فهرست مطالب سید اسحاق هاشمی

Colorectal cancer (CRC) is one of the most common human cancers. Currently, carcinoembryonic antigen (CEA) is used as the main standard biomarker of CRC, though this biomarker is not specifically made for CRC and, in a minority of cases, shows inadequate sensitivity. Therefore, searching for novel accessory biomarkers may fill these gaps in clinical management. miRNAs physiologically regulate various metabolic processes and are misregulated in various cancers. Therefore, the present investigation was conducted to evaluate miR-1 levels in CRC samples.

The CRC and adjacent tissue samples were obtained from 24 patients. In addition, sera were collected from the patient group and 24 healthy controls. Total RNA was extracted from tissue samples, and cDNA was synthesized. Real-time PCR determined the expression of miR-1. Serum levels of CEA were also measured using a Monobind ELISA assay kit.

The level of miR-1 in CRC tumors was significantly down-regulated. Moreover, patients with metastasis showed lower expression of miR-1 compared to cases without metastasis; however, this difference was not statistically significant. The ROC curve for miR-1 showed an AUC of 0.69. In addition, ROC analysis revealed a sensitivity of 70.27% and a specificity of 62.96% for miR-1.

There is still a need for new upcoming markers in addition to the main CRC biomarker, CEA. The levels of miR-1 in colorectal cancer tissue samples may provide additional information for the management and follow-up of CRC patients; though, the clinical application needs further studies.

 Atypical facial pain (AFP) is a chronic disease associated with local pain in the craniofacial area. A wide range of treatments including drug therapy, psychiatric methods and open surgery are used for its treatment. Opiorphin is a pentapeptide that can block pain and also has proven antidepressant effects. The aim of this study was conducted to investigate the opiorphin concentration in AFP patients and to compare it with healthy people.

 This study was performed on 30 AFP patients and 40 healthy individuals. Unstimulated saliva was collected from both groups by spitting method. HAD-A (Hamilton Anxiety Test) and HAD-D (Hamilton Depression Test) questionnaires were completed for all patients and controls. Psychological interview with the patients and psychological analysis were performed to determine anxiety and depression scores. Data analysis was done using SPSS (ver.24) statistical software

 The subjects of two groups were homogeneous in terms of age and sex. The mean salivary opiorphin concentrations in the case and control groups were 1.8050±0.2923 and 1.8032±0.3682 ng/ml, respectively. According to the results of t-Test, no significant difference was observed in the mean opiorphin concentration between the AFP group and control group (P=1.000). According to the Pearson's test, no significant relationship was found between the opiorphin levels and the age, sex, and anxiety or depression score in the patient and control groups (P>0.05). Also, there was no remarkable correlation between initial VAS, duration of pain and previous treatments with opiorphin levels in the AFP patients (P>0.05). No significant correlation was found between the opiorphin concentration and menopausal period in the case and control women (P>0.05).

 The results showed that most AFP patients had some degree of anxiety and depression. However, salivary opiorphin concentration did not significantly increase in the AFP patients.

Selenium is an essential mineral found naturally in soil, water, and some foods. Today, selenium, as an antioxidant, is one of the vital elements in the human body. Although the human body needs a small amount of selenium daily, recent studies have shown that the same small amount of selenium is essential for maintaining healthy body function. It is challenging to choose the right dose of selenium. According to several studies in this present review, a daily supplement of 31.5-200 micrograms seems beneficial since the amount of selenium in various diseases is less than the amount in healthy people. The articles published in PubMed, Web of Science, Google Scholar and SCOPUS databases were screened and collected based on the keywords including selenium, oxidant, antioxidant, diabetes, cancer, toxicity, heart disease and liver disease. These keywords were chosen because of the antioxidant role of selenium as well as the prominent role of oxidation in the progression of these diseases. 150 articles published over a period of 20 years from 2000 to 2020 were used in this study. Articles about nano-seleniums, non-dietary supplements, and diseases caused by the underlying disease of metabolic syndrome were excluded and finally 121 articles were included in the study. A limited number of studies show that patients with multiple disorders may need to take higher doses of selenium (82.4 to 200 micrograms) than healthy people. In this study, seleniumchr('39')s antioxidant role in chronic metabolic disorders, including hyperlipidemia and hyperglycemia, and some cancers, were investigated. Also, the clinical significance of selenium deficiency in metabolic diseases, as well as clinical and experimental observations on the effect of selenium dietary supplements in the treatment of chronic metabolic diseases such as diabetes and atherosclerosis, and cancers, are briefly mentioned. Besides, the recommended toxicity and dose of selenium have been discussed.

The cigarette compounds are associated with the increase in the incidence of oral cancer andprecancerous lesions. Salivary antioxidant system plays an important role in anti-carcinogenic capacity ofsaliva. Cotinine, a nicotine metabolite, has a longer half-life in comparison with nicotine and is a suitablemarker for exposure to cigarette smoke. This study aims to measure total antioxidant capacity (TAC) andcotinine level in saliva of smokers and non-smokers and compare salivary cotinine level and TAC in each grou.

In this cross-sectional study, 32 smokers and 34 non-smokers were recruited by consecutivesampling from Department of Oral Medicine, School of Dentistry, Mashhad University of Medical Sciences,Mashhad, Iran. Salivary cotinine and TAC concentrations were determined using the enzyme-linkedimmunosorbent assay (ELISA) technique. For data analysis, correlation tests of Spearman, Mann-WhitneyU, and independent samples t-test were used.

A significant difference was observed between the two groups in the mean cotinine level and in themean TAC (P = 0.015, P = 0.027, respectively). TAC showed a weak negative correlation with the cotininelevel, but the difference was not significant (P = 0.651).

Antioxidants are of great importance to smokers because antioxidants are able to scavenge freeradicals found in cigarette smoke. According to the results of present study, the salivary TAC in smokers waslower than that of non-smokers, and the salivary cotinine level in smokers was higher than non-smokers.Therefore, smoking endangers the oral cavity health by reducing the salivary TAC. Further studies with ahigher sample size and other factors affecting the salivary TAC are needed for definitive comment.

Periodontal disease is an inflammatory disease of the tissues supporting the teeth caused by certain microorganisms and can lead to progressive erosion of the Periodontal Ligament and alveolar bone followed by pocket formation and/or gingival recession. Nowadays, saliva is utilized as a diagnostic fluid in medicine and dentistry. The enzymes, immunoglobulin, hormones, and bacterial products of the saliva can be indicators of a periodontal disease. The present study aimed to measure and compare the Lactic Dehydrogenase (LDH) enzyme in the saliva of the patients with chronic periodontitis who referred to the Periodontal Department, School of Dentistry, Mashhad, Iran, before and after the treatment.

The population of this interventional study included the patients who referred to the Periodontal Department, School of Dentistry, Mashhad, Iran. This study was conducted on 30 patients, and the inclusion criterion was pocket attachment loss with a depth of 3-5 mm. The patients were matched regarding the plaque selection. The saliva samples of the patients with moderate periodontitis were collected before phase-1 treatment (i.e., scaling, root planning, and health education) and 4 weeks after treatment. Approximately, 3mL unstimulated whole saliva was collected from each participant using the Spitting method, placed immediately in micro tubes, stored at -20ºC, and transferred to a laboratory to be kept at -80ºC. Once the sample temperature reached room temperature, they were centrifuged at 3000g for 5min. The supernatant clear liquid was used for LDH analysis. The data were analyzed in SPSS software through t-test.

The results showed that the mean values of LDH level were 8.57±1484 and 4.25±1112 mg/l before and after the treatment, respectively. Moreover, there was a significant difference before and after the treatment regarding the LDH level of saliva (P=0.01).

The results of this study showed that LDH enzyme levels were higher considerably in the saliva of patients with a periodontal disease before treatment, compared to post-treatment. This is due to the pathological processes that occur in periodontal tissues leading to the release of intracellular enzymes.

Tachykinin peptide family is one of the largest peptide families in animals that has been first discovered in the gastrointestinal tract about 70 years ago and isolated for the first time from the small intestine and brain. Up to now, more than 40 tachykinins have been extracted from invertebrates (insects, worms and fungi) and vertebrates (skin, gastro-intestinal duct, central nervous system and peripheral nervous system). Herein we reviewed the structure, function, and role of tachykinins and their receptors in pathophysiology of main systems in human body.

Scopus, Science Direct, and PubMed databases were used in this work. The search was performed using tachykinins, neurokinin receptors, neuropeptide, and tachykinin receptors as key words from 1985 to 2018.

Mammalian tachykinins have a similar structural pattern and belong to the G protein superfamily that are derived from two pre-protachykinin genes (PPT-A and PPT-B) and exert their biological effects through binding to specific protein receptors, called neurokinin receptors. The secondary and principal effects of tachykinins depend on the activation of various receptors in the body. In addition to their role in central and peripheral nervous systems as neurotransmitter, tachykinins and their receptors play important roles in interaction among neuromuscular, respiratory, cardiovascular, immune, endocrine, digestive and urogenital systems.

Regarding the diversity of physiological functions, the involvement of tachykinins can be expected in the etiology of many diseases and their processes such as pulmonary edema, pain, sleep deprivation, depression, stress, Parkinson's disease, gastrointestinal and respiratory diseases and inflammatory processes of the neuromuscular and neurogenic systems.

β-galactosidase enzymes hydrolyze lactose into glucose and galactose for production of lactose free dairy products. However, different ions and fat content in milk may act as the inhibitor or activator for β-galactosidase enzymes. A cold-active β-galactosidase enzyme (BGalP), originally from Planococcus sp. L4, was previously expressed in Pichia pastoris to perform lactose hydrolysis in the refrigerated milk. In this study, the effects of milks major ingredients were evaluated on the enzymatic kinetics to confirm its capacity for hydrolyzing milk lactose. Material and methods: The activity was determined in different concentrations of NaCl, KCl, MgCl2, and CaCl2 as well as in the milk with low, medium or high-fat content. In these experiments ortho-Nitrophenyl β-galactoside was used as the substrate. Additionally, glucose was measured as the product after incubation of milk with BGalP enzyme for 24 h at room temperature. Results and conclusion: This study demonstrated that ions and fat content did not adversely affect the enzyme activity in the concentration corresponding to the milk contents. Ca (27.5-32.5 mM), Cl (25.3-30.9 mM), Na (15.2-39.1 mM) and Mg (3.75-5.83 mM) had no inhibitory effects, but KCl decreased the enzyme activity. Since Cl existed in MgCl2, and CaCl2 exerted no inhibitory effects, it can be concluded that inhibitory effects of KCl resulted from potassium rather than chloride. The results indicate that BGalP enzyme was not inhibited by milks major ingredients and has the potential to be used for the production of lactose-free dairy products.

A hematological finding in cobalamin and folic acid deficiency is increased neutrophil lobulation (hypersegmentation). There are contradictory reports about correlation of neutrophil hypersegmentation (NH) to iron deficiency in recent studies. This study re-examines the relationship between both iron deficiency (ID) and iron deficiency anemia (IDA) to hypersegmentation. The effect of folate deficiency was also investigated. Due to the high prevalence of iron deficiency in young Iranian women, the study groups were selected among young women. 90 subjects, 30-16 years of age, admitted to the Clinical Laboratory of Imam Reza Hospital, Mashhad (29 subjects with ID, 30 with IDA and 31 controls) were studied. Ferritin, folate and cobalamin levels in serum were measured by RIA (Kavos-hyar reagent). Iron and Total Iron Binding Capacity (TIBC) were measured using Colorimetric methods. CBC and RBC Indexes were measured by Sysmex k-21. To investigate each patient's peripheral blood hypersegmentation, 100 neutrophils were counted separately by two experts. Chi-square test revealed significant differences among NH and three groups of ID, IDA and control group (P=0.001). NH showed significant relationships with decreased serum Ferritin and Iron (P=0.001). Logistic regression analysis showed that the relationship between NH and ID / IDA is mostly due to the simultaneous presence of low normal levels of folate deficiency (P= 0.044). This study showed a correlation between NH and iron pools and Low normal levels of Folate. Therefore, when observing NH in peripheral blood of patients, especially in women of childbearing ages, it should be suspicious of coexistence of iron and mild folate deficiency and that further investigation must be done. Because NH is a simple and low-cost testing, it could be a useful diagnostic test for screening of IDA/ID and folate deficiency especially for women of childbearing ages.

Achieving the highest goals of public health needs to establish precise planning for provision of appropriate career platform for medical students, persuasion of graduates to work in public health system and recognition of weak points within the system. This study aimed to identify educational and career goals and preferences of medical students and effective factors on them. The study included entering medical students of 2005 to 2013, Mashhad University of Medical Sciences, Mashhad, Iran. The questionnaire was made up of demographic characteristics and questions about educational and career goals. Impact of demographic characteristics on the responses was also statistically analyzed. In this survey, among the target group of 256 students, 100 students (39.1%) responded to the questionnaires. Of these, 64% were men. Mean ± SD age of respondents was 22.6 ± 2.4 years. Most respondents (94%) expressed that they are inclined to higher levels of education after medical doctorate (MD). Among different specialties, cardiology (13%) and dermatology (11%) were the most popular fields. Ten percent of respondents also intended to study medical PhDs, of them genetics and biochemistry were more popular. While in the non-clinical courses, interest in a certain specialty constituted the main motivation, in clinical courses, higher income was the main motivation (P = 0.03). Increasing the efficiency of medical education, effective guidance during academic education and providing medical graduates with appropriate career platform necessitates recognition of medical student's interests and goals. Hence, investigation of these variables in other parts of Iran with larger sample sizes and also provision of suitable infrastructure for the future career of medical students seems to be inevitable.