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Farhadi Z, Rezaei E, Bazrafkan L, Amini M, Sanaiey NZ, Barati-Boldaji R, Mehrabi M. Need assessment of medical school curriculum for MOOCs: perspectives of instructors and students of Shiraz University of Medical Sciences. BMC Med Educ 2024; 24:141. [PMID: 38351037 PMCID: PMC10865553 DOI: 10.1186/s12909-024-05102-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Accepted: 01/27/2024] [Indexed: 02/16/2024]
Abstract
INTRODUCTION Designing, developing, and implementing a course without assessing and prioritizing instructional needs may result in inefficiency due to the disregard for the actual needs of the target population. The present study aimed to determine and prioritize medical students' instructional needs regarding Massive Open Online Courses (MOOCs) at Shiraz University of Medical Sciences. METHODS This survey study was carried out in three stages (2020-2021) using the Delphi technique. Purposive and snowball sampling methods were used to select the instructors. The students were selected through simple random sampling. The first round of the Delphi technique involved a questionnaire consisting of one open-ended question, completed by 49 basic/clinical faculty members and 47 senior medical students. In the second round, a 5-point Likert scale-based questionnaire was used to prioritize the instructional needs. The reliability of the questionnaire was verified by Cronbach's alpha coefficient. In the third round, a focus group was used. A total of six expert faculty members and one senior medical student were invited to the focus group session to prioritize the needs. Data were analyzed using Friedman's non-parametric ranking test in SPSS version 26. RESULTS Ten instructional needs priorities were extracted, including common pharmacotherapies (antibiotics and narcotics), prescriptions, physiology, anatomy, physical examination, electrocardiography interpretation, radiography, computed tomography scans, serum electrolyte disorders, and cardiovascular and internal (endocrine and metabolic) diseases. The chi-squared calculated value (715.584) indicated a significant difference in the importance of the questionnaire's questions (P < 0.001). These questions did not have equal value, and the importance, from the respondent's point of view and the observed distribution of ranks, was not the output of a random factor. CONCLUSIONS The findings of this study can be used to design MOOCs, revise instructional programs, and adapt the curriculum to meet the needs of general practitioners, which will, in turn, help meet the medical needs of the general population.
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Affiliation(s)
- Zahra Farhadi
- Medical Education, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Eisa Rezaei
- Department of Educational Technology in Medical Sciences, Smart University of Medical Sciences, Tehran, Iran
| | - Leila Bazrafkan
- Clinical Education Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mitra Amini
- Clinical Education Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Nahid Zarif Sanaiey
- Department of E-Learning in Medical Sciences, Virtual School (Center of Excellence for E-Learning in Medical Sciences), Shiraz University of Medical Sciences, Third Floor, Sina & Sadra Hall, Neshat Street, Shiraz, Iran
| | - Reza Barati-Boldaji
- Public Health Nutrition, Gastroenterohepatology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Manoosh Mehrabi
- Department of E-Learning in Medical Sciences, Virtual School (Center of Excellence for E-Learning in Medical Sciences), Shiraz University of Medical Sciences, Third Floor, Sina & Sadra Hall, Neshat Street, Shiraz, Iran.
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Khalilollah S, Abdolhoseinpour H, Rezaei E, Fakhr MS. The relationship between pain relief and the amount and distribution of injected cement in kyphoplasty for osteoporotic vertebral fractures. Eur Rev Med Pharmacol Sci 2023; 27:8540-8549. [PMID: 37782170 DOI: 10.26355/eurrev_202309_33779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
OBJECTIVE This study aimed to compare the relationship of pain relief with the amount and distribution of injected cement in kyphoplasty for osteoporotic vertebral fractures. PATIENTS AND METHODS This cohort study was conducted on 90 patients with osteoporotic vertebral fractures who needed chronic pain medication. Patients underwent kyphoplasty balloon surgery, and polymethylmethacrylate (PMMA) or bone cement was injected into the created cavities and the volume of injected cement was recorded. After the surgery, the distribution of cement was measured using a computed tomography (CT) scan in the coronal, sagittal, and axial axes of the vertebra, and the percentage of cement distribution was evaluated using Photoshop software in these three axes, followed by the pattern of cement distribution. The cement was measured in the entire vertebra. The patients were evaluated over a period of 6 months, and the amount of pain improvement was measured by the VAS scale in 24 hours, two weeks, six weeks, and six months after surgery. In this study, the data of 90 patients with a mean age of 72.5±10.9 years were included in the study. The mean volume of cement injected was 1.2±5.8 cc, followed by the mean percentage of cement distribution (47.7±7.4%); the mean pain score before the operation (8.7±1.3), the mean pain score 24 hours after the operation (7.7±1.4), the mean pain score 2 weeks after the operation (4.8±1.3), the mean pain score 6 weeks after the operation (3.6±1.2) and the mean pain score 6 months after the operation (3.5±1.4) were evaluated after collection. RESULTS The pain intensity 24 hours after the operation had a significant positive correlation with the percentage of cement distribution and pain intensity before the operation. The intensity of pain 2 weeks after the operation was positively correlated with the age of the patients and the intensity of pain before the operation. The pain intensity 6 weeks after the operation was significantly correlated with the age of the patients and the pain intensity before the operation. The intensity of pain 6 months after the operation was positively linked to the age of the patients and negatively correlated with the percentage of cement distribution. The pain reduction has changed significantly in the 4 measured intervals, and during a period of 6 months, there was a significant improvement in the pain level of the patients continuously. It was found that the rate of recovery of the patient's pain has increased by increased distribution of injected cement. Although this reduction in pain during the 6-month period was not significantly related to the variables of gender, smoking, history of corticosteroid use, and the volume of injected cement. CONCLUSIONS The balloon kyphoplasty is a safe and successful method for treating symptomatic vertebral fractures. Kyphoplasty is associated with significant pain relief, improved quality of life, and kyphosis correction. The volume of cement injected had no effect on reducing patients' pain after the operation, but a higher percentage of cement distribution was associated with a better response in patients.
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Affiliation(s)
- S Khalilollah
- Department of Neurosurgery, Bouali Teaching Hospital, Faculty of Medicine, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran.
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Cheraghbeigi N, Molavynejad S, Rokhafroz D, Elahi N, Rezaei E. Nursing students' learning strategies for e-learning during the Covid-19 pandemic in Iran: a qualitative study. BMC Med Educ 2023; 23:321. [PMID: 37158882 PMCID: PMC10166048 DOI: 10.1186/s12909-023-04270-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 04/17/2023] [Indexed: 05/10/2023]
Abstract
BACKGROUND In response to the emergency brought about by the Covid-19 pandemic, many universities around the world had to change their teaching methods from in-person classes to e-learning. The purpose of this study was to identify the learning strategies of nursing students in e-learning during the pandemic. METHODS This study had a qualitative design and used content analysis approach to collect and analyze the data. Sixteen semi-structured interviews were conducted with 12 Iranian undergraduate nursing students who were selected using purposive sampling method. RESULTS Most nursing students in this study generally used two different strategies for e-learning, namely self-centered learning strategies and collaborative learning strategies. Some students, on the other hand, adopted a passive approach in which they did not take any effective action to contribute to their learning. CONCLUSION In e-learning during the pandemic, students adopted different learning strategies. Therefore, designing teaching strategies tailored to the students' strategies can promote their learning and academic achievement. Also, knowledge of these strategies helps policy makers and nursing educators to take necessary measures in order to optimize and facilitate student learning in an e-learning environment.
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Affiliation(s)
- Nesa Cheraghbeigi
- Student Research Committee, School of Nursing and Midwifery, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Shahram Molavynejad
- Nursing Care Research Center in Chronic Diseases, School of Nursing and Midwifery, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
| | - Dariush Rokhafroz
- Nursing Care Research Center in Chronic Diseases, School of Nursing and Midwifery, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Nasrin Elahi
- Nursing Care Research Center in Chronic Diseases, School of Nursing and Midwifery, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Eisa Rezaei
- Department of Educational Technology in Medical Sciences, Smart University of Medical Sciences, Tehran, Iran
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Majidzadeh Heravi R, Ghiasvand M, Rezaei E, Kargar F. Assessing the viability of three Lactobacillus bacterial species protected in the cryoprotectants containing whey and maltodextrin during freeze-drying process. Lett Appl Microbiol 2021; 74:505-512. [PMID: 34904273 DOI: 10.1111/lam.13631] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 12/06/2021] [Accepted: 12/07/2021] [Indexed: 12/29/2022]
Abstract
Freeze-drying of bacteria associates with different stresses such as osmotic pressure, temperature and oxidation, and decreases bacterial viability, which seem to reduce by applying cryoprotectants. The present study evaluated the effect of four cryoprotectants on decreasing the stress caused by freeze-drying process among three Lactobacillus species. Additionally, it highlighted the use of whey and maltodextrin as a substitute for peptone and sucrose in cryoprotectants respectively. The viability of lactobacilli was measured after freeze-drying, 1 month of storage at 25 and 4°C. Based on the results, the viability rate of bacteria in protectants during freeze-drying stage was dependent on their strains. The best viability of Lacticaseibacillus rhamnosus GG and Ligilactobacillus salivarius 20687 was, respectively, observed in the protectants containing sucrose and whey, while Lactiplantibacillus plantarum NRRL B-14768 viability was equal in all protectants. The number of live bacteria reduced significantly by storing bacteria for 1 month at 25°C compared to the 4°C storage. During the storage period, the viability of L. salivarius improved by adding sucrose in protectant. Due to the positive effect of whey and sucrose in the drying and storage stage, on bacterial viability, the protectant consisting of whey and sucrose is suggested for all of the species under study.
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Affiliation(s)
- R Majidzadeh Heravi
- Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - M Ghiasvand
- Department of Microbiology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - E Rezaei
- Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
| | - F Kargar
- Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
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Hayati F, Shahbazian H, Ghorbani A, Ahmadi Halili S, Rezaei E, Sabetnia L, Beladi Mousavi SS. Mycophenolate mofetil versus cyclophosphamide for idiopathic membranous nephropathy; a double blind and randomized clinical trial. J Nephropathol 2018. [DOI: 10.15171/jnp.2019.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Introduction: The current treatment regimens for patients with idiopathic membranous nephropathy (MN) are based on cyclophosphamide-glucocorticoid or calcineurin inhibitor-glucocorticoid. Objectives: We evaluated whether mycophenolate mofetil (MMF) -glucocorticoid could be an option for first-line therapy among these patients. Patients and Methods: In a double-blinded, randomized and controlled clinical trial, we compared the effect of MMF with cyclophosphamide in inducing complete or partial remission (PR) among patients with nephrotic syndrome due to idiopathic MN. All of the patients in both groups also received steroid, renin-angiotensin blockers and statins. Diuretics were also used in the patients who had edema. The primary end point of our study was change in urinary protein/creatinine ratio. Results: A total of 30 patients completed the study. Around 17 patients received MMF (2 g/d) and 13 patients received intravenous or oral cyclophosphamide for 6 months. At the start of the study, no significant differences in demographic and biochemical parameters of patients including the urinary protein excretion rate between two groups (P = 0.432). The proportion of proteinuria was 5235 ± 1655 mg/24 in MMF group and 8781 ± 8741 mg/24 in the cyclophosphamide group at the beginning of the study. The rate of complete and PR were 5.9% and 52.9 in MMF group versus 16.7% and 100% in cyclophosphamide group which it is significantly lower in MMF group. Kidney function was stable in both groups during treatment. Conclusions: According to the result of our study, a 6-month therapy with MMF-glucocorticoid is not recommended for treatment of patients with nephrotic syndrome due to idiopathic MN.
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Affiliation(s)
- Fatemeh Hayati
- Chronic Renal Failure Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Heshmatollah Shahbazian
- Chronic Renal Failure Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Ali Ghorbani
- Chronic Renal Failure Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Shahla Ahmadi Halili
- Chronic Renal Failure Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Eisa Rezaei
- Chronic Renal Failure Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Leila Sabetnia
- Chronic Renal Failure Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Seyed Seifollah Beladi Mousavi
- Chronic Renal Failure Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
- Tehran University of Medical Sciences, Baharloo Hospital, Tehran, Iran
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Manoochehri J, Masoumi Dehshiri R, Faraji H, Mohammadi S, Dastsooz H, Moradi T, Rezaei E, Sadeghi K, Fardaei M. Family screening for a novel ATP7B gene mutation, c.2335T>G, in the South of Iran. Iran J Ped Hematol Oncol 2014; 4:26-31. [PMID: 24734161 PMCID: PMC3980019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Accepted: 12/30/2013] [Indexed: 12/05/2022]
Abstract
BACKGROUND Wilson disease (WD) is a rare autosomal recessive disorder, which leads to copper metabolism, due to mutations in ATP7B gene. The gene responsible for WD consists of 21 exons that span a genomic region of about 80 kb and encodes a copper transporting P-type ATPase (ATP7B), a protein consisting of 1465 amino acids. Identifying mutation in ATP7B gene is important to find carrier individuals for proper counseling. A novel mutation in exon 8 of ATP7B gene, c.2335T>G (p.Trp779Gly), with severe neuropsychiatric condition in the South of Iran, was recently identified. The aim of this study was to screen 120 individuals from a large family using a simple amplification refractory mutation system PCR (ARMS-PCR) for carrier screening in the South of Iran. MATERIALS AND METHODS 120 individuals from family relatives of an index case in the Nasr Abad, south of Iran, were studied for screening of the c.2335T>G mutation. One patient with homozygous mutation and one homozygous normal individual were used as controls in this experiment. RESULTS Altogether, 16 out of 120 (13.3%) individuals within this region had heterozygous mutation. One individual with homozygote mutation was also identified. CONCLUSION Identification of carriers in families with affected individuals is of great importance for counseling before marriage. The results of this study can be used for further counseling programs in this population.
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Affiliation(s)
- J Manoochehri
- Department of Medical Genetics, Medical School, Shiraz University of Medical Sciences, Shiraz, Iran,Comprehensive Medical Genetics Centre, Shiraz, Iran
| | - R Masoumi Dehshiri
- Health Policy Research Center, Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran
| | - H Faraji
- Comprehensive Medical Genetics Centre, Shiraz, Iran
| | - S Mohammadi
- Comprehensive Medical Genetics Centre, Shiraz, Iran
| | - H Dastsooz
- Department of Medical Genetics, Medical School, Shiraz University of Medical Sciences, Shiraz, Iran,Department of Molecular Medicine, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran,Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran
| | - T Moradi
- Comprehensive Medical Genetics Centre, Shiraz, Iran
| | - E Rezaei
- Comprehensive Medical Genetics Centre, Shiraz, Iran
| | - Kh Sadeghi
- Comprehensive Medical Genetics Centre, Shiraz, Iran
| | - M Fardaei
- Department of Medical Genetics, Medical School, Shiraz University of Medical Sciences, Shiraz, Iran,Comprehensive Medical Genetics Centre, Shiraz, Iran,Department of Molecular Medicine, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
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Rezaei E, Farahani A, Buekens A, Chen T, Lu SY, Habibinejad M, Damercheli F, Andalib Moghadam SH, Gandomkar M, Bahmani A. Dioxins and furans releases in Iranian mineral industries. Chemosphere 2013; 91:838-843. [PMID: 23490183 DOI: 10.1016/j.chemosphere.2013.01.064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 12/20/2012] [Accepted: 01/16/2013] [Indexed: 06/01/2023]
Abstract
In this project, emissions of Poly-Chlorinated Dibenzo-p-Dioxins and Dibenzo-Furans (PCDD/Fs) were investigated and estimated for selected Iranian mining and ore processing industries, such as integrated iron & steel plant, primary production of aluminium and copper metal, and the production of cement. As a first step of this study the annual emission of PCDD/Fs was estimated at 120gTEQannum(-1) on the base of the UNEP standardised Toolkit for identification and quantification of dioxin and furan releases. Steel and cement were identified as major emission sources and earmarked for further scrutiny. For that reason, filter dust arising in these plants was sampled and analysed, as well as all raw materials employed. After extraction and clean-up according to standard methods, the resulting liquid samples were analysed and quantified by HRGC-HRMS. Complementary analyses using methods such as XRF, TGA/DTA were performed and the emission results statistically evaluated, in order to put PCDD/F emissions in perspective. It is concluded that the dioxins load of cement dust is unusually low, following the low carbon in raw materials, the use of natural gas as a fuel and the absence of waste incineration. Also the production of iron by direct reduction of ore is a low dioxins process; dioxin loads in dust are as usual - correlated with the presence of catalytic metals. Loss on ignition and chlorine are anti-correlated with the main earth elements and with sulphur oxides.
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Affiliation(s)
- E Rezaei
- Department of Environment, Iran Mineral Processing Research Center, Karaj, Iran
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Rezaei E, Navidi I, Rokni MB, Pourmand MR. Assessing the effect of highly cited papers on the impact factor of journals in the field of public health. Iran J Public Health 2012; 41:84-5. [PMID: 23641396 PMCID: PMC3640788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 11/10/2012] [Indexed: 11/03/2022]
Abstract
BACKGROUND The aim of this study was to appraisal the effect of highly cited papers in the field of public health and find out whether the unusual citations affect the ranking order of the journals in this field or not. A total number of 142 journals titles were listed in Journal Citation Report (ISI Thomson) in the field of "Public, Environmental & Occupational Health". All but one of them had published papers at least for a year from 2009 to 2010. Journal title, number of citations and publication year of 45685 papers were collected from ISI web of knowledge database at December 25, 2011. About half of the papers (23226) had no citations and 89.4% (40835) had less than 6 citations. We concluded that the ranking of journals in the field of public health is not affected by the individual papers with unusual number of citations.
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Affiliation(s)
- E Rezaei
- Dept. of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran,Students’ Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - I Navidi
- Dept. of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - MB Rokni
- Dept. of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - MR Pourmand
- Dept. of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran,Corresponding Author:
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Rezaei B, Rezaei E. Simultaneous determination of trace amounts of nickel, cobalt, and zinc in the wastewater of a galvanic workshop by using adsorptive cathodic stripping voltammetry. J Anal Chem 2006. [DOI: 10.1134/s1061934806030129] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Rezaei E, Quek L, Watson SP. A novel inhibitory action of wheat germ agglutinin on phospholipase C in HEL and MEG-01 cell lines. Biochim Biophys Acta 1997; 1356:101-10. [PMID: 9099996 DOI: 10.1016/s0167-4889(96)00160-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Stimulation of HEL megakaryocytic cells by Fc gammaRIIA crosslinking is associated with tyrosine phosphorylation of syk and phospholipase C gamma2 (PLCgamma2) and is accompanied by formation of inositol phosphates and release of intracellular Ca2+. These responses are inhibited by the kinase inhibitors, staurosporine and ST271. In contrast, the G-protein receptor agonist, thrombin induces formation of inositol phosphates and release of intracellular calcium without an increase in tyrosine phosphorylation. The plant lectin wheat germ agglutinin (WGA) stimulates tyrosine phosphorylation of syk and PLCgamma2 but surprisingly does not stimulate formation of inositol phosphates and induce release of intracellular Ca2+. WGA also inhibited formation of inositol phosphates and release of intracellular Ca2+ by Fc gammaRIIA crosslinking and thrombin-stimulation. A similar inhibitory effect of WGA was observed against elevation of Ca2+ by the same two stimuli in MEG-01 megakaryotic cells. The results demonstrate a novel pathway of inhibition of PLC on crosslinking of cell surface proteins that is not present in platelets.
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Affiliation(s)
- E Rezaei
- Department of Pharmacology, University of Oxford, UK
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Abstract
Diabetes-induced changes in the calcium influx and contractile responses of aortic rings to various drugs were investigated in streptozotocin-treated rats. Diabetes is associated with calcium influx into the aortic rings (1.5-and 2.5-fold, respectively, after either KCl or noradrenaline stimulation compared with normal). The maximum KCl-induced contraction of the arorta in diabetic rats was reduced by 38%, but the EC50 of KCl remained unchanged. The pA2 of nifedipine for inhibiting the contractile response of aorta to KCl decreased one order of magnitude in the diabetic rats (8.26 vs 9.03 for non-diabetic rats). It is concluded that diabetes reduces the sensitivity of aortic tissue to nifedipine and may affect the stimulation-contraction coupling of vascular smooth muscle in such a way that a higher influx of calcium results after stimulation and that this may be responsible for diabetes-induced vascular complications.
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Affiliation(s)
- M Mahmoudian
- Department of Pharmacology, Iran University of Medical Science, Tehran, Iran
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Khoyi MA, Westfall DP, Buxton IL, Akhtar-Khavari F, Rezaei E, Salaices M, Sanchez-Garcia P. Norepinephrine and potassium induced calcium translocation in rat vas deferens. J Pharmacol Exp Ther 1988; 246:917-23. [PMID: 3418519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
To understand calcium regulation in smooth muscle, we studied both potassium- and norepinephrine-mediated alterations in the movement of calcium in the smooth muscle of rat vas deferens. We employed 45Ca to measure agonist-mediated calcium influx and efflux, as well as tissue calcium content. In addition we labeled tissues with [3H]myoinositol to measure the effect of norepinephrine on inositol phosphate generation. Stimulation of the vas deferens with 50 mM potassium caused a rapid influx of 45Ca (6-fold). Norepinephrine stimulation, even at a concentration maximal for contraction of the tissue (1 mM), did not result in any alteration in 45Ca influx by itself but inhibited potassium-stimulated 45Ca influx (IC50 = 3 microM). This alpha receptor-mediated effect of norepinephrine was not diminished by either pretreatment with reserpine or adrenergic denervation. Studies of the efflux of 45Ca from vas deferens revealed that efflux was not affected by potassium but was significantly stimulated by norepinephrine. Alpha receptor stimulation of vas deferens smooth muscle caused a marked elevation in the appearance of inositol phosphates, particularly inositol trisphosphate, that was not dependent on extracellular calcium. We conclude that norepinephrine does not stimulate calcium influx in vas deferens smooth muscle but leads to the release of calcium from intracellular stores via formation of inositol trisphosphate and that the resulting increase in intracellular calcium may lead to inactivation of the potential-dependent calcium channel.
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Affiliation(s)
- M A Khoyi
- Department of Pharmacology, University of Nevada School of Medicine, Reno
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Akhtar-Khavari F, Khoyi MA, Rezaei E. Effects of amiloride on contractions and the release of tritium from rat vas deferens preloaded with [3H]-noradrenaline. Br J Pharmacol 1981; 74:123-7. [PMID: 7272596 PMCID: PMC2071893 DOI: 10.1111/j.1476-5381.1981.tb09963.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
1 The effect of amiloride was studied on contractions and tritium release from rat vas deferens preloaded with [3H]-noradrenaline. 2 Amiloride had no effect on the resting tension and maximal contractile force of the vas deferens and did not alter the ED50 of noradrenaline. 3 Amiloride (10(-4)-10(-3)M) decreased the response of vas deferens to electrical stimulation dose-dependently without inhibiting the response to KCI (60mM). 4 The effect of amiloride was not prevented by preincubation of the tissue with phentolamine, propranolol, atropine or indomethacin. 5 Amiloride did not alter the spontaneous outflow of radioactivity from [3H]-noradrenaline labelled vasa deferentia. 6 Amiloride decreased the release of tritium induced by electrical stimulation or nicotine but did not inhibit the release of radioactivity induced by KCI or tyramine. 7 It is concluded that amiloride may inhibit the contractions of rat vas deferens by inhibiting the release of noradrenaline.
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