Anticonvulsant effects of Paeonia daurica subsp. macrophylla root extracts in pentylenetetrazol-induced seizure models in mice / Efectos anticonvulsivos de Paeonia daurica subsp. macrophylla extractos de raíz en modelos de convulsiones inducidas por pentilentetrazol en ratones

Introduction: In the present study, anticonvulsant effects of aqueous extract (AE), hydro-alcoholic crude extract (HE), and its fractions (F-CHCl3, F-EtOAc, F-MeOH) of Paeonia daurica subsp. macrophylla (P. daurica ssp. macrophylla) root examined by using a pentylenetetrazol-induced model (PTZ) on mice. Methods: HE and its fractions as well as AE, in concentrations of (100, 200 and 400 mg/kg), valproate (Val) (100 and 200 mg/kg), and saline (negative control) (10 mg/kg) were injected intraperitoneally (i.p.) 30 min before PTZ (80 mg/kg, i.p.). The time taken before the onset of myoclonic convulsions (MC), MC duration, time taken before the onset of generalized tonic-clonic seizures (GTCS), the duration of GTCS, and the percentage of GTCS and mortality protection recorded. The plant's anticonvulsant mechanisms were assessed using flumazenil (5 mg/kg, i.p.) before AE (100, 200, and 400 mg/kg, i.p.) injection. GraphPad Prism software was used to compare the differences between various treatment groups with one-way analysis of variance (ANOVA) followed by Tukey–Krammer multiple comparison tests. Results: All the plant samples except F-EtOAc significantly delayed the onset and decreased the duration of PTZ-induced MCS and GTCS, and significantly reduced the GTCS and mortality rate. Pretreatment with flumazenil diminished the significant anticonvulsant effects of AE against PTZ-induced seizures. Conclusions: It can report that extract of P. daurica ssp. macrophylla might be a helpful guide for future studies in the treatment of epilepsy.(AU)

Introducción: Epilepsia es el término usado para un grupo de trastornos caracterizado por las convulsiones espontáneas recurrentes. Un estudio enfocado en los productos naturales de los recursos tradicionales ofrece ventajas significativas que se están utilizando de manera más amplia en modelos animales de epilepsia y candidatos a mayor desarrollo clínico y sus fracciones (F-CHCl3, F-EtOAc, F-MeOH) de Paeonia daurica subsp. macrophylla (P. daurica ssp. macrophylla) raíz examinada utilizando un modelo inducido por pentilentetrazol (PTZ) en ratones. Métodos: La maceración dinámica utilizada para extraer HE de la planta y técnica de cromatografía en columna de sílice utilizada para obtener F-CHCl3, F-EtOAc, así como fracciones de F-MeOH. La extracción de raíces secas se utilizó con agua destilada y se provocó AE. Las muestras de plantas (100, 200 y 400 mg/kg), valproato (Val) (100 y 200 mg/kg) y suero (control negativo) se inyectaron por vía intraperitoneal (ip) 30 min antes de PTZ (80 mg/kg, ip). El tiempo transcurrido antes del comienzo de convulsiones mioclónicas (MC), duración de las MC, tiempo transcurrido antes del comienzo de convulsiones tónico-clónicas generalizadas (GTCS), la duración de GTCS, así como el porcentaje de GTCS y protección contra la mortalidad registrada. Los mecanismos anticonvulsivos de planta fueron evaluados mediante el uso de flumazenil (5 mg/kg, ip) antes de AE (100, 200 y 400 mg/kg, ip) inyección. Se utilizaba el software GraphPad Prism® comparando las diferencias entre varios grupos de tratamiento con un análisis unilateral de variación (ANOVA) seguido por las pruebas de comparación múltiple de Tukey's Krammer. Resultados: Todas las muestras de plantas, excepto F-EtOAc, retrasaron de manera considerable el inicio, y disminuyeron la duración de PTZ inducidos por MCS y GTCS, y redujo significativamente el GTCS, así como la tasa de mortalidad...(AU)

Anticonvulsant effects of Paeonia daurica subsp. macrophylla root extracts in pentylenetetrazol-induced seizure models in mice.

INTRODUCTION: In the present study, anticonvulsant effects of aqueous extract (AE), hydro-alcoholic crude extract (HE), and its fractions (F-CHCl3, F-EtOAc, F-MeOH) of Paeonia daurica subsp. macrophylla (P. daurica ssp. macrophylla) root examined by using a pentylenetetrazol-induced model (PTZ) on mice. METHODS: HE and its fractions as well as AE, in concentrations of (100, 200 and 400mg/kg), valproate (Val) (100 and 200mg/kg), and saline (negative control) (10mg/kg) were injected intraperitoneally (i.p.) 30min before PTZ (80mg/kg, i.p.). The time taken before the onset of myoclonic convulsions (MC), MC duration, time taken before the onset of generalized tonic-clonic seizures (GTCS), the duration of GTCS, and the percentage of GTCS and mortality protection recorded. The plant's anticonvulsant mechanisms were assessed using flumazenil (5mg/kg, i.p.) before AE (100, 200, and 400mg/kg, i.p.) injection. GraphPad Prism software was used to compare the differences between various treatment groups with one-way analysis of variance (ANOVA) followed by Tukey-Krammer multiple comparison tests. RESULTS: All the plant samples except F-EtOAc significantly delayed the onset and decreased the duration of PTZ-induced MCS and GTCS, and significantly reduced the GTCS and mortality rate. Pretreatment with flumazenil diminished the significant anticonvulsant effects of AE against PTZ-induced seizures. CONCLUSIONS: It can report that extract of P. daurica ssp. macrophylla might be a helpful guide for future studies in the treatment of epilepsy.

Anticonvulsant effects of Paeonia daurica subsp. macrophylla root extracts in pentylenetetrazol-induced seizure models in mice.

INTRODUCTION: In the present study, anticonvulsant effects of aqueous extract (AE), hydro-alcoholic crude extract (HE), and its fractions (F-CHCl3, F-EtOAc, F-MeOH) of Paeonia daurica subsp. macrophylla (P. daurica ssp. macrophylla) root examined by using a pentylenetetrazol-induced model (PTZ) on mice. METHODS: HE and its fractions as well as AE, in concentrations of (100, 200 and 400mg/kg), valproate (Val) (100 and 200mg/kg), and saline (negative control) (10mg/kg) were injected intraperitoneally (i.p.) 30min before PTZ (80mg/kg, i.p.). The time taken before the onset of myoclonic convulsions (MC), MC duration, time taken before the onset of generalized tonic-clonic seizures (GTCS), the duration of GTCS, and the percentage of GTCS and mortality protection recorded. The plant's anticonvulsant mechanisms were assessed using flumazenil (5mg/kg, i.p.) before AE (100, 200, and 400mg/kg, i.p.) injection. GraphPad Prism software was used to compare the differences between various treatment groups with one-way analysis of variance (ANOVA) followed by Tukey-Krammer multiple comparison tests. RESULTS: All the plant samples except F-EtOAc significantly delayed the onset and decreased the duration of PTZ-induced MCS and GTCS, and significantly reduced the GTCS and mortality rate. Pretreatment with flumazenil diminished the significant anticonvulsant effects of AE against PTZ-induced seizures. CONCLUSIONS: It can report that extract of P. daurica ssp. macrophylla might be a helpful guide for future studies in the treatment of epilepsy.

Dose concentration and spatial memory and brain mitochondrial function association after 3,4-methylenedioxymethamphetamine (MDMA) administration in rats.

MDMA-induced impairments of memory performance have been reported in different human and animal studies. However, the correlation between spatial memory impairment, brain mitochondrial function, and concentrations of MDMA and its metabolites has not yet been investigated despite it being needed for comparison with human studies. Therefore, the aim of this study was to investigate the dose concentration and spatial memory as well as brain mitochondrial function association after MDMA administration in rats. We assessed the effects of MDMA [0.5, 2.5, 5, 10 and 15 mg/kg; intraperitoneally (I.P)] on spatial memory of male Wistar rats in the Morris water maze test (MWM) and brain mitochondrial function (i.e., reactive oxygen species, mitochondrial membrane potential, swelling and outer membrane damage, cytochrome c release, and ADP/ATP ratio). Concentrations of MDMA and its metabolite, MDA, were determined in plasma, cerebrospinal fluid (CSF) and brain which was obtained immediately after probe test of MWM (i.e., 4 h after last training trial). The results of this study indicate nonlinear kinetics of MDMA after I.P adminstration. Also, an insignificant correlation was observed between MDMA doses and the MDA/MDMA ratio in plasma, CSF, and brain. Moreover, the results showed that MDMA, but not MDA, accumulated in brain tissue by increasing the administered doses. Beside, MDMA-induced impairments of spatial memory and brain mitochondrial function were significantly correlated with the concentrations of both MDMA and MDA in plasma, CSF, and brain. Therefore, it can be suggested that MDMA and its metabolite, MDA, affect spatial memory and brain mitochondrial function.

Therapeutic effects of oral liothyronine on aluminum phosphide poisoning as an adjuvant therapy: A clinical trial.

BACKGROUND: In aluminum phosphide (AlP) poisoning, death is mainly due to cardiovascular failure and refractory acute heart failure. There is a lot of evidence showing thyroid hormones have cardioprotective effects. OBJECTIVE: The purpose of this study was to evaluate the effect of oral liothyronine in the treatment of AlP poisoning. METHODS: Twenty-four patients from intensive care unit of Baharloo Hospital, Tehran, Iran, were included based on the inclusion and exclusion criteria. They were randomly divided into two parallel groups of 12 cases and 12 controls. Intervention in the case group was administration of 50 µg liothyronine via nasogastric tube after gastric lavage, in the first 6 h of poisoning. In both groups, the routine treatment of AlP poisoning was performed. Blood samples were prepared at the beginning of the study and after 12 h. Patients were followed up till discharge from the hospital or death. RESULTS: The findings demonstrated that oral liothyronine was able to significantly improve systolic blood pressure, arterial blood pH, and total thiol molecules and also could decrease lipid peroxidation, increase catalase activity, and prevent further decline in total antioxidant capacity. CONCLUSION: Liothyronine administration is effective in controlling AlP poisoning and can improve patients' outcome.

Ellagic acid ameliorates cuprizone-induced acute CNS inflammation via restriction of microgliosis and down-regulation of CCL2 and CCL3 pro-inflammatory chemokines.

Ellagic acid (EA) is a natural phenol antioxidant with various therapeutic activities. However, the efficacy of EA has not been examined in neuro-inflammatory conditions. Microglia making the innate immune system of the central nervous system (CNS) and are imperative cellular mediators of neuro-inflammatory processes. In this study, neuro-protective effects of EA on cuprizone (Cup)-induced acute CNS inflammation evaluated. C57BL/6J mice were fed with chow containing 0.2 % Cup for 3 weeks to induce acute neuro-inflammation predominantly in the corpus callosum (CC). EA was administered at different doses (40 or 80 mg/kg body weight/day/i.p) from the first day of the Cup diet. Microglia activation (microgliosis) and expression of microglia related chemokines during Cup challenge were examined. Results shows that EA significantly decreased the number of activated microglia cells (Iba-1+ cells) and also restricted proliferation of these cell population (Iba-1+/Ki67+ cells) in dose dependent manner. Consequently, concentration of microglial pro-inflammatory chemokines including monocyte chemoattractant protein-1/Chemokine (C-C motif) ligand 2 (MCP-1/CCL2), and macrophage inflammatory protein 1-alpha/Chemokine (C-C motif) ligand 3 (MIP-1-α/CCL3) dramatically reduced in CC after EA treatment. According to this results, we conclude that EA is a suitable therapeutic agent for moderation brain damages in neuro-inflammatory diseases.

Reduction of autophagy markers mediated protective effects of JNK inhibitor and bucladesine on memory deficit induced by Aß in rats.

Autophagy, the process of self-degradation of cellular components, has an important role in neurodegenerative diseases, such as Alzheimer's disease. In this study, we investigated the effects of SP600125 as c-Jun N-terminal kinase (JNK) inhibitor and bucladesine as a cyclic adenosine 3',5'-monophosphate (cAMP) analog on spatial memory and expression of autophagic factors in Aß-injected rats. Male Wistar rats were used. Rats were randomly allocated into five groups as following: amyloid beta (Aß)-only group, Aß + SP600125 (30 µg/1 µ/side, n = 7) and/or bucladesine (100 µM/1 µl/side, n = 7), and the normal control (vehicle only) group. The treatments were administered bilaterally to the CA1 sub-region of the hippocampus stereotaxically. Spatial reference memory was performed using Morris Water Maze 21 days later. The expression of authophagy markers (beclin1, Atg7, Atg12, and LC3 II/LC3 I) in the hippocampus was evaluated using western blotting. Compared to the vehicle group, Aß administration reduced spatial reference learning (P < 0.001) and memory (P < 0.01) and upregulated the expression of beclin1, Atg7, Atg12, and LC3 II/I (P < 0.0001). Compare to Aß-only group, the administration of SP600125 and/or bucladesine improved spatial reference learning (P < 0.001) and memory (P < 0.01). Compared to the Aß-only group, the treatment with SP600125 and/or bucladesine also reduced beclin1, Atg7, Atg12, and LC3 II/I (P < 0.0001) which was similar to amount of normal rats. In summary, it seems that the improvement of spatial memory by SP600125 and/or bucladesine in Aß-injected rats is in relation with normalizing of autophagy to the physiologic level, possibly through neuroprotection and/or neuroplasticity.

Formulation and evaluation of an in situ gel forming system for controlled delivery of triptorelin acetate.

The novel physical hydrogels composed of chitosan or its water soluble derivatives such as carboxymethyl chitosan (CMCh) and sodium carboxymethyl chitosan (NaCMCh) and opened ring polyvinyl pyrrolidone (OP-PVP) were used as a controlled delivery system for triptorelin acetate, a luteinizing-releasing hormone agonist. The in situ gel forming system designed according to physical interactions such as chains entanglements and hydrophilic attractions especially h-bonds of chitosan and/or NaCMCh and OR-PVP. In order to increase in situ gel forming rate the chitosan microspheres prepared through spray drying technique. The chitosan or NaCMCh/OR-PVP blends prepared at different ratios (0.05, 0.10, 0.12, 0.16, 0.20 and 0.24) and suspended in sesame oil as non-aqueous vehicle at different solid content (10-30%). The suitable ratio of polymers with faster in situ gel forming rate was selected for in vivo studies. The gel formation and drug release from the system was evaluated both in vitro and in vivo. In vitro and in vivo results were compared with Diphereline SR 3.75mg, a commercially available controlled delivery system of triptorelin. In vitro release studies showed a sustained release profile for about 192h with first order kinetics. In vivo studies on male rats by determination of serum testosterone were confirmed the acceptable performance of in situ gel forming system compared with Diphereline SR in decreasing the serum testosterone level for 35days, demonstrating the potential of the novel in situ gel forming system for controlled delivery of peptides.

Effects of training in the Morris water maze on the spatial learning acquisition and VAChT expression in male rats.

BACKGROUND AND THE PURPOSE OF THE STUDY: It has been well established that cholinergic pathway plays an important role in learning and memory processes. The present study was designed to evaluate the effects of Morris water maze (MWM) training on spatial memory acquisition and expression of the vesicular acetylcholine transporter (VAChT) in male rats. METHODS: In this study, training trials of all groups of animals were conducted in the MWM task. Rats received one training session consisting of four trials per day which continued for another four consecutive days. Controls received visible platform MWM training. The escape latency, the traveled distance and swimming speed for each rat were recorded and used to evaluate the performance of the animal during training period. For evaluation of expression of VAChT protein levels, brain tissues from animals in each experiment were obtained immediately after the last trial on the related experimental day and processed for immunohistochemistry staining and western blotting analysis. RESULTS: There was a significant difference between animals subjected to one day training and those receiving four days of training in escape latency and travel distance. There were an apparent increase in VAChT immunoreactivity in the medial septal area (MSA) and CA1 region of the hippocampus in one day and four day trained animals compared with controls (visible group). Quantitative immunostaining analysis by optical density measurements in the CA1 region and evaluation of immunopositive neurons in medial septal area of brain sections confirmed qualitative findings. Assessment of VAChT protein level expression in hippocampus by western blotting evaluation showed the same pattern of immunohistochemistry results. CONCLUSION: Overall, results of this study reveal changes in cholinergic neuron activity in different stages of training in the MWM task. Data suggest that there is a significant level of cholinergic neuronal activity during early stages of the training especially in the hippocampus region that may contribute to the apparent increase in VAChT expression.

The first phytochemical report of Galanthus transcaucasicus Fomin.

UNLABELLED: BACKGROUND AND THE PURPOSE OF STUDY: Galanthus transcaucasicus Fomin (Amaryllidaceae) is an endemic species to the Caucasia and Alborz mountains in Iran which locally named "Gole-Barfi". While there are many reports on pharmacological activities of Galanthus species' alkaloids, there is no report on G. transcaucasicus and this article is the first phytochemical study on this species. METHODS: Extracted alkaloids from G. transcaucasicus bulbs were isolated using different chromatographic methods and the structures of the components were determined by physical and spectroscopic data. RESULTS: Five isoquinoline type alkaloids namely galanthamine (8.04%), narwedine (6.90%), lycorine (19.48%), caranine (3.45%) and tazettine (5.75%) of total alkaloid extract were isolated from the bulbs of Galanthus transcaucasicus Fomin. MAJOR CONCLUSION: Because of the presence of biologically active alkaloids especially galanthamine and the major alkaloid lycorine in Gol-e-Barfi, the plant may be used as a natural source for pharmaceutical purposes.

Restoration of morphine-induced alterations in rat submandibular gland function by N-methyl-D-aspartate agonist.

The effects of morphine, 1-aminocyclobutane-cis-1,3-dicarboxylic (ACBD; NMDA agonist) and 3-((R)2-carboxypiperazin-4-yl)-propyl-l-phosphoric acid (CPP; NMDA antagonist) and their concurrent therapy on rat submandibular secretory function were studied. Pure submandibular saliva was collected intraorally by micro polyethylene cannula from anaesthetized rats using pilocarpine as secretagogue. Intraperitoneal injection of morphine (6 mg/kg) induced significant inhibition of salivary flow rate, total protein, calcium, and TGF-beta1 concentrations. Administration of ACBD (10 mg/kg) and CPP (10 mg/kg) alone did not influence secretion of submandibular glands. In combination therapy, coadministration of CPP with morphine did not influence morphine-induced changes in salivary function while ABCD could restore all morphine-induced changes. In combination treatment, ACBD prevented morphine-induced reduction of flow rate, total protein, calcium, and TGF-beta1 and reached control levels. It is concluded that morphine-induced alterations in submandibular gland function are mediated through NMDA receptors.

Rural domestic water consumption behavior: A case study in Ramjerd area, Fars province, I.R. Iran.

Identifying the factors that affect domestic water demand and consumption is very important in management of available regional water resources. In this study, relationships between water consumption and rural household activities are determined by comparing a snapshot of water consumption with rural household behavior of low, medium and high water consumers. In addition, the factors affecting water consumption in rural households are also determined. The data for this study were collected from a survey of 653 rural households in 33 villages of Ramjerd area, Fars Province, in southern Iran, using a simple random sampling technique. The daily water consumption data for a 5-year period (1999-2004) were used. Results of the study revealed that the daily average water consumption for the area was found to be 121.7 l per person per capita per day (Lpcd) (SD = 59.2). Water consumption was also found to be significantly correlated with explanatory variables such as "household size" and "age of household's head". Finally, the results of discriminant function analysis showed that in rural households, garden size, greenhouse size, and garden watering times per month with tap treated water are associated with water consumption.

Anti-infectives-induced adverse drug reactions in hospitalized patients.

OBJECTIVES: To assess the rate and seriousness of adverse drug reactions (ADRs) attributable to anti-infective agents in hospitalized patients; to estimate the likelihood of experiencing anti-infectives-induced ADRs at different length of drug usage in the hospital; to compare different classes of anti-infectives in inducing ADRs; to determine the impact of age and sex on anti-infectives-induced ADRs. DESIGN: Prospective cohort study. PARTICIPANTS: Patients admitted to the infectious diseases department at a university teaching hospital, on Sunday to Wednesday, over a 9 months period, who received at least one anti-infective agent were eligible to enter the study. MAIN OUTCOME MEASURES: Any suspected noxious and untoward medical events, including laboratory tests abnormalities following anti-infective therapy. METHODS: All patients admitted have received at least one anti-infective drug. Anti-infective agents induced ADRs were detected by interviewing patients and daily chart review. The seriousness, causality, and type of reactions were classified based on World Health Organization (WHO) definitions. Chi-square analysis was performed to assess the influence of sex and age on occurring ADRs. Both Kaplan-Meier and life table method were used to estimate the time to occur the ADR in anti-infective users. To compare the estimated risk of ADRs induced by different classes of anti-infectives, odds ratios were estimated. In all classes of anti-infectives, the odds ratio of each class was estimated with regard to anti-tuberculosis agents, which had the highest prevalence of ADRs. RESULTS: During the study period, 460 patients were entered the study. During the same period, 38 ADRs were recognized of which 20 (42%) were serious. The most recognized ADRs were suspected to be induced by anti-tuberculosis agents (29.8%). However in comparing with anti-tuberculosis agents, anti-fungal agents were associated with the highest ADR rate (odds ratio [OR], 4.21; 95% confidence interval [CI], 1.41-1.256) whereas cephalosporines were associated with the lowest rate, (OR, 0.1; 95%CI, 0.04-0.26). The survival analysis shows that the likelihood of experiencing an ADR was increased at first 14 days of drug therapy. Also Chi-square analysis shows that greater risk of anti-infectives-induced ADRs was observed in women. CONCLUSION: The rate of ADRs induced by anti-infective agents in this study was 8.2%. This is higher than a standard (5%) which has been reported in other studies. This study also shows that some of the classes of anti-infective agents like anti-fungals need more attention.

Evaluation of patient-related factors associated with causality, preventability, predictability and severity of hepatotoxicity during antituberculosis [correction of antituberclosis] treatment.

For evaluation the extent of antituberculosis drug-induced hepatotoxicity and also to determine the patient-related factors associated with causality, preventability, predictability and severity of hepatotoxicity induced by antituberculosis medications, a prospective study was conducted on 112 patients in a tertiary care university teaching hospital for three years. Causality, preventability, predictability and severity of hepatotoxicity were determined based on the available standard algorithms. Of 112 patients, 31 (27.7%) demonstrated hepatotoxicity. Two patients died from complications of liver-related illness. The mean duration of treatment before the onset of hepatotoxicity was 16.7+/-3.2 days. Malnutrition was present in 17 of 112 patients. Most of hepatotoxicity (25/31 or 80.6%) occurred within the first month of treatment. Reintroduction of antituberculosis drugs was possible in 29 of 31 patients. Univariate and multivariate analysis did not show significant relationships between the rate of hepatotoxicity with age, sex, nutrition and nationality. Our results showed that hepatotoxicity induced by antituberculosis drugs is a nonpreventable and unpredictable reaction. The causality of this reaction is classified as category A based on European grading of causality. This study noted that the frequency of hepatotoxicity induced by antituberculosis drugs in Iranian patients is higher than other studied populations.

Resonance Raman detection of carotenoid antioxidants in living human tissue.

Increasing evidence points to the beneficial effects of carotenoid antioxidants in the human body. Several studies, for example, support the protective role of lutein and zeaxanthin in the prevention of age-related eye diseases. If present in high concentrations in the macular region of the retina, lutein and zeaxanthin provide pigmentation in this most light sensitive retinal spot, and as a result of light filtering and/or antioxidant action, delay the onset of macular degeneration with increasing age. Other carotenoids, such as lycopene and beta-carotene, play an important role as well in the protection of skin from UV and short-wavelength visible radiation. Lutein and lycopene may also have protective function for cardiovascular health, and lycopene may play a role in the prevention of prostate cancer. Motivated by the growing importance of carotenoids in health and disease, and recognizing the lack of any accepted noninvasive technology for the detection of carotenoids in living human tissue, we explore resonance Raman spectroscopy as a novel approach for noninvasive, laser optical carotenoid detection. We review the main results achieved recently with the Raman detection approach. Initially we applied the method to the detection of macular carotenoid pigments, and more recently to the detection of carotenoids in human skin and mucosal tissues. Using skin carotenoid Raman instruments, we measure the carotenoid response from the stratum corneum layer of the palm of the hand for a population of 1375 subjects and develop a portable skin Raman scanner for field studies. These experiments reveal that carotenoids are a good indicator of antioxidant status. They show that people with high oxidative stress, like smokers, and subjects with high sunlight exposure, in general, have reduced skin carotenoid levels, independent of their dietary carotenoid consumption. We find the Raman technique to be precise, specific, sensitive, and well suitable for clinical as well as field studies. The noninvasive laser technique may become a useful method for the correlation between tissue carotenoid levels and risk for malignancies or other degenerative diseases associated with oxidative stress.

Gamma irradiator dose mapping simulation using the MCNP code and benchmarking with dosimetry.

The Monte Carlo transport code, MCNP, has been applied in simulating dose rate distribution in the IR-136 gamma irradiator system. Isodose curves, cumulative dose values, and system design data such as throughputs, over-dose-ratios, and efficiencies have been simulated as functions of product density. Simulated isodose curves, and cumulative dose values were compared with dosimetry values obtained using polymethyle-methacrylate, Fricke, ethanol-chlorobenzene, and potassium dichromate dosimeters. The produced system design data were also found to agree quite favorably with those of the system manufacturer's data. MCNP has thus been found to be an effective transport code for handling of various dose mapping excercises for gamma irradiators.

Effects of different periods of lithium pretreatment and aminoglycoside antibiotics on apomorphine-induced yawning in rats.

Interactive effects of intracerebroventricular administration of the aminoglycoside antibiotics, amikacin and gentamicin, and different duration of lithium pretreatment on apomorphine-induced yawning were investigated in male rats. The study was designed to investigate whether the hypothesis that the aminoglycoside antibiotics, amikacin and gentamicin, via their effects on phosphoinositide pathways and calcium channel might influence dopaminergic mechanisms as manifested in the yawning effect. Lithium is known to interact with phosphoinositide metabolism and was also tested after chronic studies on the apomorphine yawning model. Subcutaneous administration of apomorphine (0.1, 0.2 and 0.4 mg/kg) to rats induced yawning in a biphasic manner. However the maximum response was obtained by 0.2 mg/kg of the drug. Intracerebroventricular administration of aminoglycoside antibiotics amikacin (25 microg/rat) increased and gentamicin (10 and 20 microg/rat) decreased apomorphine-induced yawning. Pretreatment of animals with lithium (600 mg/l) in drinking water for 7, 14 and 21 days reduced yawning induced by apomorphine. Administration of lithium for 28 days did not induce any significant effect on yawning response. Amikacin and gentamicin function via the same mechanism on phosphoinositide cascade. Since amikacin and gentamicin did not affect the yawning response similarly, they apparently do not involve inositol trisphosphate level in the alterations of dopaminergic-induced yawning. Probably, the effect of lithium pretreatment on the number of yawns is also time-dependent and some tolerance to the inhibitory effect of lithium might occur after 28 days' treatment.

Muscle relaxant activity of methocarbamol enantiomers in mice.

Documented studies support the emerging idea that drug enantiomers could have different pharmacological activity. Our bibliographical data have shown that so far no report has been published on the pharmacological activity of individual enantiomers of methocarbamol. This study was conducted to characterize the muscle relaxant activity of methocarbamol enantiomers. The rotarod test was used to compare the muscle relaxant activity of racemic methocarbamol and pure enantiomers after intraperitoneal administration of the enantiomers to mice. The results show that (+)-R-methocarbamol has higher muscle relaxant activity compared with racemic methocarbamol or (-)-S-methocarbamol.

Effects of chronic lithium on ototoxicity induced by gentamicin and amikacin in guinea-pigs.

The effects of chronic lithium co-therapy on the expression of gentamicin and amikacin ototoxicity were tested in guinea-pigs. Intramuscular injection of different doses of gentamicin (5, 10 mg/kg/day) and amikacin (150, 300 mg/kg/day) for three weeks, induced hearing loss consistent with the established pattern of aminoglycoside ototoxicity. Lithium salts remains one of the most widely used treatment for depressive illness. Administration of lithium chloride (600 mg/l, 35 days) in drinking water changed auditory brainstem response in a time-dependent manner. Pretreatment of animals with lithium chloride after seven days induced significant alterations in wave latency and interval. The present study assesses the protective effects of chronic lithium on gentamicin-induced ototoxicity in guinea pig. The results suggest that duration of lithium administration may be involved in auditory brainstem response changes and the observations could be accounted for, at least partially, by lithium- and aminoglycosides-induced perturbations of the phosphoinositide cascade within the inner ear.

Interaction between lead acetate and morphine on antinociception in mice by formalin test.

1. In this study, the effects of lead acetate on two types of pain (nociception and inflammation) induced by formalin and its interactions with opioid system and morphine-induced analgesia were examined. Male albino mice weighing 22-27 g were used in the experiments. 2. To study nociception, the formalin test was selected. Morphine was administered subcutaneously 30 min before formalin injection. Lead acetate treatment was administered 90 min before any injection. Comparisons between groups were made by analysis of variance and then by Newman-Keuls test. Differences with P < or = 0.05 was considered statistically significant. 3. Different doses of morphine induced antinociception in both phases of the formalin test. Lead acetate induced non-dose-dependent nociception in the early phase and dose-dependent analgesia in the late phase. 4. Pretreatment with lead acetate antagonized the effect of morphine in the early phase. In the other hand, the effect of lead acetate in the early phase was reduced by morphine and its effect eliminated in the late phase. 5. It is concluded that lead can modulate pain response and interact with morphine-induced antinociception. Additional research to find the mechanisms of these effects are suggested.