Hyperbaric oxygen therapy attenuates neuropathic hyperalgesia in rats and idiopathic trigeminal neuralgia in patients

BACKGROUND

Neuropathic pain after nerve injury is severe and intractable, and current drug and non-drug therapies offer very limited pain relief. Hyperbaric oxygen (HBO 2) has been clinically used for protection of the nervous system after acute injury. We investigated whether HBO 2 treatment could prevent and/or attenuate neuropathic pain in animals and in patients.

METHODS

Mechanical allodynia and thermal hyperalgesia and neurochemical alterations of neuropathic pain were analysed in male, adult, Sprague-Dawley rats with sciatic nerve injury. Clinical trials were conducted in patients with idiopathic trigeminal neuralgia.

RESULTS

Repetitive HBO 2 treatment [a combination of pressure at 3 atmosphere absolute (ATA) and pure oxygen] greatly inhibited behavioural signs of neuropathic pain manifested as thermal hyperalgesia and mechanical allodynia. Such an HBO 2 treatment also inhibited nerve injury-induced induction of c-Fos and activation of astrocytes and increased phosphorylation of NR2B receptor and the subsequent Ca 2+-dependent signals in rats. Neither high pressure (up to 3 ATA) nor pure oxygen alone resulted in analgesic effect. In clinical trials, one course of HBO 2 therapy (10 consecutive days) produced a rapid-onset, dose-dependent and long-lasting analgesic effects evidenced by the decreased doses of carbamazepine required for keeping patient pain at a minimum and decreased scores of visual analogue scales, which was used for patient's self-evaluation.

CONCLUSIONS

These findings support that HBO 2 therapy is an effective approach for treating neuropathic pain in both animals and human beings and suggest that neural protection, anti-inflammation and inhibition of nerve injury-induced altered neural activity may contribute to the analgesic effect of HBO 2 therapy.

Microwave-assisted one-step patterning of aqueous colloidal silver

A new approach of utilizing microwave to pattern gradient concentric silver nanoparticle ring structures has been presented. The width and height of a single ring and the space between adjacent rings can be adjusted by changing the silver colloidal concentration and the microwave output power. By simply enhancing the ambient vapour pressure to the saturated value during microwave-assisted evaporation, sub-100 nm rings can be deposited in between adjacent micro-rings over a distance of millimetres. Combined with microwave sintering, this approach can also create conductive silver tracks in a single step, showing huge potential in fabricating micro- and nano-electronic devices in an ultra-fast and cost-effective fashion.

Ginsenoside Rg1 enhances endothelial progenitor cell angiogenic potency and prevents senescence in vitro

This study investigated the effect of ginsenoside Rg1 on the functions of ex vivo cultivated endothelial progenitor cells (EPCs) and whether ginsenoside Rg1 prevented EPC senescence. EPCs isolated from peripheral blood from healthy volunteers were incubated with different concentrations of ginsenoside Rg1 and the effects were observed at different time points. Cell proliferation and in vitro vasculogenesis were assayed and flow cytometry was used to determine the effects of ginsenoside Rg1 on the cell cycle. Senescence and telomerase activity in EPCs were also assayed. It was found that ginsenoside Rg1 promoted EPC proliferation and vasculogenesis in dose-and time-dependent manners. Cell-cycle analysis showed that ginsenoside Rg1 increased the proliferative phase and decreased the resting phase of EPCs. β-Galactosidase and telomerase activities increased. These results support the view that ginsenoside Rg1 induces EPC proliferation and angiogenesis, and inhibits EPC senescence.

Effect of air abrasion and dye on the surface element ratio and resin bond of zirconia ceramic

The purpose of this study was to evaluate the effect of the surface element composition and roughness of dyed or non-dyed zirconia ceramic by air abrasion on the bond durability to resin luting cement. The sintered zirconia ceramic specimens were divided into four groups as follows: polished, dyed/polished, abraded, dyed/abraded. The surface roughness of each group was measured by a 3D laser scanning microscope. Energy-dispersive spectroscopy was applied for identifying and quantifying the elemental composition of the zirconia ceramic surfaces Each group had 20 shear test specimens of zirconia to Panavia F and was divided into two subgroups (n = 10) after 0 or 10 000 thermal cycles to receive the shear test. Compared with polishing, air abrasion significantly reduced the oxygen atom and weight ratio, increased the zirconium atom and weight ratio, increased R(a) and R(y) of zirconia ceramic surface, and also increased the bond strength of dyed and non-dyed zirconia ceramic to Panavia F after 0 and 10 000 thermal cycles. The dying procedure could affect the abraded and non-abraded zirconia ceramic surface oxygen and zirconia element ratios and surface characteristics. However, the dying procedure does not affect the resin bond strength and durability of zirconia ceramic.Corrections were made to this article on 3 November 2011. The footnote for the corresponding authors was incorrectly labelled.

Cationic liposomes as gene delivery system: transfection efficiency and new application

As it has been generally reported that oppositely charged cationic liposomes (CLs) are superior to either neutral or anionic liposomes as gene delivery carrier, interest in the properties, structures, transfection mechanism of CLs and so forth arises unprecedentedly. However, our understanding about the mechanism of CLs-gene complexes (lipoplex)-cell interaction and factors influencing the transfection efficiency (TE) of CLs remains poor. In this article, we describe some new results aimed at elucidating the relationship between the chemical-physical properties of lipoplex with TE and introducing recent applications of CLs in gene therapy.

Identification of small molecular compounds and fabrication of its aqueous solution by laser-ablation, expanding primordial cartilage

OBJECTIVE

The discovery of small molecular compounds that expand cartilage is needed. We searched for small molecular compounds that expand cartilage or enhance the actions of bone morphogenetic proteins (BMPs) on cartilage.

DESIGN

Metatarsal primordial cartilage explants prepared from 14.5 days postcoitum (d.p.c.) mouse embryos were organ-cultured in the presence or absence of BMPs and/or 4-(5-Benzol[1,3]dioxol-5-yl-4-pyrldin-2-yl-1H-imidazol-2-yl)-benzamide hydrate (BPIB) and its related molecules. The perichondrium was removed from some of the cartilage explants by partial digestion with collagenase. BPIB aqueous solution was prepared by fragmenting BPIB crystals in water with laser irradiation and then added to cartilage explants in organ culture.

RESULTS

We found that small molecular compounds, BPIB, available as SB431542 from Sigma and its related molecules, expand primordial cartilage explants in organ culture. These molecules are transforming growth factor-β (TGF-β) inhibitors, and the addition of excess TGF-β reduced cartilage expansion induced by these molecules. The co-administration of BPIB and BMPs synergistically expanded cartilage explants. Removal of the perichondrium abolished BIPB-induced cartilage expansion but not BMP-induced cartilage-expansion, suggesting that BPIB, but not BMPs, expands cartilage through the perichondrium. Furthermore, we used the laser-ablation technique to generate BPIB aqueous solution in the presence of 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) without the use of hazardous dimethyl sulfoxide (DMSO). The laser-ablation-generated BPIB aqueous solution was more stable, expanded cartilage explants more effectively than BPIB colloidal solution prepared with DMSO, and synergistically enhanced BMP-induced cartilage expansion.

CONCLUSIONS

A small molecular compound, BPIB, expands primordial cartilage explants. A BPIB aqueous solution was created by laser-ablation without using DMSO and proved to be biologically active.

Immunotherapy of melanoma by GPI-anchored IL-21 tumour vaccine involves down-regulating regulatory T cells in mouse model

In this study, we developed a tumour cell vaccine expressing a glycosylphosphatidylinositol (GPI)-anchored IL-21 to test the effect of immunotherapy of melanoma in mouse model. The results indicated that the tumour vaccine was functional, exhibiting delayed tumour growth and prolonging longevity of tumour bearing mice. The immunotherapeutic effect was associated with decreasing the numbers of CD4(+) CD25(+) Foxp3(+) Treg (Tregs) cells, increasing IFN-γ level and promoting lymphocyte-infiltration in tumour tissues. Overall, our data demonstrate that the GPI-anchored IL-21 tumour vaccine regulates immune responses at least in part by down-regulating Tregs and reveals enhanced efficacy of tumour vaccine therapy of melanoma.

Characterization and in vitro cellular uptake of PEG coated iron oxide nanoparticles as MRI contrast agent

Monodisperse magnetic iron oxide nanoparticles (MNPs), coated with PEG at different molecular weight, were prepared via self-assembly method. The particle diameters were measured by dynamic light scattering and transmission electron microscope. Increasing the molecular weight of PEG in the coating polymer increased the overall particles diameter. As coating thickness increased, the saturation magnetization (Ms) and T2 relaxivity decreased. The interactions of these MNPs with macrophage cells were also investigated. The results showed that cellular uptakes of MNPs depended on nanoparticle concentration and surface chemistry. The results of this study will have implications on the chemical design of nanomaterials for bio-imaging and bio-detection.

Relationship between response to risperidone, plasma concentrations of risperidone and CYP3A4 polymorphisms in schizophrenia patients

In this study, we examined the relationships between plasma concentrations of risperidone and 9-hydroxyrisperidone and polymorphisms of CYP3A4. All 130 schizophrenia patients (45 men, 85 women, age 15-60 years) who met DSM-IV criteria were given risperidone for 8 weeks. Clinical efficacy was determined using the Positive and Negative Syndrome Scale (PANSS). CYP3A4*1G was found to be associated with the change in total PANSS scores (Kruskal-Wallis test, P = 0.021), which was not significant on adjusting for multiple testing. Our study has, for the first time, conducted a genetic association study of the CYP3A4 gene with risperidone response. Further studies on larger groups and on the effects of the longer term risperidone treatment are needed to confirm these results.

Size-controlled growth of colloidal gold nanoplates and their high-purity acquisition

A facile while flexible approach to size-controllable high-purity colloidal gold nanoplates has been presented. By adjusting the quantity of seeds and I(-) through a seed-mediated, cetyltrimethylammonium bromide (CTABr)-assisted synthetic system, the edge length of the gold nanoplates can be adjusted from 140 to 30 nm without changing their thickness or crystal structure. By simply increasing the ion concentration of the reaction solution, the as-prepared gold nanoplates can be deposited due to the different electrostatic aggregation effects between nanoplates and spherical nanoparticles. Effective storage methods to keep the structural and optical stability of these gold nanoplates are also proposed.

Fabrication of Anti-human Cardiac Troponin I Immunogold Nanorods for Sensing Acute Myocardial Damage

A facile, rapid, solution-phase method of detecting human cardiac troponin I for sensing myocardial damage has been described using gold nanorods-based biosensors. The sensing is demonstrated by the distinct change of the longitudinal surface plasmon resonance wavelength of the gold nanorods to specific antibody-antigen binding events. For a higher sensitivity, the aspect ratio of gold nanorods is increased up to ca 5.5 by simply adding small amount of HCl in seed-mediated growth solution. Experimental results show that the detecting limit of the present method is 10 ng/mL. Contrast tests reveal that these gold nanorods-based plasmonic biosensors hold much higher sensitivity than that of conventionally spherical gold nanoparticles.

Identification of tumor stem-like cells in a mouse myeloma cell line

We used colony formation assay in the soft agar media or the serum-free media, the methods of identifying BrdU-label-retaining cells and the SP cells as well as the tumorigenicity test in BALB/c mice, respectively, to analyze tumor stem like cells in the SP2/0 cell line. The results showed that a few SP2/0 cells were capable of forming colonies in the soft agar media, contained BrdU-label-immortal strand in the SP2/0 cell line. The SP2/0 cells in the serum-free media gained higher tumorigenicity in the BALB/c mice than the SP2/0 cells cultivated in the complete media did. Overall, only a few of the SP2/0 cells were found to possess the characteristics of tumor stem-like cells, such as high proliferative potency, more self-renewal and stronger tumorigenesis, or greater similarity to the tumor stem cells (TSCs) traits. The biology of tumor stem-like cells contributes to the identification of molecular targets important for future tumor therapy.

Maghemite nanoparticles and their protamine derivatives: cellular internalization and effects on cell-cycle progress

Dimercaptosuccinic acid-coated maghemite nanoparticles and their protamine derivatives were prepared. TEM revealed that the average size of nanoparticles is 10 nm and derivatives with larger size consist of several original nanoparticles. The cellular uptake of nanoparticles and derivatives by human hepatoma cells, and their effects on cell viability and cell-cycle were detected. Results showed that the internalization of nanoparticles into cells was very limited, while derivatives could be internalized into cells with high efficiency. Nanoparticles didn't display significant cytotoxicity at a wide range of concentrations (0.3-2.4 mg/ml), whereas derivatives had a narrow range of non-toxicity concentrations (0.3-0.6 mg/ml). Both nanoparticles and derivatives could affect cell-cycle progress and the mechanisms underlying were discussed.

Preparation and characterization of tea polyphenols and vitamin E loaded nanoscale complex liposome

The purpose of the present work was to prepare nanoscale complex liposome loaded both aqueous soluble drug tea polyphenols (TP) and insoluble drug vitamin E (VE) by reverse-phase evaporation method. The preparation formulation of TP-VE complex liposome was optimized by the orthogonal experiment. The entrapment efficiency of TP was (50.81 +/- 1.91)% while that of VE was (94.05 +/- 3.45)% for the optimal formulation. The results of penetration experiments of TP-VE liposome demonstrated a slight influence of the concentration of TP and the content of cholesterol on the penetration quantity of TP. These results indicate that the complex liposome offers a new approach to entrap aqueous soluble drug and poorly soluble drug, an inner liposome protection, a relatively high drug encapsulation efficiency and a sustained transdermal penetration.

Effects of proteins from culture medium on surface property of silanes- functionalized magnetic nanoparticles

Monodisperse magnetic nanoparticles (MNPs) were synthesized by thermal decomposition of iron-oleate and functionalized with silanes bearing various functional groups such as amino group (NH2), short-chain poly(ethylene glycol) (PEG), and carboxylic group (COOH). Then, silanes-functionalized magnetic nanoparticles (silanes-MNPs) were incubated in cell culture medium plus fetal calf serum to investigate the effects of proteins from culture medium on surface property of MNPs. Zeta potential measurements showed that although surface charges of silanes-MNPs were different, they exhibited negative charges at neutral pH and approximate isoelectric points after they were incubated in cell culture medium. The reason was that silanes-MNPs could easily adsorb proteins from culture medium via non-covalent binding, resulting in the formation of protein-silanes-MNPs conjugates. Moreover, silanes-MNPs with various functional groups had different adsorption capacity to proteins, as confirmed by Coomassie blue fast staining method. The in vitro cell experiments showed that protein-silanes-MNPs had higher cellular uptake by cancer cells than silanes-MNPs.

Stability of hydrophilic magnetic nanoparticles under biologically relevant conditions

Hydrophilic 2,3-dimercaptosuccinnic acid (HOOC-CH(SH)-CH(SH)-COOH, DMSA) coated monodisperse magnetic nanoparticles (Fe3O4) were dispersed in water, RPMI-1640 with 10% (v/v) fetal calf serum, RPMI-1640, PBS and MES, respectively, to investigate their stability under biologically relevant conditions. The Photon Correlation Spectroscopy (PCS) results showed that DMSA-Fe3O4 nanoparticles existed as aggregate under biological conditions. UV-vis, MRI and AFM results indicated that DMSA-Fe3O4 nanoparticles dispersed in RPMI-1640, PBS and MES presented poor stability, whereas those dispersed in RPMI-1640 with fetal calf serum exhibited excellent stability, which was due to their adsorption from fetal calf serum, as confirmed by zeta potential and IR results. Additionally, in vitro cell experiments showed that DMSA-Fe3O4 nanoparticles with adsorption from fetal calf serum had higher intracellular uptake than those without adsorption from serum, indicating that fetal calf serum could play a great role in intracellular uptake of nanoparticles.

Preparation of All-Trans Retinoic Acid Nanosuspensions Using a Modified Precipitation Method

All-Trans Retinoic Acid (ATRA) nanosuspensions were prepared with a modified precipitation method. The ATRA solution in acetone was injected into pure water by an air compressor under the action of ultrasonication. Photon correlation spectroscopy results showed that the mean particle size of ATRA nanoparticles in nanosuspensions reduced from 337 nm to 155 nm as the injection velocity increased and the polydispersity index was 0.45-0.50. The morphology of ATRA nanoparticles varied with the different concentration of ATRA solution in acetone. ATRA nanoparticles showed an amorphous state and stable in 6 months. It could be concluded that this modified precipitation method could produce stable and controllable ATRA nanosuspension to a certain extent, thus benefit for higher saturation solubility.

Photoprotection by tocopherol submicron emulsion against UV-mediated damage in HaCaT cells

alpha-Tocopherol is a lipophilic vitamin E that shows antioxidative, antiaging and antiphotodamage activity. Nanometer biotechnology is more widely used in the entrainment system of drug carriers and the development for new pharmaceutical preparations. Ultraviolet irradiation to human skin in the long term can result in photoaging and photocarcinogenesis. The purpose of this study was to observe the biological features of tocopherol submicron emulsion (vitE SME) and to clarify the roles of vitE SME on UVB-induced photodamage in HaCaT keratinocytes (KC). VitE SME was prepared by high-pressure homogenization and microemulsion technique. HaCaT KC was incubated in the culture medium supplied with 1/200 and 1/400 of VitE SME prior to different dosages of UVB irradiation. The vitamin E amount in the culture medium was measured by high-performance liquid chromatography (HPLC). Cell growth and cellular viability was detected by MTT assay. The amount of vitamin E remaining in the culture medium significantly decreased during the first 8 h, and less than 10% can be detected by the terminal experiment (24 h). No cytotoxicity effect of tocopherol NM on HaCat KC was observed. In contrast to the control group, the cellular viability of VitE SME-treated group increased 44.22% by 24 h. Compared with irradiated groups without VitE SME, cell proliferation decreased by 17.77% and 40.42% when the HaCaT KC was irradiated with 30 mJ/cm(2) and 90 mJ/cm(2) UVB irradiation, respectively. VitE SME has no toxicity to cell culture system and is characterized by stable release and penetration. Pre-incubation with VitE SME can partly reduce UV-induced cell damage, and the photoprotective efficiency to UVB irradiation also shows time dependence.

Association of TPH1 with suicidal behaviour and psychiatric disorders in the Chinese population

Tryptophan hydroxylase (TPH), the rate limiting enzyme in serotonin biosynthesis, is one of the most important regulating factors in the serotonergic system. Recently, polymorphisms of the TPH gene have been identified as being associated with suicide, but the evidence is inconsistent. To investigate the role in suicide of one of the isoforms, TPH1, we examined the association of five single nucleotide polymorphisms (SNPs) in the promoter region and in intron 7 of the TPH1 gene based on a sample from the Chinese population of 810 subjects, of whom 329 had made no suicide attempts (NSA), 297 had made suicide attempts (SA), and 184 were healthy subjects (HS). In this study, we observed statistically significant differences between NSA and HS subjects in allele distributions on one marker, -6526A (p = 0.0329; odds ratio (OR) 1.36; 95% confidence interval (CI) 1.01 to 1.81). No significant difference in genotype distribution or allele frequencies of other polymorphisms was found between the suicide victims and the controls. The overall haplotype frequency was significantly different between cases and healthy controls (p = 0.000024 NSA v HS; p < 0.000001, SA v HS; p < 0.000001, cases v HS). We found the haplotype TCAAA of -7180/-7065/-6526/218/779 to be strongly associated with suicidal behaviour and psychiatric disorders (p = 0.00243; OR = 1.62; 95% CI 1.17 to 2.24 and p = 0.018; OR = 1.41; 95% CI 1.05 to 1.91), which suggests an association of TPH1 with suicidal behaviour and indicates that TPH1 may play a significant role in the aetiology of psychiatric disorders in the Han Chinese population.

No association between the genetic polymorphisms in the RTN4R gene and schizophrenia in the Chinese population

The RTN4R gene is located in the 22q11 region and it encodes a subunit of the receptor complex (RTN4R-p75NTR) which results in neuronal growth inhibitory signals in response to Nogo-66, MAG or OMG signaling. Previous studies have suggested that RTN4R might act as a potential candidate for schizophrenia susceptibility loci. We genotyped four SNPs within the gene and conducted a case-control study and TDT analysis, involving 707 schizophrenic patients, 689 controls and 372 unrelated small nuclear families with schizophrenic offspring in the Chinese population. We examined allele and genotype frequencies and haplotype distributions in both family- and nonfamily-based samples. Our results suggest that there is no significant association between the genetic polymorphisms and schizophrenia in the Han Chinese population.