Results: Data for this study were collected from the beginning of January 2003 to October 2020 in PubMed. Our results showed that MR has an increasing trend. The data used in MR includes summarized statistical data, individual-level data, and meta-analysis. Choosing the suitable IV is essential to successfully conduct an MR. For an unbiased estimate, three main hypotheses should be considered: 1) The IV has a strong relationship with the desired exposure (i.e., potential risk factor), 2) The IV is not related to the confounding variable, and 3) The IV is not directly related to the outcome and should only relate to the outcome through exposure. If these conditions are not met, one solution is to use robust methods. Besides, this research introduced the study designs, estimation methods, limitations, software packages, and some applications of MR in medical research.
Conclusion: When we seek to find a causal relationship, but it is not possible to use a clinical trial as a standard method, the MR design can be used in observational studies. Therefore, it is possible to obtain causal relationships between exposure and outcome using the MR. |
Results: The most significant volume difference between the four groups participating in the study was related to the whole hippocampus, DG body, subiculum body, and subiculum head subfields (P<0.0001). Also, when examining pairs, the most significant difference was observed between the NC/AD pair (P<0.0001) and the least significant difference between the pair of LMCI/AD group (P<0.05) and in the subfield subiculum body showing the progressive course of hippocampal subfield atrophy with cognitive progress towards Alzheimer's disease.
Conclusion: In most subfields of the hippocampus, a significant difference in atrophy can be seen, increasing the severity of atrophy as the disorder progresses toward Alzheimer's. Such findings can help guide future studies to improve diagnostic performance to identify individuals at high risk of Alzheimer's disease. |
Methods: Our study was an interventional study from January 2015 to January 2018 on 16 lacrimal systems of 11 patients (5 males and 6 females) with congenital obstruction of the lacrimal duct (CNLDO) and a history of unsuccessful probing and stenting, in Farabi Hospital of Tehran (affiliated to Tehran University of Medical Sciences). Children who presented to our hospital and had previously been probed with or without intubation by another surgeon first underwent reprobing and re-intubation with a Crawford tube. Endoscopy of the nasolacrimal system was performed in suspected cases of false stent passage or in the presence of a history indicating nasal pathology. Crawford's Monoka tube was removed after two months. Balloon dacryoplasty with intubation was performed as the third surgery in cases who did not respond to probing and stenting after 3-6 months. The success after six months was evaluated using fluorescein dye disappearance test (FDDT) and also the resolution of the patients' symptoms.
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Conclusion: Balloon dacryoplasty combined with Monocrawford intubation is an effective surgical procedure that should be considered in cases of congenital nasolacrimal duct obstruction who have not responded to the probing and stenting of the lacrimal system.
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Results: Our study showed that within 5 years after the last follow-up, the incidence of syncope and pre-syncope in patients with a history of vasovagal syncope who did not continue the diet or tilt exercises was different between the two groups of patients (without medication and drug recipient) was not significantly different, even the incidence of presyncope increased significantly again in both groups. The incidence of syncope in the period of 5 years after the last follow-up from the previous study was slightly increased in the group of patients without medication compared to the previous periods, but in the group of patients receiving medication, this incidence decreased slightly.
Conclusion: In order to prevent recurrence, the use of non-pharmacological methods is effective, but for the stability of this recovery, follow-up and continuation of these methods is necessary. |
Results: According to the extracted data, the approach of assessment is towards formative assessment format and improvement of traditional methods along with modern methods, which was clearly observed in the study of the curriculum of Harvard-Stanford University in America and Oxford University in England. Integrating the results with Miller's evaluation levels, and the formative and cumulative evaluation format, led to the formulation of a model with the most favorable opinions of experts. In addition, the majority of opinions and suggestions of experts were related to the change in the way of executive policies of universities and providing a context for the emergence of new idea.
Conclusion: A model including measurement methods according to the levels of Miller's evaluation pyramid was developed in formative-cumulative. It is suggested that the model be reviewed by the relevant experts and notified by taking into account the implementation conditions for the correct evaluation process. |
Results: The results of this study showed heavy metal concentrations in sook tobaccos were, respectively, Fe>Zn>Mn>Ba>Pb>Ni>Cu>Mo>Cr>As>Cd. The concentration of heavy metals such as arsenic, cadmium and molybdenum in Alrah brand tobacco was higher than other types of tobacco. So that the amounts of heavy metals including arsenic, cadmium and molybdenum for this brand were 14.2±0.05, 10.4±0.06 and 11.6±0.04 micrograms per gram, respectively. The hazard index (HI) values for different types of tobacco, including Al-Rah, Amordadsub, Al-Fakher, Al-Rubi, Mazaya, traditional flavorless, and Nakhle, were 2.64, 2.41, 2.05, 1.7, 1.49, 1.46, and 1.44, respectively. The lifetime cancer risk (ILCR) for Amordadsub, Al-Rah, Nakhla, Mazaya, Al-Rubi, Al-Fakher, and traditional flavorless tobaccos was 2.8×10-3, 2.43×10-3, 1.72×10-3, 1.58×10-3, 1.43×10-3, 9.58×10-4, and 8.08×10-4, respectively. Lead in Alrah tobacco sook had the highest non-carcinogenic risk value with a value of 1.59.
Conclusion: According to the obtained results, Alrah tobacco sook has a higher cancer and non-cancer risk than regular tobacco and can cause non-carcinogenic and carcinogenic risks for consumers. Thus, it is necessary to regularly monitor the quality of prevalent tobacco to reduce delete human health risks. |
Results: The most common causes of otalgia were acute otitis media 29%, external otitis 17% and chronic otitis media 15%. Cerumen and referral ear pain were next in line (13.5%). There was significant relationship between otalgia with age groups (The age between 13 and 30 years were the most referred due to otalgia). There was no significant relationship between otalgia and gender, underlying disease, economic status, smoking and opium use.
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Results: 1099 articles were identified in the review of the investigated databases, and after removing duplicate articles, unrelated articles, as well as articles that did not have access to their full text or did not have the required information, eight studies were the final phase, and were checked. Out of the eight selected articles, three articles declared the effectiveness of lenograstim more than filgrastim. Two articles mentioned the greater effect of filgrastim and three articles published in recent years declared the effect of two drugs to be the same. Among these articles, the studies that considered the drug dosage to be the same in the investigated groups and the studies that had a larger statistical population in order to generalize to the society are more important.
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Results: He prevalence of malignancy in postmenopausal women was higher than in premenopausal women. Also, a significant difference was found between tumor size, the presence or absence of metastasis, and menopause (P<0.05), but no significant difference was found between tumor location and menopause (P>0.05).
Conclusion: Breast malignancies (invasive ductal carcinoma, invasive mixed carcinoma, mucinous, medullary, and papillary carcinoma) were more common in postmenopausal women than non-menopausal women. In both groups, ductal dilatation and chronic inflammation were the most benign findings, and fibroadenoma was found at a much lower rate in menopausal women than in non-menopausal. |
Results: After collecting the data, 43 patients in the first group and 44 patients in the second group were examined. 72.1% of the first group were women and 27.9% were men. In group two, this ratio was 72.7% for women and 27.3% for men. In this intervention, it was seen that in the 1st group, the average severity of bloating decreased until the end of the eighth week and after the second week of drug treatment, and then increased. In the second group, the average intensity of bloating decreased until the end of the fourth week and at the same time as the end of drug treatment, and then increased.
Conclusion: It was shown that in the study, the effect of this combined treatment had a greater effect in reducing the severity of functional bloating among patients with functional bloating. |
Results: Brachytherapy can be classified into 2 types of permanent implantation and temporary implantation based on the length of the treatment period. In permanent brachytherapy implants for prostate cancer, iodine (125I) or palladium (103Pd) are used as radioactive sources for low dose rate cases and for high dose rate brachytherapy. Iridium (192Ir) is used. Brachytherapy is usually used in two ways, either as a monotherapy in which LDR and HDR are used to treat some low-risk patients, or as a booster treatment after other treatments such as EBRT, which here may be part of the treatment process before, after, or during treatment. In contrast to brachytherapy alone, brachytherapy plus EBRT is an appropriate approach in patients with intermediate-risk and high-risk disease. In high-risk patients, the combined use of EBRT and HDR-BT can lead to better results than EBRT alone. Brachytherapy treatment is not suitable for every disease.
Conclusion: One of the main advantages of this treatment method is the ability to administer a high dose of radiation while minimizing radiation exposure to adjacent healthy organs. Since optimal dose distribution occurs in the treatment, quality treatment can be ensured. The results obtained from both forms of brachytherapy are generally suitable and comparable to other treatment methods with fewer side effects. |
Results: Out of 37 patients studied, 23 were female and 14 were male with a dispersion of three 3 to 60 months of age. 31 of these children had at least one abnormal finding in brain MRI images and the other six were completely normal. In relation to the imaging findings, the highest frequency is related to abnormal head circumference with a prevalence of 54% and the lowest frequency is related to abnormal myelinization with a prevalence of 10.8%. Results of MRI findings correlation with developmental domains demonstrated that Children with white matter disorder on MRI show severe gross motor abnormality (P<0.049) and who had MRI finding of cortical problems suffer from developmental delay in fine motor area. (P<0.001).
Conclusion: Considering the mentioned findings; brain MRI can be a useful diagnostic tool in children with developmental delay and also focusing on the developmental area that is more likely to be affected, MRI can help with treatment and rehabilitation process of these children in the future. |
For over 50 years, bone cement has been used to strengthen artificial joints like hip, knee, shoulder, and elbow joints. The main purpose of bone cement is to fill the space between the prosthesis and the bone. This absorbs the forces on the joint by creating an elastic area. Besides ensuring the long-term stability of the artificial implant, it also improves the damaged bone. Polymeric bone cement consists of a polymer matrix known as polymethyl methacrylate (PMMA) and a liquid monomer called methyl methacrylate (MMA). When these two components are mixed, a free radical polymerization reaction occurs, leading to the cement's hardening at the place of use. The properties of bone cement, such as mechanical strength, biocompatibility, and handling characteristics, can be adjusted by combining the effective polymerization parameters. However, there are some challenges, such as heat generation during polymerization.
Ceramic bone cement is a composite material of ceramic particles dispersed in a polymer matrix, including calcium phosphate and calcium sulfate. The ceramic particles provide strength and bioactivity, while the polymer matrix enhances the transport properties of the cement. This combination results in a mechanically stable, bone-conductive, and biocompatible cement. Moreover, ceramic bone cement can be engineered to release therapeutic agents, such as antibiotics or growth factors, to prevent infection and foster bone regeneration. Ceramic bone cement is a promising alternative material for bone cement in joint replacement. However, more research and development are required to optimize the properties of bone cement and overcome the challenges associated with its use. With continued advancements in biomaterials, ceramic and polymer bone cement could revolutionize the field of orthopedic surgery and improve patient outcomes. Recent research has focused on developing new bone cement with improved properties like bioactivity, antibacterial activity, and drug delivery capabilities. These developments aim to enhance the performance of bone cement and remove the current limitations in orthopedic applications. In this review study, we will focus on the types of bone cement, their mechanical, biological, and structural properties, and how to optimize them. |
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