Tehran University of Medical Sciences

About: Tehran University of Medical Sciences is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Population & Cancer. The organization has 35661 authors who have published 57234 publications receiving 878523 citations. The organization is also known as: TUMS.

Macrophage polarity in cancer: A review.

Abstract: Macrophages are the most abundant cells within the tumor stroma displaying noticeable plasticity, which allows them to perform several functions within the tumor microenvironment. Tumor-associated macrophages commonly refer to an alternative M2 phenotype, exhibiting anti-inflammatory and pro-tumoral effects. M2 cells are highly versatile and multi-tasking cells that directly influence multiple steps in tumor development, including cancer cell survival, proliferation, stemness, and invasiveness along with angiogenesis and immunosuppression. M2 cells perform these functions through critical interactions with cells related to tumor progression, including Th2 cells, cancer-associated fibroblasts, cancer cells, regulatory T cells (Tregs), and myeloid-derived suppressor cells. M2 cells also have negative cross-talks with tumor suppressor cells, including cytotoxic T cells and natural killer cells. Programed death-1 (PD-1) is one of the key receptors expressed in M2 cells that, upon interaction with its ligand PD-L1, plays cardinal roles for induction of immune evasion in cancer cells. In addition, M2 cells can neutralize the effects of the pro-inflammatory and anti-tumor M1 phenotype. Classically activated M1 cells express high levels of major histocompatibility complex molecules, and the cells are strong killers of cancer cells. Therefore, orchestrating M2 reprogramming toward an M1 phenotype would offer a promising approach for reversing the fate of tumor and promoting cancer regression. Macrophage switching toward an anti-inflammatory M1 phenotype could be used as an adjuvant with other approaches, including radiotherapy and immune checkpoint blockades, such as anti-PD-L1/PD-1 strategies.

The changes of metabolic profile and weight during Ramadan fasting.

Abstract: Introduction Ramadan is the holiest month in the Islamic calendar and Muslims fast during this month. We designed this study to evaluate the effect of Ramadan fasting on plasma lipids and lipoproteins. Methods This cohort study was performed during Ramadan in December 2002 (Islamic year 1423). The subjects were 81 students of Tehran University of Medical Sciences. We evaluated weight, body mass index (BMI), glucose, triglyceride (TG), cholesterol, low density lipoprotein (LDL), high density lipoprotein (HDL), and very low density lipoprotein (VLDL), before and after Ramadan. Results Body weight and BMI both decreased during Ramadan fasting in both genders. Glucose and HDL decreased and LDL increased significantly during fasting in Ramadan, but there was no significant change in total cholesterol, TG and VLDL. We did not find any association between TG, cholesterol, LDL, VLDL, HDL and the following variables: sex, body weight changes, and two or three instances of meals before Ramadan. Triglyceride level also increased in students with normal BMI while it decreased in overweight subjects. Conclusion This study indicated that Ramadan fasting led to a decrease in glucose and weight. Although there was a significant reduction in meal frequency, a significant increase in LDL and decrease in HDL was noted during Ramadan. It seems that the effect of Ramadan fasting on serum lipid levels may be closely related to the nutritional diet or biochemical response to starvation.

Ethical challenges of researchers in qualitative studies: the necessity to develop a specific guideline.

Abstract: Considering the nature of qualitative studies, the interaction between researchers and participants can be ethically challenging for the former, as they are personally involved in different stages of the study. Therefore, formulation of specific ethical guidelines in this respect seems to be essential. The present paper aimed to discuss the necessity to develop explicit guidelines for conducting qualitative studies with regard to the researchers' role. For this purpose, a literature review was carried out in domestic and international databases by related keywords. Health care providers who carry out qualitative research have an immense responsibility. As there is no statistical analysis in qualitative studies, the researcher has to both evaluate what he or she observes and to interpret it. Providing researchers with the necessary skills and applying stringent supervision can lead to better extraction of reliable information from qualitative studies. This article presents a debate in order to illustrate how researchers could cover the ethical challenges of qualitative studies and provide applicable and trustworthy outcomes. Researchers face ethical challenges in all stages of the study, from designing to reporting. These include anonymity, confidentiality, informed consent, researchers' potential impact on the participants and vice versa. It seems of paramount importance that health care providers, educators and clinicians be well informed of all the different aspects of their roles when acting as qualitative researchers. Hence, these adroit roles need to be well defined, and the use of practical guidelines and protocols in all stages of qualitative studies should be encouraged.

Bioactive Glasses: Where Are We and Where Are We Going?

Abstract: Bioactive glasses caused a revolution in healthcare and paved the way for modern biomaterial-driven regenerative medicine. The first 45S5 glass composition, invented by Larry Hench fifty years ago, was able to bond to living bone and to stimulate osteogenesis through the release of biologically-active ions. 45S5-based glass products have been successfully implanted in millions of patients worldwide, mainly to repair bone and dental defects and, over the years, many other bioactive glass compositions have been proposed for innovative biomedical applications, such as soft tissue repair and drug delivery. The full potential of bioactive glasses seems still yet to be fulfilled, and many of today’s achievements were unthinkable when research began. As a result, the research involving bioactive glasses is highly stimulating and requires a cross-disciplinary collaboration among glass chemists, bioengineers, and clinicians. The present article provides a picture of the current clinical applications of bioactive glasses, and depicts six relevant challenges deserving to be tackled in the near future. We hope that this work can be useful to both early-stage researchers, who are moving with their first steps in the world of bioactive glasses, and experienced scientists, to stimulate discussion about future research and discover new applications for glass in medicine.