Study of thermodynamic properties of imidazolium-based ionic liquids and investigation of the alkyl chain length effect by molecular dynamics simulation

In this paper, structural and dynamical properties of five imidazolium-based ionic liquids (ILs) [amim]Br (a = methyl, ethyl, butyl, pentyl, hexyl) were studied by molecular dynamics simulations. United atom force field (UAFF) has been used for the representation of the interaction between ions. Good agreement with experimental data was obtained for the simulated density based on the UAFF. The calculated densities gradually decrease with an increase in the length of alkyl side chain, which is a result of weakening the electrostatic interaction between ions. The simulated heats of vaporisation are higher than that of non-ILs and decrease with an increase in temperature. Radial distribution function (RDF) was employed to analyse the local structure of ILs. Cation–anion RDFs show that the anions are well organised around the cation in two shells (0.41 and 0.6 nm). The velocity autocorrelation functions of the anion and cations show that the relaxation time increased with an increase in the length of the alkyl side chain. The diffusion coefficients of ions were calculated by mean square displacement of the centre of mass of the ions at 400 K. The calculated diffusion coefficients using UAFF agree well with other all atom force fields. Also diffusion coefficients decrease with an increase in the length of the alkyl side chain. The calculated transference numbers show that the cation contributes more than anion in the electrical current. The diffusion coefficients increase with temperature.     

Penconazole induced changes in photosynthesis, ion acquisition and protein profile of Mentha pulegium L. under drought stress

Effect of penconazole (PEN) treatment on drought-stressed Mentha pulegium L. plants was investigated. Six weeks after sowing, seedlings were grown under soil moisture corresponding to 100, 75, 50 and 25 % field capacity (FC) with or without PEN (15 mg l⁻¹) for 4 weeks. Results showed that the seedlings at 75 % FC showed maximum growth and water supply lower than 75 % FC was the threshold of drought-initiated negative effects on seedling growth. Drought stress significantly induced proline and carbohydrate contents and the decreased chlorophyll, photosynthesis parameters, soluble proteins and ion accumulations. Exogenous PEN increased the growth parameters, pigments, photosynthesis and ion accumulations in drought stressed and unstressed plants, but the effects of PEN were more significant under water deficit conditions. PEN also reduced the negative effects of drought by osmotic balance and protein accumulations. Electrophoretic patterns indicated that PEN treatment increased the intensity of some protein bands with the molecular weights of 30 kDa in shoot and 31 kDa in roots, and several new protein bands with the molecular masses between 116 and 14 kDa appeared in leaves, shoots and roots. These results suggest that the PEN application can be a useful tool in alleviation of effects of drought stress in M. pulegium plants.     

Microstructural,Densitometric and Metabolic Variations in Bones from Rats with Normal or Altered Skeletal States

Background

High resolution μCT, and combined μPET/CT have emerged as non-invasive techniques to enhance or even replace dual energy X-ray absorptiometry (DXA) as the current preferred approach for fragility fracture risk assessment. The aim of this study was to assess the ability of µPET/CT imaging to differentiate changes in rat bone tissue density and microstructure induced by metabolic bone diseases more accurately than current available methods.

Methods

Thirty three rats were divided into three groups of control, ovariectomy and vitamin-D deficiency. At the conclusion of the study, animals were subjected to glucose (¹⁸FDG) and sodium fluoride (Na¹⁸F) PET/CT scanning. Then, specimens were subjected to µCT imaging and tensile mechanical testing.

Results

Compared to control, those allocated to ovariectomy and vitamin D deficiency groups showed 4% and 22% (significant) increase in ¹⁸FDG uptake values, respectively. DXA-based bone mineral density was higher in the vitamin D deficiency group when compared to the other groups (cortical bone), yet μCT-based apparent and mineral density results were not different between groups. DXA-based bone mineral density was lower in the ovariectomy group when compared to the other groups (cancellous bone); yet μCT-based mineral density results were not different between groups, and the μCT-based apparent density results were lower in the ovariectomy group compared to the other groups.

Conclusion

PET and micro-CT provide an accurate three-dimensional measurement of the changes in bone tissue mineral density, as well as microstructure for cortical and cancellous bone and metabolic activity. As osteomalacia is characterized by impaired bone mineralization, the use of densitometric analyses may lead to misinterpretation of the condition as osteoporosis. In contrast, µCT alone and in combination with the PET component certainly provides an accurate three-dimensional measurement of the changes in both bone tissue mineral density, as well as microstructure for cortical and cancellous bone and metabolic activity.     

Dirofilaria repens diagnosed by the presence of microfilariae in fine needle aspirates: a case report

BACKGROUND: Dirofilariasis due to Dirofilaria repens with viable microfilariae outside the worm have not been reported before. CASE: A 40-year-old truck driver from rural Shiraz, Iran, had a firm mass, 2.5 x 2.5 cm, at the dorsolateral aspect of the right forearm. Fine needle aspiration (FNA) was performed on 2 occasions. Several microfilariae with blunt heads, pointed posterior ends and empty caudal spaces resembling microfilariae of Wuchereria bancrofti but longer were seen. Since Iran is a nonendemic area for lymphatic filariae and the patient had a history of contact with a dog, with the impression of dirofilariasis, the mass was excised, and the presence of adult worms in tissue sections confirmed the diagnosis. CONCLUSION: This case ofsubcutaneous dirofilariasis was diagnosed by detecting microfilariae in FNA smears and was confirmed on histopathology.     

Efficacy of an osmotic pump delivered,GM-CSF-based tumor vaccine in the treatment of upper aerodigestive squamous cell carcinoma in rats

PURPOSE: Upper aerodigestive tract (UADT) cancer has not experienced significant overall survival improvement for over 20 years, and no successful treatments for systemic disease exist. Most patients with UADT cancer experience immune suppression, therefore immune restorative therapies may offer promise for these patients. We presently tested the efficacy of granulocyte macrophage-colony stimulating factor (GM-CSF) delivered via 28-day continuous infusion pump, in combination with irradiated tumor cells, in a flank model of UADT cancer. METHODS: Five groups of rats were inoculated with syngeneic mucosally derived squamous carcinoma cells (FAT-7). Osmotic minipumps were implanted in the contralateral flank to deliver GM-CSF at 0 (PBS), 0.1, 1, 10, or 100 ng/day (n = 6 per group) for 28 days; 10(6) irradiated FAT-7 cells (ITC) were injected at the site of the GM-CSF infusion on days 0, 3, 7, 14, and 21 immune infiltrates in tumors were analyzed. RESULTS: Rats that received 10 or 100 ng/day GM-CSF/ITC had a significantly slower tumor growth rate compared to those who received 0, 0.1, or 1 ng/day (ANOVA, P < 0.01). There were increased CD 4+, CD 8+, and CD 68+ cells in tumors of GM-CSF/ITC treated animals over controls. CONCLUSION: GM-CSF (10 or 100 ng/day) delivered locally via osmotic pump with ITC slows the growth rate of mucosally derived squamous cell carcinoma in rats while improving immune cell infiltrates. The efficacy of locally delivered GM-CSF immunotherapy in this model may be a first step toward this immunotherapy strategy for humans.     

Isozyme variation in some populations of wild diploid wheats in Iran

Isozyme electrophoresis data of seed extracts from 11 populations of diploid wheat species (Triticum boeoticum Bioss. and Triticum urartu Thumanian ex Gandilyan), distributed mainly in the western and west-northern Iran, were investigated. The five enzyme systems used were peroxidase, polyphenol oxidase, superoxide dismutase, malate dehydrogenase and catalase. The first three were found to be useful as molecular marker for characterization of diploid wheat populations. A total of 13 bands from three enzyme systems were recorded. The value of a ‘Jaccard's’ similarity coefficient ranges from 0.333 to 1.000. Data analysis was done using clustering method UPGMA. On the basis of Jaccard's coefficient, the obtained dendrogram supports previous relationship between T. boeoticum and T. urartu as separate species as well as reflecting their distinct gene pools and substantiating their specific recognition despite the overall morphological similarity.     

Analysis of Neurotrophic Factors in Limb and Extraocular Muscles of Mouse Model of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is currently an incurable fatal motor neuron syndrome characterized by progressive weakness, muscle wasting and death ensuing 3–5 years after diagnosis. Neurotrophic factors (NTFs) are known to be important in both nervous system development and maintenance. However, the attempt to translate the potential of NTFs into the therapeutic options remains limited despite substantial number of approaches, which have been tested clinically. Using quantitative RT-PCR (qRT-PCR) technique, the present study investigated mRNA expression of four different NTFs: brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), neurotrophin-4/5 (NT-4) and glial cell line-derived neurotrophic factor (GDNF) in limb muscles and extraocular muscles (EOMs) from SOD1^G93A transgenic mice at early and terminal stages of ALS. General morphological examination revealed that muscle fibres were well preserved in both limb muscles and EOMs in early stage ALS mice. However, in terminal ALS mice, most muscle fibres were either atrophied or hypertrophied in limb muscles but unaffected in EOMs. qRT-PCR analysis showed that in early stage ALS mice, NT-4 was significantly down-regulated in limb muscles whereas NT-3 and GDNF were markedly up-regulated in EOMs. In terminal ALS mice, only GDNF was significantly up-regulated in limb muscles. We concluded that the early down-regulation of NT-4 in limb muscles is closely associated with muscle dystrophy and dysfunction at late stage, whereas the early up-regulations of GDNF and NT-3 in EOMs are closely associated with the relatively well-preserved muscle morphology at late stage. Collectively, the data suggested that comparing NTFs expression between limb muscles and EOMs from different stages of ALS animal models is a useful method in revealing the patho-physiology and progression of ALS, and eventually rescuing motor neuron in ALS patients.     

Noninvasive Assessment of Cardiac Abnormalities in Experimental Autoimmune Myocarditis by Magnetic Resonance Microscopy Imaging in the Mouse

Myocarditis is an inflammation of the myocardium, but only ~10% of those affected show clinical manifestations of the disease. To study the immune events of myocardial injuries, various mouse models of myocarditis have been widely used. This study involved experimental autoimmune myocarditis (EAM) induced with cardiac myosin heavy chain (Myhc)-α 334-352 in A/J mice; the affected animals develop lymphocytic myocarditis but with no apparent clinical signs. In this model, the utility of magnetic resonance microscopy (MRM) as a non-invasive modality to determine the cardiac structural and functional changes in animals immunized with Myhc-α 334-352 is shown. EAM and healthy mice were imaged using a 9.4 T (400 MHz) 89 mm vertical core bore scanner equipped with a 4 cm millipede radio-frequency imaging probe and 100 G/cm triple axis gradients. Cardiac images were acquired from anesthetized animals using a gradient-echo-based cine pulse sequence, and the animals were monitored by respiration and pulse oximetry. The analysis revealed an increase in the thickness of the ventricular wall in EAM mice, with a corresponding decrease in the interior diameter of ventricles, when compared with healthy mice. The data suggest that morphological and functional changes in the inflamed hearts can be non-invasively monitored by MRM in live animals. In conclusion, MRM offers an advantage of assessing the progression and regression of myocardial injuries in diseases caused by infectious agents, as well as response to therapies.