uncommon uses of Bio-Oss for GTR and ridge augmentation following extractions: two case reports

Bio-Oss is natural bovine bone mineral, which has the property of bone conduction. It is recommended to be used in two- or three-walled bony defects with an ample supply of pleuripotential cells. Two cases are reported. The first was an intentional replantation, because of previous trauma, of a hopeless tooth affected with severe periodontitis. The tooth was replanted after complete elimination of granulation tissue. Bio-Oss, together with a guided tissue regeneration (GTR) membrane, was used to enhance periodontal regeneration. After 2 years of follow-up, the replanted tooth was quite stable. In the second case, Bio-Oss, together with bone taken from the retromolar area, was used in a sinus lift grafting procedure after the removal of two supernumerary teeth from the floor of the maxillary sinus. Four months after grafting, an orthodontic treatment was applied to move the two adjacent teeth through the grafted site and align them in the proper position. The clinical results of the two cases were satisfactory.     

Associations between serum lipids and causes of mortality in a cohort of 3,499 urban Thais: The Electricity Generating Authority of Thailand (EGAT) study

The association between serum lipids and mortality has not previously been established in Thailand. Baseline data from the Electricity Generating Authority of Thailand (EGAT) cohort study, plus a resurvey of the cohort 15 years later were analyzed. Participants were employees of EGAT: 2,702 men and 797 women. Total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), and triglycerides (TG) were taken as predictive variables; age, sex, hypertension, diabetes, cigarette smoking, alcohol drinking, and body mass index were taken as confounders. Dependent variables were all-causes and specific causes of mortality over 17 years of follow-up. The major cause of death among men was cardiovascular disease (CVD); among women, it was cancer. Relative risks (RR) for specific causes of death, for a mmol/L increase in each lipid, were estimated after adjustment for confounding factors using Cox proportional hazards regression. TC and LDL-C were negatively associated with liver cirrhosis mortality, although it was likely that the low cholesterol concentration was a consequence of the disease. HDL-C was negatively associated with CVD mortality (RR = 0.59; 95% confidence interval [CI], 0.39-0.93), coronary heart disease (CHD) mortality (RR = 0.36; 95% CI, 0.17-0.75) and all cause-mortality (RR = 0.68; 95% CI, 0.54-0.87). TG was not associated with mortality. HDL-C is an important risk factor for CVD in middle-class urban Thais. Health promotion programs to improve lipid profiles, such as effective exercise campaigns and dietary advice, are required to increase HDL-C and to help prevent CVD and premature death in Thailand.     

The use of SPECT to evaluate growth cessation of the mandible in unilateral condylar hyperplasia

In unilateral condylar hyperplasia, for surgical intervention to be effective, the status of condylar bone growth has to be assessed correctly. Previously this assessment relied on serial clinical observations. This study aimed to evaluate the MDP-SPECT method of assessing condylar growth in unilateral condylar hyperplasia. Twenty-six MDP-SPECT of the mandible had been performed; 21 were diagnosed as condylar hyperplasia and five as non-mandibular disease. Three isotope parameters: isotope counts, pixel counts and counts per pixel were summed for each condyle per subject. The percentage difference in isotope uptake of the three parameters between the two condyles was calculated as the ratio of the combined counts of the two sides. These differences significantly correlated with each other (Pearson r=0.78-0.98) and with the clinical status of bone growth (Spearman rho=0.72-0.86). There was a significant difference for the count per pixel between the 'growing' condyle (transaxial, T: 15.05+/-7.14, coronal, C: 12.29+/-7.88), the 'no further growth' condyle (T: 5.22+/-4.08, C: 5.67+/-3.88) and the 'normal' condyle (T: 0.82+/-0.76, C: 1.34+/-0.66). This method was able to separate 'active growth' from 'growth cessation' of the condyle by a single MDP-SPECT of the mandible. However, further studies are needed to confirm this finding.     

Photoprotection

Many agents affect the transmission of ultraviolet light to human skin. These include naturally occurring photoprotective agents (ozone, pollutants, clouds, and fog), naturally occurring biologic agents (epidermal chromophores), physical photoprotective agents (clothing, hats, make-ups, sunglasses, and window glass), and ultraviolet light filters (sunscreen ingredients and sunless tanning agents). In addition, there are agents that can modulate the effects of ultraviolet light on the skin (antioxidants and others). All of the above are reviewed in this article. LEARNING OBJECTIVE: At the conclusion of this learning activity, participants should be able to provide an overview of all aspects of photoprotection.     

The primacy of platelet-rich fibrin on bone regeneration of various grafts in rabbit's calvarial defects

AimsThis study investigated the effect of platelet-rich fibrin (PRF) on bone regeneration of various grafting materials in rabbit calvarial defects.Material and methodsTwo bicortical skull defects were prepared in 20 New Zealand white rabbits; 10 rabbits were treated with PRF and the other 10 were non-PRF. In both groups, autogenous bone was compare to empty defects in 5 rabbits and the composite of autogenous bone and deproteinized bovine bone versus deproteinized bovine bone (DBB) in the other five. The animals were sacrificed at 8 weeks. Bone formation was assessed by radiographic densitometry and histomorphometric analysis.ResultsThe mean optical density (OD) and histomorphometric analysis (HA) of the percentage of new bone showed that the PRF groups were significantly higher than the non-PRF groups in the autogenous bone graft (OD: 0.60 ± 0.19 vs 0.36 ± 0.03; HA: 38.03 ± 4.23 vs 26.21 ± 10.58) and the empty defect (OD: 0.29 ± 0.06 vs 0.11 ± 0.06; HA: 18.81 ± 9.27 vs 6.24 ± 5.01), but not in the DBB group (OD: 1.18 ± 0.17 vs 1.07 ± 0.05; HA: 13.067 ± 3.64 vs 9.63 ± 5.47) and the composite group (OD: 0.81 ± 0.15 vs 0.91 ± 0.05; HA: 22.63 ± 3.61 vs 21.29 ± 3.52).ConclusionsPRF had a positive effect on bone formation when used alone or combined with autogenous bone, but not with deproteinized bovine bone.