Cell Toxicity and inhibitory effects of Cyperus rotundus extract on Streptococcus mutans, Aggregatibacter actinomycetemcomitans and Candida albicans

Periodontitis and tooth decay are common dental diseases. There are some bacterial risk factors such as Streptococcus mutans, Aggregatibacter actinomycetemcomitans and Candida albicans fungi. Considering the increasing resistance of bacteria and fungi to antibiotics and their complications, tubers of Cyperus rotundus was used to determine the antimicrobial effect of alcoholic and aqueous extracts and essential oil on Streptococcus mutans, Aggregatibacter actinomycetemcomitans and Candida albicans, as well as an examination cytotoxicity on gingival fibroblast cells. Alcoholic and aqueous extracts and essential oil prepared from tubers of Cyperus rotundus. After bacterial and fungal cultures, the inhibition zone, Minimum inhibitory concentrations (MIC), and Minimum Bactericidal Concentration (MBC), were studied. Cytotoxicity was also evaluated using the Methyl tetrazolium test (MTT).The results showed that Cyperus rotundus alcoholic extract had the greatest effect on inhibition of growth and death of Streptococcus mutans, Aggregatibacter actinomycetemcomitans. According to the present study, Cyperus rotundus extract can be considered as a suitable candidate for the treatment and prevention of periodontitis and tooth decay

Genetic Linkage Analysis of the DFNB21 Locus in Autosomal Recessive Hearing Loss in Large Families from Khuzestan Province

Background: Hearing loss (HL) is the most common congenital defect in humans. One or two in thousand newborn babies have prelingual hearing loss. Autosomal recessive non-syndromic hearing loss (ARNSHL) is the most common form of hereditary deafness. Hearing loss is more common in the developing countries which is due to genetic and environmental (cultural -health factors) reasons. HL has a wide range of clinical demonstrations including: congenital or late onset, conductive or sensoryneural, syndromic or non-syndromic hearing loss. The goal of this project is to determine the portion of the DFNB21 (TECTA) in ARNSHL in families with negative GJB2 gene in Khuzestan province. Materials and Methods: We studied 21 families with ARNSHL with at least 4 patients and negative for GJB2 mutations from Khuzestan province. Genetic linkage analysis was performed using STR markers linked to DFNB21 locus. Results: Following genetic linkage analysis and haplotyping, out of 21 families with ARNSHL, one family showed linkage to the DFNB21 (TECTA) locus. Conclusion: The results of this project confirm other studies in Iran and give insight into the most common loci causing ARNSHL in Iran which could be helpful in research and clinic

Contributions of External Attentional Focus, Enhanced Expectancies and Autonomy Support to Enhance Learning Skills of Throwing Darts

Objective: This study aimed to investigate the effect of the combination of attention (external focus) and internal motivation (autonomy support and enhanced expectancies) on learning the skill of throwing darts. Methods: For this purpose, 60 women participated in the study. our study included 4 groups: a) autonomy support - external focus (AS-EF); b) enhanced expectancies - external focus (EE-EF); C) enhanced expectancies - autonomy support (EE-AS); and d) enhanced expectancies - autonomy support - external focus (EE-AS-EF). Participants were asked to throw darts at a target with their non-dominant arm. In the EE conditions, they received (false) positive social-comparative feedback. In the AS conditions, they were allowed to throw 5 of 10 trials in each block with their dominant arm chosen by them. In the EF conditions, participants were asked to focus on the target. on the post-test after the end of the training period and retention and transfer test 24 hours after practice, the AS-EE-EF group had the highest accuracy scores and outperformed all other groups. Results: The results of the between-group comparison for throwing accuracy showed that the EE-AS-EF group was a significant difference compared to the other groups. Conclusions: The findings provide evidence that enhanced expectancies, autonomy support, and an external focus can contribute in an additive style to optimize motor performance and learning

Changes in the Distribution of Plant Species in the Ecological Niche in Various Stages of Succession

Variation along the successional stage of a plant community is not limited to plant composition and diversity but also related to nutrient resources and plant species abundance distribution. Therefore, the use of models that consider the distribution of ecological niches in addition to the relative frequency of species in the distribution of species is also important. The object of current study was to investigate the species abundance distribution using ecological niche models in a successional stage of plant community in semi-steppe rangelands. To do so, first we selected three regions with different succession stage including 3-5, 10-15, and 30-50 years and a control site. In each region, we used 10 plots of 1 m2 along four 100 m transects to record the vegetation cover. Then Monte-Carlo test using data simulation was used to test fitness of each niche apportionment model. The results showed that frequency of species in both 3-5 and 10-15 successions fitted the random fraction model while MacArthur fraction model only accepted the model which fitted species frequency distribution in 30-50 years and control site. The results indicated that the niche occupation pattern in early stage of succession might be attributed to the random process of pioneer species. However, the chance of random niche occupation decreased by the end of succession due to nutrient availability and competition

Retrospective Evaluation of Common Dentistry Errors in Selected Dental Clinics of the Armed Forces, Iran

Background & Aims: The occurrence of errors in dental practice is an inevitable factor resulting in a reduction in the quality of medical services. These errors can prompt adverse complications, weaken the patient's trust in the dentist, and induce financial losses to the health care system. The purpose of this study was to investigate the common overt and covert errors that can be detected from medical records in selected clinics of the Armed Forces, Iran. Materials & Methods: In this study, we evaluated 3248 dental records, documented in seven selected dental clinics of the Armed Forces, Iran. The dental files were reviewed to detect flaws in the process of documentation, treatment protocols, and results. The patient and practitioner demographics were also extracted for further statistical analyses. Results: Among the studied documents, 14% of the dental records were incomplete and 17% of dental treatments showed at least one deviation from the standard treatment protocols. Also, there was a significant relationship between the occurrence of these errors and some demographic variables such as the dentist’s age, academic degree, and work experience. The prevalence of dental errors was 14%, 20%, and 30% in 1st, 2nd, and 3rd-grade dental clinics, respectively. Conclusion: Deficiencies in completing medical records and errors in the treatment process are common in Armed Forces clinics, Iran. Many of these errors can be identified through periodic evaluations and review of medical records to reduce the likelihood of recurrence

Synergy patterns of brain activity during learning of the dart throwing skill with the dominant and non-dominant hand

The mechanism and neural origin of the differences between the two hands in motor control and learning are still unknown. The aim of the present research is to examine the changes in synergy patterns in different brain regions while learning the dart throwing skill with the dominant and non-dominant hand. The sample population consisted of 10 students aged 23±2.5 divided into two groups of dominant and non-dominant hand. To record brain activities, a 32-channel wireless Electro-encephalography (EEG) system was used. Data were recorded through three stages of pre-test (pre-training), acquisition (after 4 weeks of training) and retention (after one week of non-training). EEG signals were analysed in alpha, beta and gamma bands. EEG analysis showed that the synergy patterns during acquisition and retention stages were significantly similar to each other and largely different from the pre-training stage in all three bands. Increasing activity levels of the contralateral cortical areas and formation of a different activity pattern after learning in the two groups, were other results obtained. Learning a new motor skill requires relatively lasting changes in the brain map and synergy patterns of brain activities are different for motor learning when the dominant or non-dominant hand is used. Keywords: Brain activity; Dart throwing; Motor learning; Motor skills; Synergy pattern

Expertise Influence on Anticipatory Postural Adjustment under Different Temporal Pressure

Highlights: Expert Table Tennis players demonstrate higher APA magnitude of dorsal muscles than novice counterparts. Expert and Novice Table Tennis players show similar APA onset times. Skilled Table Tennis players have the ability to anticipate body position change more effectively than novice players. The greater the available time for motor preparation, the better anticipation of the APAs Abstract Background: Skilled athletes’ optimal performance might be due to their postural ability to counteract perturbation. However, how expertise influences the coordination of anticipatory postural adjustment (APA) and main movement under temporal pressure needs more investigation. This study aimed to investigate how available time (temporal pressure) for the central nervous system to prepare postural and motor commands, differentiates skilled and novice postural capacity during performing Table Tennis Forehand stroke. Methods: 10 skilled (20.3±1.15 years old) and 10 novices (19.9±0.99 years old) Table Tennis players while maintaining Forehand stroke position on two force plates stand in front of a screen that presents a Coincident Anticipation Timing stimulus. Participants completed a block of 20 trials consisting of random-order presentation of fast and slow stimuli and surface muscle activity of postural muscles was recorded using an Electromyography device, simultaneously. Results: The results of two-way MANOVA showed that more/less temporal pressure for the central nervous system led to later/earlier onset time of APA with lower/higher magnitude, respectively. Skilled players’ postural strategy was the higher magnitude of APA in dorsal muscles (Erector Spainae, Biceps Femoris, and Gasterocnemous), more backward peak excursion, and lower velocity of the center of pressure. Conclusion: Although such findings may be beneficial factors for coaches in programming athletes’ training, however, the similarity in anticipatory postural adjustments’ onset time of novice and skilled players, do not let a certain conclusion about the effects of expertise on feed-forward control of posture

The current markers of cancer stem cell in oral cancers

Head and neck cancer (HNC) constitute 5 of all reported cancers. Among all, the oral cavity cancer is the most frequent type of HNC which accounts for over half of HNC cases. Mouth cancer ranks the sixth leading cause of cancer-related mortality. Generally, conventional chemotherapy has shown success at decreasing relapse and metastasis rates and improves the overall prognosis. Recently, target therapy and targeted drug delivery systems have been introduced as promising treatments. The elimination of efficiency of current therapeutic strategies due to the spared cancer stem cells that cause chemotherapy resistance, relapse and metastasis. Inefficiency methodologies in the elimination of all cancer cells in the body are a major problem that remained to be resolved before to confront the new cancer therapies. Many studies imply to cancer stem cell markers as important agents for targeted anti-cancer as well as improving chemotherapy efficiencies. The potentials of targeted cancer therapy led us to search for novel markers in the mouth cancer stem cells especially in rare cancers. The aimed of this research was, first a comprehensive critical review of the previous studies on the markers of cancer stem cells in oral cancers including oral squamous cell carcinoma, salivary gland cancers, and to highlight the most common cancer stem cell markers which have potential to be exploited as indicators for the preneoplastic lesion malignancy, oral cancer progression, and/or treatment prognosis

Feasibility Analysis of Using Anatomic and Dental Formulas in Human Identification

Background and purpose: Dental and skeletal features, unlike soft tissues, remain unchanged in events where most body tissues are destroyed such as car accidents, plane crash, crimes, etc. Panoramic and lateral cephalometric radiographs can provide useful information about dental and cephalometric indicators in human identification. Materials and methods: A cohort retrospective study was carried out in five stages, including collecting the samples, using a specific tooth counting system, identifying the landmarks in panoramic radiographs and designing a dental formula, designing anatomical formula with cephalometric indicators and identifying operator errors, and matching and data analysis. Results: We studied 180 people, including 97 (54%) women and 83 men aged 15-59 (mean age= 25.5) years in Tehran. Average indexes of missing (M), filled (F), Root Canal Therapy (RCT) teeth, crown (C), (Body/Go-Go), (Mf-Mf/Mf-Go(R+L)), De, P, ER, Go in lateral Cephalometry, SNA, SNB, Basal, N-Ans-Me, Ans-Pns/Go-Me, and S-Go/N-Me were not significantly different between cases by comparing the graphs before and after treatments (P>0.05). Examination of average indices of implant and dilacerated teeth in general and without considering the number of teeth, did not show a significant difference when the pre/post-treatment graphs were compared (P>0.05). In examining the Co-Ans/Co-Gn, Go in panoramic graph, (S-N/S-Ba) and S-N-Ba, no significant difference was observed between the cases (P>0.05). Conclusion: Panoramic, lateral cephalometric graphs and designing creative formula can be used in human identification

Current natural bioactive materials in bone and tooth regeneration in dentistry: a comprehensive overview

Tissue regeneration is a vital phenomenon in the skeletal system of human beings during their life span. The structure of bony architecture and teeth are highly dependent to this ongoing procedure to maintain their functional form. Regarding the fundamental function of our skeletal system, all the involved components are at constant risk for injuries and deformations throughout the life. Therefore, in modern medicine, promotion of bone and tooth regeneration has become a critical counter measure to correct these acquired defects. There are numerous ways to address the bone and tooth related erosive pathologies but utilization of natural compounds has gained immense popularity in recent years. These materials provide a broad spectrum of therapeutic agents with a variety of biological characteristics. In this review, a comprehensive exploration has been implemented to extract and categorize the relevant scientific evidence on this issue, based on the source of natural candidates and the potential clinical indications. Database searching presented a considerable data pool with more than 300 references in this field. According to the results, all the proposed items can be categorized in two major groups including scaffolding and osteogenesis (or dentinogenesis) induction. The clinical applicability of a number of them is properly demonstrated in clinical trials but for the rest, more examinations are required to reach a conclusive decision