Burnout Rates in Clinical Radiation Oncology and Variations across Professional Subgroups

PURPOSE/OBJECTIVE(S)

Physician and medical professional burnout has emerged as an important issue in clinical medicine and has been shown to negatively affect patient outcomes. The aim of this study is to determine how rates of burnout vary between different radiation oncology professional subgroups.

MATERIALS/METHODS

Participants were selected from those employed in one of the professional subgroups (radiation therapists, nurses, physicists, dosimetrists, and physicians) at two institutions that cover a total of seven sites. 126 individuals were recruited to participate. In addition to demographics, participants were asked to respond to questions regarding professional burnout utilizing the Maslach Burnout Inventory (MBI). Responses were on a seven-point Likert scale with subcategories of Exhaustion, Depersonalization, and Personal Achievement. Each participant's score per subcategory was categorized as either low, moderate, or high. For our primary outcome, frequencies and proportions were reported and Fisher's Exact Test was used to evaluate whether there was a statistically significant difference in proportions in categorized burnout scores across professional subgroups. Secondary analyses were performed comparing burnout across sex, age, and categorized years in position. An alpha level of 0.05 was used for all analyses.

RESULTS

In total, 55 participants responded to the survey: 12 nurses, 8 dosimetrists, 12 physicians, 5 physicists, and 18 radiation therapists for a response rate of 43.6%. Demographics were consistent across professional subgroups with the exception of participant sex (p = .0397), which had a greater proportion of females (72.22%) in the Radiation Therapist subgroup. Among the three subcategories, only Exhaustion had a significant difference between groups (p = .0494) with Dosimetrists (62.50%) and Physicists (40.00%) experiencing the highest level of burnout. For Depersonalization, at least one individual in each subgroup identified high burnout with higher rates among the Dosimetrists (25.00%) and Physicists (40.00%). Similarly, at least one person in each subgroup reported high burnout in Personal Achievement, but the highest response was among Dosimetrists (37.50%). In total, at least 12.75% of participants reported high burnout in at least one subcategory. No statistically significant differences in burnout were detected in our secondary analyses across sex, age, and years in position.

CONCLUSION

Our study showed that burnout rates are moderate in members of the radiation oncology team, with dosimetrists and physicists displaying the highest levels of burnout. In order to better estimate professional burnout, larger studies should be conducted to determine causes of burnout. Furthermore, wellness programs should be encouraged and incentivized to help reduce burnout and improve workplace morale, occupational fulfillment, and effective patient care.

Designing a Predictive Model for Colorectal Neoplasia Diagnosis Based on Clinical and Laboratory Findings in Colonoscopy Candidate Patients

BACKGROUND

Health authorities have expanded two strategies to diminish CRC-related influence: CR screening and improve diagnostic process in symptomatic patients. The aim of the current study is to design a predictive model to identify the most important risk factors that can efficiently predict patients who have high risk of colorectal neoplasia.

METHOD

A cross-sectional study was constructed to include all patients who had positive test for FIT or had one or more risk factors for colorectal cancer based on the guidelines of detecting high-risk groups for colorectal cancer in Iran. Multivariable binary logistic regression model was constructed for prediction of colorectal neoplasia. We used sensitivity, specificity, positive and negative predictive value, and positive and negative likelihood ratio to check the accuracy. The Hosmer-Lemeshow test, chi-square test, and p value were used to determine the precision of model.

RESULT

Following an AIC stepwise selection model, only nine potential variables, namely gender, watery diarrhea, IBD, abdominal pain, melena, body mass index, depression drug, anti-inflammatory drug, and age, were found to be a predictor of colorectal neoplasia. The best cut-point probability in the final model was 0.27 and results of sensitivity and specificity, based on maximizing these two criteria, were 66% and 62%, respectively.

CONCLUSION

Overall, our model prediction was comparable with other risk prediction models for colorectal cancer. It had a modest discriminatory power to distinguish an individual's neoplasia colorectal risk.

Climate effects on the COVID-19 outbreak: a comparative analysis between the UAE and Switzerland

The main aim of the present study is to disclose the similarities or differences of the climate effects on the COVID-19 outbreak in two countries, which have different climatic conditions. Using the correlation modeling, the results revealed that some climatic factors, such as the ULR, temperature, and CH₄ in the UAE and aerosol index and NO₂ in Switzerland have positive lagged correlations with the outburst of COVID-19 by intensifying role within − 9, − 7, and − 2 days. The mitigating role was also observed for ozone/solar radiation and temperature/long-wave radiation in the UAE and Switzerland, respectively. The initial hypotheses of the research have confirmed the correlations between new cases of COVID-19 and ULR and aerosol indices in the UAE and Switzerland. However, the main finding revealed that the climate effects on the COVID-19 outbreak show different roles in the different countries, locating in dissimilar climatic zones. Accordingly, the COVID-19 can be intensified by increases of the ULR and temperature in an arid region, while it can be exactly mitigated by increases of these factors in a temperate area. This finding may be useful for future researches for identifying the essential influencing factors for the mitigating COVID-19 outbreak.

Experimental and theoretical studies of frequency response function of dagger-shaped atomic force microscope cantilever in different immersion environments

In this study, the amplitude of frequency response functions of vertical and rotational displacements and resonant frequency of a dagger-shaped atomic force microscope cantilever have been investigated. To increase the accuracy of theoretical model, all necessary details for cantilever and sample surface have been taken into account. In this paper, carbon tetrachloride (CCL₄ ), methanol, acetone, water and air have been considered as the environments. In the most cases, presence and absence of tip-sample interaction force have studied. For a sample cantilever immersed in air, both of the Euler-Bernoulli and Timoshenko beam theories have been compared. The results indicate that the tip-sample interaction force raises the resonant frequency. Increasing the liquid viscosity leads to a decrease in the resonant frequency and the amplitude of frequency response functions of vertical and rotational displacements. Increasing the rectangular and tapered parts lengths, decreases the resonant frequency and amplitude of frequency response functions of vertical and rotational displacements. By increasing the cantilever thickness the resonant frequency and amplitude of frequency response functions of vertical and rotational displacements increases. Theoretical model for air and water has been compared with experimental work. Results show good agreement.

Modelling and optimizing of calcium and non-phytate phosphorus requirements of male broiler chickens from 1 to 21 days of age using response surface methodology

The skeleton is the main site of P and Ca deposition; therefore, accurate estimation of Ca and P requirements is necessary to maintaining health and optimum performance of broiler chickens. A response surface methodology (RSM) using a central composite design (CCD) was used for evaluating and optimizing of Ca and non-phytate P (NPP) requirements of broiler chickens for optimal performance, ileal nutrient digestibility and bone mineralization from 1 to 21 days of age. A total of 750 one-day-old male broiler chickens (Ross 308) were randomly distributed into 50 cages including 9 treatments, each replicated 5 times (except central treatment with 10 replicates) and 15 birds in each cage by CCD. The dietary Ca levels of 4.3, 5.6, 8.6, 11.7 and 13.0 g/kg and NPP of 2.5, 2.9, 4.0, 5.0 and 5.4 g/kg were used for nine treatments of CCD. The results indicated that the linear and quadratic effects of NPP, quadratic effects of Ca and Ca × NPP were significant for average weight gain (AWG, P < 0.05), average feed intake (AFI, P < 0.05), feed conversion ratio (FCR, P < 0.05) and Ca and P apparent ileal digestibility (AID, P < 0.05); however, the linear effect of Ca was significant only for FCR (P < 0.05). On the other hand, tibia and toe ash were affected by NPP (linear and quadratic, P < 0.01) and Ca (quadratic, P < 0.01). The second-order polynomial regression model was significant for AWG (R2 = 0.93, P < 0.001), AFI (R2 = 0.88, P < 0.001), FCR (R2 = 0.78, P < 0.001), AID of Ca (R2 = 0.78, P < 0.001) and P (R2 = 0.88, P < 0.001), tibia ash (R2 = 0.86, P < 0.001) and toe ash (R2 = 0.85, P < 0.001). The multi-objective optimization indicated that broiler chickens from 1 to 21 days of age need 7.03 and 4.47 g/kg of Ca and NPP, respectively, to achieve optimal AWG, FCR, tibia and toe ash. However, the dietary Ca and NPP levels can be reduced to 6.57 and 3.95 g/kg with a slight negative impact on performance and bone mineralization, respectively. In conclusion, the findings indicate that using multi-objective optimization model such as RSM provides more information regarding optimum Ca and NPP requirements of broiler chickens, considering the complex interaction between these two minerals. While the NPP levels are in line with current recommended requirements, Ca levels are considerably lower and suggest that current recommended Ca requirements may be in excess of the needs of the broiler.

Serogroups, and drug resistance of nontyphoidal Salmonella in symptomatic patients with community-acquired diarrhea and chicken meat samples in Tehran

BACKGROUND

Salmonella is considered as a main cause of community-acquired diarrhea in humans, however, sources of the multi-drug resistant (MDR) strains and their link with the disease are not well known.

AIMS

This study aimed to investigate the frequency, serogroup diversity, and antimicrobial susceptibility patterns of Salmonella strains in poultry meat and stool samples of patients with community acquired diarrhea in Tehran.

METHODS

We compared the frequency of non-typhoidal Salmonella serogroups, the similarities of their resistance patterns to 10 antimicrobial compounds, the prevalence of extended spectrum β-lactamase (ESBL) and ampicillinase C (AmpC) genetic determinants, and class 1 and 2 integrons in 100 chicken meat and 400 stool samples of symptomatic patients in Tehran during June 2018 to March 2019.

RESULTS

Salmonella was isolated from 75% and 5.5% of the chicken meats and human stool samples, respectively. The chicken meat isolates mainly belonged to serogroup C (88%, 66/75), while the human stool isolates were mainly related to serogroup D (59.1%, 13/22). The MDR phenotype and the most common rates of resistance to antibiotics, including tetracycline, trimethoprim/sulfamethoxazole (TS) and azithromycin, were detected in 4.5% and 45.3%, 59% and 13.6%, 43% and 9.1%, 42% and 9.1% of the human stool and chicken meat samples, respectively. Carriage of bla _CTX, bla _SHV, and bla _PER genes in the meat isolate with ESBL resistance phenotype and bla _ACC, bla _FOX, and bla _CMY-2 among the 7 meat strains with AmpC resistance phenotype was not confirmed using polymerase chain reaction (PCR). High prevalence of class 1 and 2 integrons was characterized and showed a correlation with resistance to TS and chloramphenicol.

CONCLUSION

These findings showed a lack of association between chicken meats and human isolates due to discrepancy between the characterized serogroups and resistance phenotypes.

A Langevin equation that governs the irregular stick-slip nano-scale friction

Friction force at the nanoscale, as measured from the lateral deflection of the tip of an atomic force microscope, usually shows a regular stick-slip behavior superimposed by a stochastic part (fluctuations). Previous studies showed the overall fluctuations to be correlated and multi-fractal, and thus not describable simply by e.g. a white noise. In the present study, we investigate whether one can extract an equation to describe nano-friction fluctuations directly from experimental data. Analysing the raw data acquired by a silicon tip scanning the NaCl(001) surface (of lattice constant 5.6 Å) at room temperature and in ultra-high vacuum, we found that the fluctuations possess a Markovian behavior for length scales greater than 0.7 Å. Above this characteristic length, the Kramers-Moyal approach applies. However, the fourth-order KM coefficient turns out to be negligible compared to the second order coefficients, such that the KM expansion reduces to the Langevin equation. The drift and diffusion terms of the Langevin equation show linear and quadratic trends with respect to the fluctuations, respectively. The slope 0.61 ± 0.02 of the drift term, being identical to the Hurst exponent, expresses a degree of correlation among the fluctuations. Moreover, the quadratic trend in the diffusion term causes the scaling exponents to become nonlinear, which indicates multifractality in the fluctuations. These findings propose the practical way to correct the prior models that consider the fluctuations as a white noise.

Conceptualizing and determining core clinical competencies in nursing students: a qualitative study

AIM

This study aimed to conceptualize and explain the core clinical competencies of nursing students in Iran.

BACKGROUND/INTRODUCTION

Despite the national and international efforts to modify nursing curricula such that the students' clinical competencies are improved, there is still a widespread concern about this issue, perhaps due to the impact of factors other than the curriculum itself, such as the lack of a clear definition for the concept of clinical competency and its main components in nursing students.

METHODS

This qualitative study was conducted using conventional content analysis. The participants were selected through purposive sampling and included 14 senior students of bachelor of nursing, four nurses working in teaching hospitals and six clinical instructors. Individual semi-structured interviews were used for data collection. After recording and transcribing the interviews, content analysis was used to extract the concepts.

FINDINGS

The main theme of the study was 'multidimensionality of the concept of clinical competency,' which had six main categories, namely 'adoption of and adaptation with the nursing practice,' 'nursing knowledge,' 'self-direction in clinical learning,' 'patient care skills,' 'professional ethics' and 'the development of professional behaviours.'

DISCUSSION/CONCLUSION

Clinical competency and its dimensions among students comprise a multidimensional concept. Having a clear and comprehensive understanding of this concept and focusing on its core axes may be the most important step in improving students' clinical competency.

IMPLICATIONS FOR NURSING, HEALTH AND EDUCATION POLICY

Policymakers and nursing education authorities can identify the problems existing in the students' clinical competency and provide them with practical solutions for a standard professional education through a clear understanding of the concept of clinical competency and its dimensions.

Evaluation of safety and antifungal activity of Lactobacillus reuteri and Pediococcus diacetilactis isolates against aflatoxigenic Aspergillus flavus

Biocontrol of moulds by lactic acid bacteria (LAB) instead of antibiotics and chemical preservatives is a new approach in veterinary medicine. The aims of present research were to perform molecular identification of dominant sourdough LAB isolates and to evaluate their in vivo safety and in vitro antifungal properties for using as biopreservative agents. Sequencing results of PCR products led to identification of Lactobacillus reuteri and Pediococcus diacetilactis as LAB isolates. Antifungal activity of the isolates and their cell-free culture filtrate (CCF) were also confirmed against aflatoxigenic Aspergillus flavus, respectively by overlay and spore spot methods. Accordingly, antagonistic effect of P. diacetilactis and its CCF were significantly (P<0.05) higher than L. reuteri and CCF of mentioned LAB isolate. Clinical chemistry and haematological findings in mice fed LAB demonstrated also insignificant difference vs control mice and were in the normal range, which confirmed the safety of LAB isolates. By considering the importance of safe, food grade biocontrol agents, L. reuteri and P. diacetilactis isolates and their CCF may be considered as an alternative for antibiotics and other chemical preservatives in food and feed processing chain

Alternative healthy eating index and risk of hip fracture: a systematic review and dose-response meta-analysis

BACKGROUND

A high adherence to healthy dietary patterns, such as an alternative healthy eating index (AHEI), has been suggested to have protective effects on bone mineral density and to decrease the incidence of fractures, although the evidence for this is not clear. We conducted a dose-response meta-analysis of available observational studies aiming to assess the association between adherence to a healthy dietary pattern, as assessed by the AHEI score, and risk of hip fracture in the general population.

METHODS

Studies published up to March 2018 were identified on the basis of a literature search in PubMed, Scopus and ISI Web of Science databases using Mesh and non-Mesh relevant keywords. Relative risks (RRs) with 95% confidence intervals (CIs), the linear and nonlinear relationships were calculated using random-effects models.

RESULTS

In the meta-analysis of five effect sizes, as obtained from four studies (265 771 participants with 6938 cases of incident hip fracture), we found that a higher AHEI score was associated with a 31% reduced risk of hip fracture (pooled RR = 0.69; 95% CI = 0.52-0.91) in high versus low intake meta-analysis. In addition, there were inverse relationships between AHEI score and risk of hip fracture, such that a five-unit increase in the score of AHEI was associated with a reduction in the risk of hip fracture in linear (pooled RR = 0.97; 95% CI = 0.95-0.99) and nonlinear (Pnonlinearity < 0.001) models, respectively.

CONCLUSIONS

Adherence to the AHEI (as an indicator of diet quality) was associated with a reduced risk of hip fracture.

Multiscaling behavior of atomic-scale friction

The scaling behavior of friction between rough surfaces is a well-known phenomenon. It might be asked whether such a scaling feature also exists for friction at an atomic scale despite the absence of roughness on atomically flat surfaces. Indeed, other types of fluctuations, e.g., thermal and instrumental fluctuations, become appreciable at this length scale and can lead to scaling behavior of the measured atomic-scale friction. We investigate this using the lateral force exerted on the tip of an atomic force microscope (AFM) when the tip is dragged over the clean NaCl (001) surface in ultra-high vacuum at room temperature. Here the focus is on the fluctuations of the lateral force profile rather than its saw-tooth trend; we first eliminate the trend using the singular value decomposition technique and then explore the scaling behavior of the detrended data, which contains only fluctuations, using the multifractal detrended fluctuation analysis. The results demonstrate a scaling behavior for the friction data ranging from 0.2 to 2 nm with the Hurst exponent H=0.61±0.02 at a 1σ confidence interval. Moreover, the dependence of the generalized Hurst exponent, h(q), on the index variable q confirms the multifractal or multiscaling behavior of the nanofriction data. These results prove that fluctuation of nanofriction empirical data has a multifractal behavior which deviates from white noise.

Geographic Information Systems (GIS), an Informative Start for Challenging Process of Etiologic Investigation of Diseases and Public Health Policy Making

Background: The public health has been always concerned of the immediate environment of human as causal factors for different diseases and health outcomes. Epidemiology, as one of the fundamental basis of public health, is concerned of how diseases are distributed in terms of geographical, chronological, and human population characteristics and employees the descriptive nature of such spread to draw conclusion on the etiology of health or disease utcome for further policy making on prevention of disease or promotion of health.Methods: In this paper, we present the importance of GIS technology in epidemiology from both descriptive and etiologic standpoints and elaborate how this technology can stand in the forefront of disease and health outcome measures in the coming decades. The paper will address the history of geo-related health and disease issues. The mapping tool as a traditionally strong resource in the public health will be explored. The advances in Information Technology and one of its best utilized offshoot, GIS, in Health and disease will be discussed. How the huge repository of generated or ever generating geo-related data and information is utilized to address etiology of diseases or to help public health authorities in making informed policy making decisions are explored.Results: The utilization of GIS technology in diseases with intermittent host such as malaria, yellow fever, or other parasitic diseases has already been well established. The GIS technology and its utilization in chronic and degenerative diseases such as cancer, diabetes, and aging are under development and new frontiers are discovering. The limitation of GIS technology in addressing host environment interaction in micro-environment (at the molecular biology and tissue pathogenicity level) and gene–environment interaction (at the individual level) will further be discussed.Conclusion: We then distress on the efficient use of GIS both in the etiologic investigation of diseases and health events as well as the utilization of the GIS technology as a administrative tool in the help of public health authorities and policy makers in strategic management of health of a community or emergency management of man-made or technological disasters (e.g., wars) or naturally occurring disasters (e.g., earthquake and floods).

A plant-inspired robot with soft differential bending capabilities

We present the design and development of a plant-inspired robot, named Plantoid, with sensorized robotic roots. Natural roots have a multi-sensing capability and show a soft bending behaviour to follow or escape from various environmental parameters (i.e., tropisms). Analogously, we implement soft bending capabilities in our robotic roots by designing and integrating soft spring-based actuation (SSBA) systems using helical springs to transmit the motor power in a compliant manner. Each robotic tip integrates four different sensors, including customised flexible touch and innovative humidity sensors together with commercial gravity and temperature sensors. We show how the embedded sensing capabilities together with a root-inspired control algorithm lead to the implementation of tropic behaviours. Future applications for such plant-inspired technologies include soil monitoring and exploration, useful for agriculture and environmental fields.

Clearance of HBV DNA in immunized children born to HBsAg-positive mothers, years after being diagnosed with occult HBV infection

In a previous study, we observed immunoprophylaxis failure due to occult hepatitis B virus (HBV) infection (OBI) despite the presence of adequate levels of anti-HBs in 21 (28%) of 75 children born to HBsAg-positive mothers. The aim of the study was to explore the maintenance of this cryptic condition in this population. Of 21 OBI-positive children, 17 were enrolled. HBV serological profiles were determined by enzyme-linked immunosorbent assay. Highly sensitive real-time and standard PCR followed by direct sequencing were applied in positive cases. The mean age (±SD) of studied patients was 6.57 ± 2.75 years. All children still were negative for HBsAg. All but one (94%) were negative for HBV DNA. Only two children were positive for anti-HBc. The results of the most recent anti-HBs titration showed that 4 (23.5%) and 13 (76.5%) had low (<10 IU/mL) and adequate (>10 IU/mL) levels of anti-HBs, respectively. The only still OBI-positive patient had an HBV DNA level of 50 copy/mL, carried the G145R mutation when tested in 2009 and again in 2013 in the 'a' determinant region of the surface protein. Further follow-up showed that after 18 months, he was negative for HBV DNA. In high-risk children, the initial HBV DNA positivity early in the life (vertical infection) does not necessarily indicate a prolonged persistence of HBV DNA (occult infection). Adequate levels of anti-HBs after vaccine and hepatitis B immune globulin immunoprophylaxis following birth could eventually clear the virus as time goes by. Periodic monitoring of these children at certain time intervals is highly recommended.

Early-onset Alzheimer's disease in two Iranian families: a genetic study

BACKGROUND

Early-onset Alzheimer's disease (EOAD) represents less than 5% of all AD cases. Autosomal dominant EOAD has been defined as the occurrence of at least three cases in three generations. Mutations in the amyloid precursor protein (APP), presenilin-1 and presenilin-2 genes have been recognized to be the cause of EOAD.

OBJECTIVE

We investigated the genotype of EOAD in two generations of two families with EOAD living in an Iranian village.

METHODS

The polymerase chain reaction method was used to study the presenilin-1 and APP genes in 25 subjects of these generations.

RESULTS

A guanine-to-adenine transition in exon 17 of the APP gene resulting in a valine-to-isoleucine substitution at codon 717 was detected in 14 subjects including 6 patients with EOAD.

CONCLUSION

This mutation demonstrates the importance of γ-secretase, the necessity of early detection of patients with memory decline in the susceptible population and raising public awareness of consanguinity marriages.

The relationship of thoracic kyphosis to gait performance and quality of life in women with osteoporosis

Thoracic kyphosis angle (TKA) increases with osteoporosis. This study aimed to investigate the relationship between magnitude of TKA and quality of life and gait performance in 34 osteoporotic women. Our results suggest that increasing TKA is significantly associated with decreasing quality of life (r = -0.48, p < 0.005) and gait performance (r = -0.74, p < 0.0005).

INTRODUCTION

Osteoporosis and its related effects are threatening health and quality of life especially in postmenopausal women. Increased thoracic kyphosis angle (TKA), as one of the most common adverse musculoskeletal changes, could be regarded as a quantitative index for osteoporotic patients' assessment. Dual digital inclinometer (DDI) is one of the latest tools for non-invasive TKA measurement. The main purpose of this study was to determine whether a relationship existed between the magnitude of TKA, gait performance, and quality of life in a group of osteoporotic women.

METHODS

Thirty-four osteoporotic women, aged 50-68, participated in this descriptive analytic study. The magnitude of TKA measured by using DDI and expressed as the kyphosis index (KI). Quality of life and gait performance were assessed using short form 36 (SF36) questionnaire and functional gait assessment test, respectively. Back extension range of motion (ROM) and back extensor strength were also assessed. Pearson's correlation test was used to analyze the data, with the significance level of p < 0.05.

RESULTS

The findings revealed a statistically significant negative correlation between KI and quality of life (r = -0.48, p < 0.005) and KI and gait performance (r = -0.74, p < 0.0005). There was also a significantly negative relation between KI and back extension ROM and back extensor strength (p < 0.05).

CONCLUSION

The results of this study demonstrated that increased thoracic kyphosis negatively affects gait performance and quality of life. This finding could be regarded as an important implication for therapist to pay more attention to the magnitude of thoracic kyphosis angle and its changes, when selecting appropriate therapeutic methods to improve gait performance and quality of life in osteoporosis women.

Study of antibacterial activity of Ag and Ag2CO3 nanoparticles stabilized over montmorillonite

Silver carbonate and silver nanoparticles (NPs) over of stabilizer montmorillonite (MMT) have been synthesized in aqueous and polyol solvent, respectively. Dispersions of silver nanoparticles have been prepared by the reduction of silver nitrate over of MMT in presence and absence of Na2CO3 compound in ethylene glycol. It was observed that montmorillonite was capable of stabilizing formed Ag nanoparticles through the reduction of Ag(+) ions in ethylene glycol. Na2CO3 was used as carbonate source in synthesis of Ag2CO3 NPs in water solvent and also for controlling of Ag nanoparticles size in ethylene glycol medium. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and ultraviolet-visible diffuse reflectance spectroscopy (DRS). The TEM images showed that Ag NPs size in presence Na2CO3 salts was smaller than without that. The results indicated intercalation of Ag and Ag2CO3 nanoparticles into the montmorillonite clay layers. The diffuse reflectance spectra exhibited a strong surface plasmon resonance (SPR) adsorption peak in the visible region, resulting from Ag nanoparticles. The antibacterial testing results showed that the Ag2CO3-MMT nanocomposite exhibited an antibacterial activity higher than Ag-MMT sample against Escherichia coli.

Relationship between disease activity and serum levels of vitamin D and parathyroid hormone in rheumatoid arthritis

OBJECTIVE

Measuring vitamin D and its regulating hormones in the serum might be an accurate method for assessment of rheumatoid arthritis (RA) activity. We tested the hypothesis that the serum levels of vitamin D and parathyroid hormone (PTH) are associated with the grade of disease activity in an unselected cohort of patients with RA.

METHODS

A total of 158 patients who met the American College of Rheumatology criteria for RA were examined and categorized as the patients with the active RA (n = 87) and silent RA (n = 71). Blood samples were obtained after at least eight-hour overnight fasting and the levels of 25-OH-vitamin D and PTH were measured.

RESULTS

The levels of the vitamin D in patients with active RA were significantly lower than in those with silent RA (49.38±38.21 versus 64.64±43.61 nmol/l; p = 0.022). The PTH serum level lower than the normal range (< 0.8 nmol/l) was statistically observed similar in the active RA group compared with another ones (10.3 % versus 4.2 %, p = 0.149). Serum levels of vitamin D and PTH were not influenced by patients' gender and age as well as the duration of disease.

CONCLUSION

Serum level of vitamin D was inversely related to RA activity and this relationship might be independent of PTH secretion or activity.

Synthesis and antioxidant evaluation of some novel ortho-hydroxypyridine-4-one iron chelators

A series of ortho-hydroxypyridine-4-ones were prepared in high yields and evaluated for antioxidant and iron chelating activities. N(1)-H hydroxypyridinones Va, Vb, and Ve were the best radical scavengers in DPPH free radical scavenging assay. Compound Vb was proved to be the most potent compound in hydrogen peroxide scavenging assay. All of the synthesized compounds had very close chelating ability, compounds containing N(1)-CH3 hydroxypyridinone ring were stronger chelating agents.

Effects of methanolic and butanolic fractions of Allium elburzense Wendelbo bulbs on blood glucose level of normal and STZ-induced diabetic rats

Allium elburzense (A. elborzense, Alliaceae), a plant rich in saponins, is an edible vegetable in northern Iran with a folk background use as antidiabetic which has not yet been examined for this indication. To evaluate the antidiabetic potential of A. elburzense, its hydroalcoholic (HdAE) and butanolic extracts (BuE) were examined. The acute (1, 2, 3, 4, 8 h) and sub-acute (11 days) effects of oral (p.o.) and intraperitoneal (i.p.) administration of HdAE and BuE of A. elburzense bulbs in different doses were evaluated on blood glucose levels of normal and streptozotocin (STZ, 55 mg/kg body weight)-induced diabetic rats. Glibenclamide (1 mg/kg b.w.) was used as reference drug. Sub-acute treatment with HdAE for 11 days reduced significantly blood glucose levels in diabetic rats (at least P<0.05), while BuE was effective only following i.p. administration (P<0.01). Acute administration did not reduce blood glucose level in normal and diabetic animals. It is concluded that HdAE of A. elburzense exhibited a significant antihyperglycemic activity following chronic administration. These results provide evidence for potential use of A. elburzense in diabetes mellitus considering the fact that this plant is endemic to a location of Iran where diabetes is a high prevalence disorder.

The effect of saffron, Crocus sativus stigma, extract and its constituents, safranal and crocin on sexual behaviors in normal male rats

In this study, the aphrodisiac activities of Crocus sativus stigma aqueous extract and its constituents, safranal and crocin, were evaluated in male rats. The aqueous extract (80, 160 and 320mg/kg body wt.), crocin (100, 200 and 400mg/kg body wt.), safranal (0.1, 0.2 and 0.4ml/kg), sildenafil (60mg/kg body wt., as a positive control) and saline were administered intraperitoneally to male rats. Mounting frequency (MF), intromission frequency (IF), erection frequency (EF), mount latency (ML), intromission latency (IL) and ejaculation latency (EL) were the factors evaluated during the sexual behavior study. Crocin, at all doses, and the extract, especially at doses 160 and 320mg/kg body wt., increased MF, IF and EF behaviors and reduced EL, IL and ML parameters. Safranal did not show aphrodisiac effects. The present study reveals an aphrodisiac activity of saffron aqueous extract and its constituent crocin.

Evaluation of intravenous hydrocortisone in reducing headache after spinal anesthesia: a double blind controlled clinical study [corrected]

BACKGROUND

Headache after spinal anesthesia is a common complication is patients undergoing this procedure. In this study we evaluated the efficacy of intravenous hydrocortisone in the treatment of headache after spinal anesthesia in women who have undergone cesarean section.

METHODS

Sixty patients with headache after spinal anesthesia were included. Patients randomly allocated into two groups, 30 patients received only conventional therapy (complete bed rest, hydration, acetaminophen and pethidine). Other 30 patients received conventional therapy plus intravenous hydrocortisone (200 mg first, then 100 mg TID for 48 hours). Mean (+/- SD) of headache intensity at 0, 6, 24, and 48 hours after beginning of treatment was measured using visual analog scale.

RESULTS

There was no significant difference in headache intensity between two groups before beginning of treatment. After 6 hours, the mean of headache intensity in 30 patients treated conventionally was 6.63 (+/- 1.35) while it was 2.77 (+/- 1.07) in other patients received intravenous hydrocortisone too (p <0.001). After 24 hours, mean headache intensity was 3.87 (+/- 1.63) in conventionally treated group versus 0.73 (+/- 0.74) in hydrocortisone group (p <0.001). After 48 hours, mean headache intensity was 1.87 (+/- 0.93) in conventionally treated group versus 0.63 (+/- 0.61) in hydrocortisone group (p = 0.001).

CONCLUSIONS

This study showed the therapeutic effects of intravenous hydrocortisone in reducing headache after spinal anesthesia in women who underwent cesarean section. Its mechanism of action is yet to be determined.

Highly selective thiocyanate membrane electrode based on butane-2,3-dione bis(salicylhydrazonato)zinc(II) complex

A highly selective poly(vinyl chloride) (PVC) membrane electrode based on butane -2,3-dione bis(salicylhydrazonato) zinc(II) [Zn (BDSH)] complex as carrier for thiocyanate-selective electrode is reported. The influence of membrane composition, pH and possible interfering anions were investigated on the response properties of the electrode. The sensor responds to thiocyanate in linear range from 1.0x10(-6) to 1.0x10(-1)M with a slope -56.5+/-1.1mVdecade(-1), over a wide pH range of 3.5-8.5. The limit of detection of the electrode was 7.0x10(-7)M SCN(-). Selectivity coefficients determined with fixed interference method (FIM) indicate a good discriminating ability towards SCN(-) ion in comparison to other anions. The proposed sensor has a fast response time of about 5-15s and can be used for at least 3 months without any considerable divergence in potential. It was applied as indicator electrode in titration of thiocyanate with Ag(+) and in potentiometric determination of thiocyanate in saliva and urine samples.

Attenuating mutations in coxsackievirus B3 map to a conformational epitope that comprises the puff region of VP2 and the knob of VP3

Ten antibody escape mutants of coxsackievirus B3 (CVB3) were used to identify nucleotide substitutions that determine viral virulence for the heart and pancreas. The P1 region, encoding the structural genes of each mutant, was sequenced to identify mutations associated with the lack of neutralization. Eight mutants were found to have a lysine-to arginine mutation in the puff region of VP2, while two had a glutamate-to-glycine substitution in the knob of VP3. Two mutants, EM1 and EM10, representing each of these mutations, were further analyzed, initially by determining their entire sequence. In addition to the mutations in P1, EM1 was found to have two mutations in the 3D polymerase, while EM10 had a mutation in stem-loop II of the 5' nontranslated region (5'NTR). The pathogenesis of the mutants relative to that of CVB3 strain RK [CVB3(RK)] then was examined in A/J mice. Both mutants were found to be less cardiotropic than the parental strain, with a 40-fold (EM1) or a 100- to 1,000-fold (EM10) reduction in viral titers in the heart relative to the titers of CVB3(RK). The mutations in VP2, VP3, and the 5'NTR were introduced independently into the RK infectious clone, and the phenotypes of the progeny viruses were determined. The results substantiated that the VP2 and VP3 mutations reduced cardiovirulence, while the 5'NTR mutation in EM10 was associated with a more virulent phenotype when expressed on its own. Stereographic imaging of the two mutations in the capsomer showed that they lie in close proximity on either side of a narrow cleft between the puff and the knob, forming a conformational epitope that is part of the putative binding site for coreceptor DAF.