Evaluation of in vitro antiviral activity of a brown alga (Cystoseira myrica) from the Persian Gulf against herpes simplex virus type 1

The hot water extract of a brown marine alga, Cystoseira myrica, from the Persian Gulf was evaluated as an antiviral compound against KOS strain of HSV-1 in cell culture. The extract exhibited antiviralactivity against herpes simplex virus type 1 (HSV-1) not only during absorption of virus to the cells, but also on post attachment stages of virus replication. The water extract of C. myrica was sterilized byfiltration and autoclaving, respectively. The IC50 for filtered extract was 99 ìg/ml and the IC50 for autoclaved extract was 125 ìg/ml. Based on resulted selectivity index (SI) values of the extracts, whichwere 33.4 and 28.2 for filtered and autoclaved extracts, respectively, we found that the antiviral compound(s) in the water extract of C. myrica to be heat stable. Also, the SI values for inhibition of thepost attachment stages of HSV-1 replication were 23.1 and 21.7 for filtered and autoclaved extracts, respectively. The IC50 in this phase of study were 143 and 162 ìg/ml for filtered and autoclaved extracts,respectively. Therefore, C. myrica could be a good candidate as a natural source for anti-HSV-1 compound(s) isolation

Abnormalities in the GABAergic Inhibitory System Leading to the Development of Spike-Wave Discharges in the Somatosensory Cortex of WAG/Rij Rats

We investigated the effects of muscimol on generation of spike-wave discharges (SWDs) and short-term plasticity alterations in the somatosensory cortex of WAG/Rij rats. The rats were implanted with a twisted tripolar electrode into the above cortex region and with an intraventricular cannula into the right cerebral ventricle. EEG recordings were made before and after muscimol and saline injections. Paired-pulse stimulations (200 µsec, 100-1000 µA, 0.1 sec⁻¹) were applied to the somatosensory cortex at 50-, 100-, 400-, and 500-mseclong intervals for 50 min. Pharmacological amplification of GABAergic transmission in the somatosensory cortex exerted an inhibitory effect on the thalamo-cortical circuit underlying the generation of spike-wave discharges (SWDs). Ten minutes post-injection of muscimol, paired-pulse facilitation was significantly reduced at 50- and 100-msec-long interpulse intervals (P < 0.05). The data obtained suggest that muscimol suppresses generation of SWDs and changes short-term plasticity via imitation of the effects of GABA in inhibitory synapses.Ми досліджували впливи мусцимолу на генерацію комплексів пік-хвиля (КПХ) та феномен короткочасної пластичності у щурів лінії WAG/Rij. Тваринам імплантували триполярний електрод у соматосенсорну кору та канюлю в правий мозковий шлуночок. Перед внутрішньошлунковою ін’єкцією мусцимолу або фізіологічного розчину реєстрували ЕЕГ. Соматосенсорну кору стимулювали парними стимулами (200 мкс, 100–1000 мкА, 0.1 с–1) з інтервалами 50, 100, 400 або 500 мс протягом 50 хв. Фармакологічне посилення ГАМК-ергічної передачі в соматосенсорній корі призводило до гальмування таламо-кортикальних нейромереж, відповідальних за генерацію КПХ. Через 10 хв після ін’єкції мусцимолу полегшення при парній стимуляції істотно зменшувалось та переходило у депресію у тих випадках, коли міжстимульні інтервали дорівнювали 50 або 100 мс (P < 0.05). Як вказують отримані дані, мусцимол пригнічує генерацію КПХ та змінює короткочасну пластичність, оскільки він імітує дію ГАМК у гальмівних синапсах

Study on potential of some solid natural substances in production of Beauveria bassiana (Ascomycota, Cordycipitaceae) conidia

In this study, two fungus isolates, Beauveria bassiana EUT105 and B. bassiana EUT116, were evaluated for production of aerial conidia on wheat, wheat flour, wheat bran, rice flour, rice bran, rice paddy, millet and corn flour using two phasic liquid-solid system. Data analysis showed that there are significant differences among treatments (simple media) in both isolates. In B. bassiana EUT105, the maximum and minimum productions were achieved on wheat bran, 2.3 Ã 1010 conidia/g and on rice paddy, 1.5 Ã 109 conidia/g of medium, respectively. In B. bassiana EUT116, wheat bran with 6.1 Ã 109 conidia/g and millet with 8 Ã 108 conidia/g had the maximum and minimum productions, respectively. Effect of adding nutritional complementary compounds to the growth media was significant in increasing of conidial yield. Related results showed that adding permeate increased the production but molasses did not it in comparison with control in both isolates. Wheat bran plus permeate had the maximum production, 5 Ã 1010 and 4.6 Ã 1010 conidia/g in B. bassiana EUT105 and EUT116, respectively and minimum production was obtained with rice flour plus molasses, 1.5 Ã 108 and 6 Ã 108 conidia/g in B. bassiana EUT105 and EUT116, respectively

Microfluidic systems for the analysis of the viscoelastic fluid flow phenomena in porous media

In this study, two microfluidic devices are proposed as simplified 1-D microfluidic analogues of a porous medium. The objectives are twofold: firstly to assess the usefulness of the microchannels to mimic the porous medium in a controlled and simplified manner, and secondly to obtain a better insight about the flow characteristics of viscoelastic fluids flowing through a packed bed. For these purposes, flow visualizations and pressure drop measurements are conducted with Newtonian and viscoelastic fluids. The 1-D microfluidic analogues of porous medium consisted of microchannels with a sequence of contractions/ expansions disposed in symmetric and asymmetric arrangements. The real porous medium is in reality, a complex combination of the two arrangements of particles simulated with the microchannels, which can be considered as limiting ideal configurations. The results show that both configurations are able to mimic well the pressure drop variation with flow rate for Newtonian fluids. However, due to the intrinsic differences in the deformation rate profiles associated with each microgeometry, the symmetric configuration is more suitable for studying the flow of viscoelastic fluids at low De values, while the asymmetric configuration provides better results at high De values. In this way, both microgeometries seem to be complementary and could be interesting tools to obtain a better insight about the flow of viscoelastic fluids through a porous medium. Such model systems could be very interesting to use in polymer-flood processes for enhanced oil recovery, for instance, as a tool for selecting the most suitable viscoelastic fluid to be used in a specific formation. The selection of the fluid properties of a detergent for cleaning oil contaminated soil, sand, and in general, any porous material, is another possible application

Effects of Acute Intracerebroventricular Microinfusions of Bupropion on Background Spike Activity of Locus Coeruleus Neurons in Rats

Considering that noradrenergic (NAE) neurons of the locus coeruleus (LC) play significant roles in the formation of biological rhythms, pain, addictions, and mood disorders, we tested the effects of acute intracerebroventricular microinfusions of bupropion, an inhibitor of NA reuptake used in clinics as an antidepressant, on background spike activity on LC neurons in chloral-hydrate anesthetized rats. Ten microliters of the solutions containing 0.001, 0.01, 0.1, 1.0, or 10.0 µmol bupropion were infused during 3 min; spike activity of single LC neurons identified according to the known characteristics was recorded extracellularly by glass microelectrodes. Microinfusions of 0.01 to 10.0 µmol bupropion suppressed background spiking of the above neurons in a dose-dependent manner. The normalized mean intensities and durations of inhibition were 17.3, 19.4, 26.3, and 41.1% and 1.4, 7.1, 12.4, and 18.3 min, respectively. The smallest dose (0.001 µmol) was ineffective. It is assumed that bupropion increases the NA level in proximity to NAE LC neurons. The actions of bupropion on other cerebral neuromodulatory systems need further examination. Inhibition of LC neuronal activity by bupropion can help to explain some acute, chronic, and side effects of this agent used in clinics for correction of mood disorders.Враховуючи, що норадренергічні (НАЕ) нейрони блакитної плями (locus coeruleus – LC) відіграють істотну роль у формуванні біологічних ритмів, болю, фармакологічних залежностей та розладів настрою, ми тестували впливи гострих інтрацеребровентрикулярних мікроінфузій антидепресанта бупропіону на фонову активність нейронів LC у щурів. Уводили 10 мкл (тривалість інфузій 3 хв) розчинів, що вміщували різні дози (0.001, 0.01, 0.1, 1.0 або 10.0 мкмоль) бупропіону – інгібітора зворотного захоплення норадреналіну, що використовується в клініці як антидепресант. Імпульсну активність поодиноких нейронів LC відводили позаклітинно скляними мікроелектродами. Мікроінфузії 0.01–10.0 мкмоль бупропіону дозозалежно пригнічували фонову імпульсацію цих нейронів. Середня нормована інтенсивність та тривалість гальмування складали в даних випадках 17.3, 19.4, 26.3 і 41.1 % та 1.4, 7.1, 12.4 і 18.3 хв відповідно. Найменша доза бупропіону (0.001 мкмоль) була неефективною. Вважається, що бупропіон зумовлює підвищення рівнів цього катехоламіну в зоні розташування НАЕ-нейронів LC. Взаємодія бупропіону з іншими центральними нейромодуляторними системами потребує подальшого вивчення. Факт гальмування нейронної імпульсної активності в LC під впливом бупропіону може сприяти інтерпретації особливостей гострих та хронічних впливів цього агента та його побічних ефектів при застосуванні в клініці для корекції розладів настрою

Comparison of Short-Term Estrogenicity Tests for Identification of Hormone-Disrupting Chemicals

The aim of this study was to compare results obtained by eight different short-term assays of estrogenlike actions of chemicals conducted in 10 different laboratories in five countries. Twenty chemicals were selected to represent direct-acting estrogens, compounds with estrogenic metabolites, estrogenic antagonists, and a known cytotoxic agent. Also included in the test panel were 17β-estradiol as a positive control and ethanol as solvent control. The test compounds were coded before distribution. Test methods included direct binding to the estrogen receptor (ER), proliferation of MCF-7 cells, transient reporter gene expression in MCF-7 cells, reporter gene expression in yeast strains stably transfected with the human ER and an estrogen-responsive reporter gene, and vitellogenin production in juvenile rainbow trout. 17β-Estradiol, 17α-ethynyl estradiol, and diethylstilbestrol induced a strong estrogenic response in all test systems. Colchicine caused cytotoxicity only. Bisphenol A induced an estrogenic response in all assays. The results obtained for the remaining test compounds—tamoxifen, ICI 182.780, testosterone, bisphenol A dimethacrylate, 4-n-octylphenol, 4-n-nonylphenol, nonylphenol dodecylethoxylate, butylbenzylphthalate, dibutylphthalate, methoxychlor, o,p′-DDT, p,p′-DDE, endosulfan, chlomequat chloride, and ethanol—varied among the assays. The results demonstrate that careful standardization is necessary to obtain a reasonable degree of reproducibility. Also, similar methods vary in their sensitivity to estrogenic compounds. Thus, short-term tests are useful for screening purposes, but the methods must be further validated by additional interlaboratory and interassay comparisons to document the reliability of the methods