Showing 9 results for Yunesian
M Qorbani, M Yunesian, A Fotouhi, H Zeraati, S Sadeghian, Y Rashidi,
Volume 3, Issue 1 (21 2007)
Abstract
Background & Objectives: Recent evidence suggests that long-term exposure to air pollution contributes to progression of atherosclerosis and the risk of cardiac morbidity and mortality short-term exposure may also lead to thrombosis and acute ischemic events. To evaluate the relation between the levels of major air pollutants (CO and PM10) and hospital admission for acute coronary syndrome (ACS) in Tehran, we performed a case-crossover design and checked whether individual characteristics act as effect modifiers.
Methods: We selected 250 Tehran residents who had been hospitalized with an acute coronary syndrome from 4th of April to 10th of June, 2007. The following individual data were gathered: sex, age, date of hospitalization, and coexisting illnesses (hypertension, diabetes). Daily air pollution data were taken from the Air Quality Control Center. Temperature, humidity, stress, physical activity and weekend days were treated as confounding variables, and a conditional logistic regression model was used for statistical analysis.
Results: We found a positive association between ACS and average 24-hour CO levels. The OR for each unit increase of the average 24-hour CO was 1.18 (95%CI: 1.03-1.34). The relation between ACS and 24-hour average PM10 did not reach statistical significance (OR for average 24-hour PM10 was 1.005, 95%CI: 0.99-1.01). The association between ACS and 24-hour average CO tended to be stronger in women (OR=1.68 for each unit increase, 95%CI: 1.25-2.26). The relation between 24-hour average PM10 and ACS did not change across the layers of the effect modifiers.
Conclusions: The results suggest that an increase in average 24-hour CO levels will augment the risk of ACS, and the effect is stronger in females. On the other hand, we were unable to document an association between ACS and average 24-hour PM10 levels.
R Chaman , M Yunesian , B Golestan , K Holakouie Naieni ,
Volume 3, Issue 3 (18 2008)
Abstract
Background and Objectives: A pregnancy can be considered high-risk if there are conditions that put the mother or the baby at higher-than-average risk of morbidity or mortality. Neonatal mortality rate is one of the most important indices of children's health status. The present study was conducted to evaluate the effects of high-risk states on neonatal mortality.
Methods: We performed a nested case-control study in the rural areas of Kohgiluyeh and Boyerahmad province. Within the study cohort, 97 cases and 97 controls were selected by a risk-set sampling method. Data were analyzed with univariate and multivariate conditional logistic regression models.
Results: Neonatal mortality was shown to increase significantly in high-risk pregnancies. There were no substantial differences between crude odds ratios and those adjusted for the presence of other risk factors (crude odds ratio decreased from 5.5 to an adjusted figure of 3.25 for pregnancies with one risk factor and from 5.21 to adjusted level of 4.80 for pregnancies with more than one risk factor).
Conclusions: High-risk pregnancies need great attention in family health and prenatal care programs, especially in remote rural areas. Within our rural health network there are potential cohorts for use in nested case-control studies, especially in the evaluation of neonatal mortality risk factors.
M Qorbani, M Yunesian,
Volume 4, Issue 1 (22 2008)
Abstract
The case-crossover design was developed in the early 1990s to study the effects of transient, short-term exposures on the risk of acute events such as myocardial infarction. To estimate relative risk, the exposure frequency during a period just before outcome onset (hazard period) is compared with exposure frequency during control time(s) in that person rather than in a control. One or more "control times" are supplied by each of the cases themselves to control for confounding by constant characteristics and self-confounding between the trigger's acute and chronic effects.
In the analysis of case-crossover studies, exposure frequency in the hazard period is compared with the control period or the individual's usual frequency of exposure. The design has been used frequently for heart diseases, injuries and air pollution epidemiology. This review article looks at published case-crossover studies and is intended to help the reader gain a better understanding of the strengths and limitations of the case-crossover design in studying the epidemiology of injuries and air pollution.
Mr Mohebbi, M Yunesian, K Nadafi, R ,
Volume 4, Issue 2 (20 2008)
Abstract
Background and objectives: The scattered state of villages both from their geographic aspect and the distance between residential units within a single village has made the task of supply, distribution and monitoring the quality of water a difficult one. Ideas of experienced people in the field of rural water quality control, has been obtained to reach gain a view on existing difficulties in supplying safe water to villages and the ways to overcome them.
Methods: Using a three-iteration Delphi procedure, consensus was built and measured among eleven managers and experts of rural water quality control. Given the large number of opinions and views ,the problems were discussed and were given priority according to the alphabetical order of the names of the participants.
Results: The difficulties were summarized as of being, the main source of water supply, economic, human resources , facilities, cultural and extra organization issues.
Conclusion: The cooperation rate was 100% in this study and most of the problems were concerning no credible financial support in supplying of costs for the maintenance facilities, upkeep of networks and the incorrect choice made in selecting of the water resource. We can overcome to these problems by implementing reforms, teaching, retraining, constant supervision and efficient management of the working staff , supervision of special operations projects including mending of breaks in pipelines and thus could lead to a more efficient distribution to the villages on time.
M Qorbani , M Yunesian ,
Volume 5, Issue 4 (11 2010)
Abstract
London fog obviously revealed the role of air pollution in increasing mortality and morbidity rates associated with this phenomenon but several studies in the 70’s and 80’s couldn’t establish sufficient link between air pollution and death. In the 1990’s, time series studies conducted in a different locations, showed that air pollution levels, even at lower concentrations, were associated with increased rates of morbidity and mortality in several cities in all over the world. Since several studies have been designed for investigating the association between air pollution and health outcomes in recent years with controversial conclusions, this article reviews the latest studies in this field. We also will mention main strengths and weaknesses of epidemiological designs including time-series, case-crossover, cross sectional, panel and cohort studies in indoor and outdoor air pollution epidemiology.
M Qorbani, M Yunesian,
Volume 8, Issue 1 (20 2012)
Abstract
Background & Objectives: Some case-report studies in Iran showed probable
association between anthracosis and smoke exposure due to baking homemade
bread, population. Therefore we estimated the population attributable fraction
(PAF) for this probable association in Iranian population.
Methods: A
hospital-based case-control study, including 83 anthracotic subjects (cases)
with 72 controls from surgical ward which were matched by age, conducted in
Imam Khomeini hospital in Tehran (From September 2009 to December 2010). Patients in both case and control groups were
interviewed according to "American Thoracic Society" guideline. Exposure
to smoke was
considered both as a binary and continuous variable (number of years being
exposed to smoke) and the population attributable fraction (PAF) were estimated
due to smoke exposure.
Results: Univariate
analysis showed that exposure to smoke as binary variables, age and occupation
exposure to dust and education were associated with anthracosis. After
Adjusting, only smoke exposure (OR: 3.35, 95% CI: 1.49-7.55) remain
significant. Univariate logistic regression model showed exposure to smoke as
continuous variable has significant association with anthracosis. In multiple
logistic model only duration (years) of
smoke exposure remained significant (OR: 1.05, 95%CI: 1.01-1.09). PAF due to
smoke exposure estimated approximately 48% in our population.
Conclusion: Based
on the findings of this study, it could be concluded that approximately half of
the anthracotic cases are attributed to smoke exposure.
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E Pourbakhtyaran, Mh Sowlat, A Rashidian, P Pasalar, N Rastkari, M Yunesian,
Volume 8, Issue 4 (9 2013)
Abstract
Background & Objectives: In the last decade, there have been some claims about hazards of Sodium bicarbonate in bread, in public and scientific sites. Currently, the use of sodium bicarbonate in bread processing is forbidden in Iran. Therefore, the present study sought to assess the current evidence on the adverse effects of sodium bicarbonate use from oral route on public health.
Methods: Different databases, including Scopus, Pubmed, and Ovid were searched for hazards of sodium bicarbonate in baking.
Results: Based on this systematic review, there was no study showing any adverse effects of Sodium bicarbonate when used in producing bread. However, we found many studies about the use and medical application of it. The reported adverse effects mostly included gastrointestinal and electrolytes implications at medical doses which are significantly higher than those used in bakery, or some complications due to accidental or excessive oral ingestion of sodium bicarbonate.
Conclusion: Not only was there no evidence on the adverse effects of sodium bicarbonate on public health, but at medical doses, many useful effects were also reported in clinical trial studies. Therefore, it is assumed that the use of Sodium bicarbonate at normal doses does not have any adverse effects on human and can be used for bakery in Iran.
A Motevalian, R Sahebi, A Rahimi Movaghar , M Yunesian,
Volume 11, Issue 2 (Vol 11, No 2 2015)
Abstract
Background & Objectives: The aim of the study was to determine age, period, and cohort effects on trend of alcohol and drug use in the students of Tehran University of Medical Sciences from 2006 to 2009.
Methods: Between 2006 and 2009, the students of Tehran University of Medical Sciences were surveyed annually using a structured self-administered and anonymous questionnaire. Intrinsic estimator, which is a new method for resolving linear dependency between age, period, and cohort in linear regression models, was used for data analysis.
Results: In the present study, in the descriptive method, the prevalence of alcohol consumption increased in males and females with an increase in age. The prevalence of illicit drug use was higher in 2007 in comparison with other periods for males and females. In the analytical method (intrinsic estimator), there were no age, period and cohort effects for alcohol and drug use for females. For males, the age effect exhibited an increasing-decreasing-increasing trend and period and cohort effects showed a decreasing trend for alcohol use. As for drug use, the age effect exhibited gradual increases. The period effect displayed an increasing-decreasing trend and the cohort effect exhibited an increasing-decreasing-increasing trend.
Conclusion: The IE method showed no age, period and cohort effects for alcohol and drug use in females. The prevalence of drug and alcohol use increased with an increase in age in males. The high prevalence of drug use could be due to easy accessibility and low price of drugs.
Samaneh Dehghani, Masud Yunesian,
Volume 19, Issue 4 (Vol.19, No.4, Winter 2024)
Abstract
Microplastics refer to plastic particles and fragments smaller than 5 millimeters in various forms, derived from the breakdown of larger plastics or initially introduced into the environment from the primary constituent particles of plastic. The exact date of the emergence of microplastics in the environment is not precisely known, but it certainly predates the naming of these particles (2004). These particles can enter the bodies of living organisms, including humans, primarily through ingestion and inhalation. Their effects on the body depend on their size, chemical composition, and the composition of substances that later absorb these particles. In this article, we will first briefly examine the classification of these particles in terms of chemical composition and their origins, and then review some evidence of their presence in biological tissues and fluids. Given the increasing production and use of plastics in human life and the fact that most microplastics in nature derive from the breakdown of larger plastics, sometimes several years after their disposal, it is expected that even if plastic production decreases or stops, we will continue to see an increase in their presence in nature for years and decades, leading to human exposure to these compounds (whose effects and consequences of this exposure are not yet fully understood).
