Comparison of methods for the extraction of DNA from formalin-fixed, paraffin-embedded archival tissues.

AIM: Discussing a protocol involving xylene-ethanol deparaffinization on slides followed by a kit-based extraction that allows for the extraction of high quality DNA from FFPE tissues. METHODS: DNA was extracted from the FFPE tissues of 16 randomly selected blocks. Methods involving deparaffinization on slides or tubes, enzyme digestion overnight or for 72 hours and isolation using phenol chloroform method or a silica-based commercial kit were compared in terms of yields, concentrations and the amplifiability. RESULTS: The highest yield of DNA was produced from the samples that were deparaffinized on slides, digested for 72 hours and isolated with a commercial kit. Samples isolated with the phenol-chloroform method produced DNA of lower purity than the samples that were purified with kit. The samples isolated with the commercial kit resulted in better PCR amplification. CONCLUSION: Silica-based commercial kits and deparaffinized on slides should be considered for DNA extraction from FFPE.

Recurrent unicystic mural type ameloblastoma in a 9-year-old boy, 8 years follow-up.

Unicystic ameloblastoma is not a rare odontogenic tumor in the pediatric population. A significant care should be given to unicystic ameloblastoma if it has mural invasions due to its local aggressiveness, high recurrence rates and radical management options as in conventional ameloblastoma. Fine needle aspiration (FNA) cytology is a rapid, non-traumatic diagnostic method that provides a required attention prior to surgery. We present an excisionsl biopsy proved FNA diagnosed mural type unicystic ameloblastoma in a 9-year-old child recurred as a solid ameloblastoma after 8 years. When distinctive features of ameloblastoma are known, an accurate diagnosis can be made by FNA cytology, in combination with clinicoradiological findings. This method gives benefit to the patients especially the younger ones both for the pre-operative surgical planning and the post-operative follow-up.

Investigation of interleukin-1 alpha and interleukin-6 expressionand interleukin-1 alpha gene polymorphism in keratocysticodontogenic tumors and ameloblastomas

Objective: In jawbones, ameloblastomas and odontogenic keratocysts share many clinical features in commonsuch as aggressiveness, high recurrence rates and radical management options. Understanding the pathogenesisand biological aspects of these tumors would improve the success of diagnose and treatment procedures. Theaim of this study was to exhibit the reasons of high recurrence rates and growth potentials of ameloblastomas andkeratocystic odontogenic tumours by investigating the expression of IL-1α and IL-6 and IL-1α -889 gene polymorphism.IL-1α and IL-6 are shown as very effective tissue degrading factors in bone remodelling.Study Design: This study included 25 cases of ameloblastomas, 41 cases of keratocystic odontogenic tumors (parakeratinizedodontogenic keratocysts) and 8 cases of orthokeratinized odontogenic keratocysts. All histologicalslides were stained immunohistochemically to show the expression of IL-1α and IL-6. Restriction fragment lengthanalysis was used to investigate the cytokine gene polymorphism.Results and Conclusions: The higher expression rates of IL-1α and IL-6 were associated with tumor size in ameloblastomasand with cyst wall thickness in keratocystic odontogenic tumors. This finding suggested us that thecytokines IL-1α and IL-6 play a role on aggressive behaviour of ameloblastomas and keratocystic odontogenictumors by making easy bone resorption. In addition, IL-1α (-889) T polymorphism was found consistent withincreased IL-1α expression but not seem as a risk factor on the development of these tumors (AU)

Investigation of interleukin-1 alpha and interleukin-6 expression and interleukin-1 alpha gene polymorphism in keratocystic odontogenic tumors and ameloblastomas.

OBJECTIVE: In jawbones, ameloblastomas and odontogenic keratocysts share many clinical features in common such as aggressiveness, high recurrence rates and radical management options. Understanding the pathogenesis and biological aspects of these tumors would improve the success of diagnose and treatment procedures. The aim of this study was to exhibit the reasons of high recurrence rates and growth potentials of ameloblastomas and keratocystic odontogenic tumours by investigating the expression of IL-1α and IL-6 and IL-1α -889 gene polymorphism. IL-1α and IL-6 are shown as very effective tissue degrading factors in bone remodelling. STUDY DESIGN: This study included 25 cases of ameloblastomas, 41 cases of keratocystic odontogenic tumors (parakeratinized odontogenic keratocysts) and 8 cases of orthokeratinized odontogenic keratocysts. All histological slides were stained immunohistochemically to show the expression of IL-1α and IL-6. Restriction fragment length analysis was used to investigate the cytokine gene polymorphism. RESULTS AND CONCLUSIONS: The higher expression rates of IL-1α and IL-6 were associated with tumor size in ameloblastomas and with cyst wall thickness in keratocystic odontogenic tumors. This finding suggested us that the cytokines IL-1α and IL-6 play a role on aggressive behaviour of ameloblastomas and keratocystic odontogenic tumors by making easy bone resorption. In addition, IL-1α (-889) T polymorphism was found consistent with increased IL-1α expression but not seem as a risk factor on the development of these tumors.

Evaluation of natural killer cell defense in oral squamous cell carcinoma.

This research aims to give a new insight to the relationship between host local immune response and the biological behaviour of the tumor by evaluating of intratumoral natural killer (NK) cells and tumor necrosis factor-alpha (TNFalpha) expressions in oral squamous cell carcinomas. New paraffin sections of the deepest parts of the 46 cases of oral squamous cell carcinomas were immunohistochemically treated by CD57, selected as NK cell indicator, and TNFalpha monoclonal antibodies. The tumors were graded according to histopathologic grading scores of invasive margins and categorized into 2 groups as "good" and "poor" prognostic groups. Fifteen cases, from which could be obtained full clinical data, were clinically staged and because of the scarcity of the cases in each group were divided, again, two groups as group 1: stage I+stage II and group 2: stage III+stage IV. The expression levels of CD57 and TNFalpha were evaluated according to histopathologic grading groups and clinical staging groups. The results showed that the density of CD57+cells (NK cells) was statistically lower in tumors graded as poor prognostic group compared to the cases in good prognostic group. On the contrary, expression level of TNFalpha was statistically higher in poor prognostic group. These findings suggested that increased secretion of TNFalpha in the tumors, which show high invasive potential, may be one of the facilitating factors for tumor invasion and be responsible from suppression of NK cells. Withdrawal of NK cells in the high invasive tumor areas also reminds the necessity of certain shared genetic rearrangements in tumor cells for getting protected from NK cell attacks and moving ahead within the extracellular matrix.

Suspected familial odontogenic keratocysts related to Gorlin Goltz syndrome.

This report represents the suspected familial case series of odontogenic keratocysts OKCs related to Gorlin Goltz syndrome GGS, a rare genetic disorder characterized mainly by multiple basal cell carcinomas, OKCs and other less frequent skeletal and neurological manifestations. Familial cases included grandmother's father, grandmother, father and son. Although they had all OKCs, father additionally possessed some of the other characteristics of GGS. We described all the patients' diagnoses, treatments and long-term follow-ups under the light of current literature.

Healing of artificial fenestration defects by seeding of fibroblast-like cells derived from regenerated periodontal ligament in a dog: a preliminary study.

The purpose of this study was to assess the seeding of fibroblast-like cells to promote periodontal healing in artificial fenestration defects in a dog. Fibroblast-like cells were cultured by incubating regenerated periodontal ligament tissue, that had been surgically taken, underneath a Teflon membrane. Fenestration defects were surgically induced on the maxillary canine and first molar teeth at a spacing of 5 to 5 mm. Passage 4 cells (2 x 10(5) cells) in autologous blood coagulum were placed on root surfaces in two defects; the remaining two defects were used as controls. Healing was evaluated histomorphometrically on postoperative day 42. The main periodontal healing pattern consisted of connective tissue adaptation in three of the four specimens including one control, with cementum formation at 9-12%; one control specimen that exhibited 100% cementum formation. New bone formation was greater in the cell-seeding group (84%) compared with control (39%). In the cell-seeding group, one specimen exhibited total regeneration of bone (100%); however, the connective tissue located between newly formed bone and the root surface was observed to adapt to the dentin surface, with limited cementum formation. Seeding of cells from periodontal ligament may be promising to promote periodontal regeneration, but needs to be investigated in further studies.

Effect of a collagen membrane enriched with fibronectin on guided tissue regeneration in dogs.

The present study was planned to assess the capacity of a resorbable collagen membrane enriched with fibronectin to prevent the apical migration of epithelium and to facilitate new attachment and new bone. Experimental osseous dehiscence defects were produced on the bilateral labial aspect of mandibular 2nd, 3rd and 4th premolar teeth in six mongrel dogs. Guided tissue regeneration therapy using collagen membranes, which were rehydrated with fibronectin solution, was performed on one quadrant (group A). In the contralateral quadrant, the same collagen membranes, but rehydrated only with saline (group B), were placed over the bony defects. The third premolar teeth, which were treated by open-flap debridement, served as control (group C). Flaps were positioned slightly coronally and sutured; sutures were removed 10 days later. The dogs were killed 30 days after reconstructive therapy. Tissue blocks containing the experimental and control teeth were excised, demineralized in EDTA, and embedded in paraffin. Histological and histometric evaluation revealed that all groups demonstrated similar effects on preventing the down-growth of epithelium and formation of new cementum and new bone. Collagen membranes were tolerated well within the tissues, and membrane remnants were identified at 30 days. In summary, this study indicated that in this dog model similar healing results could be achieved with a bovine type I collagen membrane with or without fibronectin solution and open-flap debridement.

Assessment of periodontal healing by seeding of fibroblast-like cells derived from regenerated periodontal ligament in artificial furcation defects in a dog: a pilot study.

The regeneration of periodontal supporting tissues lost as a result of disease could be accomplished by repopulating the exposed root surfaces with cells originating from periodontal ligament. Thus, we aimed to assess the seeding of cells derived from regenerated periodontal ligament (RPL) to promote the regeneration in artificial furcation defects of a dog. The fibroblast-like cells were obtained by incubating the explants of RPL tissue taken under a teflon (E-PTFE) membrane. Class II furcation defects were induced on the second and fourth mandibular premolars. Control defects were also included on the contralateral side. A suspension of the fourth passage cells (2 x 10(5) cells) in 0.5 mL of autologous blood coagulum was placed over each furcation area. The healing was histomorphometrically evaluated at the 42nd day postoperatively and expressed as percentage. The healing by new connective tissue attachment with cementum formation was found 75% in the cell-seeding defects whereas, it was 71% in controls. Bone formation was found to fill 51% of furcation defects; however, it was 35% of the defects in the control sites. In this pilot study, we suggested that regeneration of furcation defects by cell-seeding technique may be useful, but further studies are needed to determine the outcome of the procedure.