Résumé
Statement of Problem: Periodontal regeneration in the furcation defect is considered as one of the most challenging aspects of periodontal therapy. Among different approaches, GTR has shown promising biologic and clinical results. There is evidence indicating that the use of platelet-rich plasma [PRP] may improve the outcome of regenerative periodontal therapy
Purpose: This study aimed to examine the effect of the combination of PRP and Bio-oss on bone regeneration in class II furcation defects in dogs
Materials and Method: 48 experimental defects with 5 mm horizontal and 5 mm vertical open probing depth were created in furcation areas of each premolar of dogs. The defects were randomly divided into 3 groups: test group in which the defects were grafted with bio-oss and PRP; control group in which the defects were grafted with bio-oss alone; and negative control group in which no graft was used. An absorbable collagen membrane was placed over each defect site and the flaps were sutured. The animals were sacrificed 3 months later and biopsy samples were taken from the defect sites for histologic and histomorphometric assessment. In each section, the area fractions [%] within the bone specimens occupied by newly formed bone, soft tissue, and residual grafting particles were determined. The data were analyzed statistically using Student's t test through SPSS software [version 13.0]
Results: The bone fill was 61% in the test group, 58 % in the control group, and 39 % in the negative control group. Although no significant difference was observed between the test and control groups, the differences between the test and control groups with negative control group were significant [p <0.05]. In the control group, the lamellar bone formation was higher and the chronic inflammatory infiltration was lower
Conclusion: Within the limitations of this study, the use of bio-oss and PRP in the treatment of class II furcation involvement has no additional benefit over bio-oss alone. However, it seems that PRP can improve the quality of the new bone while decreasing the amount of tissue inflamation
Résumé
Minor aphta has a high incidence in the populations ranging from 2-50%. In spite of its frequency and severity of discomfort, there is not an absolute treatment for it. So, the main objective of this study was to evaluate the efficacy of a herbal medicine in the control of Minor aphta. In this double-blind, randomized study 137 patients with Minor aphta [with not more than four days from the onset] were selected and then placed into one of the groups of A [solution containing 5 percent Myrtus communis and Melissa officinalis in ethanol 80] and B [solution containing 10 percent Myrtus communis and Melissa officinalis in ethanol 80] or C [placebo containing ethanol 80]. Mean duration for complete recovery in minor aphta was 3.5 days in group A, 7.5 days in group B and 7.3 days in group C. There significant statistical differences the three groups [p<0.0005]. The results of this study revealed that using a combination of Myrtus Communis and Melissa Officinalis plants was effective in the treatment of recurrent aphtous stomatits [RAS]. In order to obtain the accurate concentrations of the ingredients of this compound, further studies are necessary
Résumé
Human telomerase has been associated with most malignant tumors such as squamous cell carcinoma [SCC] of the oral cavity. One simple non-aggressive method for early diagnosis of oral SCC is taking smears. The aim of this study was to assess the frequency of telomerase expression in smears of oral SCC, compared with normal mucosa. Smears were obtained from 18 subjects with SCC of different sites in the oral cavity, presenting with various degrees of malignancy. Control samples were taken from the contra-lateral normal epithelium of the same subjects. The expression of hTERT, the most reliable marker of telomerase activity, was registered by extracting RNA, performing RT-PCR and then nested PCR by specific primers. Fisher's exact test was used to analyze the data. Positive expression of telomerase was detected in 8 of the 18 cases, while the normal epithelial samples demonstrated no such expression of telomerase. A significant difference in the expression of telomerase was reported between the two groups by Fisher's Exact test [P<0.003]. There is a potential for telomerase enzyme activity to act as a simple non - aggressive diagnostic tool in detection of oral SCC using smears of the lesion
Sujets)
Humains , Carcinome épidermoïde/diagnostic , Bouche , Tumeurs de la bouche , ARN , Réaction de polymérisation en chaîneRésumé
To date, studies about the systemic effects of statins on bone tissue have led to different resuts. The aim of this study was to assess the osteoinductivity by statins when injected intramuscularly or subcutaneously in rats. In this experimental study, 68 injections of Simvastatin, Lovastatin, Atorvastatin in polyethyleneglycole with 1mg/ml and polyethyleneglycole 300 were injected either S.C in rat`s backs or I.M into their hand and foot. After 6 weeks, the rats were killed and samples of the injection areas were provided and were studied under a microscope. In two of the samples, few bony areas were seen which were a mixture of lamellar and woven bone. Around these areas' an osteoblastic rim was visible. In another sample, a chondral area with an active mesanchimal connective tissue which was in a differentiation state to become cartilage, was seen. Finding of this study and the gradual differentiation of muscular tissue to bony stem tissue in around samples, confirms the probable osteoinductivity effect of theses compound. To confirm further we propose that this effect should be investigated on stem cell cultures, in vitro
Sujets)
Animaux de laboratoire , Lovastatine/pharmacologie , Simvastatine/pharmacologie , Pyrroles/pharmacologie , Acides heptanoïques/pharmacologie , Os et tissu osseux , Microscopie électronique en transmission à balayageRésumé
Nitinol [NiTi] is the most interesting smart material used in orthopedic surgery and production of artificial muscles. Considering its medical applications, Nitinol biocompatibility is, therefore, quite important. This issue is discussed in this paper. Nitinol alloy experimentally produced by melting and casting under vacuum, plus imported commercial AO samples were implanted in limb tissue of a number of male rats. Twenty one days after the implantation, fibroblast and fibrosis formation in the tissues around the alloy were studied. The amount of the alloy that was corroded under the experimental invitro conditions was acceptable. The biocompatibility of the experimentally made alloy implanted in limb tissue was nearly similar to that of the imported alloy. According to the results obtained, utilization of Nitinol in medicine is scientifically justifiable. Possibilities of its wide industrial and medical applications favorably support the mass production of the alloy in the country, and its biocompatible parallels that of the imported material
Sujets)
Test de matériauxRésumé
Porosity is a frequently observed casting defect in titanium dental casting. This study measured the effects of different sprue design on the internal porosity of cast titanium crowns. Sixty complete veneer crowns were fabricated on a stainless steel die with a 150- degree sloping shoulder using customized wax patterns. All wax patterns were sprued with 3 different sprue design [Reservoir, Runner bar and Rousseau] and were invested with an alumina- magnesia investment. Castings were made with commercially pure titanium [CP Ti [grade II]] according to the manufacturer's instructions. The castings were carefully cleaned. Internal porosities were quantified with photographs and radiographs by computerized image analyses. Data were analyzed with an ANOVA with a confidence level of 95%. There were statistically significant differences in the values of porosity between 3 types of sprue design. The reservoir sprue design had the least internal porosity comparing to the other designs. Improvements in the porosity of titanium crowns was the result of the Reservoir sprue design with vent. Effects of Different sprue designs on internal porosity and their effects on casting accuracy and marginal adaptation of cast titanium crown and bridges must be evaluated to achieve better evidence and clinical relevance
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In this study in the Islamic Republic of Iran 365 measles cases were evaluated to distinguish between primary infection with measles and reinfection due to secondary vaccine failure. All cases previously confirmed by detection of specific IgM were tested for IgG avidity. A secondary immune response was seen in 18.4% of patients. All unvaccinated patients [16.7%] showed a primary immune response. Of 244 patients with documented vaccination, 75.8% showed a primary immune response and 24.2% showed a secondary immune response, thereby indicating a secondary vaccine failure. Almost all measles reinfections [99%] were seen in patients >10 years old, indicating that vaccination for 10- year- old children is recommended
Sujets)
Adolescent , Adulte , Enfant , Enfant d'âge préscolaire , Humains , Vaccin contre la rougeole , Dosage immunologique , Monitorage immunologique , Appréciation des risquesRésumé
Orthodontic ligature cutting pliers are expensive. Methods of sterilization should be safe considering patients' health as well as lifetime of orthodontic pliers. The purpose of this study was to compare the wear of orthodontic ligature cutting pliers after sterilizing with dry heat or steam autoclave. In this experimental study, thirty ligature cutting pliers from 3 different factories [Dentarum-Germany, RMO and ETM-USA] were sterilized in either dry heat or steam autoclave. The amount of wear at the tip of each plier in both groups was measured with a stereomicroscope and digital photomicrography. Wear was defined as the difference of the initial length and the length after 10, 20, 30 cycles of sterilization measured by the distance from a reference line on the tip of the plier. Three way ANOVA was used to compare wear between the two sterilization groups. P<0.05 was considered as the limit of significance. The amount of wear of the ligature cutting pliers' tip after 10, 20 and 30 cycles in dry heat sterilization was 1.0 +/- 0.16, 0.98 +/- 0.22 and 0.94 +/- 0.31 mm respectively. These figures were 1.16+0.15, 1.16 +/- 0.13 and 1.15 +/- 0.14mm for steam heat sterilization. The higest wear was observed after 20 cycles of sterilization in autoclavce whereas the lowest was seen in dry heat sterilization after 30 cycles. The differences between the two studied groups were statistically significant [P<0.0001]. In addition, increasing sterilization cycles decreased the rate of wear in both groups. Based on the results of this study routine autoclaving caused more damage and wear at the tip of the pliers than dry heat sterilization
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Vitiligo is a common skin disorder, characterized by depigmented patches due to selective destruction of melanocytes. The etiology of this disease is unknown. A number of hypotheses including viral theory have been proposed to explain the etiology. To determine the prevalence of antibody to hepatitis C virus infection in vitiligo patients, the present study was performed. Third generation ELISA test was used for detection of antibodies to HCV in human sera. All normal controls were anti-HCV negative whereas only one patient was positive for anti-HCV and there was no significant difference in the prevalence of anti-HCV between patients and controls. These results indicate that hepatitis C virus has not a direct causal role in the pathogenesis of vitiligo, however, this does not rul out a "hit and run" virus induced disease
Sujets)
Humains , Mâle , Femelle , Vitiligo/étiologie , Maladies de la peau , Mélanocytes , Test ELISA , Sérum , Virus , Auto-immunitéRésumé
With the aim of controlling malaria by reducing vector population, the effects of antibodies produced against salivary glands and deglycosylated midgut antigens of Anopheles stephensi mosquitoes on fecundity and longevity of the same species were tested. Three deglycosylated preparations of midgut and two preparations of salivary glands were produced, conjugated with aluminum hydroxide gel, and subcutaneously injected to shoulders of TO [Turner Out-bred] mice. After 4 immunizations and assurance of enough antibody production against utilized antigenic suspensions, effects of blood feeding on immunized and control mice were assayed. Insoluble preparation of midgut showed the strongest effect with 23.5% reduction in egg laying, and increasing death rate of vectors in third day after feeding. No significant reduction in fecundity or survivorship was seen with other preparations. Anopheles midgut insoluble antigens are potential candidates for designing vaccines against malaria vectors and further investigations need to be done to find effective antigens and the best way of their use
Sujets)
Animaux de laboratoire , Insectes , Paludisme/transmission , Glandes salivaires/parasitologie , Longévité , Souris , Vaccins , AnticorpsRésumé
This report presents an extremely rare tumor and provides information to deal with such tumors; intraosseous mucoepidermoid carcinoma. It's pathogenesis is still unknown and is rare in children. The conservative surgical procedures result to metastasis. An 11 year old girl was referred for a nonpainful swelling in maxillary region. Central mucoepidermoid carcinoma was diagnosed by clinical and paraclinical examinations. The lining of maxillary sinus was considered to be the source of the tumor. Hemimaxillectomy and adjuvant I radiotherapy was performed as treatment option and patient was reported to be in good health. Early diagnosis and radical resection with adjuvant radiotherapy offered the best chance for eradication of this tumor and that essential to prevent local recurrence and late distant methastasis
Sujets)
Humains , Femelle , Carcinome mucoépidermoïde/thérapie , Tumeurs de la mandibule/anatomopathologie , Tumeurs de la mandibule/diagnostic , Tumeurs de la mandibule/chirurgie , RécidiveRésumé
Mycobacterium tuberculosis [H37Rv strain] was used in this study. The bacterial cells were disintegrated by sonication. The separation and characterization of the soluble molecules were attempted by various techniques including gel filtration, ion exchange chromatographies and polyacrylamide gel electrophoresis, using SDS and 2ME. Eight protein molecules with molecular weights ranging from 6.3 up to 204 kD were identified. Following reduction of the 204 kD molecule with 2ME, six smaller molecules with 12a, 12b, 21,29,45 and 81.5 kD molecular weights were obtained- All isolated protein molecules were able to induce delayed hypersensitivity skin reaction in sensitized guinea pigs and proliferation of T-cells in vitro.Regarding the fact that an effective protective immunity in tuberculosis is dependent mainly on T-cell response, it is suggested that the molecules isolated in this study may be useful in conceiving a vaccine and/or diagnostic tests for tuberculosis
Sujets)
Animaux de laboratoire , Antigènes/immunologie , Immunité cellulaire/immunologie , Cochons d'Inde , Vaccin BCG , Mycobacterium tuberculosis/isolement et purificationRésumé
Serum IgG subclass levels were measured using an indirect immunoenzymatic assay [ELISA] with monoclonal antibodies in 16 children with asthma and 13 children with atopy who had mostly recurrent infections. Seven of the asthmatic children had marked low or low normal levels of IgG[4], six had marked low or low normal levels of IgG[3], two had marked low normal levels of both IgG[2] and IgG[3] and one had low levels of IgG[2], IgG[3] and IgG[4]. All these patients suffered from recurrent sinopulmonary infections- There were low percentages of IgG[3] and IgG[4] defects [about 15%] in the atopic patients, while a significant increase in the serum IgG[4] levels were observed [six patient out of 13 patients, 46.2%]