Publications by authors named "Mohamad Najafi"

5 Publications

  • Page 1 of 1

Effects of organic acid alone and in combination with HO and NaCl on Escherichia coli O157:H7: An evaluation of antioxidant retention and overall acceptability in Basil leaves (Ocimum basilicum).

Int J Food Microbiol 2019 Mar 14;292:56-63. Epub 2018 Dec 14.

Health and Food Quality Control Department, Faculty of Veterinary, Zabol University, Bonjar Ave, Zabol, Iran.

In this study, the efficacy of household sanitizers application on reduction of Escherichia coli O157:H7, ascorbic acid, total phenolics, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging and overall acceptability of inoculated fresh basil leaves (Ocimum basilicum), at temperature of 40 °C was investigated. Sanitizers containing lactic acid (LA), acetic acid (AA) and citric acid (CA) were used at concentration of 2%, individually or in combination with HO (1% or 2%), and NaCl (7%). Control a and b were unwashed and washed leaves with distilled, deionized and sterilized water, respectively. All sanitizing treatments, in comparison to the control a, reduced the numbers of E. coli O157:H7 (0.24 ± 0.12-3.37 ± 0.48 log CFU/g) at day 1 (1 h after sanitizing). The lowest number of E. coli O157:H7 population (2.35 ± 0.26 log CFU/g) was observed by applying the LA + HO (%2) treatment at first day of chilled storage. The highest amount of ascorbic acid (27.77 ± 0.06 mg/100 g), total phenolic (112.2 ± 0.5 mg gallic acid equivalents/100 g) and DPPH radical scavenging activity (95.2 ± 0.5%) was observed in control a at first day (P < 0.05). The results showed that the amount of ascorbic acid, total phenolics, DPPH radical scavenging activity and overall acceptability of basil leaves decreased during chilled storage. On day 2 of storage, the scores of sensory attributes for the control group were less than the minimum score of acceptance (i.e. 5 points). The results of this study indicated that LA + HO (2%) treatment rendered the samples favorable in terms of overall appearance (≥5) up to 48 h.
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http://dx.doi.org/10.1016/j.ijfoodmicro.2018.12.010DOI Listing
March 2019

Effects of Vitamin E on seizure frequency, electroencephalogram findings, and oxidative stress status of refractory epileptic patients.

Adv Biomed Res 2016 16;5:36. Epub 2016 Mar 16.

Department of Neurology, Isfahan University of Medical Sciences, Isfahan, Iran.

Background: Oxidative stress has been a frequent finding in epileptic patients receiving antiepileptic drugs (AEDs). In this study, the influence of Vitamin E on the antiseizure activity and redox state of patients treated with carbamazepine, sodium valproate, and levetiracetam has been investigated.

Materials And Methods: This double-blind, placebo-controlled trial was carried out on 65 epileptic patients with chronic antiepileptic intake. The subjects received 400 IU/day of Vitamin E or placebo for 6 months. Seizure frequency, electroencephalogram (EEG), and redox state markers were measured monthly through the study.

Results: Total antioxidant capacity, catalase and glutathione were significantly higher in Vitamin E received group compared with controls (P < 0.05) whereas malodialdehyde levels did not differ between two groups (P < 0.07). Vitamin E administration also caused a significant decrease in the frequency of seizures (P < 0.001) and improved EEG findings (P = 0.001). Of 32 patients in case group, the positive EEG decreased in 16 patients (50%) whereas among 33 patients in control group only 4 patients (12.1%) showed decreased positive EEG.

Conclusion: The results of this preliminary study indicate that coadministration of antioxidant Vitamin E with AEDs improves seizure control and reduces oxidative stress.
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http://dx.doi.org/10.4103/2277-9175.178780DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4815530PMC
April 2016

Tracing of false negative results in phenotypic methods for identification of carbapenemase by Real-time PCR.

Gene 2016 Jan 9;576(1 Pt 1):166-70. Epub 2015 Oct 9.

Department of Microbiology, Iran University of Medical Sciences, Tehran, Iran. Electronic address:

Background: Carbapenemase production causes multi antibiotics resistant in Gram-negative bacteria. A simple rapid and accurate phenotypic test for detection of Gram-negative carbapenemase-producing bacteria is useful for the treatment of infections. The aim of this study was to track the negative results in carbapenemase phenotypic test by Real-time PCR.

Materials And Methods: In this study, 161 imipenem resistant Gram-negative bacteria were surveyed. Modified Hodge Test (MHT), boronic acid (BA), EDTA and dipicolinic acid were used for detection of Klebsiella pneumoniae carbapenemase (KPC) and metallo-beta-lactamase (MBLs). Different phenotypic methods and PCR confirmation followed by Real-time PCR for determination of phenotypic false-negative results were used.

Results: Our results indicated that 85, 51 and 112 strains were MHT, BA and dipicolinic acid positive, respectively. No synergistic effect was observed between imipenem and EDTA. Sixty-nine strains were confirmed as carbapenemase-producers according to the results of molecular tests. All of the isolates carried the gene and expressed carbapenemase.

Conclusion: Comparison between the results of phenotypic and genotypic methods showed that the phenotypic methods could be used as the primary screening and the PCR remains as the gold standard for detection of carbapenemase positive strains.
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http://dx.doi.org/10.1016/j.gene.2015.10.008DOI Listing
January 2016

Global dust Detection Index (GDDI); a new remotely sensed methodology for dust storms detection.

J Environ Health Sci Eng 2014 Jan 9;12(1):20. Epub 2014 Jan 9.

Department of Remote Sensing and GIS, Faculty of Geography, University of Tehran, Tehran, Iran.

Dust storm occurs frequently in arid and semi-arid areas of the world. This natural phenomenon, which is the result of stormy winds, raises a lot of dust from desert surfaces and decreases visibility to less than 1 km. In recent years the temporal frequency of occurrences and their spatial extents has been dramatically increased. West of Iran, especially in spring and summer, suffers from significant increases of these events which cause several social and economic problems. Detecting and recognizing the extent of dust storms is very important issue in designing warning systems, management and decreasing the risk of this phenomenon. As the process of monitoring and prediction are related to detection of this phenomenon and it's separation from other atmospheric phenomena such as cloud, so the main aim of this research is establishing an automated process for detection of dust masses. In this study 20 events of dust happened in western part of Iran during 2000-2011 have been recognized and studied. To the aim of detecting dust events we used satellite images of MODIS sensor. Finally a model based on reflectance and thermal infrared bands has been developed. The efficiency of this method has been checked using dust events. Results show that the model has a good performance in all cases. It also has the ability and robustness to be used in any dust storm forecasting and warning system.
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http://dx.doi.org/10.1186/2052-336X-12-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3898669PMC
January 2014

Vitamin B(12) Deficiency and Multiple Sclerosis; Is there Any Association?

Int J Prev Med 2012 Apr;3(4):286-9

Department of Neurology and Isfahan Neuroscience Research Center, Isfahan, Iran.

Background: Vitamin B(12) (Cobalamin) deficiency can result in some clinical and paraclinical characteristics similar to what is seen in multiple sclerosis (MS) patients. This study aimed to evaluate the controversial association between vitamin B(12) deficiency and MS.

Methods: We measured serum vitamin B(12) in 60 patients with MS and 38 healthy controls. Clinical disability was evaluated according to the Extended Disability Status Scale (EDSS). Serum B(12) concentration was measured with Radioimmunoassay Dual Isotope method. The cutoff value for low serum vitamin B(12) concentrations was 75 pg/mL. Patients were in remission at the time of blood draw.

Results: There were 13 (21.6%) MS patients and 10 (26.3%) controls with low serum B(12) concentration with no significant difference between the groups; P>0.05. The mean serum vitamin B(12) concentration in MS patients (108.9±45.3 pg/mL) was not significantly different compared with controls (98.9±44.4 pg/mL); P=0.284. Likewise, there was no correlation between the concentration of serum vitamin B(12) and disease' age of onset, duration, subtypes, or disability status.

Conclusions: In contrast to some previous reports, our findings did not support any association between B(12) deficiency and MS.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3354399PMC
April 2012