Effect of green tea extract as antioxidant on shear bond strength of resin composite to in-office and home-bleached enamel

Statement of Problem: shear bond strength [SBS] of home and office bleached enamel will be compromised by immediate application of composite restoration. Antioxidant agent may overcome this problem

Objectives: this in vitro study assessed the effect of green tea extract on shear bond strength of resin composite to in-office and home-bleached enamel

Materials and Methods: in this experimental study, 40 extracted intact human incisors were embedded in cylindrical acrylic resin blocks [2.5 ×1.5 cm], with the coronal portion above the cemento enamel junction out of the block. Then, after bleaching labial enamel surfaces of 20 teeth with 15% carbamide peroxide 6 hours a day for 5 days, they were randomly divided into two groups: A1 and A2 [n = 10], depending upon whether or not they are treated with antioxidant. Labial enamel surfaces of the remaining 20 teeth were bleached with 38% hydrogen peroxide before being randomly divided into groups B1 and B2 [n = 10], again depending on whether or not the antioxidant was used in their treatment . The experimental groups [A2,B2] were treated with 5% solution of green tea extract before resin composite restoration was done by a cylindrical Teflon mould [5×2 mm]. Shear bond strength of the specimens was tested under a universal testing machine [Zwick/Roell Z020]. The SBS data were analyzed by using One-way ANOVA and Tukey HSD tests [p < 0.05]

Results: there were no statistically significant differences between shear bond strength of the control group [A1] and treated group [A2], but there were statistically significant differences between the groups B1 and B2 [p < 0.05]

Conclusions: application of antioxidant did not increase the shear bond strength of home-bleached enamel to resin composite but its application increased the shear bond strength of in-office bleached enamel to resin composite

Genomic diversity of Clostridium perfringens strains isolated from food and human sources

Clostridium perfringens is a serious pathogen which causes enteric diseases in domestic animals and food poisoning in humans. Spores can survive cooking processes and play an important role in the possible onset of disease. In this study, RAPD-PCR and REPPCR were used to examine the genetic diversity of 49 isolates of C. perfringens type A from three different sources. The results of RAPD-PCR revealed the most genetic diversity among poultry isolates, while human isolates showed the least genetic diversity. Cluster analysis obtained from RAPD-PCR and based on the genetic distances split the 49 strains into five distinct major clusters [A, B, C, D, and E]. Cluster A and C were composed of isolates from poultry meat, cluster B was composed of isolates from human stool, cluster D was composed of isolates from minced meat, poultry meat and human stool and cluster E was composed of isolates from minced meat. Further characterization of these strains by using [GTG] 5 fingerprint repetitive sequence-based PCR analysis did not show further differentiation between various types of strains. In conclusion, RAPD-PCR method seems to be very promising for contamination source tracking in the field of food hygiene

[Molecular identification and successful treatment of Chlamydophila psittaci [genotype B] in a clinically affected Congo African grey parrot [Psittacus erithacus erithacus]]

Avian chlamydiosis is caused by Chlamydiophila psittaci with the highest infection rate in parrots [Psittacidae] and pigeons [Columbiformes]. A two-year-old Congo African grey parrot was examined since the bird had shown clinical signs of anorexia, depression, diarrhea, and mild dyspnea and based on biochemical and hemathological analysis the bird was diagnosed as having anemia, leukocytosis, heterophilia, lymphopenia and monocytosis. With regards to clinical and paraclinical findings, the case was diagnosed to be carrying Chlamydiophila spp. In addition, choanal cleft and cloaca swabs were positive for Chlamydiophila spp. in a diagnostic polymerase chain reaction [PCR] [600 bp amplicon]. Polymerase chain reaction products were typed by ompA gene-based PCR, using CTU/CTL primers [1050 bp amplicon]. The PCR product sequence was compared with the sequences obtained from GenBank. The phylogenetic tree has revealed 100% identity with genotype B obtained from previous studies. The bird was hospitalized and treated with doxycycline regimen for 45 days, with a weekly sampling process to trace the presence of C. psittaci DNA in faecal and choanal swabs, this process continued to the point where the specimens turned negative after two weeks. Laboratory and radiology results were within normal limits after the treatment. Genotype B is predominantly isolated from Columbidae and there have not been any reports regarding the clinically affected African gray parrot with this genotype. Subsequently, to the best of our knowledge, this is the first report of chlamydiosis by genotype B on Congo African grey parrot

Increased rates of descemet's stripping automated endothelial keratoplasty [dsaek] graft failure and dislocation in glaucomatous eyes with aqueous shunts

To investigate the rates of Descemet's stripping automated endothelial keratoplasty [DSAEK] graft dislocation and failure in glaucomatous eyes, including eyes with history of trabeculectomy and/or aqueous shunts. A retrospective, case-control study on a total of 424 consecutive eyes undergoing DSAEK at an academic setting compared 96 glaucomatous eyes to a control group of 328 eyes. Pre- and post DSAEK procedure data was aggregated for up to 2 years [mean follow-up, 6.5 +/- 6.9 months] including rates of graft dislocation and failure. Out of 96 glaucomatous eyes, 20 had undergone trabeculectomy, 27 had received one or more aqueous shunts, 12 had undergone both procedures and 37 were on medical therapy. Complete DSAEK graft dislocation and failure occurred in 2.7% and 3% of non-glaucomatous patients, respectively. Eyes with history of aqueous shunt surgery experienced graft dislocation and failure rates of 26.0% [OR=4.6, 95% CI 1.5-13.7, p=0.0067] and 26.0% [OR=10.3, 95% CI 3.8-27.1, p<0.0001], respectively. In contrast, glaucomatous eyes only on medical therapy [p=0.13] or with history of trabeculectomy [p>0.40] had no significant increase in graft dislocation or failure rates. Eyes with medically controlled glaucoma or prior trabeculectomy demonstrated comparable rates of graft dislocation and failure as compared to controls. Aqueous shunt surgery was associated with increased rates of graft dislocation and failure after DSAEK.

[Evaluation of lavandula officinalis extract on lymphocyte proliferation and tumor necrosis factor-aplha production]

Studies have demonstrated that plant extracts have various biological effects including immunomodulatory effect. In the present study, the immunomodulatory effects of Lavandula officinalis on lymphocyte proliferation and tumor necrosis factor alpha cytokine production were investigated. [3H] - thymidine incorporation assay on stimulation of the peripheral lymphocytes with PHA and determination of tumor necrosis factor alpha production was assayed, using LISA method. The herbal extract in a concentration of 50 micro g/ml and lesser, in the presence of mitogen increased peripheral blood lymphocytes proliferation. However, there was not significant effect in concentrations more than 50 micro g/ml. Also, the extract in the concentration of higher than 50 micro g/ml suppressed the production of tumor necrosis factor alpha in the exposed cells. The extract showed immunomodulatory effect by increasing of lymphocyte proliferation in a concentration of 50 micro g/ml and lesser. Also, decreasing in tumor necrosis factor alpha in the concentration of more than 50 micro g/ml was observed. Further studies, should focus on identifying the immunomodulatory mediator of this herbal extract

Endothelial keratoplasty: from DLEK to DMEK

The last decade has heralded a revolutionary shift in the treatment of corneal endothelial disease. Only 15 years ago, the only surgical treatment for pseudophakic bullous keratopathy and Fuchs dystrophy was penetrating keratoplasty [PK]. Although used successfully for over a century, PK requires many months of refractive adjustments before the eye achieves visual stability. Starting with the advent of posterior lamellar keratoplasty in the late 1990s, a number of procedures have been developed, refined, and widely adopted, which have given patients faster recoveries and improved globe stability in comparison to traditional corneal transplantation. Each iteration of endothelial keratoplasty [EK] has involved the increasingly selective transplantation of corneal endothelial cells. Preliminary results of the most recent form of EK, Descemet's membrane EK, suggest that pure endothelial cell transplantation is on the horizon

Procedural skills training in the internal medicine residency in Iran: a national survey of recent graduates of residency programs

Procedural skills training is an important part of internal medicine residency and knowing which procedures residents are performing and the quality of their training is a necessary step to ensure sufficient training opportunities. To obtain the opinions of recent graduates of residency programs of internal medicine in Iran about the quality of training in procedural skills. A questionnaire was given by hand to the all 187 general internists who had graduated from 22 universities of medical sciences in 2003. Thirty-three ambulatory and inpatient procedures were included in the questionnaire. For each skill the newly graduated internists were asked to answer questions about: the number of procedure they have done during their residency, level of supervision they received during performing the procedure, level of confidence to performing it independently, quality of training and level of importance for a general internist to do it independently. They also were asked to rate the overall quality of procedural skills training and their overall competency to perform these skills. Finally they were asked to answer open questions regarding: Assessment of their procedural skills competency during residency training, Introducing useful references and materials by residency programs, the most important problems in their training and suggestions for improving the quality of procedural skills training. Three postal and an email [for those who have email addresses] reminders were sent for nonresponders. 57/187 [30%] questionnaires were analyzed. More than 50% of respondents said that the quality of teaching procedural skills were not adequate. Meanwhile only 32% of respondents believe that their competencies in performing procedures are well or more. Statistical difference has been observed between male and female regarding their ideas about competencies to performing procedures [p<0. 001]. Only 36% of respondents recall that their performance on procedures had been evaluated, which nearly all of them in only 1 procedure. Eleven procedures were indicated by 90% or more of the respondents as those should be learned by all the graduates. Current residency training in internal medicine does not assure the minimum competency of graduates in most of the more important procedural skills. Residency programs must pay more attention to teaching procedural skills to the residents and assessing their competence