Shahid Beheshti University of Medical Sciences and Health Services

About: Shahid Beheshti University of Medical Sciences and Health Services is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Population & Cancer. The organization has 19456 authors who have published 33659 publications receiving 365676 citations.

Marrow-derived mesenchymal stem cells-directed bone regeneration in the dog mandible: a comparison between biphasic calcium phosphate and natural bone mineral.

Abstract: Objective This study was designed to compare mesenchymal stem cell (MSC)-based alveolar bone regeneration in biphasic bone substitutes and natural bone mineral in a canine full-thickness alveolar defect model. Materials and methods MSCs were isolated from bone marrow aspirates and culture expanded through 3 successive subcultures. The bone differentiation potential of third passage cells was evaluated and confirmed in vitro before cells were used in the transplantation experiment. Undifferentiated cells were then incubated with 3 × 3 × 3 mm 3 hydroxyapatite/β-tricalcium phosphate (HA/TCP) matrices (Kasios, Lanauguet, France) and 1- to 2-mm Bio-Oss spongiosa (Geistlich Biomaterials, Osteohealth, Switzerland), which is a natural bovine bone mineral (NBM). Kasios/cell, Kasios alone, Bio-Oss/cell, and Bio-Oss alone were implanted in masseter muscle and 4 cylindrical (10-mm diameter) through-and-through bilateral mandibular body defects in 4 mongrel dogs. Histomorphometric analysis was performed 6 weeks after insertion of the scaffold loaded with MSCs. Results H&E staining of the decalcified scaffold and scanning electron microscopy demonstrated large MSC coverage of the HA/TCP and Bio-Oss. Cell-loaded Kasios matrices showed the greatest amount of the bone regeneration among the groups in both the muscle (29.11%) and the bone specimens (65.78%). Cell-free biphasic scaffold revealed 44.9% bone fill in bone defects and 23.55% in muscle specimen, and Bio-Oss alone matrices had the least amount of new bone formation: 36.84% and 24.16% in bone and muscle specimens respectively. Kasios loaded with MSCs demonstrated more bone regeneration than Bio-Oss/cell but there was no significant statistical difference ( P > .05). Conclusions New biphasic synthetic bone substitutes may offer better conditions for bone regeneration than traditional bone substitute in combination with MSCs. They remained in the defect and contributed to bone regeneration.

Antioxidants: Positive or Negative Actors?

Abstract: The term “antioxidant” is one of the most confusing definitions in biological/medical sciences. In chemistry, “antioxidant” is simply conceived “a compound that removes reactive species, mainly those oxygen-derived”, while in a cell context, the conceptual definition of an antioxidant is poorly understood. Indeed, non-clinically recommended antioxidants are often consumed in large amounts by the global population, based on the belief that cancer, inflammation and degenerative diseases are triggered by high oxygen levels (or reactive oxygen species) and that through blocking reactive species production, organic unbalances/disorders can be prevented and/or even treated. The popularity of these chemicals arises in part from the widespread public mistrust of allopathic medicine. In fact, reactive oxygen species play a dual role in dealing with different disorders, since they may contribute to disease onset and/or progression but may also play a key role in disease prevention. Further, the ability of the most commonly used supplements, such as vitamins C, E, selenium, and herbal supplements to decrease pathologic reactive oxygen species is not clearly established. Hence, the present review aims to provide a nuanced understanding of where current knowledge is and where it should go.

The prevalence of anxiety and depression among healthcare workers during the COVID-19 pandemic: An umbrella review of meta-analyses.

Abstract: BACKGROUND: Healthcare workers, who are at the forefront of the fight against COVID-19, are particularly susceptible to physical and mental health consequences such as anxiety and depression. The aim of this umbrella review of meta-analyses is to determine the prevalence of anxiety and depression among healthcare workers during the COVID-19 pandemic. METHODS: Using relevant keywords, data resources including PubMed, Scopus, Web of Science, Cochrane, ProQuest, Science Direct, Google Scholar and Embase were searched to obtain systematic reviews and meta-analyses reporting the prevalence of anxiety and depression among healthcare workers during the COVID-19 pandemic from the beginning of January to the end of October 2020. The random effects model was used for meta-analysis, and the I2 index was employed to assess heterogeneity among studies. Data was analyzed using STATA 14 software. RESULTS: In the primary search, 103 studies were identified, and ultimately 7 studies were included in the umbrella review. The results showed that the overall prevalence of anxiety and depression among healthcare workers during the COVID-19 pandemic was 24.94% (95% CI: 21.83-28.05, I2 = 0.0%, P = 0.804) and 24.83% (95% CI: 21.41-28.25, I2 = 0.0%, P = 0.897), respectively. CONCLUSION: This umbrella review shows that the prevalence of anxiety and depression is relatively high among healthcare workers during the COVID-19 pandemic. Healthcare workers should be provided with resources to minimize this risk.

The emotional-psychological consequences of infertility among infertile women seeking treatment: Results of a qualitative study.

Abstract: Background: Infertility is a major life event that brings about social and psychological problems. The type and rate these problems in the context of socio-cultural of different geographical areas and sex of people is different. Objective: The aim of this qualitative study was to explain the psychological consequences of infertility in Iranian infertile women seeking treatment. Materials and Methods: This qualitative study was done using qualitative content analysis on 25 women affected by primary and secondary infertility with no surviving children in 2012. They were purposefully selected with maximum sample variation from a large Fertility Health Research Center in Tehran, Iran. Data were collected using 32 semi-structured interviews and analyzed by the conventional content analysis method. Results: The findings of this study include four main themes: 1. Cognitive reactions of infertility (mental engagement; psychological turmoil). 2. Cognitive reactions to therapy process (psychological turmoil; being difficult to control in some situations; reduced self-esteem; feelings of failure). 3. Emotional-affective reactions of infertility (fear, anxiety and worry; loneliness and guilt; grief and depression; regret). 4. Emotional-affective reactions to therapy process (fear, anxiety and worry; fatigue and helplessness; grief and depression; hopelessness). Conclusion: This study revealed that Iranian infertile women seeking treatment face several psychological-emotional problems with devastating effects on the mental health and well-being of the infertile individuals and couples, while the infertility is often treated as a biomedical issue in Iranian context with less attention on the mental-emotional, social and cultural aspects