39 research outputs found
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Sex-Specific Effects of a Wartime-Like Radiation Exposure on Cognitive Function.
Evaluating the risk for central nervous system (CNS) effects after whole-body or partial-body irradiation presents challenges due in part to the varied exposure scenarios in the context of occupational, accidental or wartime releases. Risk estimations are further complicated by the fact that robust changes in brain function are unlikely to manifest until significantly late post exposure times. Collectively, the current data regarding CNS radiation risk are conflicting in humans and a survey of the animal model data shows that it is similarly inconsistent. Due to the sparseness of such data, the current study was conducted using male and female mice to evaluate the brain for the delayed effects of a 2 Gy whole-body exposure to c rays starting six months postirradiation. Behavioral testing indicated sex-specific differences in the induction of anxiety-like behaviors and in the ability to abolish fear memories. Molecular analyses showed alterations in post-synaptic protein levels that might affect synaptic plasticity and increased levels of global DNA methylation, suggesting a potential epigenetic mechanism that might contribute to radiation-induced cognitive dysfunction. These data add to the understanding of the CNS response to whole-body irradiation and may lead to improved risk assessment and provide guidance in the development of effective radiation countermeasures to protect military personnel and civilians alike
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New Concerns for Neurocognitive Function during Deep Space Exposures to Chronic, Low Dose-Rate, Neutron Radiation.
As NASA prepares for a mission to Mars, concerns regarding the health risks associated with deep space radiation exposure have emerged. Until now, the impacts of such exposures have only been studied in animals after acute exposures, using dose rates ∼1.5×105 higher than those actually encountered in space. Using a new, low dose-rate neutron irradiation facility, we have uncovered that realistic, low dose-rate exposures produce serious neurocognitive complications associated with impaired neurotransmission. Chronic (6 month) low-dose (18 cGy) and dose rate (1 mGy/d) exposures of mice to a mixed field of neutrons and photons result in diminished hippocampal neuronal excitability and disrupted hippocampal and cortical long-term potentiation. Furthermore, mice displayed severe impairments in learning and memory, and the emergence of distress behaviors. Behavioral analyses showed an alarming increase in risk associated with these realistic simulations, revealing for the first time, some unexpected potential problems associated with deep space travel on all levels of neurological function
Global injury morbidity and mortality from 1990 to 2017 : results from the Global Burden of Disease Study 2017
Correction:Background Past research in population health trends has shown that injuries form a substantial burden of population health loss. Regular updates to injury burden assessments are critical. We report Global Burden of Disease (GBD) 2017 Study estimates on morbidity and mortality for all injuries. Methods We reviewed results for injuries from the GBD 2017 study. GBD 2017 measured injury-specific mortality and years of life lost (YLLs) using the Cause of Death Ensemble model. To measure non-fatal injuries, GBD 2017 modelled injury-specific incidence and converted this to prevalence and years lived with disability (YLDs). YLLs and YLDs were summed to calculate disability-adjusted life years (DALYs). Findings In 1990, there were 4 260 493 (4 085 700 to 4 396 138) injury deaths, which increased to 4 484 722 (4 332 010 to 4 585 554) deaths in 2017, while age-standardised mortality decreased from 1079 (1073 to 1086) to 738 (730 to 745) per 100 000. In 1990, there were 354 064 302 (95% uncertainty interval: 338 174 876 to 371 610 802) new cases of injury globally, which increased to 520 710 288 (493 430 247 to 547 988 635) new cases in 2017. During this time, age-standardised incidence decreased non-significantly from 6824 (6534 to 7147) to 6763 (6412 to 7118) per 100 000. Between 1990 and 2017, age-standardised DALYs decreased from 4947 (4655 to 5233) per 100 000 to 3267 (3058 to 3505). Interpretation Injuries are an important cause of health loss globally, though mortality has declined between 1990 and 2017. Future research in injury burden should focus on prevention in high-burden populations, improving data collection and ensuring access to medical care.Peer reviewe
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
Clinical Manifestations of Herpes Zoster, Its Comorbidities, and Its Complications in North of Iran from 2007 to 2013
Background. Herpes zoster infection is a painful worldwide disease. Inappropriate and delayed treatment causes prolongation of the disease with debilitating symptoms and postherpetic neuralgia. Method. A cross-sectional study evaluated shingles cases admitted in a teaching hospital with one-year followup in north of Iran from 2007 to 2013. Results. From 132 patients, 60.4% were male. Head and neck involvement occurred in 78 people (59.1%), thoracoabdominal region in 37 cases (28%), and extremities in 16 cases (12.1%), and one case (0.8%) got multisites involvement. 54 cases (40.9%) had predisposing factors including diabetes mellitus in 26 cases (19.7%), malignancy in 15 (11.4%), immunosuppressive medication in 7 (5.03%), HIV infection in 3 (2.3%), radiotherapy in 2 (1.5%), and tuberculosis in one patient (0.8%). The most common symptoms were pain (95.5%), weakness (56%), fever (31.1%), headache (30.3%), ocular complaints (27.3%), itching (24.2%), and dizziness (5.3%). 21 cases (15.9%) had bacterial superinfection on blistering areas and overall 18 cases (13.6%) had opium addiction. 4 cases (3.03%) died during admission because of comorbidities. Postherpetic neuralgia was reported in 56 patients (42.5%) after three months and seven cases (5%) in one-year followup. Conclusion. Shortening interval between skin lesion manifestation and starting medication can accelerate lesion improvement and decrease disease course, extension, and complication
Can cytokines response play a role in the treatment of fatal leptospirosis?
Background: The northern coastal regions of Iran are endemic for leptospirosis which may range from a subclinical illness to a progressively fatal disease. There has been growing evidence that inflammatory markers play a significant role in the severity and prognosis of leptospirosis. This study aimed to investigate inflammatory cytokines in patients with leptospirosis. Methods: This descriptive-analytical prospective study was performed in 75 patients over 18 years old who had a positive microscopic agglutination test (MAT) titer from January to June 2019. SPSS software Version 20 was used for statistical analysis and the significance level was considered as p<0.05. Results: The patients’ age enrolled in this study are from 21 to 75 years with a mean and standard deviation of 48.6 ± 14.0. The male to female ratio in our participants was 54/21. Fever was the most common symptoms in 66 (88.0) patients, followed by myalgia in 62 (82.7) cases. The level of interleukin 10 was significantly higher in severe illness (P=0.003) and fatal cases (p<0.028) compared with recovered patients. The level of TNF-α level was also higher in the severe illness and Weil's syndrome compared with the mild kind (P=0.022). Conclusion: Our results showed that the levels of TNF-α and IL-10 significantly increased in severe leptospirosis. Also, IL-10 was significantly higher in fatal cases. The inhibition of IL-10 production might play an important role in decreasing the risk of fatal outcomes in leptospirosis
Green synthesis of silver nanoparticles and evaluation of their effects on the Porphyromonas gingivalis bacterial biofilm formation
Abstract Objective This study aimed to evaluate the impact of silver nanoparticles (AgNPs) synthesized from propolis on the formation of Porphyromonas gingivalis biofilms. Material and Methods AgNPs were synthesized from propolis, and their inhibitory effect on P. gingivalis biofilm formation was assessed. Different concentrations of AgNPs (0.1%, 0.3%, and 0.5%) were tested to determine the dose‐dependent antibacterial activity. Results The results of this study indicated that AgNPs exhibited an inhibitory effect on P. gingivalis biofilm formation. The antibacterial activity of AgNPs was dose‐dependent, with concentrations of 0.1%, 0.3%, and 0.5% showing effectiveness. Notably, the concentration of 0.5% demonstrated the most significant anti‐biofilm formation activity. Conclusion The results of this study suggest that AgNPs synthesized from propolis have potential as an effective option for enhancing periodontal treatment outcomes. The inhibitory effect of AgNPs on P. gingivalis biofilm formation highlights their potential as alternative antimicrobial agents in the management of periodontal diseases
Challenges and strategies for the promotion of research in Tabriz University of Medical Sciences: The Analysis of stakeholders’ views
Introduction: The intention of this study was to identifying and prioritizing challenges in research in Tabriz University of Medical Sciences (TUMS), Iran, and giving exact solutions to remove those challenges from the perspective of stakeholders (the members of faculty board, students, administrators, and research staff of the university). Methods: This mix-method study (quantitative-qualitative) conducted in summer-2014 in TUMS. The participants of this study included 139 of the members of faculty board, 349 of the students, and 39 of administrators and research staff (in total, 525 individuals). The data collection tool in the qualitative section was an open-ended questionnaires (3 questions), and in the quantitative section it consists close question questionnaires (26 questions). For prioritizing these challenges, it was used by prioritization matrix that it had four criteria: Importance, the ability to solve, cost-effectiveness and immediacy. Results: The important challenges from the perspective of participant included: Lack of co-operations of administrative centers with researchers, the existence of cumbersome rules, lack of motivation in researchers from authorities, being non-economic of doing a research to the professors and students, The lack of research result in decision-making, the low capacity and ability of members of faculty board, students, and staff on issues related to research procedures, and lack of attention to the quality of research. Conclusion: Lack of attention to the quality of research, and the existence of cumbersome rules in research area have the most priority in challenging research in TUMS, which they need more attention and planning to resolve these challenges of the authorities and managers of this university
Clinical Epidemiology and Paraclinical Findings in Tuberculosis Patients in North of Iran
Background. Mycobacterium tuberculosis (M.TB) causes a wide spectrum of clinical diseases. The prevalence of TB is different in various parts of Iran and throughout the world. The present study aimed to determine the clinical epidemiology and paraclinical findings of TB. Methods. A cross-sectional study was conducted from 2008 to 2013. Patient demographic, clinical, and radiologic characteristics, picked up from the TB patient’s files, were collected using a standard questionnaire format. Data was entered and analyzed using the SPSS version 16 statistical software and P value < 0.05 was considered statistically significant. Results. Out of 212 patients enrolled in this study 62% were male and the mean age was about 50 years old. 98.6% were Iranian, and 46.2% were rural. Prevalence of smear-positive TB was 66.4%. Prevalence of positive PPD was 50.7% with no significant difference between HIV-positive and -negative patients (P = 0.8). Prevalence of diabetes mellitus was 17%. 36% of the patients had history of smoking and about 29.3% were addicted to narcotics. Cough was the most common symptom (94.5%) and 84% had sputum. 15 cases (7%) had extrapulmonary TB. The mean time between the onset of symptoms and admission was 46.5 days. The delay for admission between urban and rural populations was not significantly different (P = 0.68); but for those who were in prison, the delay was significant (P = 0.02). About 46% of the patients had cavitary lesions in CXRs. Conclusion. Timely diagnosis of TB especially in prisoners by understanding its most important epidemiologic characteristics and clinical features can help to make an early treatment and prevent spread of mycobacteria and their complications