Comparison between the LLC-MK2 and MDCK cell lines in the isolation of parainfluenza virus from nasopharyngeal aspirates

BACKGROUND: We report a prospective comparative study of the efficacy of three commercial cell lines in the isolation of the parainfluenza (PI) virus from nasopharyngeal samples. MATERIAL AND METHODS: In a 16 months period we studied all nasopharyngeal samples from patients with the suspension of a viral respiratory infection. The compared cell lines were LLC-MK2 and MDCK. All samples were processed by the shell-vial assay, incubated 3 days at 36 degrees C. The monolayers were stained by an indirect immunofluorescence assay with a monoclonal antibody against the nucleoprotein of the PI virus. RESULTS: In the study period 746 samples were analyzed, 46 PI virus were isolated, all belonged to the serotype 3. The LLC-MK2 cell line isolated 44 viruses (95.6%) and the MDCK cell line 41 (89.1%), no statistically significant differences were detected (p = 0.14) (qualitative sensitivity). In 84.8% of positive samples, the PI virus was isolated simultaneously in the two cell lines. Neither cell line isolated all PI virus. No statistical differences were detected in the quantitative sensitivity, although the LLC-MK2 cell line detected a slightly more samples with a low viral load (70.4 vs 68.2%). CONCLUSIONS: In view of the results obtained in this study, we believe that anyone of the two cell lines would be used in the isolation of the PI virus from respiratory samples.     

Presence of epithelial cells in the medullary canal after spinal anesthesia

BACKGROUND AND AIM: Several authors have focused on a causal link between the onset of neurological complications after lumbar injections and the fact that epithelial cells may be drawn into the vertebral canal during these procedures. Complications may arise both early (cephalea, septic and aseptic meningitis) and late (epidermoid tumours). The authors aimed to evaluate whether skin fragments which are carried down by the needle during subarachnoid anesthesia may even be present in the epidural or subarachnoid space three days later and may therefore justify the onset of the above neurological syndromes. METHODS: Five adult cats under narcosis underwent subarachnoid anesthesia using disposable 22G Quincke type needles. Between 0.7 and 1 ml isobaric bupivacaine at 0.50% was injected. The presence of the motor block of the lower limbs was ascertained once the effects of general anesthesia wore off. On the third day, again under general anesthesia, cardio-respiratory arrest was provoked by intravenous injection. Samples of meninges were collected in the injection area. After fixation in a phosphate glutaraldehyde buffer, dehydration in acetone, dehydration by critical point and gold metalisation, the samples were examined using SEM. RESULTS: No epidermal cells were found on the surface of the meninges. On the other hand, a squamous epithelial cell was observed which drained inside a sectioned epidural vessel towards the systemic circulation. CONCLUSIONS: This study confirms the possibility that, after subarachnoid anesthesia using 22G Quincke needles, skin fragments may enter the spinal canal. The permanence or otherwise of the epithelial fragments on the third day depends on the size of the fragment drawn down and the efficacy of the drainage system which removes isolated epithelial cells. This phenomenon may justify the self-limiting character of cephalea and meningisms which, even if not treated, regress in a few days, as well as the scarce development of epidermoid tumours.     

Improving discovery phase of reactive ad hoc routing protocols using Jaccard distance

Recently, more and more research focus has been directed towards optimum designs for Mobile Ad Hoc Networks (MANETs). In this paper, the authors explore novel broadcasting schemes to improve the discovery phase of reactive routing protocols in MANETs. The objective is to reduce the redundancy of routing packets during the discovery phase of the reactive routing protocols for MANETs. For this purpose, the Jaccard distance is used to select dissimilar nodes during the discovery phase in order to reduce redundancy. Furthermore, it is shown that the Jaccard distance is correlated to the Euclidean distance. The simulation results obtained indicate that the Jaccard distance is a suitable metric for improving the discovery phase of the reactive routing protocols in MANETs.     

Silphinene Sesquiterpenes as Model Insect Antifeedants

Silphinene sesquiterpenes are established chrysomelid antifeedants. In this work, nine silphinene analogs, 11-acetoxy-5-angeloyloxysilphinen-3-one (1), 11-acetoxy-5-tigloyloxysilphinen-3-one (2), 11-acetoxy-5-iso- butyryloxysilphinen-3-one (3), 11-hydroxy-5-angeloyloxysilphinen-3-one (4), 11,5-dihydroxysilphinen-3-one (5), 11,5-diacetoxysilphinen-3-one (6), 5,11-diisobutyryloxysilphinen-3-one (7), silphinen-3,5,11-trione (8), and O-methyl-5-epicantabrenolic acid methyl ester (10), and a presilphiperfolane sesquiterpene (9) were tested against several divergent insect species, including the lepidopteran Spodoptera littoralis, the chrysomelid Leptinotarsa decemlineata, and five aphid species, and their antifeedant effects were compared with those of picrotoxinin, a GABA-antagonist, and thymol, an allosteric modulator for insect GABA receptors. All insects tested responded to at least one silphinene analog and/or GABA antagonist. Compound 3 and thymol were effective antifeedants against all species tested except S. littoralis, with varying potencies according to their feeding ecologies. The toxicity of these compounds was species-dependent and did not correlate with their antifeedant effect.     

Coherent Culling and Shading for Large Molecular Dynamics Visualization

Molecular dynamics simulations are a principal tool for studying molecular systems. Such simulations are used to investigate molecular structure, dynamics, and thermodynamical properties, as well as a replacement for, or complement to, costly and dangerous experiments. With the increasing availability of computational power the resulting data sets are becoming increasingly larger, and benchmarks indicate that the interactive visualization on desktop computers poses a challenge when rendering substantially more than millions of glyphs. Trading visual quality for rendering performance is a common approach when interactivity has to be guaranteed. In this paper we address both problems and present a method for high‐quality visualization of massive molecular dynamics data sets. We employ several optimization strategies on different levels of granularity, such as data quantization, data caching in video memory, and a two‐level occlusion culling strategy: coarse culling via hardware occlusion queries and a vertex‐level culling using maximum depth mipmaps. To ensure optimal image quality we employ GPU raycasting and deferred shading with smooth normal vector generation. We demonstrate that our method allows us to interactively render data sets containing tens of millions of high‐quality glyphs.     

Comprehensive characterization of the functional activities of pressurized liquid and ultrasound-assisted extracts from Chlorella vulgaris

Chlorella vulgaris has been referred as a potential source of bioactive compounds (carotenoids and fatty acids). In this work, the ability of an environmentally friendly extraction technique such as Pressurized Liquid Extraction (PLE) and a traditional extraction technique such as Ultrasound-Assisted Extraction (UAE) to obtain functional compounds from C. vulgaris, at analytical scale, has been demonstrated. Seeked bioactivities were antioxidant and antimicrobial, for their interest in the food industry. Therefore, a methodology including analytical extraction, in-vitro assays and chemical characterization via HPLC-DAD and GC–MS has been used to determine the interest of Chlorella as a source of functional food ingredients. Results demonstrated that PLE provide higher yields than UAE while similar bioactivities were obtained. Important concentration of carotenoids (lutein, neoxanthin, β-carotene, etc.), chlorophylls, sterols, phytols, and fatty acids (among others) have been found in Chlorella extracts that could be correlated to the observed biological activity.     

Highly active Cu-ZnO catalysts for the WGS reaction at medium–high space velocities: Effect of the support composition

Cu-ZnO based catalysts are the benchmark materials for the low-temperature WGS reaction. However, they present a crucial drawback which limits their application in portable devices: they only work under very low space velocities. In this study, we have developed a series of multicomponent Cu-ZnO catalysts able to work at relatively high space velocities with outstanding activity and stability. Different reference supports have been utilised with CeO₂-Al₂O₃ being the most promising system. Overall, this work describes a strategy to design advanced Cu-based catalysts that can overcome the residence time restrictions in the WGS reaction.     

Bacterial contamination of cucumber fruit through adhesion

In this study, the adhesion of bacteria to fresh cucumber surfaces in aqueous suspension was shown to be dependent on time of incubation, inoculum species and concentration, and temperature. The adhesion of bacteria to the fruit in wash water was less extensive at lower temperatures and shorter exposure times. Various species of bacteria were adsorbed to cucumber surfaces in the following relative order: Salmonella Typhimurium > Staphylococcus aureus > Lactobacillus plantarum > Listeria monocytogenes. Cells were adsorbed at all temperatures tested (5, 15, 25, and 35 degrees C) at levels that depended on incubation time, but the numbers of cells adsorbed were larger at higher incubation temperatures. Levels of adhesion of bacteria to dewaxed fruit were higher for L. monocytogenes and lower for Salmonella Typhimurium, L. plantarum, and S. aureus than were levels of adhesion to waxed fruit.     

Effect of acute ethanol administration on serum magnesium concentration in the rabbit

The size of the Lactobacillus plantarum CCM 1904 chromosome was determined by pulse-field gel electrophoresis. It was found to be 3.3-3.4 Mb using SfiI or AscI restriction endonucleases, compared to 3-4 Mb found for the other L. plantarum strains tested. L. plantarum CCM 1904 5S rDNA was clonedl by polymerase chain reaction, sequenced, and used as a probe to characterize strains. At least five rrn loci were found. The pulsed-field gel electrophoresis macrorestriction patterns were strain-specific, while the rDNA restriction hybridization patterns were species-specific.     

Structural Diversity and Defensive Properties of Norditerpenoid Alkaloids

We have tested the insect antifeedant and toxic activity of 43 norditerpenoid alkaloids on Spodoptera littoralis and Leptinotarsa decemlineata including eserine (physostigmine), anabasine, and atropine. Antifeedant effects of the test compounds were structure- and species-dependent. The most active antifeedants to L. decemlineata were 1,14-diacetylcardiopetaline (9) and 18-hydroxy- 14-O-methylgadesine (33), followed by 8-O-methylconsolarine (12), 14-O-acetyldelectinine (27), karakoline (7), cardiopetaline (8), 18-O-demethylpubescenine (13), 14-O-acetyldeltatsine (18), takaosamine (21), ajadine (24), and 8-O-methylcolumbianine (6) (EC50 < 1 microg/cm2). This insect showed a moderate response to atropine. S. littoralis had the strongest antifeedant response to 24, 18, 14-O-acetyldelcosine (19), and delphatine (29) (EC50 < 3 microg/cm2). None of the model substances affected the feeding behavior of this insect. The most toxic compound to L. decemlineata was aconitine (1), followed by cardiopetalidine (10) (% mortality > 60), 14-deacetylpubescenine (14), 18-O-benzoyl-18-O-demethyl-14-O-deacetylpubescenine (17), 14-O-acetyldelcosine (19), 14-deacetylajadine (25) and methyllycaconitine (30) (% mortality > 45). Orally injected S. littoralis larvae were negatively affected by 1, cardiopetaline (8), 10, 1,14-O-acetylcardiopetalidina (11), 12, 14, 1,18-O-diacetyl-19-oxo-gigactonine (41), olivimine (43), and eserine in varying degrees. Their antifeedant or insecticidal potencies did not parallel their reported nAChR binding activity, but did correlate with the agonist/antagonist insecticidal/antifeedant model proposed for nicotininc insecticides. A few compounds [14, tuguaconitine (38), 14-demethyldelboxine (40), 19, dehydrodelsoline (36), 18-O-demethylpubescenine (13), 41, 9, and delcosine (23)] had selective cytotoxic effects to ward insect-derived Sf9 cells. None were cytotoxic to mammalian CHO cells and none increased Trypanosoma cruzi mortality. The selective cytotoxic effects of some structures indicate that they can act on biological targets other than neuroreceptors.