mohsen hassanzadeh

Mutans Streptococci are significant pathogens isolated from dental plaques. Due to the increasing frequency of antimicrobial resistance among pathogens causing dental caries, more studies have focused on using natural agents against them. This study aimed to evaluate the antibacterial effects of Trachyspermum ammi essential oil against Streptococcus mutans isolated from dental plaques.

Twenty human dental plaque samples were collected, and eight S. mutans isolates were detected using biochemical and molecular tests. The antibiotic susceptibility patterns of the isolates were determined by the disc diffusion method. Also, T. ammi essential oil antibacterial activity was investigated using the disc diffusion method and determining minimum inhibitory concentration (MIC50) and minimum bactericidal concentration (MBC) values.

Phenotypic and genotypic characterization identified S. mutans in 40% of the samples. The antibiotic susceptibility assay revealed the highest resistance patterns against cefotaxime (100%), ceftriaxone (100%), and penicillin (87.5%). The T. ammi essential oil demonstrated 20 µg/ml MIC and 80µg/ml MBC against S. mutans.

The present study revealed a potent antibacterial activity for T. ammi essential oil against S. mutans isolates.

A novel carbon paste electrode modified with ionic liquid (n-hexyl-3-methylimidazolium hexafluoro phosphate) and magnetic core-shell manganese ferrite nanoparticles (MCSILCPE) was fabricated. The electrochemical study of the modified electrode, as well as its efficiency for electro-oxidation of tryptophan, is described. Cyclic voltammetry (CV), choronoamperometry (CHA) and square wave voltammetry (SWV) were used to investigate oxidation of tryptophan in aqueous solution. The diffusion coefficient (D=3.53 ×10-6 cm2/s), was determined using electrochemical approaches. It has been found that under an optimum condition (pH 7.0), the oxidation of tryptophan at the surface of such an electrode occurs at a potential about 150 mV less positive than that of an unmodified carbon paste electrode. SWV exhibits a linear dynamic range from 5.0×10-6 to 4.0×10−4 M tryptophan. The morphology of the modified electrode was studied using SEM. The limit of detection was equal to 1.1×10-6 M. The electrode was also employed to determination of tryptophan in urine samples.

Lateral sphincterotomy is the standard treatment for chronic anal fissure. In recent years, chemical sphincterotomy by several pharmacological agents, i.e. botulinum toxin, nifedipin, glyceryl trinitrate, has been used as alternative treatment. The objective of this study was to compare the results of botulinum toxin injection with lateral sphincterotomy in patients with this condition. In this trial 40 patients were randomized into two groups; 19 patients underwent surgical sphincterotomy and 21 cases were treated with injections of 30 units of botulinum toxin into the internal sphincter at 3 different sites (anterior and lateral). Patients were followed for up to 6 months to appraise the results. There was no significant difference in sex, age, duration of symptoms and anatomical variability of the disease between two groups. The frequency of healing on follow-up visits in the Botox group at 2 weeks, 2 months, 4 months and 6 months was respectively 33.3%, 76.2%, 85.7% and 85.7% and in the sphincterotomy group it was 47.4%, 89.5%, 100% and 94.7%, respectively (p>0.4). None of patients in either groups developed fecal incontinence. The frequency of incontinence to flatus in follow-up visits in Botox group was respectively 38.1%, 19%, 4.8% and 0% and in sphincterotomy group it was respectively 63.2%, 31.6%, 26.3% and 21.1%. The difference in the frequency of flatus incontinence was only statistically significant at the 6th month visit (p=0.04). Chemical sphincterotomy with injection of 30 units of Botox into the internal sphincter at 3 sites is an effective treatment for chronic anal fissure and accompanied by fewer complications. It is suggested as the primary step in treatment of chronic fissure with surgical sphincterotomy reserved for refractory cases.