ABSTRACT
Background: Vibrio paraheamoloyticus is one the causative agents of vibriosis with high mortality in farmed fish and shrimp and under predisposing conditions
Objectives: This study was aimed to assess the effect of gamma irradiation on the inactivation of V. paraheamoloyticus under fresh and freeze-dried conditions
Methods: Vials of 0.5 ml fresh culture of the bacterial suspensions at 1.5[asterisk]10[10] cfu/ml were subjected to 1, 1.5,2, 2.5, 3 and 4 KGy. Also, vials of 0.5 ml freeze-dried culture of the bacterial suspensions at 1.5 x 1010 cfu/ml were subjected to 2, 4, 7 and 8 KGy. The bacterial growth behavior was then evaluated on fresh medium
Results: The obtained results showed that the minimum doses of 4 and 10 KGy were sufficient for the inactivation of fresh and freeze-dried bacteria, respectively
Conclusions: The result of this study shows that inactivation of V. paraheamolyicus in fresh culture condition requires below half- dosage of gamma ray required for the inactivation of the freeze- dried of bacterial cells
ABSTRACT
Saffron, the dried stigmas of crocus sativus, is the world's most expensive spice which has been used as food additive and flavoring agent. The aim of the present study has been to investigate the combination effects of gamma irradiation and silver nano particles packing on the chemical properties of saffron during storage time. A combination of hurdles can ensure stability and microbial safety of foods. To investigate the combination effects, saffron samples were packed by Poly Ethylene films which were possed up to 300 ppm nano silver particles as antimicrobial agents and then irradiated in cobalt-60 irradiator [gamma cell Model: PX30, dose rate 0.55 Gy/sec] to 0, 1, 2 ,3 and 4 kGy at room temperature. UVspectrophotometer was used to quantify the most important components crocin, picrocrocin and safranal which were respectively responsible for color, taste and odor. Statistical analysis showed that irradiation and silver nano particles films packing could increase the flavor and aroma of saffron, and the best optimum dose of irradiation was 2 kGy. Also, sensory evaluation showed no significant difference between them [P<0.05]. Hurdle technology has been more effective than irradiation or nano-silver particles packing methods. Therefore combined method can be used for microbial decontamination of saffron with no significant differences on chemical characteristics and sensory attributes
Subject(s)
Gamma Rays , Nanoparticles , Silver , Crocus/chemistryABSTRACT
Today evidence-based medicine [EBM] has been accepted as a new and reliable paradigm in medical sciences and considered to improve the quality of medical practice. The objective of this study was to assess the knowledge and attitudes of Kerman Medical University [KMU] residents about EBM and the rate of its application. This cross sectional study was conducted in November 2009. A valid and reliable questionnaire was completed by residents at KUM. Ninety four residents participated in the study in which 55.3% were male, the mean age was 32.7 years and the mean time from graduation as a General Physician was 5.6 years, 83.3% of respondents thought that EBM was beneficial in patient care but only 5.3% of them claimed they use EBM in more than half of their clinical work and 88.3% of the participants expressed interest in learning EBM. The information source for clinical decision making in 59.6% of the residents was the text book, 41.4% clinical judgment combined with text books and only 19.2% articles. The residents of KMU have limited knowledge about EBM and it is a necessity to schedule EBM education programs to increase the resident's knowledge and application
ABSTRACT
Background and aim: Some investigators believe that the amount of REM sleep is increased after learning of some tasks, and learning processing and memory consolidation occur during some of these periods. These specific periods are called Paradoxical Sleep Windows [PSW]. The neurochemical nature of PSW and its active neurotransmitter are unknown
Methods: NMRI rats were trained in a two-way shuttle avoidance task [100 trials per one session] and memory retention was tested one week later. Those animals that reached to 70% learning criterion were divided into 8 groups. In drug section, the animals of each group were administrated saline, caffeine [25mg/kg], adenosine [7mg/kg], adenosine [50mg/kg], physostigmine [0.1mg/kg] or Scopolamine [5mg/kg i.p.], after learning. In drug-deprivation section, the first group was deprived from REM sleep for 1-4hr after learning with platform technique. Animals in second group were administrated caffeine [25mg/kg] in addition to REM sleep deprivation for 1-4 hr after learning
Results: Injection of caffeine caused a significant increase in memory [P<0.05]. Deprived animals showed a significant memory deficit [P<0.05] and caffeine attenuated memory impairment which was induced by paradoxical sleep deprivation. Other drugs had no significant effect on memory
Conclusion: Caffeine can enhance memory and attenuate paradoxical sleep deprivation-induced memory impairment. Effects of caffeine on memory involve systems other than cholinergic and adenosine systems. Memory processing which occurs in PSW can not be attributed to one neurotransmitter system
ABSTRACT
REM sleep has a role in memory processing. The period of post-learning, that REM sleep is higher than normal level and deprivation of REM sleep impairs memory, is called paradoxical sleep windows [PSW]. In this experimental study, male N.M.RI rats were trained in a two-way shuttle avoidance task [100 trials/one sessions] then memory retention was tested in next week. In electrophysiology section, different sleep-memory factors were recorded in basal level and 1-4 hours after training. In behavioral section, animals that reached 70% learning criterion [learner group] were deprived of PS in the two periods of 1-4 hours and 5-8 hours after learning by Maze water technique. The amount of REM sleep in group which gained 70% learning after 1-4 hours training, and group without it. In v.s of basic level, significantly increase [p<0.01]. Other factors were showed no significant difference between two groups before training. In behavioral section those animals were deprived in 1-4 hr post-learning show significant memory impairment [p<0.05]. Paradoxical increased REM sleep is effective in memory consolidation after 1-4 hours training. This period can be consider as paradoxical sleep window
Subject(s)
Male , Animals, Laboratory , Sleep, REM , Memory Disorders/etiology , Avoidance Learning , Rats , Sleep StagesABSTRACT
Gamma-amino butyric acid [GABA], an amino acid, present in some inhibitory neurons of the central nervous system, is also found in relatively high levels in the islets of Langerhans. Results of different studies concerning the effect of GABA on insulin secretion are controversial. The aim of this study was to determine the role of GABA and GABAB receptors on glucose-stimulated insulin secretion in isolated islets of rats. The collagenase digestion technique was used to isolate the islets from pancreata of 45 male Wistar rats [200-250g]. Insulin secretion was assessed in eight islets in each cup exposed to different concentrations of glucose [8.3 and 16.7 mM] in the presence or absence of GABA [25, 50, 100 micro M], baclofen [10, 20, 50 micro M] [GABAB agonist] and saclofen [50,100 micro M] [GABAB antagonist]. Insulin concentration was measured by the ELISA method. Insulin release was reported as mean +/- SEM micro U/isIet/50 min and p values of <0.05 were considered significant. GABA inhibited glucose [8.3 and 16.7 mM]-induced insulin secretion in isolated islets [P<0.05]. Different concentrations of baclofen had no significant effect on glucose-induced insulin secretion; however glucose [16.7 mM] stimulated insulin secretion in the presence of 100 micro M saclofen [91 +/- 8.8 micro U/islet/60 min] was significantly [p<0.05] higher compared to insulin secretion stimulated by 16.7 mM glucose alone [67.7 +/- 2.58 micro U/islet/60 min]. These findings indicate that GABA has an inhibitory effect on glucose-induced insulin secretion; and therefore it may play a regulatory role in insulin secretion. This effect needs to be taken in to account in the pathophysiology of diabetes
Subject(s)
Male , Animals, Laboratory , Islets of Langerhans/physiology , Diabetes Mellitus/physiopathology , Insulin/metabolism , Rats, Wistar , Baclofen/analogs & derivativesABSTRACT
Introduction: The nucleus locus coeruleus [LC] is located next to the fourth ventricle of the brain. Behavioral and electrophysiological studies have revealed the importance of LC noradrenergic projections in processes such as attention, learning and memory. Long-term potentiation [LTP] in hippocampal neurons is believed to be neural basis of learning and memory. The effects of LC on hippocampal electrophysiology have been investigated since many years ago, but have had different and conflicted results
Objective: In this study the effect of reversible inactivation of LC on induction and maintenance of LTP in hippocampal dentate gyrus [DG] of male anesthetized rats was investigated
Materials and Methods: This is an expelimental study. Inactivation of LC was conducted through bilateral injection of 0.5microl lidocaine [4%]. For producing LTP, two high frequency stimulations [HFS], 5 minutes apart were given to perforant pathway [PP] neurons. The amplitude of population spikes [PS] and the slope of population excitatory post synaptic potentials [PEPSP] were recorded before and 5, 10, 20, 40, 60 and 120 minutes after tetanic stimulations in DG
Results: The findings of this study showed that inactivation of LC had no effect on DG granule cells baseline activity. Also, LC inactivation 5 minutes before HFS had no effect on LTP induction. However, PS amplitude was decreased significantly [P<0.05, P<0.01 respectively] in comparison with control group, 60 and 120 minutes after tetanization. Lidocaine injection after HFS had no effect on induced LTP
Conclusion: According to results, we can conclude that, LC inactivation has no effect on LTP production in DG area, but probably LC neurons regulate part of events that occurs during tetanic stimulations in granular cells and are necessary for maintenance of LTP in PS amplitude
ABSTRACT
[[18]F]KF, considered as a reference standard for positron emission tomography of the skeletal system, was produced by the bombardment of enriched water [[18O]H2O>95%] with high energy protons in NRCAM cyclotron. After the extraction of fluoride from enriched water as KF, and passing it through microbial filter and fine adjustment of acidity and osmolality, it was converted into an injectable form. Pre-clinical investigations and biological controls were performed to determine radioisotope distribution in laboratory rats, thus suitable information was gathered for imaging in humans. This radiopharmaceutical was proved to be quite safe and of high quality as a result of testing in laboratory rats
ABSTRACT
The role of red nucleus [RN] in the acquisition of rabbit eyeblink conditioned response has been a controversial issue. In the present study the effect of an RN lesion and changes in RN electrical activity during eyeblink conditioning have been investigated. Eighteen male albino rabbits, 1.5 to 2 kg in weight, were used. Animals were divided into four groups: The RN lesioned group which received a contralateral RN electrical lesion [2mA, 15 sec], the sham operated group, the electrophysiological group in which recording electrodes were implanted in the contralateral RN, and the intact [control] group. Rabbits received training for classical conditioning of the eyeblink response. A tone was the conditioned stimulus and an airpuff was the unconditioned stimulus. Our data shows that in the RN lesioned group eyeblink conditioned and unconditioned response amplitudes were significantly lower than the control and sham operated groups. Also the percentage of conditioned response incidence was decreased in the lesioned group and the latency of unconditioned response was significantly greater than the other two groups. In the electrophysiological group, RN rhythm was increased during learning. In conclusion it seems that the output of RN is capable of modulating the pathways mediating both conditioned and unconditioned responses