Tomasz Gedrange

Histological changes in masticatory muscles of mdx mice

OBJECTIVEnDuchenne muscular dystrophy (DMD) patients have distorted dentofacial morphology that could be a result of changed force balance of masticatory muscles due to unequal dystrophic changes in various masticatory muscles. Skeletal muscles of DMD patients and those of murine model of DMD - mdx mice - are both characterized by Ca(2+) induced muscle damage, muscle weakness and characteristic histological changes. Therefore, to determine the pathological changes in this animal model of DMD, we examined the masticatory muscles of the mdx mice for histological abnormalities including nuclei localization, fibre diameters, and collagen expression.nnnDESIGNnMuscle sections from masseter (MAS), temporal (TEM), tongue (TON) and soleus (SOL) of mdx and control normal mice were stained with hemalaun/eosin or with Sirius Red and morphometrically analysed. Levels of collagen staining in normal and mdx muscles were measured using image analysis and the mean optical density (mod) was determined.nnnRESULTSnDystrophin deficient masticatory muscles contained 11-75% fibres with centralised nuclei. In mdx mice an increased mean fibre diameter was observed as compared to the age-matched control muscles (control vs. mdx; MAS: 33.44+/-0.49microm vs. 37.76+/-0.68microm, p<0.005; TEM: 32.93+/-0.4microm vs. 42.93+/-0.68microm, p<0.005; SOL: 33.15+/-0.29microm vs. 40.62+/-0.55microm, p<0.005; TON: 13.44+/-0.68microm vs. 15.63+/-0.18microm, p<0.005). Increased expression of collagen was found in MAS (mod control vs. mdx: 1.34 vs. 3.99, p<0.005), TEM (mod control vs. mdx: 3.11 vs. 4.73, p<0.01) and SOL (mod control vs. mdx: 2.36 vs. 3.49, p<0.01).nnnCONCLUSIONnOur findings revealed that mdx masticatory muscles are unequally affected by the disease process. The masticatory muscles of the mdx mice could present a useful model for further investigating the influence of dystrophin deficiency on muscles function.

Increased oxidative stress in dystrophin deficient (mdx) mice masticatory muscles.

BACKGROUNDnIt has been suggested that increased oxidative stress and the glutathione antioxidant system play an important role in the pathogenesis of Duchenne muscular dystrophy. However, there is still a lack of data about the oxidative status in dystrophic masticatory muscles.nnnMETHODSnIn the masticatory muscles of the mouse model of Duchenne muscular dystrophy (mdx and controls; 100 days old, n=8-10 each group) we examined the GSH and GSSG content (glutathione reduced/oxidized form) and the level of lipid peroxidation (LPO) as measured by the thiobarbituric acid-reaction.nnnRESULTSnIn the mdx mice masticatory muscles we found increased oxidative stress as compared to the controls. The GSH values in mdx muscles were decreased (mean±SEM; masseter 339.8±37.6 μg/g vs. 523.1±36.1 μg/g, temporal 304.1±49.6 μg/g vs.512.6±60.6 μg/g, tongue muscle 243.3±28. 8 μg/g vs. 474.9±40.1 μg/g; Fig. 1) as compared to normal mice. The GSH/GSSG ratio in mdx mice was consequently decreased. No significant differences in GSSG content and LPO levels were found between mdx and control mice.nnnCONCLUSIONSnThe results imply that oxidative stress is present in all three studied mdx mouse masticatory muscles.

Immunolocalization of glycodelin in human adenocarcinoma of the lung, squamous cell carcinoma of the lung and lung metastases of colonic adenocarcinoma

Glycodelin (Gd), which is localized in cells of bronchial epithelium, type II pneumocytes and alveolar macrophages in rats and humans, plays an important role in the pulmonary immune response in asthmatic inflammation. In this study, sections of paraffin-embedded tumor adjacent lung tissue and sections of adenocarcinoma of the lung, squamous cell carcinoma of the lung and metastases of colonic adenocarcinoma were investigated for the distribution and expression of Gd using a polyclonal anti-Gd antibody. Glycodelin protein is located in the cytoplasm of bronchial epithelial cells, pneumocytes and alveolar macrophages. Furthermore, Gd is expressed in adenocarcinoma and squamous cell carcinoma of the lung as well as in lung metastases of colonic adenocarcinoma. Densitometric analyses showed a significantly increased expression of glycodelin protein in cancer tissue compared to tumor adjacent lung tissue. The Gd protein level was 1.7-2.6-fold increased in lung carcinoma compared to tumor adjacent lung tissue. The Gd protein level did not differ from each other between the investigated types of cancer tissue. Because these data validate the recent findings of Gd mRNA expression, it may be concluded that glycodelin plays an important role in the pathogenesis of lung cancer and lung metastases.

Early loading of plalatal implants (ortho-type II) a prospective multicenter randomized controlled clinical trial.

BackgroundIn orthodontic treatment, anchorage control is a fundamental aspect. Usually conventional mechanism for orthodontic anchorage control can be either extraoral or intraoral that is headgear or intermaxillary elastics. Their use are combined with various side effects such as tipping of occlusal plane or undesirable movements of teeth. Especially in cases, where key-teeth are missing, conventional anchorage defined as tooth-borne anchorage will meet limitations. Therefore, the use of endosseous implants for anchorage purposes are increasingly used to achieve positional stability and maximum anchorage.Methods/DesignThe intended study is designed as a prospective, multicenter randomized controlled trial (RCT), comparing and contrasting the effect of early loading of palatal implant therapy versus implant loading after 12 weeks post implantation using the new ortho-implant type II anchor system device (Orthosystem Straumann, Basel, Switzerland).124 participants, mainly adult males or females, whose diagnoses require temporary stationary implant-based anchorage treatment will be randomized 1:1 to one of two treatment groups: group 1 will receive a loading of implant standard therapy after a healing period of 12 week (gold standard), whereas group 2 will receive an early loading of orthodontic implants within 1 week after implant insertion. Participants will be at least followed for 12 months after implant placement.The primary endpoint is to investigate the behavior of early loaded palatal implants in order to find out if shorter healing periods might be justified to accelerate active orthodontic treatment. Secondary outcomes will focus e.g. on achievement of orthodontic treatment goals and quantity of direct implant-bone interface of removed bone specimens. As tertiary objective, a histologic and microtomography evaluation of all retrieved implants will be performed to obtain data on the performance of the SLA surface in human bone evaluation of all retrieved implants. Additionally, resonance frequency analysis (RFA, Osstell™ mentor) will be used at different times for clinically monitoring the implant stability and for histological comparison in order to measure the reliability of the resonance frequency measuring device.Trial registrationCurrent Controlled Trials ISRCTN97142521.

Erratum to: Immediate versus conventional loading of palatal implants in humans: a first report of a multicenter RCT

This study aims to analyze the clinical performance of two loading concepts on second-generation palatal implants (Orthosystem, Straumann, Basel, Switzerland) in a prospective multicenter randomized controlled clinical trial. At the time of this interim analysis, 41 patients have been randomized on a 1:1 basis to one of two treatment groups. Group 1 underwent conventional loading of palatal implants after a healing period of 12xa0weeks (gold standard) while group 2 underwent immediate implant loading within 1xa0week after implant insertion. We report initial results at 6xa0months after functional loading. The primary outcome parameter was implant success (no implant mobility, no implant loss). The implants in both groups were initially stable at the time of insertion, and all were eligible for randomization. Twenty-two patients (group 1) were subjected to conventional implant loading after 12xa0weeks while 19 patients (group 2) received immediate functional loading within the first week after insertion. Direct (e.g. distal jet appliances) as well as indirect forms of anchorage (conventional or modified transpalatal arch) were used. The magnitude of orthodontic forces ranged between 1 and 4xa0N for the immediate loading group and between 1 and 5xa0N for the conventional loading group. One implant in group 1 was lost during the healing phase. One dropout was registered in group 2. Thirty-nine implants were functionally loaded for over 6xa0months now. These preliminary data provide first evidence of the fact that immediate loading of palatal implants yields equivalent success rates as conventional loading to 4xa0N after 6xa0months.

Caries-preventive and remineralizing effect of fluoride gel in orthodontic patients after 2 years

Patients with orthodontic appliances exhibit a higher caries risk, but they are often excluded from preventive studies. Thus, the aim of this observational study was to assess the caries-preventive and remineralizing effect of a high-fluoride gel in orthodontic patients. Two hundred twenty-one orthodontic patients (age, 6–19xa0years; mean, 13.1u2009±u20092.3; nu2009=u2009104 with use of a 1.25% fluoride gel weekly at home, 117 participants without) were recruited and followed for 2xa0years, recording caries (decayed/missing/filled teeth (DMFT)/decayed/missing/filled surface (DMFS), active/inactive lesions), orthodontic treatment, use of fluorides, plaque and gingivitis. Baseline values regarding demographic and clinical parameters were equivalent for the 75 participants using fluoride gel and the 77 individuals of the control group who completed the study. The initial plaque and gingivitis values (approximal plaque index (API), 37%u2009±u200934 and 42%u2009±u200939, resp.; papillary bleeding index (PBI), 19%u2009±u200928 and 22%u2009±u200927, resp.) deteriorated slightly during the 2-year study (API, 54%/56%; PBI, 25%/28%). The increase in carious defects or fillings was minimal in both groups (fluoride, 0.75 DMFTu2009±u20091.2, 1.27 DMFSu2009±u20091.9; control, 0.99u2009±u20091.3 and 1.62u2009±u20092.6, resp.) without reaching statistical significance (pu2009=u20090.12 for DMFT, 0.44 for DMFS). The main statistically significant effect of the fluoride use was the reversal of active initial lesions diagnosed (fluoride group, −0.96u2009±u20091.82; control, −0.19u2009±u20092.0, pu2009=u20090.004), while the number of inactive initial lesions increased (2.3u2009±u20092.1 and 1.7u2009±u20092.1, resp.; pu2009=u20090.02). In conclusion, the weekly application of a fluoride gel in orthodontic patients can reduce their caries activity. Initial caries lesions in orthodontic patients can be inactivated by weekly fluoride gel use at home.

The expression of myogenic regulatory factors and muscle growth factors in the masticatory muscles of dystrophin-deficient (MDX) mice

The activities of myogenic regulatory factors (MRF) and muscle growth factors increase in muscle that is undergoing regeneration, and may correspond to some specific changes. Little is known about the role of MRFs in masticatory muscles in mdx mice (the model of Duchenne muscular dystrophy) and particularly about their mRNA expression during the process of muscle regeneration. Using Taqman RT-PCR, we examined the mRNA expression of the MRFs myogenin and MyoD1 (myogenic differentiation 1), and of the muscle growth factors myostatin, IGF1 (insulin-like growth factor) and MGF (mechanogrowth factor) in the masseter, temporal and tongue masticatory muscles of mdx mice (n = 6 to 10 per group). The myogenin mRNA expression in the mdx masseter and temporal muscle was found to have increased (P < 0.05), whereas the myostatin mRNA expressions in the mdx masseter (P < 0.005) and tongue (P < 0.05) were found to have diminished compared to those for the controls. The IGF and MGF mRNA amounts in the mdx mice remained unchanged. Inside the mdx animal group, gender-related differences in the mRNA expressions were also found. A higher mRNA expression of myogenin and MyoD1 in the mdx massterer and temporal muscles was found in females in comparison to males, and the level of myostatin was higher in the masseter and tongue muscle (P < 0.001 for all comparisons). Similar gender-related differences were also found within the control groups. This study reveals the intermuscular differences in the mRNA expression pattern of myogenin and myostatin in mdx mice. The existence of these differences implies that dystrophinopathy affects the skeletal muscles differentially. The finding of gender-related differences in the mRNA expression of the examined factors may indicate the importance of hormonal influences on muscle regeneration.

Talin, vinculin and nestin expression in orofacial muscles of dystrophin deficient mdx mice.

The activity of cytoskeletal proteins like talin, vinculin and nestin increases in muscle that regenerates. Little is known about their role or at least their expression in the process of regeneration in masticatory muscles of mdx mice, a model of Duchenne muscular dystrophy. To determine a potential role of cytoskeletal proteins in the regeneration process of mdx masticatory muscles, we examined the expression of talin 1, talin 2, vinculin and nestin in 100-day-old control and mdx mice using quantitative RT-PCR, Western blot analyses and histochemistry. The protein expression of talin 1, talin 2, nestin and vinculin in mdx muscles remained unchanged as compared with normal mice. However, in mdx masseter it was found a relative increase of nestin compared to controls. The protein expression of talin 1 and vinculin tended to be increased in mdx tongue and talin 2 to diminish in mdx masseter and temporal muscle. In mdx mice, we found significantly lower percentage of transcripts coding for nestin, talin 1, talin 2 and vinculin in masseter (pxa0<xa00.05) and temporal muscle (pxa0<xa00.001). In contrast, the mRNA expression of nestin was found to be increased in mdx tongue. Activated satellite cells, myoblasts and immature regenerated muscle fibres in mdx masseter and temporal revealed positive staining for nestin. The findings of the presented work suggest dystrophin-lack-associated changes in the expression of cytoskeletal proteins in mdx masticatory muscles could be compensatory for dystrophin absence. The expression of nestin may serve as an indicator for the regeneration in the orofacial muscles.

Biomaterials Applicable for Alveolar Sockets Preservation: In Vivo and In Vitro Studies

Bone density and quantity are primary conditions for the insertion and stability of dental implants. In cases of a lack of adequate maxillary or mandibulary bone, e.g. in terms of front to back depth or thickness, bone augmentation will be necessary. Lack of bone or bone defects can be caused by inflammation, congenital malformation, trauma or oncological surgery. Several procedures and materials for augmenting bone height have been developed to overcome the problem of a reduced amount of bone. In dentistry, bone substitution materials were used for the following applications: (1) socket preservation; (2) periodontal defects; (3) third molar extraction sites to support 2nd molars; (4) ridge augmentation; (5) defects following cyst removal / apicoectomies; (6) sinus lifts; (7) distraction osteogenesis; and (8) implant dentistry. The treatment of bone-defects and socket preservation include autografting (from one location to another within the same individual), xenografting (from a donor of another species) and allografting (from a genetically dissimilar member of the same species) cancellous bone. After blood, bone is the most commonly transplanted tissue. Worldwide, an estimated 2.2 million grafting procedures are performed annually to repair bone defects in orthopaedics, neurosurgery, and dentistry (Giannoudis et al. 2005). The increasing number of grafting procedures and the disadvantages of current autograft and allograft treatments (e.g. limited graft quantity, risk of disease transmission) drive the quest for alternative methods to treat bone defects. The use of synthetic bioactive bone substitute materials is of increasing importance in modern dentistry as alternatives to autogenous bone grafts. Various alloplastic bone substitution materials of different origin, chemical composition, and structural properties have been investigated in the last years. The materials commonly used in all approaches are ceramics, polymers or composites (Burg et al. 2000). These alloplastic materials are either absorbable or non-absorbable, as well as naturally derived or synthetically manufactured (Figure 1). Various types of biomaterials (minerals and non-mineral based materials as well as natural and artificial polymers) with different characteristics have been used for studying ossification and bone formation. For example, calcium phosphate ceramics include a variety of ceramics such as hydroxyapatite, tricalcium phosphate, calcium phosphate cement, etc. These mentioned ceramics have excellent biocompatibility and bone bonding or bone regeneration properties. Recently non-biodegradable and degradable membranes have been

Influence of examiner differences on KIG-classification when assessing malocclusions.

Objective:Indication systems such as the German KIG system (Kieferorthopädische Indikationsgruppen = Orthodontic Indication Groups) presuppose the objective assessment of underlying malocclusions. In this survey, we aimed to investigate the degree of agreement among the findings of several examiners in the assessment of different malocclusions and their classification according to the KIG system.Subjects and Methods:Calibrated examiners assessed in the clinical evaluation and on plaster models orthodontic malocclusions in 180 adults (aged 20–49, 64 male, 116 female) from the population-based Study of Health in Pomerania (SHIP). Clinical examination was carried out by an experienced orthodontist, and the plaster models were also analysed by an examiner experienced in orthodontics. To compare inter- and intra-individual model examiners, we had two examiners with differing orthodontic experience carry out additional analyses of 60 of the 180 models (29 male, 31 female).Results:The examiner differences yielded various KIG classifications and hence different assessments (i. e., whether KIG case-costs should be borne by health insurance). The comparison “clinical examination versus model analysis” revealed differences regarding 16.7% of the study participants in the assessment of whether the expense would be borne by the statutory health insurance fund. At 5.0–8.3%, the number of participants whose assessments had differed was much smaller in the inter-individual comparison of model-examiners and was smallest (at 3.3–6.7%) when comparison was made between intra-individual assessments (by a sole examiner). With regard to overall malocclusion assessment, the greatest examiner differences were again revealed when comparing the clinical examination with the model analysis (median kappa 0.57). The model-examiner comparison revealed larger differences among examiners with less orthodontic experience (median kappa 0.61 and 0.62) than the comparison between examiners with orthodontic experience (median kappa 0.70).Conclusions:There can occasionally be considerable examiner differences in the classification of participants according to orthodontic indication groups and hence varying assessments of whether such persons are KIG cases or not. Various means of data collection (clinical evaluation—plaster models) in the assessment of malocclusions by multiple examiners and by those with little orthodontic experience may negatively influence agreement among examiners.ZusammenfassungZiel:Indikationssysteme wie die „Kieferorthopädischen Indikationsgruppen“ (KIG) setzen eine objektive Bewertung der ihnen zugrunde liegenden Dysgnathiesymptome voraus. In der vorliegenden Untersuchung sollte erörtert werden, wie gut die Befunde mehrerer Untersucher bei der Erhebung unterschiedlicher Dysgnathiesymptome und die Einstufung in die „KIG“ übereinstimmen.Probanden und Methodik:Bei 180 erwachsenen Probanden (64 männlich, 116 weiblich, im Alter von 20–49 Jahren) aus der populationsbasierten Study of Health in Pomerania (SHIP) wurden von kalibrierten Untersuchern kieferorthopädische Dysgnathiesymptome klinisch und am Modell erhoben. Die klinische Untersuchung erfolgte durch eine erfahrene Kieferorthopädin, die Modellanalyse ebenfalls durch eine kieferorthopädisch erfahrene Untersucherin. Für einen inter- und intraindividuellen Modelluntersuchervergleich werteten zwei kieferorthopädisch unterschiedlich erfahrene Untersucher 60 der 180 Modelle (29 männlich, 31 weiblich) zusätzlich aus.Ergebnisse:Bei der Einteilung in das KIG-System führten die Untersucherunterschiede zu unterschiedlichen Einstufungen (KIG-Fall/Kostenübernahme—ja oder nein). Der Vergleich „klinische Untersuchung/Modellanalyse“ zeigte für 16,7% der Probanden eine unterschiedliche Einstufung für die Kostenübernahme. Die Gruppe der unterschiedlich beurteilten Probanden fiel bei dem Vergleich der Modelluntersucher untereinander mit 5,0–8,3% deutlich geringer und bei ein und demselben Untersucher mit 3,3–6,7% am geringsten aus. Bei der Erhebung der Dysgnathiesymptome insgesamt zeigten sich im Vergleich der klinischen Untersuchung mit der Modellauswertung wiederum die größten Untersucherunterschiede (Kappa-Median 0,57). Im Modelluntersuchervergleich traten bei dem kieferorthopädisch unerfahrenen Untersucher größere Unterschiede (Kappa-Median 0,61 und 0,62) auf als beim Vergleich der kieferorthopädisch erfahrenen Untersucher untereinander (Kappa-Median 0,70).Schlussfolgerungen:Es gibt teilweise erhebliche Untersucherunterschiede bei der Einstufung von Probanden in die Kieferorthopädischen Indikationsgruppen und damit unterschiedliche Einteilungen dieser in KIG-Fälle oder Non-KIG-Fälle. Unterschiedliche Erhebungsmethoden (Klinik/Modell) bei der Befundung von Dysgnathiesymptomen durch mehrere Untersucher sowie kieferorthopädisch unerfahrene Untersucher können einen ungünstigen Einfluss auf die Untersucherübereinstimmung haben.