Comparative Evaluation of Radicular Push-out Bond Strength of EndoSequence BC, MTA FillApex, Apexit Plus and AH Plus Sealers as Affected by the Modified Plunger: Base Orifice Size Relation

Background: Sealers are universally used along with gutta-percha to obturate the root canals in three dimensions. Push-out bond strength is considered appropriate to measure the adhesion capacity of sealers. Aim: To compare the bond strength of recently introduced bioceramic sealer with commonly used sealers and to evaluate the effect of plunger: base orifice size ratio on push-out bond strength. Methods:One hundred mandibular premolars with single canals were decoronated and instrumented up to master apical file F3 Protaper. Specimens were randomly divided into four groups (n=25) based on the sealer used: Group 1-EndoSequence BC Sealer, Group 2-MTA FillApex sealer, Group3-Apexit Plus sealer & Group 4-AH Plus sealer and obturated using cold lateral compaction technique. After two weeks, 1±0.1mm thick slice of each radicular third of specimens was subjected to push-out testing with modified and standardised plunger: base orifice size ratio for each slice and bond strength calculated. Subsequently the slices were observed under stereomicroscope for failure mode analysis. Results: Results showed that AH Plus sealer had the highest overall bond strength followed by EndoSequence BC sealer and MTA FillApex while as Apexit Plus had lowest bond strength. Bond strength of all sealers reduced from coronal to apical direction except in EndoSequence BC sealer which showed better strength in critical apical third. Higher bond strength values were obtained due to modified relation of plunger with base orifice size. Conclusion: Bond strength of all sealers tested except EndoSequence BC reduces in apical direction and is impacted by plunger: base orifice size ratio.

Pathologic analysis of control plans for air pollution management in Tehran metropolis: a qualitative study

Regarding the importance of air pollution issue for large cities, as Tehran metropolis, many plans, programs, projects and regulations have been developed to manage urban air pollution. However, most of them failed to decline the pollution. The purpose of this study is to pathologically analyze air-pollution control plans in order to offer effective solutions for Tehran metropolis. A qualitative content analysis and a semi-structured interview with 14 practicing professionals were used to identify key causes and sources of Tehran's air pollution, to recognize challenges and obstacles towards effective performance of air-pollution control plans in this metropolitan area, and to suggest the most effective controlling solutions. Challenges related to air-pollution control plans can be divided into two major categories: Firstly lack of integrated and organized stewardship and secondly those related to political, economical, social and technical environmental abbreviated as PEST, challenges. For effective control of the Tehran air pollution, the following eight controlling alternatives were identified: Systematization of plan preparation process, organizing the stewardship, standardization and utilization of new technologies and professional experts, cultural and infrastructural development, realization of social justice, developing coordination and controlling mechanisms, improving citizen's participatory capacity, and focusing on effective management of fuel and energy. Controlling air pollution in Tehran should be considered as a priority for policymakers to make enforcements through applying a systemic cycle of preparation effective and comprehensive plans. Further, implement the enforcements and evaluate the environmental impact of the plans through involving all stakeholders

Rabies antibody levels in pregnant women and their newborns after rabies post-exposure prophylaxis

Rabies is a fatal infectious disease and rabies post-exposure prophylaxis is the method of choice for prevention of human rabies. We report rabies antibody levels in cord blood and also in serum of pregnant women who were bitten by suspected animals to rabies and were immunized by purified Vero cell rabies vaccine [PVRV] and Human Rabies immunoglobulin [HRIG] serum. During the years of 2007-2010, six pregnant women by the age range of 22-35 years were admitted in treatment and prevention of rabies center in Pasture institute of Iran, in Tehran. Among them two cases were at first trimester, one at second trimester and three at third trimester of conception. The interval between biting with delivery was 5-265 days [mean 121 days]. Results of immunoglobulin illustrate that levels of rabies antibody in maternal sera with the fetus are not equal and uniform but it is proved that baby will find efficient immunity as well with minimum protective level of 0.5 IU/ml in all cases except a newborn whom had been born just 5 days after the mother's immunization and in a shorter time than the appropriate immunization of the mother who had received her second vaccination courses

Rabies neutralizing antibody level in immunosuppressed patients after receive of rabies post-exposure prophylaxis

Introduction: Rabies is a fatal disease and has a threatening risk for the public health. Immunosuppression is related to a wide variety of diseases. It is recommended that immunosuppressed patients receive the full post exposure vaccination, concerning that the immune response may be inadequate. The aim of this study is to determine the level of rabies neutralizing antibody in immunosuppressed patients after receiving rabies post-exposure prophylaxis. Consequently we assess the efficiency of antibody level in immunosuppressed patients admitted at Pasteur Institute of Iran. The study was performed at Pasteur Institute of Iran. Data related to immunosuppressed patients, doses of anti-rabies vaccine and serum, and level of rabies neutralizing antibody titer collected from the patients admitted to the Prevention and Treatment of Rabies Center, Department of Vaccination at Pasteur Institute of Iran, during 2008 to 2010. Subjects who received chemotherapy, immunosuppressive drugs, and chronic renal failure were included in this study. Results: Twenty two cases were evaluated. The Immunosuppressed state was related to cancer [in 8 cases], 4 cases of hematologic disorders, 6 cases of autoimmune disease, and 4 cases of chronic renal failure or kidney transplant. Mean age of 46.45 +/- 21.5 year. All cases received HRIG serum [human rabies immunoglobulin] plus PVRV [Purified Vero cell rabies vaccine]. The level of rabies neutralizing antibody was checked two weeks after the last dose of vaccine. Mean level of rabies neutralizing antibody was 12.07 +/- 6.72 IU/ml. All cases achieved minimum protective level of antibody which is = 0.5 IU/ml. The amount of the antibody level had no relation to age or kind of immunosuppressive disease of patients. Conclusion: It is recommended that Rabies-exposed immunosuppressed patients receive rabies post exposure prophylaxes. We have to be cautious about the cases who have not achieved the appropriate level of rabies antibody. Keywords: Post-exposure rabies prophylaxis, Immunosuppressed patients, Rabies neutralizing antibody

[Study on lasting immunity in previously treated persons against rabies and investigation of booster effect of Vero rabies vaccine]

Human rabies is preventable by prompt post-exposure prophylaxis. The total number of rabies vaccine doses administered during post-exposure prophylaxis is 5; given on days 0, 3, 7, 14 and 30. The aim of this study was to measure the durability of rabies neutralizing antibody in exposed persons treated 14-17 years ago and to investigate the effect of 2 boosters of rabies vaccine. This study was conducted in 2 phases. In phase 1 blood samples were taken from 100 rabies vaccine recipients 14-17 years after they had received the vaccine. In the 2nd stage of the studies 30 volunteers from the first phase of the study were divided into 2 groups of 15 subjects each; the first group was given 2 booster doses of the vaccine intra-dermally on days 0 and 3. In the 2[nd] group the 2 doses were administered through the intramuscular route; blood samples were collected 10 days after the booster doses. Rapid Focus Fluorescent Inhibition Test [RFFIT] was used for measuring the antibodies in both phases. The rabies neutralizing antibody was detected in the sera of all 100 individuals who had received the rabies vaccine, 85% of whom demonstrated titers ?0.5 IU/ml. In the groups who received the booster doses, serology results demonstrated higher rabies neutralizing antibody titers in persons who had received the two booster injections intradermally. This study confirms the persistence of rabies neutralizing antibody for at least 14 years after a full course of primary post-exposure prophylaxis; furthermore two booster inoculations of Vero rabies vaccine on days 0 and 3, given intradermally resulted in a sharp increase in the level of antibodies, indicating that two boosters could protect against rabies after a repeat exposure

[Comparing knowledge, attitude and practice of American, Chinese and Iranian college students about tobacco use]

To assess and compare knowledge, attitudes and practice regarding tobacco use of college students in Iran, US and Chain. A modified questionnaire used in each of country US, Chain and Iran. A total of 3089 usable surveys were collected [47.5% for male and 52.5% for female]. Both descriptive and inferential statistical tests were employed in data analysis. Compared to male participants, American's female and male students scored higher in knowledge, Iranian genders [both female and male] students scored higher in negative attitude scale of the questionnaire regarding tobacco use. Knowledge of female students was a little greater than male students and their attitude was more negative. Male respondents also were more likely to smoke cigarettes and use other tobacco products and in heavier quantities. The findings provide exploratory information about aspects of tobacco use among students [as an important and reference class of the Iranian society], and based on the results, recommendations are made to national health policy makers and health educators for reducing tobacco related risks through improving associated knowledge, attitude and practice

Production of rabies vaccine using BHK - 21 with roller bottle cell culture technique

Compared to other methods of vaccine production, [e.g. culture flask and bioreactor system], the roller culture method for producing rabies vaccine is simpler, and the equipment easier to install and maintain, and also in the event of contamination of one roller, the entire batch need not be discarded. This system provides a much larger surface area than the culture flask, and also ensures a much higher surface area to volume ratio. Gas exchange is also made easier because the cells are alternately aerated and fed with medium every few minutes. Production of rabies vaccine using BHK-21 cultivated by roller bottle cell culture technique can be suitable for countries where rabies is an important health problem. For this project, the PV-PARIS/BHK-21 rabies virus strain was used. The vaccine thus obtained was tested on mice and a satisfactory immune response was observed, and also the potency of vaccine met the requirements of the World Health Organization [WHO]

Reduced regiment for human pre-exposure immunization against rabies

The main aim of this study was to find a suitable rabies vaccination protocol which would allow usage of lower volumes of vaccine, fewer clinical visits and above all, enough serological effectiveness for high-risk individuals requiring pre-exposure immunization. Human diploid cell rabies vaccine was administered intradermally and intramuscularly in 60 previously unvaccinated volunteers, aged 19 to 21, following different vaccination protocols. The participants were divided into six groups, and rabies antibody titration was accomplished by ELISA. The comparison of the mean titers 30 days after termination of vaccination protocols shows that a protocol requiring only two clinical visits and ID injection of a total volume of only 0.3 ml of human diploid cell rabies vaccine [0.1+0.1 ml on day 0,one in each arm, and 0.1 ml on day 28] provides good serological response [6.92 IU/ml]