Which are best for successful aging prediction? Bagging, boosting, or simple machine learning algorithms?

BACKGROUND

The worldwide society is currently facing an epidemiological shift due to the significant improvement in life expectancy and increase in the elderly population. This shift requires the public and scientific community to highlight successful aging (SA), as an indicator representing the quality of elderly people's health. SA is a subjective, complex, and multidimensional concept; thus, its meaning or measuring is a difficult task. This study seeks to identify the most affecting factors on SA and fed them as input variables for constructing predictive models using machine learning (ML) algorithms.

METHODS

Data from 1465 adults aged ≥ 60 years who were referred to health centers in Abadan city (Iran) between 2021 and 2022 were collected by interview. First, binary logistic regression (BLR) was used to identify the main factors influencing SA. Second, eight ML algorithms, including adaptive boosting (AdaBoost), bootstrap aggregating (Bagging), eXtreme Gradient Boosting (XG-Boost), random forest (RF), J-48, multilayered perceptron (MLP), Naïve Bayes (NB), and support vector machine (SVM), were trained to predict SA. Finally, their performance was evaluated using metrics derived from the confusion matrix to determine the best model.

RESULTS

The experimental results showed that 44 factors had a meaningful relationship with SA as the output class. In total, the RF algorithm with sensitivity = 0.95 ± 0.01, specificity = 0.94 ± 0.01, accuracy = 0.94 ± 0.005, and F-score = 0.94 ± 0.003 yielded the best performance for predicting SA.

CONCLUSIONS

Compared to other selected ML methods, the effectiveness of the RF as a bagging algorithm in predicting SA was significantly better. Our developed prediction models can provide, gerontologists, geriatric nursing, healthcare administrators, and policymakers with a reliable and responsive tool to improve elderly outcomes.

Establishing machine learning models to predict the early risk of gastric cancer based on lifestyle factors

BACKGROUND

Gastric cancer is one of the leading causes of death worldwide. Screening for gastric cancer greatly relies on endoscopy and pathology biopsy, which are invasive and pose financial burdens. Thus, the prevention of the disease by modifying lifestyle-related behaviors and dietary habits or even the prevention of risk factor formation is of great importance. This study aimed to construct an inexpensive, non-invasive, fast, and high-precision diagnostic model using six machine learning (ML) algorithms to classify patients at high or low risk of developing gastric cancer by analyzing individual lifestyle factors.

METHODS

This retrospective study used the data of 2029 individuals from the gastric cancer database of Ayatollah Taleghani Hospital in Abadan City, Iran. The data were randomly separated into training and test sets (ratio 0.7:0.3). Six  ML methods, including multilayer perceptron (MLP), support vector machine (SVM) (linear kernel), SVM (RBF kernel), k-nearest neighbors (KNN) (K = 1, 3, 7, 9), random forest (RF), and eXtreme Gradient Boosting (XGBoost), were trained to construct prognostic models before and after performing the relief feature selection method. Finally, to evaluate the models' performance, the metrics derived from the confusion matrix were calculated via a test split and cross-validation.

RESULTS

This study found 11 important influence factors for the risk of gastric cancer, such as Helicobacter pylori infection, high salt intake, and chronic atrophic gastritis, among other factors. Comparisons indicated that the XGBoost had the best performance for the risk prediction of gastric cancer.

CONCLUSIONS

The results suggest that based on simple baseline patient data, the ML techniques have the potential to start the prescreening of gastric cancer and identify high-risk individuals who should proceed with invasive examinations. Our model could also considerably lessen the number of cases that need endoscopic surveillance. Future studies are required to validate the efficacy of the models in a larger and multicenter population.

Pre-Exposure to Radiofrequency Electromagnetic Fields and Induction of Radioadaptive Response in Rats Irradiated with High Doses of X-Rays

Background

Some evidence shows that a pre-exposure to RF can mitigate the effects of subsequent exposures to high doses of ionizing radiation.

Objective

We aimed to assess the effect of a pre-exposure to non-ionizing RF radiation on survival, weight changes, food consumption, and water intake of lethally irradiated rats.

Material and Methods

In this case-control study, we used a commercial mobile phone (GSM, 900/1800 MHz) as well as a 2.4 GHz Wi-Fi router as the sources of pre-exposure to RF radiation. Forty-eight rats were randomly divided into six groups of control, "8 Gy X-rays", mobile phone, "mobile phone+8 Gy", Wi-Fi, and "Wi-Fi+8 Gy". Then, the survival fraction, weight loss, water, and food consumption changes were compared in different groups.

Results

The survival analysis indicated that the survival rates in all of the exposed animals ("8 Gy X-rays", "mobile phone+8 Gy", "Wi-Fi+8 Gy") were significantly lower than the control, "Wi-Fi", and "mobile phone" groups. The changes in survival rates of "mobile+8 Gy", "Wi-Fi+8 Gy", and 8 Gy alone were not statistically significant. However, food and water intake were significantly affected by exposure to both RF pre-exposures and exposure to high dose ionizing radiation.

Conclusion

To the best of our knowledge, the existence of a dose window for the induction of AR can be the cause of the lack of AR in our experiment. Our findings confirm that in a similar pattern with the adaptive responses induced by pre-exposure to ionizing radiation, the induction of adaptive response by RF-pre-exposures requires a minimum level of damage to trigger adaptive phenomena.

Developing the minimum data set of the corrosive ingestion registry system in Iran

Background

Corrosive ingestion is still a major health problem, and its outcomes are often unpredicted. The implementation of a registry system for poisoning with corrosive substances may improve the quality of patient care and might be useful to manage this type of poisoning and its complications. Therefore, our study aimed to establish a minimum data set (MDS) for corrosive ingestion.

Methods

This was an applied study performed in 2022. First, a literature review was conducted to identify the potential data items to be included in the corrosive ingestion MDS. Then, a two-round Delphi survey was performed to attain an agreement among experts regarding the MDS content, and an additional Delphi step was used for confirming the final MDS by calculating the individual item content validity index (CVI) and content validity ratio (CVR) and by using other statistical tests.

Results

After the literature review, 285 data items were collected and sent to a two-round Delphi survey in the form of a questionnaire. In total, 75 experts participated in the Delphi stage, CVI, kappa, and CVR calculation. Finally, the MDS of the corrosive ingestion registry system was identified in two administrative and clinical sections with 21 and 152 data items, respectively.

Conclusions

The development of an MDS, as the first and most important step towards developing the corrosive ingestion registry, can become a standard basis for data collection, reporting, and analysis of corrosive ingestion. We hope this MDS will facilitate epidemiological surveys and assist policymakers by providing higher quality data capture to guide clinical practice and improve patient-centered outcomes.

Design, development, and evaluation of a surveillance system for suicidal behaviors in Iran

BACKGROUND

Suicide is a serious cause of morbidity and mortality in Iran and worldwide. Although several organizations gather information on suicide and suicide attempts, there is substantial misperception regarding the description of the phenomenon. This study proposes the minimum data set (MDS) for suicidal behaviors surveillance.

METHODS

A literature review was first conducted to achieve a thorough overview of suicide-related items and map the existing evidence supporting the development of the MDS. The data items included in the literature review were then analyzed using a two-round Delphi technique with content validation by an expert panel. The suicidal behaviors surveillance system was then established based on the confirmed MDS, and ultimately, its performance was assessed by involving the end-users.

RESULTS

The panel of experts consisted of 50 experts who participated in the Delphi phase and validity content review. Of these, 46% were men, and their mean age and average work experience were (36.4, SD ± 6.4) and (12.32, SD ± 5.2) years, respectively. The final MDS platform of our study contained 108 items classified into eight main categories. A web-based system with a modular and layered architecture was developed based on the derived MDS.

CONCLUSION

The developed system provides a framework for recording suicidal behaviors' data. The integration of multiple suicide-related information systems at the regional and national levels makes it possible to assess the long-term outcomes and evolutions of suicide prevention interventions.

Predictive modeling for COVID-19 readmission risk using machine learning algorithms

Introduction

The COVID-19 pandemic overwhelmed healthcare systems with severe shortages in hospital resources such as ICU beds, specialized doctors, and respiratory ventilators. In this situation, reducing COVID-19 readmissions could potentially maintain hospital capacity. By employing machine learning (ML), we can predict the likelihood of COVID-19 readmission risk, which can assist in the optimal allocation of restricted resources to seriously ill patients.

Methods

In this retrospective single-center study, the data of 1225 COVID-19 patients discharged between January 9, 2020, and October 20, 2021 were analyzed. First, the most important predictors were selected using the horse herd optimization algorithms. Then, three classical ML algorithms, including decision tree, support vector machine, and k-nearest neighbors, and a hybrid algorithm, namely water wave optimization (WWO) as a precise metaheuristic evolutionary algorithm combined with a neural network were used to construct predictive models for COVID-19 readmission. Finally, the performance of prediction models was measured, and the best-performing one was identified.

Results

The ML algorithms were trained using 17 validated features. Among the four selected ML algorithms, the WWO had the best average performance in tenfold cross-validation (accuracy: 0.9705, precision: 0.9729, recall: 0.9869, specificity: 0.9259, F-measure: 0.9795).

Conclusions

Our findings show that the WWO algorithm predicts the risk of readmission of COVID-19 patients more accurately than other ML algorithms. The models developed herein can inform frontline clinicians and healthcare policymakers to manage and optimally allocate limited hospital resources to seriously ill COVID-19 patients.

Establishing a minimum data set for suicide and attempted suicide registry system in Iran

BACKGROUND

Suicidal behavior is a major cause of mortality and disability worldwide. Accurate and consistent collection of data on suicide, suicide ideation, and suicide attempts presents many challenges for public health practitioners, policymakers, and researchers. This study aimed to establish a minimum data set (MDS) for integrating data across suicide registries and other data sources.

METHODS

The MDS proposed in this study was developed in two-stepwise stages. First, an extensive literature review was performed in order to identify the potential data items. Then, we conducted a two-round Delphi stage to reach a consensus among experts regarding essential data items and a supplementary one-round Delphi stage for validating the content of the final MDS by calculating the individual item content validity index (CVI) and content validity ratio (CVR) and using other statistical tests.

RESULTS

After the literature review, 189 data items were extracted and sent to a panel of experts in the form of a questionnaire. In the Delphi stage and CVI calculation, 55 and 10 experts participated in kappa and CVR calculation, respectively. Finally, the MDS of the suicide registry was finalized with 84 data elements that were classified into four categories, including patient profile, socio-economic status, clinical and psychopathological status, and suicide circumstances.

CONCLUSIONS

The suicide MDS can become a standardized and consistent infrastructure for meaningful evaluations, reporting, and benchmarking of suicidal behaviors across regions and countries. We hope this MDS will facilitate epidemiological surveys and support policymakers by providing higher quality data capture to guide clinical practice and improve patient-centered outcomes.

Development and evaluation of an electronic nursing documentation system

Background

Nursing documentation is a critical aspect of the nursing care workflow. There is a varying degree in how detailed nursing reports are described in scientific literature and care practice, and no uniform structured documentation is provided. This study aimed to describe the process of designing and evaluating the content of an electronic clinical nursing documentation system (ECNDS) to provide consistent and unified reporting in this context.

Methods

A four-step sequential methodological approach was utilized. The Minimum Data Set (MDS) development process consisted of two phases, as follows: First, a literature review was performed to attain an exhaustive overview of the relevant elements of nursing and map the available evidence underpinning the development of the MDS. Then, the data included from the literature review were analyzed using a two-round Delphi study with content validation by an expert panel. Afterward, the ECNDS was developed according to the finalized MDS, and eventually, its performance was evaluated by involving the end-users.

Results

The proposed MDS was divided into administrative and clinical sections; including nursing assessment and the nursing diagnosis process. Then, a web-based system with modular and layered architecture was developed based on the derived MDS. Finally, to evaluate the developed system, a survey of 150 registered nurses (RNs) was conducted to identify the positive and negative impacts of the system.

Conclusions

The developed system is suitable for the documentation of patient care in nursing care plans within a legal, ethical, and professional framework. However, nurses need further training in documenting patient care according to the nursing process, and in using the standard reporting templates to increase patient safety and improve documentation.

Meta-analysis: COVID-19 diagnosis in chest CT—master key for radiologists

Background

COVID-19 was discovered in February in China. Due to the high prevalence of the disease, early detection and rapid isolation of patients are the vital points for controlling the outbreak. The purpose of this study was to determine the correct location of chest CT scan in the diagnosis of COVID-19.

Main text

The current study is a systematic review and meta-analysis. 2959 papers were found in all national and international databases. The study has been reported based on the PRISMA checklist. All analyses were done by CMA Ver. 2 software. The statistical analysis results show that the GGO observation level in the available shape was 46% in CT scan results, and the consolidation observation level in the general form was 33% in CT scan results. Pleural effusion was 7%, and linear opacity observation level was 24% in CT scan results in the general form. The CT scan test sensitivity level was gained 94.7%, and PCR test sensitivity level was achieved as 94.8%. This level was 89% in the early stage.

Conclusion

The chest CT has about 24% higher diagnostic sensitivity than the PCR test, in the early stage. GGO revealed a declining process and also indicates that GGO is an early symptom of the disease in CT scan. Linear opacity is the reason behind the initial dyspnea in coronavirus suffering patients referring to the medical centers. The extra-pulmonary lesions increase in the last stage of the disease that makes the patient’s worse.

Supplementary Information

The online version contains supplementary material available at 10.1186/s43055-021-00457-6.

Case report: Diagnosis and emergency surgery on a young patient with extensive aortic dissection without any risk factors

Background

Type A aortic dissection is a very dangerous, fatal, and emergency condition for surgery. Acute aortic dissection is a rare condition, such that many patients will not survive without reconstructive surgery.

Case presentation

We present a case 24-year-old male who came with symptoms of shortness of breath and cough. The patient underwent ECG, chest radiology, and ultrasound, where the patient was found to have right pleural effusion while his ECG was normal. In the history taken from the patient, he had no underlying disease, no history of heart diseases in his family. For a better diagnosis, ETT and aortic CT angiography was performed on the patient which confirmed the evidence of dissection. Immediately after the diagnosis, necessary arrangements were made for open heart surgery and the patient was prepared for surgery. The patient was admitted in the cardiac surgery ICU for 5 days and his medication was carefully administered. After the conditions were stabilized, the patient was transferred to the post-cardiac surgery ICU ward. The patient was discharged from the hospital one week after the surgery and returned to the office as an OPD one week after his discharge.

Conclusion

Various risk factors can play a role in creating aortic dissection. Therefore, it is necessary to pay attention to patients’ history for achieving a quick and definitive diagnosis. Therefore, to control the complications of placing the cannula as well as the duration of the surgery, it is very important to reduce the duration of pumping on the patient and to be very careful during the cannula placement.

Can healthy life style predict successful aging among Iranian older adults?

Background: Successful aging is a prominent and worldwide theme in gerontology. However, until recently, only few studies were conducted about successful aging in Iran. This study examined whether a healthy lifestyle could predict successful aging among older Iranians.

Methods: This cross sectional and descriptive study included 975 older Iranians who were selected through a multistage cluster-quota method from the health centers of Shiraz, Iran. A 5-part questionnaire, including demographic characteristics, the Seniors’ Healthy Lifestyle, Barthel Index, the Diner Life Satisfaction and Quality of Life, was used to collect the data. A logistic regression analysis was used in data analysis; data were analyzed using SPSS 21; and significance level was set at α = 0.05.

Results: The prevalence of successful aging among older Iranians was calculated at 24.0%. Results of multiple logistic regression analysis revealed that age (95% CI = 1.129- 1.702 and OR = 1.352), gender (95% CI = 0.412-0.764 and OR = 0.687), education level (95% CI = 1.443 – 1.699 and OR = 1.454), job (95% CI = 1.063-1.413 and OR = 1.185), monthly income (95% CI = 1.355-4.055 and OR = 2.272), insurance (95% CI = 0.344-0.842 and OR = 0.540), source of income (95% CI = 1.014-1.298 and OR = 1.145), and healthy lifestyle (95% CI = 0.772 - 0.858 and OR = 0.814) were predictors for successful aging.

Conclusion: Findings indicated that successful agers were mostly younger men, with higher education level and monthly income, who had insurance and a job and a healthy lifestyle. Thus, to age successfully, one must maintain and improve healthy lifestyle to prolong one’s health.

The effect of fatty meal and water on interfering extracardiac activity in myocardial perfusion single-photon emission computed tomography

Background

There are several ways to diagnose coronary artery disease. Myocardial perfusion imaging (MPI) is used for the diagnosis of coronary artery disease. One of the practical challenges in scan’s interpretation is interfering liver radiotracer uptake with appropriate cardiac visualization. For many years, different approaches were evaluated for conquering this problem. A relatively common method is using fat-containing meals before imaging. Fatty meals may cause some problems for some patients, especially elderly with digestive disorders, as well as an extra cost. We designed a study to compare the efficacy of water and fatty meal as a liver clearing agents to facilitate MPI results interpretation.

Result

Totally, 30 patients (consist of 30 stress phases and 30 rest phases), including 18 women and 12 men, were evaluated. The fatty meal was used before 32 scans and cold water in the other 28 scans. Finally, 40 scans had the suitable quality for reporting by nuclear physicians among 60 scans, which included 20 of 28 scans with water and 20 of 32 scans with a fatty meal.

Conclusions

This comparison showed that scans performed with the water group had similar results with the fatty meal group. Water is better than fatty meals because of its ease of use and lower cost. Therefore, the use of water can be a good alternative for routine use in NM centers.

Combined Effects of Radiofrequency Electromagnetic Fields and X-Ray in Renal Tissue and Function

PURPOSE

Biochemical and histopathological properties of renal tissues were reported to be affected by both radiofrequency electromagnetic fields (RF-EMF) and ionizing radiation. The radiation-induced changes in the kidney, including the serum levels of blood urea nitrogen (BUN) and creatinine (Cr), could lead to adverse health outcomes such as chronic kidney disease. These complications signify the importance of the research in this field. Thus, in this study, the effects of ionizing and non-ionizing radiations, as well as their combination, were assessed by evaluating the alteration in BUN, Cr, and histopathological changes in kidney tissue.

MATERIALS AND METHODS

Ninety-six male Wistar rats were randomly divided into six groups and were exposed to either 900/1800MHz (mobile phone) or 2.4 GHz RF-EMF (Wi-Fi) radiation for 14 days, 8Gy x-ray, or their combination. Sera were collected from 2 mL of rat blood, then BUN and Cr levels were determined. Also, renal samples were stained with hematoxylin and eosin and evaluated histopathologically.

RESULTS

Both BUN and Cr levels raised non-significantly after exposure to 8 Gy x-rays. Moreover, all measurements in the samples of x-ray groups were in borderline or higher than normal values. The BUN levels of control, Wi-Fi, x-ray, and Wi-Fi+x-ray groups were not significantly different. However, Cr levels in the Wi-Fi group were significantly higher than those of the controls, and BUN to Cr ratio levels were significantly lower than those of the controls. Also, tubular atrophy and vessel wall thickening were associated with these exposures.

CONCLUSION

Exposure to 900/1800MHz, 2400 MHz EMF can alter the kidney function. However, pre-exposure to 900/1800MHz EMF could modulate the acute adverse effects of lethal x-ray dose, which addresses the adaptive response in the kidney.

Assessment of function, histopathological changes, and oxidative stress in liver tissue due to ionizing and non-ionizing radiations

BACKGROUND

Compared to past decades, humans are exposed to rapidly increasing levels of radiofrequency electromagnetic radiations (RF-EMF). Despite numerous studies, the biological effects of human exposure to different levels of RF-EMF are not fully understood yet. This study aimed to evaluate the bioeffects of exposure to "900/1800 MHz" and "2.4 GHz" RF-EMFs, and x-rays alone as well as their potential interactions, i.e. inducing simple additive, adaptive, or synergistic effects.

METHODS

120 Wistar rats were randomly divided into ten groups of 12 each. The rats were exposed to RF-EMF, 10 cGy, and 8 Gy x-rays, a combination of these exposures, or only sham-exposed. The levels of liver enzymes were determined in serum samples by an auto-analyzer. Moreover, the histopathological changes, and the levels of malondialdehyde (MDA), nitric oxide, ferric reducing antioxidant power, total thiols, and protein carbonyl (PCO) were measured.

RESULTS

Among the markers of liver function, gamma-glutamyltransferase was not associated with irradiation but, aspartate transaminase, alanine transaminase, and alkaline phosphatase showed some levels of association. MDA and PCO levels after 8 Gy irradiation increased, but pre-exposure to RF-EMF could modulate their changes. At the cellular level, the frequency of lobular inflammation was associated with the type of intervention.

CONCLUSION

The exposure to both ionizing and non-ionizing radiations could alter some liver function tests. A short term pre-exposure to RF-EMF before exposure to an 8 Gy challenging dose of x-rays caused the alterations in oxidative stress markers and liver function tests, which indicate that oxidative stress is possibly involved in the adaptive response.

Exploring Changes in Thalamus Metabolites as Diagnostic Biomarkers in Idiopathic Generalised Epilepsy Patients Using Magnetic Resonance Spectroscopy

Introduction

Idiopathic generalised epilepsy (IGE) refers to a group of epilepsies resulting from the activation of neurons in the whole brain. This study aimed to evaluate the metabolite changes in thalamus as diagnostic biomarkers in IGE patients compared to healthy individuals using magnetic resonance spectroscopy (MRS) technique.

Methods

The MRS was performed on 35 IGE patients (26 women and 11 men) with average age of 32 (ranged from 18 to 43) and 35 healthy individuals (13 women and 22 men) with average age of 31 (ranged from 21 to 50) as the control group. The levels of N-acetylaspartate (NAA), creatine (Cr) and choline (Cho) were measured using MRS. The NAA/Cr and NAA/Cho ratios were calculated for all participants. These values were statistically compared using t-test between the groups.

Results

The NAA had significant lower values in IGE patients, 9.6 (SD = 0.8) and 9.9 (SD = 0.7) for right and left thalamus, respectively, compared to 10.9 (SD = 0.9) and 10.7 (SD = 0.9) in control group. The Cr values in the left side of thalamus were significantly higher in IGE patients (6.7 [SD = 0.8] versus 5.8 [SD = 0.5]); however, there was no difference in right thalamus. Measurements showed no difference for amounts of Cho between the groups in both sides of thalamus. The NAA/Cr ratio was 1.48 (SD = 0.14) and 1.48 (SD = 0.16) for right and left thalamus, respectively, in IGE patients in comparison with 1.83 (SD = 0.2) and 1.86 (SD = 0.26) in controls. There was no meaningful variation between the NAA/Cho ratio of the right and left thalamus among the groups.

Conclusion

Thalamic NAA, Cr and NAA/Cr ratio values in IGE patients showed statistical differences compared to healthy individuals. Evaluating metabolites variations in thalamus using MRS is suggested for differentiating IGE patients from healthy individuals.

Chromosomal aberrations in C-arm fluoroscopy, CT-scan, lithotripsy, and digital radiology staff

We have assessed chromosome-type aberrations and micronuclei in the peripheral lymphocytes of personnel working with C-arm fluoroscopy, multi-slice CT-scan, lithotripsy, and digital radiology medical procedures. The study population comprised of 46 exposed workers and 35 controls matched for age, gender, and other confounding factors. Chromosome-type aberrations and micronuclei were analyzed and compared with occupational dosimetry data. The highest frequency of both chromosome aberrations (1.62 CA/100 cells) and MN (MN = 7.47 ± 2.55) was observed in the operating room group. According to occupational dosimetry, surgeons and medical staff received 0-2.99 mSv over the previous year, well below the limit established by the International Committee on Radiation Protection. An increased level of chromosomal aberrations was observed among workers exposed in the operating rooms. We recommend that operating room radiation safety programs be improved and better supervised, in particular for orthopedic surgeons and personnel performing fluoroscopically guided procedures.

A study to assess the knowledge and practice of medical professionals on radiation protection in interventional radiology

OBJECTIVE

Ionizing radiation has been extensively used in medical procedures throughout the world. Such interventional radiological procedures could result in occupational exposure that needs urgent control. Therefore, MPs (medical professionals) should receive education and appropriate training on occupational radiation protection. In this context, the present study is aimed to investigate the MPs' knowledge and practice regarding radiation protection principles during interventional radiological procedures.

MATERIAL AND METHODS

A descriptive questionnaire-based study was carried out among 215 MPs involved in interventional fluoroscopy procedures. The practice of 31 MPs was studied using a checklist based on ALARA principles and ICRP guidelines.

RESULTS

A total of 43.3% and 45.1% answered correctly for knowledge and practice. However, the difference between radiation protection knowledge and practice between the physicians and nurses was statistically significant. The knowledge and practice survey of MPs demonstrated that nurses rarely adhered to radiation-protection measures.

CONCLUSION

The present study reflects the lack of knowledge and practice concerning radiation protection concepts among the nurses. This deficiency needs to be resolved by periodic practical radiation protection courses in the curriculum of medicine.

Association of dietary patterns and risk of cardiovascular disease events in the MASHAD cohort study

BACKGROUND

Cardiovascular disease (CVD) is the principal cause of mortality and disability in Iranian adults. We aimed to evaluate the relationship between dietary patterns and CVD incidence in a large sample of adults in northeastern Iran.

METHODS

The present study comprised a prospective study of 5706 CVD-free men and women aged 35-65 years who participated in a cohort study. All of the participants were followed up for a 6-year period. Dietary patterns were derived from a 65-item validated food frequency questionnaire and the factor analysis method was used to determine dietary patterns.

RESULTS

We identified two major dietary patterns: (i) a Balanced dietary pattern (a high intake of green leafy vegetables, other vegetables, fruits, dairy products, red meats, poultry, seafoods, legumes and nuts, as well as a low intake of sugar) and (ii) a Western dietary pattern (a high intake of sugar, tea, egg, snacks, fast foods, potato, carbonated beverages, pickled foods, organs meat and butter) by factor analysis. The hazard ratio (HR) and 95% confidence intervals (CIs) of total CVD in the highest versus lowest tertiles of the Balanced pattern were 1.29 (95% CI = 0.67-2.47; P = 0.44). The HR and 95% CIs of CVD in the highest versus lowest tertiles of Western pattern were 2.21 (95% CI = 1.08-4.45; P = 0.03).

CONCLUSIONS

During the 6-year follow-up, we found that adherence to a Balanced dietary pattern was not significantly associated with CVD events. However, adherence to a Western dietary pattern was associated with a significantly increased risk of CVD events and its associated risk.

Determination of intra-axial brain tumors cellularity through the analysis of T2 Relaxation time of brain tumors before surgery using MATLAB software

Introduction

Timely diagnosis of brain tumors could considerably affect the process of patient treatment. To do so, para-clinical methods, particularly MRI, cannot be ignored. MRI has so far answered significant questions regarding tumor characteristics, as well as helping neurosurgeons. In order to detect the tumor cellularity, neuro-surgeons currently have to sample specimens by biopsy and then send them to the pathology unit. The aim of this study is to determine the tumor cellularity in the brain.

Methods

In this cross-sectional study, 32 patients (18 males and 14 females from 18–77 y/o) were admitted to the neurosurgery department of Shohada-E Tajrish Hospital in Tehran, Iran from April 2012 to February 2014. In addition to routine pulse sequences, T2W Multi echo pulse sequences were taken and the images were analyzed using the MATLAB software to determine the brain tumor cellularity, compared with the biopsy

Results

These findings illustrate the need for more T2 relaxation time decreases, the higher classes of tumors will stand out in the designed table. In this study, the results show T2 relaxation time with a 85% diagnostic weight, compared with the biopsy, to determine the brain tumor cellularity (p<0.05).

Conclusion

Our results indicate that the T2 relaxation time feature is the best method to distinguish and present the degree of intra-axial brain tumors cellularity (85% accuracy compared to biopsy). The use of more data is recommended in order to increase the percent accuracy of this techniques.

Evaluation of miR-146a expression level in macrophages exposed to Candida glabrata

Background and Purpose:

MicroRNAs are small non-coding RNAs with 19-24 nucleotides in length. Up- or down-regulation of many miRNAs has been shown by stimulation of Toll-like receptors (TLRs) in the innate immune system. Up-regulation of miR-146a has been reported by both TLR and heat-killed Candida albicans. In this study, we aimed to evaluate the expression of miR-146a in cultured monocyte-derived macrophages (MDMs) infected by Candida glabrata at 12, 24, and 48 hours.

Materials and Methods:

miR-146a expression was evaluated by qRT-real time polymerase chain reaction (PCR) at three time points in C. glabrata-infected MDMs. The data was analyzed using repeated measures ANOVA.

Results:

miR-146a expression was down-regulated in infected MDMs compared to the control group (P<0.018). The expression of miR-146a was at its highest level at 48 h, as compared to 12 and 24 h (P<0.018) .The differences between the experimental group compared to the control group were statistically significant (P<0.018).

Conclusion:

These results suggest that miR-146a can be involved in regulating macrophage function following TLR stimulation in C. glabrata-infected MDMs.

Hematological Findings in Medical Professionals Involved at Intraoperative Fluoroscopy

<p>Medical professionals involved at intraoperative fluoroscopy are exposed to low doses of the occupational radiation exposures. The biological effects of chronic low-dose radiation on human health are complex and have not been well established. The aim of the present study is to follow up hematological parameter changes during 2 years in medical professionals exposed to ionization radiation in operating rooms.<strong></strong></p><p>22 medical professionals (medical specialists and technicians), chronically exposed to ionizing radiation of mobile C-Arm X ray machine, were selected. The seven hematological parameters were examined each time. The statistical analyses were done by Student’s t test and one way ONOVA test.</p><p>The data analysis led to the following observations: (1) the present study incorporated that the basic hematological parameters including the mean value of red blood cells (P=0.90), white blood cells (P=0.68), and platelets count (P=0.45) did not show a significant difference between two years. (2) The mean values corpuscular hemoglobin concentration, corpuscular hemoglobin, and hematocrit parameters were found disturbed low or high in some of medical professionals but their means were not significantly different between two measurements. (3)A statistically significant relation in mean value of RBCs with the duration of exposure and sex were observed.</p><p>It seems that, hematological parameters survey could not be a reliable test as the biological indicator of long term exposure to very low dose of radiation exposure in medical professionals which their physical dosimetry values are lower than dose limits. </p>

Efficacy of Eye Movements Desensitization and Reprocessing on the Quality of Life of the Patients with Myocardial Infarction

<p>Myocardial infarction causes limitations in the physical activity and perturbation of quality of life.The aim of this study was to evaluate the effect of eye movements desensitization and reprocessing (EMDR) on the quality of life of these patients. This study was conducted in two groups as the before and after while the effect of eye movements desensitization and reprocessing on the quality of life of the patients with Myocardial infarction. Sampling was done based on the purposive sampling. Patients were randomly divided into two experimental and control groups (30 patients in each group). Samples were assigned through randomized allocation. In the experimental group, the EMDR method was carried out on the patients in five 90-minute sessions over a two week period. In the control group no intervention was received. Data of Quality of life, pre-treatment, post-treatment were analyzed using SPSS. The results showed that the quality of life increase in all its dimensions of the experimental group, after performing the EMDR therapy significantly (P=0.001). Treatment what has already been stated, was effective on the quality of life in patients. Treatment team members can use this method as an effective intervention in order to improve the quality of life of their patients.</p>

Analysis of survival data in thalassemia patients in Shiraz, Iran

OBJECTIVES

The survival rate of thalassemia patients has not been conclusively established, and the factors associated with survival remain unclear. This study aimed to determine the survival rate of thalassemia among patients in southern Iran and to identify the factors associated with mortality from thalassemia.

METHODS

This retrospective cohort study was conducted based on a retrospective review of the medical records of 911 beta-thalassemia patients in 2014. Data analysis was conducted using the Kaplan-Meier method and Cox regression analysis.

RESULTS

Overall, 212 patients (23.3%) died, and 26.8% had thalassemia intermedia. The 20-year, 40-year, and 60-year survival rates were 85%, 63%, and 54%, respectively. Both crude and adjusted analyses found that education, marital status, ferritin levels, and comorbidities were related to mortality.

CONCLUSIONS

Sociodemographic and hematological factors were found to be significantly associated with the survival rate of thalassemia. Addressing these factors may help healthcare providers and physicians to provide the best possible care and to improve the survival rate.

Gas barrier and mechanical properties of crosslinked ethylene vinyl acetate nanocomposites

In this research, the effects of crosslinking agent and clay content on the morphology, barrier and mechanical properties of ethylene vinyl acetate-organoclay nanocomposites prepared by solution method were studied. Dicumyl peroxide has been used as crosslinking agent. The morphology of the prepared nanocomposites was investigated using wide-angle X-ray diffraction and transmission electron microscopy. Wide-angle X-ray diffraction and transmission electron microscopyindicated that the prepared nanocomposites had predominantly intercalated morphologies. The obtained results of permeability tests showed that the permeability of ethylene vinyl acetate films dramatically decreases with addition of organoclay and dicumyl peroxide. Mechanical tests showed that tensile modulus and tensile strength of ethylene vinyl acetate increase with addition of organoclay. Furthermore, the mechanical properties of ethylene vinyl acetate nanocomposites significantly improved in presence of crosslinking agent (dicumyl peroxide).

An integrated Shannon's Entropy-TOPSIS methodology for environmental risk assessment of Helleh protected area in Iran

This study aims to use integrated Shannon's Entropy-TOPSIS methodology for environmental risk assessment of the Helleh protected area in Iran. In this research, first, with regard to field visits, interview with natives of the area, and investigation of the environment of the study area, the risks existing in the region were identified. Then, for final identification of the risks, the Delphi method was applied. Analysis and prioritization of risks of the area of Helleh were performed by multi-criteria decision-making methods of Shannon's Entropy and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). In this research, risks were assessed by three criteria of severity, probability of occurrence, and vulnerability. Twenty six of the risks were identified which were specified in two groups, natural events and environmental risks. The environmental ones were classified into four groups: physicochemical, biological, social-economic, and cultural. Results of the research showed that the construction of the Rayis-Ali-Delvari Dam at the upper part of the study area threatens the wetland. Water supply for the dam 75 km away from the area with concession of 0.9999 holds the first priority of risk-generating factors. Of the managerial workable solutions suggested controlling the risks, the stopping of the pumping of water from the wetland and observation of hunting season length and permissible type and number of hunting in the area can be mentioned.

New bis(SATE) prodrug of AZT 5'-monophosphate: in vitro anti-HIV activity, stability, and potential oral absorption

The in vitro anti-HIV activity, stability, and potential for oral absorption of a phosphotriester derivative of AZT (zidovudine; 3'-azido-2',3'-deoxythymidine) bearing a new esterase-labile S-acyl-2-thioethyl (SATE) group as transient phosphate protection are reported. The biolabile protection is characterized by the presence of a hydroxyl function in the acyl chain. In accordance with previously reported data in the bis(SATE) prodrug series, the present results demonstrate that the studied bis(hydroxytBuSATE)phosphotriester exerts its biological effects via intracellular delivery of the 5'-monophosphate of AZT. The hydroxyl function confers a high resistance against esterase hydrolysis, and the studied prodrug is able to cross the Caco-2 cell monolayers in intact form, suggesting that its further development as a possible anti-HIV pronucleotide candidate is warranted.

Species-dependent and site-specific intestinal metabolism of ester prodrugs

In order to select a species for drug absorption studies of ester prodrugs and to identify a possible absorption window with low esterase activity and hence increased absorption of the ester prodrug, the esterase activity was investigated in homogenates from various intestinal segments of different species. p-Nitrophenyl acetate and tenofovir disoproxil [bis(POC)-PMPA] were used as substrates for esterases. p-Nitrophenyl acetate is a model substrate for esterase activity, while tenofovir disoproxil (fumarate salt) is an ester prodrug of the potent antiviral nucleoside phosphonate analogue tenofovir. As esterase-mediated degradation during transepithelial transport may be a limiting factor for its oral absorption, targeting the prodrug to a region of the intestine with lower esterase activity may lead to an increase in oral absorption of the prodrug. The results obtained with p-nitrophenyl acetate and tenofovir disoproxil showed both a site-specific (duodenum > or = jejunum > ileum > or = colon) and species-dependent (rat > man > pig) degradation in intestinal homogenates. Degradation of tenofovir disoproxil in homogenates from Caco-2 monolayers (0.016+/-0.003 nmol. s(-1). mg protein(-1)) was low compared to its degradation in homogenates from human ileum (0.177+/-0.052 nmol. s(-1). mg protein(-1)). Rat ileum appears to be a suitable model to evaluate the influence of esterase activity on the oral absorption of the ester prodrug, as the degradation rate for tenofovir disoproxil (0.245+/-0.054 nmol. s(-1). mg protein(-1)) in rat ileum was similar to degradation in human ileum. The results also suggest that colon targeting may be a useful strategy to reduce the esterase-mediated degradation of ester prodrugs, hence resulting in a possible increase in their oral absorption.

Evaluation of the potential of ion pair formation to improve the oral absorption of two potent antiviral compounds, AMD3100 and PMPA

9-(2-phosphonyomethoxypropyl)adenine (PMPA) and AMD3100 are highly potent and selective antiretroviral agents. Since PMPA is negatively charged and AMD3100 positively charged at physiological pH, their transepithelial transport and their potential for oral drug delivery is very low. In this study, ion pair formation was evaluated as a possible strategy to enhance transepithelial transport of PMPA and AMD3100. Positively charged counter ions such as t-hexyl-, t-heptyl-, t-octylammonium bromide and dodecyl-, tetradecyl-, hexadecyltrimethylammonium bromide were used to form ion pairs with PMPA, while sodium taurodeoxycholate (in vitro experiments) and sodium taurocholate (in vivo experiments) were used as counter ions for AMD3100. The effect of counter ions on transepithelial transport of PMPA (1 mM) and AMD3100 (1 mM) was investigated by measuring the flux across Caco-2 monolayers. An enhancement in drug transport could be observed at a concentration of 2 mM of hexadecyltrimethylammonium bromide (counter ion for PMPA) and 10 mM of sodium taurodeoxycholate (counter ion for AMD3100), but at the concentrations used, the absorption enhancing effect could be attributed to a reduction of the integrity of the monolayers. When AMD3100 transport was tested at a concentration of 200 microM, no flux was observed, even in the presence of relatively high concentrations of counter ion (20 times the concentration of AMD3100). Results obtained from partitioning studies of the drugs in the presence or absence of counter ion revealed that competition by other ions was responsible for the absence of an effect: when pure water was used as the aqueous phase, a reduction up to 24.4+/-1.4% and 17.0+/-1.3% of the initial aqueous concentration was observed for PMPA and AMD3100, respectively; however, as soon as other ions were present in the aqueous phase, the effect of the counter ion was diminished (25-50 mOsm) or completely abolished (270-305 mOsm). The absorption enhancing effect of counter ions was also studied in vivo: pharmacokinetic studies in rabbits showed that the oral bioavailability of AMD3100 in the presence of 4 equivalents of taurocholic acid remained very low and was only 3.2-fold better (i.e. 3.6%) in comparison to pure AMD3100. In view of the results obtained in the Caco-2 system, this absorption enhancement can be attributed to an effect on monolayer integrity rather than to the potential to form ion pairs. We can conclude that the formation of ion pairs may not be very efficient as a strategy to enhance transepithelial transport of charged hydrophilic compounds, as competition by other ions may abolish the beneficial effect of counter ions.

Synthesis of new fluorescent nucleoside analogues and application to the study of human deoxycytidine kinase

We have determined the affinity of human deoxycytidine kinase with respect to new fluorescent N-methylanthraniloyl cytidine derivatives or non fluorescent enantiomeric cytidine analogues. New results regarding the enantioselectivity and the mechanism of the enzyme are presented.

A comparison of the enantioselectivities of human deoxycytidine kinase and human cytidine deaminase

The stereoselectivities of recombinant human deoxycytidine kinase (EC 2.7.1.74) (dCK) and of recombinant human cytidine deaminase (EC 3.5.4.5) (CDA) were investigated with respect to a series of cytidine analogs, most of them having the unnatural L-stereochemistry. The enantioselectivity of dCK was always low and generally favored the L-enantiomers in the case of beta-2',3'-dideoxycytidine (beta-ddC), 5-fluoro-beta-2',3'-dideoxycytidine (beta-FddC) and beta-cytidine (beta-riboC). Concerning beta-2'-deoxycytidine, dCK showed a preference for the D-enantiomer. All other examined beta-L-cytidine analogs, [1-beta-L-lyxofuranosyl cytosine (beta-L-lyxoC), l-beta-L-xylofuranosyl cytosine (beta-L-xyloC), and 5-fluoro-1-beta-L-xylofuranosyl cytosine (beta-L-Fxylo C)], were substrates of dCK regardless of the nature of the pentose. None of the studied alpha-L-anomers (alpha-L-riboC, alpha-L-araC, alpha-L-lyxoC, or alpha-L-xyloC) was a substrate of dCK. Contrasting with the relaxed enantioselectivity of dCK, CDA had a strict requirement for D-cytidine analogs since none of the already listed beta-L- or alpha-L analogs was a substrate or an inhibitor of the enzyme. The conjunction of the preceding stereochemical properties of dCK and CDA confers to L-cytidine analogs important potentialities in antiviral and anticancer therapies.

Study of the substrate-binding properties of bovine liver adenosine kinase and inhibition by fluorescent nucleoside analogues

Adenosine kinase (AK) catalyzes the phosphorylation of adenosine to AMP with ATP as phosphate donor. Intrinsic fluorescence of bovine liver AK was shown previously to be a sensitive probe to quantify the binding of substrates to the enzyme [Elaloui, A., Divita, G., Maury, G., Imbach, J.-L. & Goody, R. S. (1994) Eur. J Biochem. 221, 839-846]. AK contains two catalytic, sites: a high-affinity site, which binds adenosine and AMP selectively; and a site for ATP and ADP. In the present work, these two sites were characterized by combining the quenching of protein fluorescence induced by the binding of the ligands and the fluorescence enhancement observed upon binding of the N-methylanthraniloyl-derivated nucleotides or adenosine. A new fluorescent analog of adenosine, 5'-N-methylanthraniloyl-adenosine, was synthesized and shown to bind selectively to the high-affinity adenosine-binding site with an affinity similar to that of adenosine (Kd 1 microM). In contrast, 2'(3')-N-methylanthraniloyl derivatives of ATP, adenosine (5')tetraphospho(5')adenosine (Ap4A), and adenosine (5')pentaphospho(5')adenosine (Ap5A), bind to the enzyme at the ATP site. Methylantraniloyl derivatives of ATP and adenosine were used as tools for selective characterization of a series of adenosine analogues. The bisubstrate inhibitors Ap4A and Ap5A bind to the ATP site with high affinity and apparently not to the adenosine site, thus acting more as ATP analogues than true bisubstrate ligands. The binding properties of a series of adenosine analogues were strongly dependent on the structural modifications on adenosine. The analogues modified at positions 2' or 3' show similar affinities for AK as that of adenosine, whereas adenosine analogues modified at the base present a relatively low affinity for the enzyme.