ANTIMICROBIAL POTENTIAL OF ALKALOIDS AND FLAVONOIDS EXTRACTED FROM TAMARIX APHYLLA LEAVES AGAINST COMMON HUMAN PATHOGENIC BACTERIA

Background: Alkaloids and flavonoids are secondary metabolites extracted from different medicinal plants. Tamarix aphylla a traditionally valuable medicinal plant; was used for the extraction of alkaloids and flavonoids in order to evaluate their antibacterial activity. Methodology: The leaves of the plant were collected from district Kohat, Pakistan, and their alkaloids and flavonoids were extracted with ethanol and methanol, respectively. Four bacteria i.e. Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa) were selected for the biological screening of these phyto-constituents. Results: The concentration of alkaloids was found to be more in the leaves of Tamarix aphylla than flavonoids. The extracted phytochemicals showed varied inhibition zones against tested bacterial isolates. Alkaloids showed highest inhibitory activity against Staphylococcus aureus (14±0.6 mm) followed by Pseudomonas aeruginosa (13±0.7 mm). Conversely, flavonoids showed the highest inhibitory affect against Salmonella typhi (17±0.7 mm) followed by Staphylococcus aureus (14±0.7 mm). However, both extracts showed the lowest inhibitory effects against Escherichia coli. Conclusions: It was concluded that the alkaloids and flavonoids from Tamarix aphylla leaves have antimicrobial potential against common human bacterial pathogens. However, flavonoids were found to be more active phytochemical against tested bacterial strains as compared to alkaloids

Subnational mapping of HIV incidence and mortality among individuals aged 15–49 years in sub-Saharan Africa, 2000–18 : a modelling study

Background: High-resolution estimates of HIV burden across space and time provide an important tool for tracking and monitoring the progress of prevention and control efforts and assist with improving the precision and efficiency of targeting efforts. We aimed to assess HIV incidence and HIV mortality for all second-level administrative units across sub-Saharan Africa. Methods: In this modelling study, we developed a framework that used the geographically specific HIV prevalence data collected in seroprevalence surveys and antenatal care clinics to train a model that estimates HIV incidence and mortality among individuals aged 15–49 years. We used a model-based geostatistical framework to estimate HIV prevalence at the second administrative level in 44 countries in sub-Saharan Africa for 2000–18 and sought data on the number of individuals on antiretroviral therapy (ART) by second-level administrative unit. We then modified the Estimation and Projection Package (EPP) to use these HIV prevalence and treatment estimates to estimate HIV incidence and mortality by second-level administrative unit. Findings: The estimates suggest substantial variation in HIV incidence and mortality rates both between and within countries in sub-Saharan Africa, with 15 countries having a ten-times or greater difference in estimated HIV incidence between the second-level administrative units with the lowest and highest estimated incidence levels. Across all 44 countries in 2018, HIV incidence ranged from 2 ·8 (95% uncertainty interval 2·1–3·8) in Mauritania to 1585·9 (1369·4–1824·8) cases per 100 000 people in Lesotho and HIV mortality ranged from 0·8 (0·7–0·9) in Mauritania to 676· 5 (513· 6–888·0) deaths per 100 000 people in Lesotho. Variation in both incidence and mortality was substantially greater at the subnational level than at the national level and the highest estimated rates were accordingly higher. Among second-level administrative units, Guijá District, Gaza Province, Mozambique, had the highest estimated HIV incidence (4661·7 [2544·8–8120·3]) cases per 100000 people in 2018 and Inhassunge District, Zambezia Province, Mozambique, had the highest estimated HIV mortality rate (1163·0 [679·0–1866·8]) deaths per 100 000 people. Further, the rate of reduction in HIV incidence and mortality from 2000 to 2018, as well as the ratio of new infections to the number of people living with HIV was highly variable. Although most second-level administrative units had declines in the number of new cases (3316 [81· 1%] of 4087 units) and number of deaths (3325 [81·4%]), nearly all appeared well short of the targeted 75% reduction in new cases and deaths between 2010 and 2020. Interpretation: Our estimates suggest that most second-level administrative units in sub-Saharan Africa are falling short of the targeted 75% reduction in new cases and deaths by 2020, which is further compounded by substantial within-country variability. These estimates will help decision makers and programme implementers expand access to ART and better target health resources to higher burden subnational areas

Analysis and correlation study of human masseter muscle with EMG, ultrasonography & 3D imaging.

Form and function are inextricably intertwined in orthodontics. Our understanding of the hard tissue relationship has been comprehensive, with extensive clinical trials both cross sectional and longitudinal over the past several decades. The majority of studies have used standardized cephalograms that reflect our current concepts. However, the same cannot be stated for soft tissues and, more specifically, the muscles that envelope the skeletal bases. The aim of the current study was to objectively evaluate the masseter muscle – one of the key elevator muscles in the human masticatory system with innovative diagnostic tools like electromyography (EMG), ultrasonography (US) and 3-D imaging (Mona Lisa®). Standard lateral cephalometrics were used as the gold standard for measuring the vertical facial dimensions and correlating the findings to the above mentioned modalities. This extensive study comprised three major components and involved subjects from the same cohort. Firstly, the masseter muscle spindle reflexes were studied in dynamic chewing and the responses recorded with EMG in 28 human subjects. These were then analysed and correlated to the vertical facial proportion from standardized lateral cephalograms. Although substantial work has been done to evaluate the various trigeminal reflexes¹⁻³, limited research has investigated the reflexes from the muscle spindles in different facial proportions⁴. This is primarily due to the inherent complexity of the neurophysiology compounded by noise within the experimental models. Most often the method used to elicit a muscle spindle reflex in the human jaw involves a brief mechanical depression of the mandible, either by use of a tendon hammer or, if a more controlled stimulus is required, a computer-controlled stretching device⁵⁻⁷. In the current study, a sophisticated apparatus was utilized to deliver precise profile stimulus at predetermined intervals. Significant correlations were observed between the muscle spindle response and selected vertical proportions. The second phase of study was to utilize US for measuring masseter muscle dimensions in the same cohort and once again correlate the various dimensions of the masseter muscle to the facial proportions generated by the lateral cephalometrics. US has been studied in dentistry for over four decades and it has been established as a safe, non-invasive, comfortable and cost-effective diagnostic implement. Also, US produces high resolution images of soft tissues more readily than MRI and CT scans⁸. Among the limitations for US there is the concern about reproducibility and standardization particularly between operators. Hence, it is advisable to have a single operator for data collection in order to preclude interexaminer variability. Future use of US in dentistry will be favoured especially where periodic evaluation is needed and there are concerns about radiation. Finally, for a more holistic assessment, 3D optical scanning was used in the same sample cohort to analyse and correlate masseter muscle dimensions to vertical and transverse facial proportions. Regression equations were generated, albeit from the convenience sample, to explore a mathematical model for deriving variables of interest rather than physically conducting the individual measurements, particularly if that required radiation. Current work shows strong correlations between lateral cephalometric and 3D imaging variables, but relatively weak associations with the ultrasonography. The findings from this study support the use of predictive equations from 3D imaging for lateral cephalometric variables but larger scale studies are required to confirm reproducibility. Moreover, curvilinear measurements from 3D images were significantly different (p < 0.0001) to the linear and should be adopted for more meaningful representation of the soft tissues. These findings are relevant to facial form and function assessment which is used in orthodontic diagnosis and treatment planning; in particular, orthodontic functional appliance therapy. Analyses of the face can be carried out with a myriad of cephalometric packages; however, the role of the elevator muscles is often overlooked and their contribution to changes and/or characteristics that could benefit the orthodontic treatment is not fully appreciated. Thus, the assessment not only of anatomical but also physiological variations in the masseter muscles is important in the management of different facial patterns. The above tools provide a means to evaluate muscle functions which would be of particular interest in growing children and where functional orthopaedic appliances utilize forces from the muscles of mastication. Furthermore, periodic evaluation of such cases is generally desirable and needs to be safe, radiation free and cost-effective.Thesis (Ph.D.) -- University of Adelaide, School of Dentistry, 200

Introducing scenario based learning interactive to postgraduates in UQ Orthodontic program

E-learning has gained momentum in health sciences and seems to have great potential in specialist dental education. Higher acceptability by learners is particularly associated with the surge of smart devices. Currently, there are limited number of e-learning modules available for dental education, particularly in Orthodontics.Scenario Based Learning interactive (SBLi(®)) software was used for the first time in Orthodontics Postgraduate training at the University of Queensland. Nine interactive modules were created embedded with clinical procedure videos, web-links, evidence-based literature, along with opportunity for self-assessment and evaluation. Qualitative data were collected before and after the administration of the SBLi(®) for Orthodontics. The purpose of this data was to investigate learning styles and the acceptance of e-modules as part of postgraduate training.Advantages of the package included high acceptance rate, greater confidence in the application of clinical skills covered in the modules and reduced contact time particularly with limited academic staff. E-modules demonstrated high compatibility with the learning styles of the participants and were considered engaging.It seems apparent that e-learning is most effective in a blended learning environment, supplemented with the traditional classroom approach, rather than as a sole mechanism for postgraduate training

Work-related musculoskeletal disorders in dentists and orthodontists: a review of the literature

Work-related musculoskeletal disorders (WMSD's) are on the rise worldwide. These disorders have numerous repercussions, from serious ill-health effects at the individual level to decreased workplace efficiency and productivity affecting not only quality of life but the economy.This review aims to provide an overview of WMSD's in the dental profession, more specifically, among general dental practitioners and specialist orthodontists.Literature was hand searched from Pubmed with greater emphasis on contemporary literature as the professionals demands have evolved over the years.While there have been numerous papers published relating to the prevalence of ergonomic problems among general dentists, orthodontists have received little investigation.This review highlights the need for research into the risk factors of WMSD's in the dental profession (both general dentistry and orthodontics), as this would provide a more direct approach for prevention which is essential as professionals work for longer years in practice

Work-related musculoskeletal disorders in Australian dentists and orthodontists: Risk assessment and prevention

BACKGROUND: As professionals work longer hours and live longer there have been concerns regarding the Work related Musculoskeletal Disorders (WMSD) affecting both professional and personal lives. Moreover, past decade has seen a surge in interest in all allied health sciences personnel with self reporting cross sectional studies. OBJECTIVE: Health professionals often suffer WMSD due to occupational stress. It is important to assess the problem in order to find ways to prevent it. Hence, the focus of this cross-sectional survey. The aim was to investigate the prevalence and risk factors of WMSD between Australian dentists and orthodontists. MATERIALS AND METHOD: A postal survey was sent to 447 Australian orthodontists and 450 Queensland dentists using the universal Nordic scale previously piloted at UQ and refined for this cross-sectional study. Questions were directed towards individuals, workplace and psychosocial variables and were designed to gather information regarding health, lifestyle, education, awareness of musculoskeletal problems and current preventative strategies. RESULTS:Ahigh prevalence of musculoskeletal problemswas found for both dentists (88.9%) and orthodontists (83.6%) reported in the last 12 months. The main predictor in both groupswas increasedwork stress. Less than a third of those professionals surveyed had received education regarding dental practice ergonomics during their tertiary education. CONCLUSION: Dentists and orthodontists experienced a high rate of musculoskeletal problems which were associated with increased levels of stress at work. Further research should be directed toward interventions aimed at reducing stress in the work environment as well as improving work posture