Cleavage of SNAP-25 ameliorates cancer pain in a mouse model of melanoma.

BACKGROUND: Cancer pain is associated with increased pain sensitivity to noxious (hyperalgesia) and normally innocuous (allodynia) stimuli due to activation of nociceptors by tumour-derived mediators or tumour infiltration of nerves. The pain sensitization is accompanied by modifications in gene expression, but specifically regulated genes are largely unknown. The 25 kDa synaptosomal-associated protein (SNAP-25) is involved in chemical neurotransmission at the synaptic cleft. Its inhibition by Botulinum neurotoxin A (BoNT/A) has been associated with antinociceptive effects in migraine, inflammatory and neuropathic pain. However, its potential to reduce tumour-associated pain remains to be clarified. METHODS: We applied a melanoma model of tumour pain in C57BL/6 mice and investigated SNAP-25 expression and regulation by qRT-PCR, Western Blot and immunofluorescence as well as tumour-associated mechanical allodynia with and without BoNT/A treatment. RESULTS: We found increased SNAP-25 expression in the dorsal root ganglia and the sciatic nerve. Intraplantar injection of BoNT/A induced the cleavage of SNAP-25 in these tissues and was associated with decreased mechanical allodynia after therapeutic treatment at early and late stages of tumour pain while the tumour size was not affected. CONCLUSIONS: Our data indicate that SNAP-25 plays a role in tumour pain but has no influence on the initiation and progression of skin cancer. Its cleavage inhibits the development of allodynia in the mouse melanoma model and might be useful as new therapeutic approach for the treatment of cancer pain. WHAT DOES THIS STUDY ADD?: SNAP-25 is differentially regulated during melanoma-induced tumour pain. Its cleavage by BoNT/A might be a suitable therapeutic option for tumour pain patients since tumour-associated pain can be strongly and significantly reduced after preventive and therapeutic BoNT/A treatment, respectively.

Effects of glutamine, glucose, and oxygen concentration on the metabolism and proliferation of rabbit adipose-derived stem cells.

The use of adipose-derived stem cells (ASCs) for tissue engineering involves exposing them to metabolically adverse conditions. This study examined the metabolism, proliferation, and viability of ASCs under various oxygen, glucose, and glutamine concentrations to determine how these cells respond to such environments. ASCs were cultured in each of 8 media preparations containing 4.8 or 21.5 mM glucose, and 0, 2, 4, or 6 mM glutamine. The ASCs were cultured under normoxic (20% O(2)) and hypoxic (0.1% O(2)) conditions. Conditioned media were collected and assayed for glucose, glutamine, lactate, pyruvate, and glutamate. Cell proliferation and cell death were measured after 5 days of culture. ASCs remained metabolically active under all culture conditions; however, their proliferation rate was significantly reduced in the absence of glutamine. Hypoxia resulted in increased cell death. ASCs are a viable source of stem cells for tissue engineering purposes, although substantial challenges remain. These cells are able to survive in environments with limited oxygen and glutamine and thus may be able to survive brief periods of limited nutrient transport after implantation.

[Current perspectives of orthogonal polarization spectral imaging in plastic surgery]. / Orthogonal Polarization Spectral Imaging und derzeitige Perspektiven in der Plastischen Chirurgie.

The technology of Orthogonal Polarization Spectral Imaging (OPSI), patented in the United States in 1999, has been heralded as an alternative to conventional intravital microscopy for several reasons, including ease of application and ability to perform continued observations. In the following examples, OPSI was applied to reconstructive plastic surgery. Two experimental and one clinical model are presented. Currently, the image quality does not allow a qualitative analysis of the microvasculature. The data analysis of images remains inconclusive. However, a technically modified version with improved image resolution and software could become a valuable experimental as well as clinical tool in the field of reconstructive plastic surgery in the future.

Long- and short-term effects of biological hydrogels on capsule microvascular density around implants in rats.

Fibrous capsule formation around implants can inhibit solute exchange between implantable devices and the circulation. Parylene-n coated polycarbonate disks surrounded with growth factor reduced Matrigel (MG) or several gelatin-based matrices were implanted intramuscularly into rats for 21 or 50 days. MG supplemented with vascular endothelial growth factor (VEGF) or basic fibroblast growth factor (bFGF) increased capsule microvascular density at 21 days (p < 0.05) when compared to bare parylene-coated polycarbonate disks (control). The increased microvascular density around VEGF- and bFGF-treated implants regressed by 50 days and was no longer significantly different from controls. The microvascular density induced by the gelatin-based matrices was not significantly different from controls at 21 days, but was increased at 50 days (p < 0.05), suggesting a slower, long-term effect. Disks treated with MG and gelatin-based matrices had thinner capsules at 21 days (p < 0.05). By 50 days, the capsule thicknesses around these implants were no longer statistically thinner than controls. The capsule thickness around implants treated with VEGF, bFGF, and essential gelatin-based matrix was thinner than controls at 50 days (p < 0.05). These results indicate that it is possible to increase functional microvascular density within fibrous capsules using angiogenic growth factors and gelatin-based matrices. However, this effect may be short-lived, requiring chronic administration of growth factors.

Water permeability and mechanical strength of polyunsaturated lipid bilayers.

Micropipette aspiration was used to test mechanical strength and water permeability of giant-fluid bilayer vesicles composed of polyunsaturated phosphatidylcholine PC lipids. Eight synthetic-diacyl PCs were chosen with 18 carbon chains and degrees of unsaturation that ranged from one double bond (C18:0/1, C18:1/0) to six double bonds per PC molecule (diC18:3). Produced by increasing pipette pressurization, membrane tensions for lysis of single vesicles at 21 degrees C ranged from approximately 9 to 10 mN/m for mono- and dimono-unsaturated PCs (18:0/1, 18:1/0, and diC18:1) but dropped abruptly to approximately 5 mN/m when one or both PC chains contained two cis-double bonds (C18:0/2 and diC18:2) and even lower approximately 3 mN/m for diC18:3. Driven by osmotic filtration following transfer of individual vesicles to a hypertonic environment, the apparent coefficient for water permeability at 21 degrees C varied modestly in a range from approximately 30 to 40 microm/s for mono- and dimono-unsaturated PCs. However, with two or more cis-double bonds in a chain, the apparent permeability rose to approximately 50 microm/s for C18:0/2, then strikingly to approximately 90 microm/s for diC18:2 and approximately 150 microm/s for diC18:3. The measurements of water permeability were found to scale exponentially with the reduced temperatures reported for these lipids in the literature. The correlation supports the concept that increase in free volume acquired in thermal expansion above the main gel-liquid crystal transition of a bilayer is a major factor in water transport. Taken together, the prominent changes in lysis tension and water permeability indicate that major changes occur in chain packing and cohesive interactions when two or more cis-double bonds alternate with saturated bonds along a chain.

Effect of chain length and unsaturation on elasticity of lipid bilayers.

Micropipette pressurization of giant bilayer vesicles was used to measure both elastic bending k(c) and area stretch K(A) moduli of fluid-phase phosphatidylcholine (PC) membranes. Twelve diacyl PCs were chosen: eight with two 18 carbon chains and degrees of unsaturation from one double bond (C18:1/0, C18:0/1) to six double bonds per lipid (diC18:3), two with short saturated carbon chains (diC13:0, diC14:0), and two with long unsaturated carbon chains (diC20:4, diC22:1). Bending moduli were derived from measurements of apparent expansion in vesicle surface area under very low tensions (0.001-0.5 mN/m), which is dominated by smoothing of thermal bending undulations. Area stretch moduli were obtained from measurements of vesicle surface expansion under high tensions (>0.5 mN/m), which involve an increase in area per molecule and a small-but important-contribution from smoothing of residual thermal undulations. The direct stretch moduli varied little (< +/-10%) with either chain unsaturation or length about a mean of 243 mN/m. On the other hand, the bending moduli of saturated/monounsaturated chain PCs increased progressively with chain length from 0.56 x 10(-19) J for diC13:0 to 1.2 x 10(-19) J for diC22:1. However, quite unexpectedly for longer chains, the bending moduli dropped precipitously to approximately 0.4 x 10(-19) J when two or more cis double bonds were present in a chain (C18:0/2, diC18:2, diC18:3, diC20:4). Given nearly constant area stretch moduli, the variations in bending rigidity with chain length and polyunsaturation implied significant variations in thickness. To test this hypothesis, peak-to-peak headgroup thicknesses h(pp) of bilayers were obtained from x-ray diffraction of multibilayer arrays at controlled relative humidities. For saturated/monounsaturated chain bilayers, the distances h(pp) increased smoothly from diC13:0 to diC22:1 as expected. Moreover, the distances and elastic properties correlated well with a polymer brush model of the bilayer that specifies that the elastic ratio (k(c)/K(A))(1/2) = (h(pp) - h(o))/24, where h(o) approximately 1 nm accounts for separation of the headgroup peaks from the deformable hydrocarbon region. However, the elastic ratios and thicknesses for diC18:2, diC18:3, and diC20:4 fell into a distinct group below the correlation, which showed that poly-cis unsaturated chain bilayers are thinner and more flexible than saturated/monounsaturated chain bilayers.

Atypical heparin-induced thrombocytopenia complicated by intracardiac thrombus, effectively treated with ultra-low-dose rt-PA lysis and recombinant hirudin (Lepirudin).

A serious retroperitoneal bleeding occurred in a 56-year-old male patient receiving unfractionated heparin due to multiple pulmonary embolism. After reducing the heparin dose, the patient developed a new pulmonary embolism and a large thrombus in the right atrium. Concomitantly, the platelet count dropped to a value of 29 g/l. Heparin-induced thrombocytopenia (HIT) was confirmed by a functional assay, the heparin-induced platelet activation (HIPA) assay, whereas the results of a platelet factor 4/heparin complex ELISA were repeatedly negative. This indicated that the patient's HIT antibodies were directed towards an antigen other than platelet factor 4/heparin complexes. For treatment of the atrial thrombus, an ultra-low-dose lysis with rt-PA (2 mg/h, intravenously) was administered for a period of 52 h, overlapping with systemic treatment with recombinant hirudin (Lepirudin, Refludan, 0.06-0.14 mg/kg/h intravenously). The aim was to enhance lysis of the thrombus without increasing the haematoma, and at the same time keep the risk of fulminant pulmonary embolism due to thrombus fragmentation as low as possible. The cardiac thrombus disappeared within 48 h, without new signs of pulmonary embolism. Platelet counts normalized within nine days.

Surfaces modified with covalently-immobilized adhesive peptides affect fibroblast population motility.

Cell population motility and adhesion of rat skin fibroblasts were evaluated on aminophase glass modified with covalently-immobilized biologically active peptides, specifically, either arginine glycine-aspartic acid-serine (RGDS) or tyrosine-isoleucine-glycine-serine-arginine-glycine (YIGSRG). Fibroblast population motility was decreased and adhesion was increased on substrates modified with covalently immobilized RGDS peptide compared to substrates with the covalently immobilized non-adhesive peptides arginine-glycine-glutamic acid-serine and arginine-aspartic acid-glycine-serine. Fibroblast motility was not significantly changed on substrates modified with covalently-immobilized YIGSRG peptide; however, fibroblast adhesion was decreased on that substrate.

Computerized long-term trending of respiratory parameters.

This paper presents a program that analyzes data recorded from a Puritan-Bennett 7200a mechanical ventilator. The program generates graphs of major ventilatory parameters, as well as the derivatives of the parameters, such as respiratory rate and minute volume with respect to time. The program also creates a series of reports that summarizes setting changes, alarm violations and resets, and lung mechanics maneuvers during the process of respiratory therapy. These graphs and reports provide clinicians with information, which was not captured for review before, in an organized format allowing them to easily identify trends and, in some cases, events that may affect the patient. The results of a clinical study are also presented. The study was designed to determine the effect of routine patient care on the primary and derived respiratory data so that a correct interpretation of the recorded data could be made. The study showed that the data acquisition program was not sensitive to routine bedside activities, and some significant events, such as patient disconnects, are identifiable in a timely manner and with good accuracy.

[Occurrence of vascular canals in alveolar bone]. / Untersuchungen über das Auftreten von Gefässkanälen im alveolären Knochen.

The authors present the results from the investigation of 414 full-mouth X-rays from periodontally diseased individuals for the occurrence of visible bone canals. The frequency, the form the most frequent location and the age-distribution of the vascular canals as well as the possibility of classifying them according to type and severity of the periodontal disease are discussed. Follow-up examinations in 18 patients, on an average 15 years after the first examination, permit the conclusion that the bone canals cannot be influenced by periodontal treatment, and that they are not associated with the periodontal disease.