The effect of pressurized carbon dioxide as a temporary plasticizer and foaming agent on the hot stage extrusion process and extrudate properties of solid dispersions of itraconazole with PVP-VA 64.

The aim of the current research project was to explore the possibilities of combining pressurized carbon dioxide with hot stage extrusion during manufacturing of solid dispersions of itraconazole and polyvinylpyrrolidone-co-vinyl acetate 64 (PVP-VA 64) and to evaluate the ability of the pressurized gas to act as a temporary plasticizer as well as to produce a foamed extrudate. Pressurized carbon dioxide was injected into a Leistritz Micro 18 intermeshing co-rotating twin-screw melt extruder using an ISCO 260D syringe pump. The physicochemical characteristics of the extrudates with and without injection of carbon dioxide were evaluated with reference to the morphology of the solid dispersion and dissolution behaviour and particle properties. Carbon dioxide acted as plasticizer for itraconazole/PVP-VA 64, reducing the processing temperature during the hot stage extrusion process. Amorphous dispersions were obtained and the solid dispersion was not influenced by the carbon dioxide. Release of itraconazole from the solid dispersion could be controlled as a function of processing temperature and pressure. The macroscopic morphology changed to a foam-like structure due to expansion of the carbon dioxide at the extrusion die. This resulted in increased specific surface area, porosity, hygroscopicity and improved milling efficiency.     

Human Mannose-Binding Protein Inhibits Infection of HeLa Cells by Chlamydia trachomatis

The role that collectin (mannose-binding protein) may play in the host’s defense against chlamydial infection was investigated. Recombinant human mannose-binding protein was used in the inhibition of cell culture infection by Chlamydia trachomatis (C/TW-3/OT, E/UW-5/Cx, and L₂/434/Bu), Chlamydia pneumoniae (AR-39), and Chlamydia psittaci (6BC). Mannose-binding protein (MBP) inhibited infection of all chlamydial strains by at least 50% at 0.098 μg/ml for TW-3 and UW-5, and at 6.25 μg/ml for 434, AR-39, and 6BC. The ability of MBP to inhibit infection with strain L₂ was not affected by supplementation with complement or addition of an L₂-specific neutralizing monoclonal antibody. Enzyme-linked immunosorbent assay and dot blot analyses showed MBP bound to the surface of the organism to exert inhibition, which appeared to block the attachment of radiolabeled organisms to HeLa cells. Immunoblotting and affinity chromatography indicated that MBP binds to the 40-kDa glycoprotein (the major outer membrane protein) on the outer surface of the chlamydial elementary body. Hapten inhibition assays with monosaccharides and defined oligosaccharides showed that the inhibitory effects of MBP were abrogated by mannose or high-mannose type oligomannose-oligosaccharide. The latter carbohydrate is the ligand of the 40-kDa glycoprotein of C. trachomatis L₂, which is known to mediate attachment, suggesting that the MBP binds to high mannose moieties on the surface of chlamydial organisms. These results suggest that MBP plays a role in first-line host defense against chlamydial infection in humans.     

Biomass growth,micronucleus induction,and antioxidant stress enzyme responses in Vicia faba exposed to cadmium in solution

Biomass growth, micronucleus induction, and antioxidative stress enzymes (superoxide dismutase, peroxidase, glutathione reductase, and catalase) were investigated simultaneously in the Vicia faba plant exposed to cadmium in solution. The biomass lowest-observed-effect concentration (LOEC) value was 2,000 microM Cd2+. In the shoots, enzymic activities increased without concentration-response relationships. In the roots, after an initial increase, activities of all enzymes showed negative concentration-response relationships. A significant increase in micronucleus induction was observed at 20 microM Cd2+. Regarding sensitivity, our results showed that biomass endpoint was less sensitive than micronucleus induction, which was less sensitive than antioxidative enzyme activities. The increase of antioxidant stress enzyme activities in response to cadmium exposure may be taken as evidence for an enhanced detoxification capacity of V. faba plants toward reactive oxygen species (and derivatives) that might be generated in the stressed plants. Concomitant micronucleus induction may be also interpreted as a consequence of oxidative stress, upholding the view that cadmium-induced DNA damage is, to some extent, via generation of reactive (intermediate) oxygen species.     

Development of Systems for Targeting the Regional Lymph Nodes for Diagnostic Imaging: In Vivo Behaviour of Colloidal PEG-Coated Magnetite Nanospheres in the Rat Following Interstitial Administration

Purpose. Nanoparticles can be utilised for targeting drugs to the regional lymph nodes or as diagnostic agents. The surface modification of magnetite nanospheres with poly(ethylene glycol) (PEG) has been assessed by in vitro characterisation and in vivo studies following subcutaneous administration to the rat. Methods. Magnetite nanospheres were prepared with a grafted PEG layer using various PEG lengths from 350 to 1000 Da. Thermogravimetric analysis was utilised to measure the adsorbed amount of PEG. Colloid stability was confirmed by measurement of the particle size and electrophoretic mobility. The kinetics of injection site drainage and lymph node retention were determined 2 hours after subcutaneous administration, for nanospheres coated with PEG lengths of 350, 550, 750, and 1000 Da. For the 750 PEG coated nanospheres, the kinetics of distribution was determined over a 48–hour time course. Results. The distribution of the nanospheres was modified and the lymph node localisation enhanced by altering the surface coverage of PEG on the magnetic surface. Conclusions. PEG–coated magnetite nanospheres with different surface characteristics can be utilised to target a diagnostic agent to regional lymph nodes.     

A report of a galactan from marine alga Gelidium crinale with in vivo anti‐inflammatory and antinociceptive effects

The sulfated galactan of the red marine alga Gelidium crinale (SG‐Gc) was purified by ion exchange chromatography and tested by intravenous (i.v.) route in rodent experimental models of inflammation and nociception. The anti‐inflammatory activity of SG‐Gc (0.01, 0.1 and 1 mg/kg) was evaluated in the model of rat paw edema induced by different inflammatory stimuli, while SG‐Gc (0.1, 1 and 10 mg/kg) antinociceptive effect was assessed in models of nociception/hyperalgesia elicited by chemical (formalin test), thermal (hot plate), and mechanical (von Frey) stimuli in mice. In addition, the toxicity was evaluated after rat treatment with SG‐Gc (1 mg/kg; i.v.) during 10 days, followed by analysis of the wet weight of animal’s body/organs and hematological/biochemical parameters. Sulfated galactan of G. crinale inhibited the time course of dextran‐induced paw edema, at all doses, showing maximal effect at 1 mg/kg (42%) and that induced by carrageenan at 0.01 (18%) and 1 mg/kg (20%), but was ineffective on the edema elicited by zymosan. At the highest dose, SG‐Gc also inhibited the paw edema induced by histamine (49%), compound 48/80 (32%), and phospholipase A₂ (44%). Sulfated galactan of G. crinale inhibited both neurogenic and inflammatory phases of the formalin test, at all doses, and at 10 mg/kg, the animals flinch reaction in the von Frey test in the 1st and 3rd h by 19 and 26%, respectively. Additionally, SG‐Gc treatment was well tolerated by animals. In conclusion, SG‐Gc presents anti‐inflammatory effect involving the inhibition of histamine and arachidonic acid metabolites and also antinociceptive activity, especially the inflammatory pain with participation of the opioid system.     

Selective frontal,parietal, and temporal networks in generalized seizures

Are "generalized" seizures truly generalized? Generalized tonic-clonic seizures are classified as either secondarily generalized with local onset or primarily generalized, without known focal onset. In both types of generalized seizures widespread regions of the nervous system engage in abnormally synchronous and high-frequency neuronal firing. However, emerging evidence suggests that all neurons are not homogeneously involved; specific nodes within the network may be crucial for the propagation and behavioral manifestations of generalized tonic-clonic seizures. Study of human tonic-clonic seizures has been limited by problems with patient movement and variable seizure types. To circumvent these problems, we imaged generalized tonic-clonic seizures during electroconvulsive therapy, in which seizure type and timing are well controlled. (99m)Tc-hexamethylpropylene amine oxime injections during seizures provide a "snapshot" of cerebral blood flow that can be imaged by single photon emission computed tomography (SPECT) after seizure termination. Here we show that focal regions of frontal and parietal association cortex show the greatest relative signal increases. Involvement of the higher-order association cortex may explain the profound impairment of consciousness seen in generalized seizures. In addition, focal involvement of the dominant temporal lobe was associated with impaired retrograde verbal memory. Similar focal increases were also seen in imaging of spontaneous secondarily generalized tonic-clonic seizures. Relative sparing of many brain regions during both spontaneous and induced seizures suggests that specific networks may be more important than others in so-called generalized seizures.     

Cerebral energetics and spiking frequency: the neurophysiological basis of fMRI

Functional MRI (fMRI) is widely assumed to measure neuronal activity, but no satisfactory mechanism for this linkage has been identified. Here we derived the changes in the energetic component from the blood oxygenation level-dependent (BOLD) fMRI signal and related it to changes in the neuronal spiking frequency in the activated voxels. Extracellular recordings were used to measure changes in cerebral spiking frequency (Deltanu/nu) of a neuronal ensemble during forepaw stimulation in the alpha-chloralose anesthetized rat. Under the same conditions localized changes in brain energy metabolism (DeltaCMR(O2)/CMR(O2)) were obtained from BOLD fMRI data in conjunction with measured changes in cerebral blood flow (DeltaCBF/CBF), cerebral blood volume (DeltaCBV/CBV), and transverse relaxation rates of tissue water (T(2)(*) and T(2)) by MRI methods at 7T. On stimulation from two different depths of anesthesia DeltaCMR(O2)/CMR(O2) approximately Deltanu/nu. Previous (13)C magnetic resonance spectroscopy studies, under similar conditions, had shown that DeltaCMR(O2)/CMR(O2) was proportional to changes in glutamatergic neurotransmitter flux (DeltaV(cyc)/V(cyc)). These combined results show that DeltaCMR(O2)/CMR(O2) approximately DeltaV(cyc)/V(cyc) approximately Deltanu/nu, thereby relating the energetic basis of brain activity to neuronal spiking frequency and neurotransmitter flux. Because DeltaCMR(O2)/CMR(O2) had the same high spatial and temporal resolutions of the fMRI signal, these results show how BOLD imaging, when converted to DeltaCMR(O2)/CMR(O2), responds to localized changes in neuronal spike frequency.     

Mistaken identity of widely used esophageal adenocarcinoma cell line TE-7

Cancer of the esophagus is the seventh leading cause of cancer death worldwide. Esophageal carcinoma cell lines are useful models to study the biological and genetic alterations in these tumors. An important prerequisite of cell line research is the authenticity of the used cell lines because the mistaken identity of a cell line may lead to invalid conclusions. Estimates indicate that up to 36% of the cell lines are of a different origin or species than supposed. The TE series, established in late 1970s and early 1980s by Nishihira et al. in Japan, is one of the first esophageal cancer cell line series that was used throughout the world. Fourteen TE cell lines were derived from human esophageal squamous cell carcinomas and one, TE-7, was derived from a primary esophageal adenocarcinoma. In numerous studies, this TE-7 cell line was used as a model for esophageal adenocarcinoma because it is one of the few esophageal adenocarcinoma cell lines existing. We investigated the authenticity of the esophageal adenocarcinoma cell line TE-7 by xenografting, short tandem repeat profiling, mutation analyses, and array-comparative genomic hybridization and showed that cell line TE-7 shared the same genotype as the esophageal squamous cell carcinoma cell lines TE-2, TE-3, TE-12, and TE-13. In addition, for more than a decade, independent TE-7 cultures from Japan, United States, United Kingdom, France, and the Netherlands had the same genotype. Examination of the TE-7 cell line xenograft revealed the histology of a squamous cell carcinoma. We conclude that the TE-7 cell line, used in several laboratories throughout the world, is not an adenocarcinoma, but a squamous cell carcinoma cell line. Furthermore, the cell lines TE-2, TE-3, TE-7, TE-12, and TE-13 should be regarded as one single squamous cell carcinoma cell line.