Non-Detection of HCMV Total Genomic DNA in Human Glioma Cells Genome.

AIM: To demonstrate if the human cytomegalovirus (HCMV) genome, that is involved in the pathogenesis of gliomas, is part of the genomic DNA of glioma cells or not. MATERIAL AND METHODS: The study included U87MG glioblastoma cell culture and tumor samples from glioma patients. The genomic DNA of tumor samples and U87MG cells were extracted and real-time quantitative PCR was used to assess the presence of the human cytomegalovirus genomic DNA. RESULTS: Consequently, HCMV positivity was not detected in the tumor and cell line genomic DNA under the aforementioned experimental conditions. CONCLUSION: We found that the genomic DNA of all the samples was negative for HCMV genomic DNA. Thus, HCMV could not be detected in human glioma tumors and we put forward that HCMV genomic DNA was not incorporated into the genomic DNA of glioma cells. Thus, total viral DNA is not involved in the pathogenesis of glioma; however, small viral particles or specific genes might be incorporated into the genomic DNA of glioma cells, leading to cancer development. This prompts further studies for verification.

Distribution of Aquaporin-4 channels in hippocampus and prefrontal cortex in mk-801-treated balb/c mice.

Functional disorders of the glymphatic system and Aquaporin-4 (AQP-4) channels take part in the pathophysiology of neurodegenerative disease. The aim of this study was to describe the distribution of AQP-4 channels in the prefrontal cortex and hippocampus in a mouse model of NMDA receptor blocking agent-induced schizophrenia-like behavior model. NMDA receptor antagonist MK-801 was used to produce the experimental schizophrenia model. MK-801 injections were administered for eleven days to Balb/c mice intraperitoneally. Beginning from the sixth day of injection, the spatial learning and memory of the mice were tested by the Morris water maze (MWM) task. A group of mice was injected with MK-801 for ten days without the MWM task. Hippocampus and prefrontal specimens were collected from this group. Tissue samples were stained immunohistochemically and AQP-4 channels were examined by electron microscope. Time to find the platform was significantly longer at MK-801 injected group than the control group at the MWM task. Also, time spent at the target quadrant by the MK-801 group was shorter compared to the control group. AQP-4 expression increased significantly at MK-801 group glial cells, neuronal perikaryon, perineuronal and pericapillary spaces. In the MK-801 group, there was remarkable damage in neurons and glial cells. Increased AQP-4 channel expression and neurodegeneration at the MK-801 group induced with schizophrenia-like behavior model. MK-801 induced NMDA receptor blockade causes a decline in cognitive and memory functions. Increased AQP-4 expression at the prefrontal cortex and hippocampus to elicit and transport products of synaptic neurotransmitters and end metabolites is suggested.

Effects of Theranekron and alpha-lipoic acid combined treatment on GAP-43 and Krox-20 gene expressions and inflammation markers in peripheral nerve injury.

Peripheral nerve injury (PNI) is a major health problem that results in loss of motor and sensory functions. In treatment of PNI, various methods such as anastomosis, nerve grafts, nonneural tissue grafts, and nerve conduits are applied. In the present study, it was aimed to investigate the effects of Theranekron and Alpha-lipoic acid (ALA) combined treatment on nerve healing in experimental PNI by using histomorphometric, electron microscopic, immunohistochemical and molecular biological methods. Sixty-two Wistar rats were divided into six groups; the normal control group, sham operation group, experimental control group having a crush type injury with no treatment, Theranekron treatment group, ALA treatment group and Theranekron+ALA combined treatment group. Sciatic nerve tissue samples were obtained on days 1, 7 and 14 following injury in all groups. GAP-43 expression was upregulated in all PNI received groups compared to the control group. Krox-20 expression was downregulated in all groups that received PNI compared to the control group. While intensely positive TNF-α and IL-6 expressions were observed up to the 1st to the 14th day for the experimental control group, these expressions were seen as "weakly positive" in the treatment groups from the 1st day to the 14th day. The number of myelinated fibers was higher in the control and sham operation groups. Additionally, the number of myelinated nerve fibers increased in the combined treatment group. In conclusion, these findings suggest that combined therapy of Theranekron and ALA promotes structural recovery and it should be considered as an effective treatment protocol following PNI.

Effects of combined treatment of minocycline and methylprednisolone on the expression of tumor necrosis factor alpha and interleukine-6 in experimental spinal cord injury: a light and electron microscopic study.

Spinal cord injury (SCI) is an important health problem, and there is no universal treatment protocol for it today. Following SCI pro-inflammatory mediators such as tumor necrosis factor- alpha (TNF-α) and interleukin-6 (IL-6) increase at the lesion site and play important roles in secondary tissue damage. Methylprednisolone (MP) is a glucocorticoid, and minocycline is a tetracycline-derived antibiotic both with neuroprotective effects on central nervous system trauma. However, there are limited studies on their effects on SCI. In this study, we aimed to evaluate effects of MP+minocycline combined treatment on cellular distribution and localization of TNF-α And IL-6 after SCI. Eighty Wistar rats were divided into three main groups as the intact control group, sham operation group, and experimental control group that received spinal cord compression injury. Following the injury, the experimental control group was subdivided into four groups as control, methylprednisolone treatment, minocycline treatment and, MP+minocycline combined treatment groups. Tissue samples were obtained from all groups at 24 hours and 72 hours after the injury. We found a significant decrease in TNF-α And IL-6 expressions in combined treatment group at 24 hours after injury. Also, there was a significant decrease in MDA and increase in SOD levels in this group. Furthermore, decreased lipid peroxidation and neuronal and glial cell death were also observed in combined treatment group. These results suggest that MP+minocycline combined treatment promotes functional recovery and, it should be considered as an effective treatment protocol following SCI.

Evaluation of a metal artifact reduction algorithm and an optimization filter in the estimation of peri-implant dehiscence defects by using cone beam computed tomography: an in-vitro study.

OBJECTIVES: The aim of this study was to assess the effect of a metal artifact reduction (MAR) algorithm and the adaptive image noise optimizer (AINO) optimization filter in the detection of peri-implant dehiscences with cone beam computed tomography (CBCT). STUDY DESIGN: Nine implants (3 zirconium, 3 titanium, and 3 zirconium-titanium) were placed in 3 sheep heads. Dehiscences were created on the buccal and lingual/palatal surfaces. A total of 9 defects and 9 controls with no defects were evaluated by 3 observers. Each sheep head was scanned 5 times with 4 scan modes; (1) without MAR/without AINO; (2) with MAR/without AINO; (3) without MAR/with AINO; and (4) with MAR/with AINO. Receiver operating characteristic analysis and weighted kappa coefficients were used to calculate diagnostic efficacy and intra- and interobserver agreements for each implant type and scan mode. RESULTS: For all implant types, dehiscences were most accurately detected when both MAR and AINO were applied (P ≤ .045). Detection of dehiscences was more accurate with titanium implants (P ≤ .040). There were no significant differences in agreement among and between the observers. CONCLUSIONS: The use of both MAR and AINO enhanced the detection accuracy of artificially created dehiscences in proximity to implants. Their combined use is recommended for detecting peri-implant dehiscences.

Relationships between microRNA-20a and microRNA-125b expression and apoptosis and inflammation in experimental spinal cord injury.

Objectives: The aim of the study was to determine the relationships between microRNA-20a and microRNA-125b expression and apoptosis and inflammation in a rat model of spinal cord injury (SCI) using microscopy, immunohistochemistry, and molecular biology. Methods: Sixty-one rats were divided into three groups: a control group that was not subjected to any operation; a sham-operated group; and an experimental group that was subjected to spinal cord compression. The experimental group was further subdivided into two subgroups: the experimental control group, which did not receive any drug treatment; and the methylprednisolone treatment group, which received 30 mg/kg methylprednisolone on day 0 followed by 10 mg/kg/day methylprednisolone from days 1-14. Results: Tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6 levels increased in the experimental control group on days 1 and 3, and decreased in the experimental control group and methylprednisolone treatment group on days 7 and 14. Caspase-3 levels increased in the experimental control group on day 1, and decreased in the experimental control group and methylprednisolone treatment group on days 3, 7, and 14. MicroRNA-20a expression was upregulated in the experimental control group on days 1 and 3, and microRNA-125b expression was downregulated on days 3 and 7. Conclusions: After SCI, upregulated microRNA-20a expression and increased proinflammatory cytokines may lead to an increase in inflammation. MicroRNA-125b may be associated with caspase-3, and microRNA-125b downregulation may inhibit apoptosis. Although the results of this study suggest potential relationships between microRNA-20a and microRNA-125b expression and apoptosis and inflammation in SCI, further studies are needed to confirm microRNA-20a and microRNA-125b as biomarkers in SCI and to develop new strategies for the treatment of SCI.

Stem Cells for the Oromaxillofacial Area: Could they be a promising source for regeneration in dentistry?

Oromaxillofacial tissues (OMT) are composed of tooth and bone, together with nerves and blood vessels. Such a composite material is a huge source for mesenchymal stem cells (MSCs) that can be obtained with ease from extracted teeth, teeth structures and socket blood, flapped gingiva tissue, and mandibular/maxillar bone marrow. They offer a biological answer for restoring damaged dental tissues such as the regeneration of alveolar bone, prevention of pulp tissue defects, and dental structures. Dental tissue-derived mesenchymal stem cells share properties with bone marrow-derived mesenchymal stem cells and there is a considerable potential for these cells to be used in different stem cell-based therapies, such as bone and nerve regeneration. Dental pulp tissue might be a very good source for neurological disorders whereas gingiva-derived mesenchymal stem cells could be a good immune modulatory/suppressive mediators. OMT-MSCs is also promising candidates for regeneration of orofacial tissues from the perspective of developmental fate. Here, we review the fundamental biology and potential for future regeneration strategies of MSCs in oromaxillofacial research.

Analysis of Cavernous Malformations: Experience with 18 Cases.

AIM: To analyze the results of stereotactic radiosurgery (SRS) or surgical treatment of 18 cases with cavernous malformation and report 2 cases with unusual localization and size. MATERIAL AND METHODS: We present 11 and 8 patients who underwent surgery and SRS between 2010 and 2018 respectively. The operated group comprised six men and five women (mean age, 33.6 years). SRS was performed in five men and three women (mean age, 33.3 years). All patients were diagnosed and followed-up with magnetic resonance imaging. Stereotactic navigation was not used for lesion localization. The lesion, including the area with hemosiderin, was easily excised using microsurgical approach. RESULTS: Except for recurrent headache, all symptoms of patients who underwent surgery resolved rapidly. Hemorrhage developed in two of our patients after SRS. One of them refused to undergo surgery and recovered completely with steroid therapy, whereas the other underwent surgery after detection of cavernous malformation at the posterior fossa, with a dimension of 26.8x26.2 mm and occluding the fourth ventricle. CONCLUSION: In patients without significant preoperative morbidity risk, surgical excision is the gold standard of treatment. SRS is performed in surgically inaccessible, deeply located, multiple cavernous malformations in the brain stem and eloquent area. Of note, giant aneurysm is defined as an aneurysm with a diameter of at least 25 mm; however, there is no dimension threshold defined for giant CM, and the size of giant aneurysm can be accepted as a valid criterion for giant CM. Our 2 cases had giant CM and up to our knowledge the case with giant CM at the posterior fossa is the first giant CM at the posterior fossa in the English literature.

Recurrent Chronic Subdural Hematoma: Report of 13 Cases.

Chronic subdural hematoma is a frequent type of hemorrhage, which terminates with mortality if not diagnosed and treated early. The aim of this clinical study is to evaluate the patients with unilateral and bilateral recurrent chronic subdural hematoma. The study group consisted of 13 cases with unilateral and bilateral recurrent chronic subdural hematomas who underwent aggressive wide craniotomy, duraectomy, inner and outer membranectomy, dural border coagulation, incision through cortical vein trace and hang up of dural edge, between 2009 - 2016. All of our patients were diagnosed by preoperative Magnetic Resonance Imaging. We evaluated the age, gender, complaints and neurologic signs, localization and thickness of the hematoma. We can estimate that wide craniotomy, duraectomy and membranectomy is a good option in preventing recurrent chronic subdural hematoma and complications.

The Causes of Postoperative Meningitis: The Comparison of Gram-Negative and Gram-Positive Pathogens.

AIM: To determine the microbiological etiology in critically ill neurosurgical patients with nosocomial meningitis (NM) and to show the impact of Gram-negative rods and the differences between patient characteristics and the clinical and prognostic measures in Gram-negative and Gram-positive meningitis. MATERIAL AND METHODS: In this prospective, single-center study, we reviewed all adult patients hospitalized during a 12-year period and identified pathogens isolated from post-neurosurgical cases of NM. Demographic, clinical, and treatment characteristics were noted from the medical records. RESULTS: Of the 134 bacterial NM patients, 78 were male and 56 were female, with a mean age of 46±15.9 and a median age of 50 (18-80) years. One hundred and forty-one strains were isolated; 82 (58.2%) were Gram-negative, 59 (41.8%) were Grampositive. The most commonly isolated microorganism was Acinetobacter baumannii (34.8%). Comparison of mortality data shows that the patients who have meningitis with Gram-negative pathogens have higher mortality than with Gram-positives (p=0.034). The duration between surgery and meningitis was shorter in Gram-negative meningitis cases compared to others (p=0.045) but the duration between the diagnosis and death was shorter in Gram-positive meningitis cases compared to Gram-negatives (p=0.017). Cerebrospinal fluid protein and lactate levels were higher and glucose level was lower in cases of NM with Gram-negatives (p values were respectively, 0.022, 0.039 and 0.049). CONCLUSION: In NM, Gram-negative pathogens were seen more frequently; A. baumanni was the predominant pathogen; and NM caused by Gram-negatives had worse clinical and laboratory characteristic and prognostic outcome than Gram-positives.

The Effects of Hypericum perforatum L. on the Proliferation, Osteogenic Differentiation, and Inflammatory Response of Mesenchymal Stem Cells from Different Niches.

The aim of this study is to demonstrate and compare the differentiation, proliferation, migration and inflammatory behavior of dental pulp- and bone marrow-derived mesenchymal stem cells (DP-MSCs and BM-MSCs) in response to a Hypericum perforatum ethanol extract. Using xCELLigence, a real-time monitoring system, a dose of 10 µg/mL was found to be the most efficient concentration for vitality. The IC50 values and doubling time were calculated. The results showed that H. perforatum L. was able to accelerate osteogenic differentiation in DP-MSCs, but calcium granulation was impaired in BM-MSCs. H. perforatum L.-induced migration increased when compared to the TNF-α-induced migration in a Transwell migration assay, and the IL-6 cytokine levels between cells also differed. It can be suggested that tissue memory is an important factor in MSCs, and that they differ in their response to external factors. In conclusion, H. perforatum L. can be considered an excellent osteoinductive agent for DP-MSCs but should not be used for BM-MSCs. Tissue-specific osteoinductive agents should be discussed in future studies.

The Effect of Ascorbic Acid over the Etoposide- and Temozolomide-Mediated Cytotoxicity in Glioblastoma Cell Culture: A Molecular Study.

AIM: Glioblastoma (GBM) is one of the lethal central nervous system tumors. One of the widely used chemical agents for the treatment of glioblastoma is temozolomide. It is an orally administered, deoxyribonucleic acid (DNA) alkylating agent. DNA alkylation triggers the death of tumor cells. However, some tumor cells are able to repair this type of DNA damage and thus lower the therapeutic effect of temozolomide. Laboratory and clinical studies indicate that temozolomide"s anticancer effects might be strengthened when combined with other chemotherapeutic agents like etoposide or antioxidant agents like ascorbic acid. In this study, we aimed to evaluate the cytotoxic and oxidative stress effects of ascorbic acid (1000 ?M), temozolomide (100 ?M) and etoposide (25 ?M) agents alone and in dual and triple combinations in a glioblastoma U87 MG cell culture. MATERIAL AND METHODS: The cytotoxic and oxidative stress effects were investigated by the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) and liquid chromatography tandem-mass spectrometry (LC-MS/MS) analysis methods. RESULTS: Cytotoxicity tests showed that etoposide, temozolomide, "etoposide+ascorbic acid", "temozolomide+ascorbic acid", "temozolomide+etoposide" and "temozolomide+etoposide+ascorbic acid" combinations have anti-proliferative effects. The maximum anti-proliferation response was observed in the "temozolomide+etoposide+ascorbic acid"-added group. Similarly LCMS/ MS analyses showed that minimum oxidative DNA damage occurred in the "temozolomide+etoposide+ascorbic acid"-added group. CONCLUSION: Ascorbic acid decreases the cytotoxic and genotoxic effect of etoposide and etoposide-temozolomide combination but it has no meaningful effect on temozolomide"s toxicity.

Effects of Arginine Vasopressin and V1 Receptor Antagonist on Cerebral Vasospasm Secondary to Subarachnoid Hemorrhage: An Experimental Study.

AIM: To examine morphological, radiological and biochemical effects of arginine vasopressin (AV) and V1 receptor antagonist on cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) in rabbits. MATERIAL AND METHODS: Forty male New Zealand white rabbits were randomly divided into four groups comprising 10 rabbits each. The groups were; 1) Control group, 2) SAH group, 3) SAH+AV group, 4) SAH+V1 antagonist group. Diameters of the basilar artery in all groups were measured on angiograms. All animals were sacrificed two days following basilar angiography and tissue samples of basilar artery were obtained under microscope immediate after craniectomy for ultrastructural and biochemical examinations. RESULTS: The artery diameters were found to be 50% and 50% at the 30th minute in the groups 2 and 3 respectively. In group 3, CVS was 13% more in comparison with the 2nd group. In group 4, vascular constriction was 34.5% at the 30th minute and about 30.9% at the 300th minute. Despite the increase in regional blood flow, AV did not provide morphological change. Histological appearance was related to vascular stenosis due to CVS. Histological outcome was the best in group 4 because of less CVS. CONCLUSION: Arginine vasopressin plays an important role in CVS. We detected morphological and radiological recovery in basilar artery, besides moderate improvement due to AV receptor antagonist in CVS.

Immunohistochemical Evaluation of Hemostatic Changes in Glioblastoma Multiforme and Low-Grade Astrocytoma.

AIM: In glioblastoma multiforme, the balance between the procoagulant system, anticoagulant system and fibrinolytic system is impaired in favour of hypercoagulability. The aim of this study was to compare glioblastoma multiforme with astrocytoma grade II by subjectively evaluating the levels of prothrombin and biotinylation thrombin, and G protein serum protease activatin receptors, as tissue factors causing hypercoagulation and affecting coagulation. MATERIAL AND METHODS: Specimens from 35 cases with glioblastoma multiforme and 23 cases with astrocytoma grade II were evaluated immunohistochemically. The specimens were stained with hematoxylen-eosin and immunohistochemically for prothrombin, biotinylation thrombin and protease activating factor receptors to determine the correlation between the tumor malignancy and coagulation factor receptors. RESULTS: An increase in malignancy was seen to result in an increase in prothrombin, biotinylation thrombin, protein activator receptor 1, protein activator receptor 3, and protein activator receptor 4 levels, and a decrease in protein activator receptor 2 level. These data showedthat there was hypercoagulability in glioblastoma multiforme. Descriptive statistics and Mann-Whitney U analysis were used to evaluate the results. CONCLUSION: In glioblastoma multiforme, if there is no radiologicalevidence of hemorrhage, low molecular weight heparin should be administered peroperatively and continued for 3 months postoperatively to prevent the development of deep venous thrombosis. This will also be useful in the prevention of invasion, angiogenesis, metastasis and tumour progression.

Effects of Syzygium aromaticum, Cinnamomum zeylanicum, and Salvia triloba extracts on proliferation and differentiation of dental pulp stem cells.

INTRODUCTION: Hypersensitivity, local irritative and cytotoxic effects are known for the chemical components of Syzygium aromaticum and Cinnamomum zeylanicum contained in dental materials. However, there is no intimate data in dentistry using the whole extracts of these plants and introducing new ones. Salvia triloba is a well-known anti-inflammatory plant that correspondingly could be used in several dental traumas. OBJECTIVES: We aimed to show and compare the effect of S. aromaticum, C. zeylanicum, and S. triloba extracts on dental pulp stem cells (DPSCs) proliferation, differentiation, and immune responses. MATERIAL AND METHODS: Using xCELLigence, a real time monitoring system, we obtained a growth curve of DPSCs with different concentrations of the Extracts. A dose of 10 µg/mL was the most efficient concentration for vitality. Osteogenic differentiation and anti-inflammatory activities were determined by using an ELISA Kit to detect early and late markers of differentiation. RESULTS: The level of osteonectin (ON, early osteogenic marker) decreased, which indicated that the osteogenic differentiation may be accelerated with addition of extracts. However, the level of osteocalcin (OCN, late osteogenic marker and sign of calcium granulation) differed among the extracts, in which S. aromaticum presented the highest value, followed by S. triloba and C. zeylanicum. Surprisingly, the determined calcium granules were reduced in S. aromaticum and S. triloba. In response to tumor necrosis factor alpha (TNF-α), S. triloba-treated DPSCs showed the most reduced level of IL-6 cytokine level. We suggest C. zeylanicum as a promising osteogenic inducer and S. triloba as a potent anti-inflammatory agent, which could be used safely in biocomposite or scaffold fabrications for dentistry. CONCLUSIONS: Because calcium granule formation and cell viability play a critical role in hard tissue formation, S. aromaticum in dentistry should be strictly controlled, and the mechanism leading to reduced calcium granule formation should be identified.

Lactobacillus rhamnosus could inhibit Porphyromonas gingivalis derived CXCL8 attenuation.

UNLABELLED: An increasing body of evidence suggests that the use of probiotic bacteria is a promising intervention approach for the treatment of inflammatory diseases with a polymicrobial etiology. P. gingivalis has been noted to have a different way of interacting with the innate immune response of the host compared to other pathogenic bacteria, which is a recognized feature that inhibits CXCL8 expression. OBJECTIVE: The aim of the study was to determine if P. gingivalis infection modulates the inflammatory response of gingival stromal stem cells (G-MSSCs), including the release of CXCL8, and the expression of TLRs and if immunomodulatory L. rhamnosus ATCC9595 could prevent CXCL8 inhibition in experimental inflammation. MATERIAL AND METHODS: G-MSSCs were pretreated with L. rhamnosus ATCC9595 and then stimulated with P. gingivalis ATCC33277. CXCL8 and IL-10 levels were investigated with ELISA and the TLR-4 and 2 were determined through flow cytometer analysis. RESULTS: CXCL8 was suppressed by P. gingivalis and L. rhamnosus ATCC9595, whereas incubation with both strains did not abolish CXCL8. L. rhamnosus ATCC9595 scaled down the expression of TLR4 and induced TLR2 expression when exposed to P. gingivalis stimulation (p<0.01). CONCLUSIONS: These findings provide evidence that L. rhamnosus ATCC9595 can modulate the inflammatory signals and could introduce P. gingivalis to immune systems by inducing CXCL8 secretion.

Effects of fly ash and boric acid on Y2O3-stabilized tetragonal ZrO2 dispersed with MgAl2O4: An experimental study on rat subcutaneous tissue.

The aim of this study was to evaluate the subcutaneous tissue reaction around zirconia-based materials. Forty-eight male Wistar Albino rats were used in this study. Disk-shaped (1mm height and 5mm diameter) samples composed of 67% spinel (MgAl2O4), 27% tetragonal zirconia polycrystal, 4% (m/m) fly ash and 2% (m/m) boric acid were inserted into dorsal muscles of rats. After 1, 4, 8 and 16 weeks, the animals were sacrificed and zirconia materials were removed with the surrounding tissue. Tissue sections were made with a microtome and then stained with hematoxylin and eosin. Sections were evaluated for the intensity of inflammation. Additionally, the somatic and visceral lymph nodes were evaluated. Data were submitted to one-way analysis of variance (ANOVA) and Tukey HSD tests at a significant level of p < 0.05. There were statistically significant differences between mean inflammatory scores in different experimental periods (p <0.05). In addition, the inflammatory reaction decreased over time. The tested materials had no damaging effect on the rat lymph nodes and did not have a toxic action on the internal organs. Therefore, zirconia polycrystal tested in the present study may offer a promising treatment alternative after further mechanical and biological studies are performed.

Effects of sodium selenite and amiloride on calvarial calcification in closing small cranial defects.

OBJECT: Fresh autogenous bone graft is the most preferred osteoplastic material, whether the purpose is cosmetic, psychological, or for the protection of the brain. These grafts are not rejected and do not react immunologically. The aim of this study was to evaluate the efficacy of autogenous fat rolled with bone dust derived from the bur hole in closing small cranial defects. Additionally, the authors examined the morphological and biochemical effects of Na selenite and amiloride on calvarial calcification. METHODS: The study group consisted of 20 domestic pigs. These animals were randomly divided into 4 groups. A bur hole with a diameter of 10 mm was made at the right parietal region in all animals, and then the periosteum around the bur hole was cauterized following exposure of the dura mater. The dura was coagulated with bipolar cautery. Group 1 (controls): only a bur hole was opened, and it was then closed with a mixture of the bone dust that had been created during the opening of the bur hole and fat tissue that was taken from the animal's neck. Group 2 (amiloride): 1 nmol/g body weight of amiloride was applied subcutaneously within 15 minutes after closure of the bur hole with bone dust and fat, and then amiloride was applied once a day for 4 weeks. Group 3 (Na selenite): 30 nmol/g body weight of Na selenite was applied subcutaneously within 30 minutes after closure of the bur hole with bone dust and fat, and then Na selenite was applied once a day for 4 weeks. Group 4 (amiloride and Na selenite): 1 nmol/g body weight of amiloride was applied subcutaneously at 15 minutes, and 30 nmol/g body weight of Na selenite was applied subcutaneously at 30 minutes after closure of the bur hole with bone dust and fat, and these 2 injections were repeated once a day for 4 weeks. At the end of 4 weeks, the animals were anesthetized to evaluate the closure of the bur hole. Tissue samples were obtained for ultrastructural and biochemical examination. RESULTS: The defect was covered with diffuse connective tissue in the control group. Although multiple capillary vessels were present, the authors did not observe osteogenic differentiation. Histological examination of the second group revealed osteogenic changes. Although new matrix was formed, calcification was not detected. The authors observed fibroblast, collagen fibers, and dense connective tissue filled with capillary in the third group of pigs, which had undergone Na selenite application. Calcification was not detected in this group. Both connective and osteogenic tissue were observed in specimens obtained in the fourth group, which had undergone amiloride and Na selenite application. CONCLUSIONS: The authors experimentally evaluated the supplementary osteogenic effects of Na selenite and amiloride by using them separately and together. The findings seem promising as a lead-in to new studies in restoring cranial defects.

Prosthetic rehabilitation of edentulous ridges following alveolar distraction osteogenesis: clinical report of three cases.

Patients with complete edentulism who have insufficient bone for endosseous dental implant treatment present a challenge for dental practitioners. Distraction osteogenesis of the edentulous alveolar ridges is a process for augmentation of atrophic alveolar bone before dental implant placement. This clinical report describes the use of distraction osteogenesis and rehabilitation of patients with a fixed or removable implant-supported prosthesis to treat mandibular defects. Two female patients with segmental alveolar atrophy at the posterior regions of mandible and one female patient with defect at the anterior region of mandible were treated using distraction devices. However, lingual tipping of the distraction vector occurred during the distraction phase in patient 1. The morphology of the alveolar bone was also analyzed in relation to the planned implant position. After a consolidation period of 12 weeks on average, radiologic observation suggested that there was sufficient bone formation for implant installation. In all patients, implant-supported fixed or removable prosthetic oral rehabilitation was successfully performed, and the clinical and radiologic findings were satisfactory. After 4 years of follow-up, no functional or esthetic difficulties with the implants and restorations were noted. These case reports suggest that although alveolar distraction osteogenesis seems to be an effective technique for augmenting atrophic alveolar bone for creating bone and soft tissue, complications may occur after surgical procedures.