Gelatin-encapsulated iron oxide nanoparticles for platinum (IV) prodrug delivery,enzyme-stimulated release and MRI

A facile method for transferring hydrophobic iron oxide nanoparticles (IONPs) from chloroform to aqueous solution via encapsulation of FITC-modified gelatin based on the hydrophobic–hydrophobic interaction is described in this report. Due to the existence of large amount of active groups such as amine groups in gelatin, the fluorescent labeling molecules of fluorescein isothiocyanate (FITC) and platinum (IV) prodrug functionalized with carboxylic groups can be conveniently conjugated on the IONPs. The nanoparticles carrying Pt(IV) prodrug exhibit good anticancer activities when the Pt(IV) complexes are reduced to Pt(II) in the intracellular environment, while the pure Pt(IV) prodrug only presents lower cytotoxicity on cancer cells. Meanwhile, fluorescence of FITC on the surface of nanoparticles was completely quenched due to the possible Förster Resonance Energy Transfer (FRET) mechanism and showed a fluorescence recovery after gelatin release and detachment from IONPs. Therefore FITC as a fluorescence probe can be used for identification, tracking and monitoring the drug release. In addition, adding pancreatic enzyme can effectively promote the gelatin release from IONPs owing to the degradation of gelatin. Noticeable darkening in magnetic resonance image (MRI) was observed at the tumor site after in situ injection of nanoparticles, indicating the IONPs-enhanced T₂-weighted imaging. Our results suggest that the gelatin encapsulated Fe₃O₄ nanoparticles have potential applications in multi-functional drug delivery system for disease therapy, MR imaging and fluorescence sensor.     

A tumoral acidic pH-responsive drug delivery system based on a novel photosensitizer (fullerene) for in vitro and in vivo chemo-photodynamic therapy

Fullerene has shown great potential both in drug delivery and photodynamic therapy. Herein, we developed a doxorubicin (DOX)-loaded poly(ethyleneimine) (PEI) derivatized fullerene (C60–PEI–DOX) to facilitate combined chemotherapy and photodynamic therapy in one system, and DOX was covalently conjugated onto C60–PEI by the pH-sensitive hydrazone linkage. The release profiles of DOX from C60–PEI–DOX showed a strong dependence on the environmental pH value. The biodistributions of C60–PEI–DOX were investigated by injecting CdSe/ZnS (Qds) labeled conjugates (C60–PEI–DOX/Qds) into tumor-bearing mice. C60–PEI–DOX/Qds showed a higher tumor targeting efficiency compared with Qds alone. Compared with free DOX in an in vivo murine tumor model, C60–PEI–DOX afforded higher antitumor efficacy without obvious toxic effects to normal organs owing to its good tumor targeting efficacy and the 2.4-fold greater amount of DOX released in the tumor than in the normal tissues. C60–PEI–DOX also showed high antitumor efficacy during photodynamic therapy. The ability of C60–PEI–DOX nanoparticles to combine local specific chemotherapy with external photodynamic therapy significantly improved the therapeutic efficacy of the cancer treatment, the combined treatment demonstrating a synergistic effect. These results suggest that C60–PEI–DOX may be promising for high treatment efficacy with minimal side effects in future therapy.     

pH-responsive drug delivery system based on luminescent CaF(2):Ce(3+)/Tb(3+)-poly(acrylic acid) hybrid microspheres

In this study, we design a controlled release system based on CaF₂:Ce³⁺/Tb³⁺-poly(acrylic acid) (PAA) composite microspheres, which were fabricated by filling the pH-responsive PAA inside CaF₂:Ce³⁺/Tb³⁺ hollow spheres via photopolymerization route. The CaF₂:Ce³⁺/Tb³⁺ hollow spheres prepared by hydrothermal route possess mesoporous structure and show strong green fluorescence from Tb³⁺ under UV excitation. Doxorubicin hydrochloride (DOX), a widely used anti-cancer drug, was used as a model drug to evaluate the loading and controlled release behaviors of the composite microspheres due to the good biocompatibility of the samples using MTT assay. The composite carriers provide a strongly pH-dependent drug release behavior owing to the intrinsic property of PAA and its interactions with DOX. The endocytosis process of drug-loaded microspheres was observed using confocal laser scanning microscopy (CLSM) and the in vitro cytotoxic effect against SKOV3 ovarian cancer cells of the DOX-loaded carriers was investigated. In addition, the extent of drug release could be monitored by the altering of photoluminescence (PL) intensity of CaF₂:Ce³⁺/Tb³⁺. Considering the good biocompatibility, high drug loading content and pH-dependent drug release of the materials, these hybrid luminescent microspheres have potential applications in drug controlled release and disease therapy.     

A 13C NMR Study of the Products and Mechanism of the Thermal Oxidative Degradation of Poly(ethylene oxide)

The products and mechanism of the thermal oxidative degradation of poly(ethylene oxide) at 150 °C have been analysed using ¹³C NMR spectroscopy. The analysis was assisted by the use of distortionless enhancement by polarisation transfer spectra, longitudinal relaxation time measurements, long-range ¹³C ¹H coupling and chemical shift simulation software. The major result of degradation was chain scission resulting in two formate ester chain ends. Minor products were in-chain esters, peroxy groups, oxymethylene links and hydroxy and methoxy chain ends.

Initial steps for the mechanism of chain scission.     

The neuronal nitric oxide synthase (nNOS) gene contributes to the regulation of tyrosine hydroxylase (TH) by cocaine

Recently, we demonstrated that intact nitric oxide (NO) signaling is essential for the development of cocaine behavioral sensitization in adulthood [M.A. Balda, K.L. Anderson, Y. Itzhak, Differential role of the nNOS gene in the development of behavioral sensitization to cocaine in adolescent and adult B6;129S mice, Psychopharmacology (Berl) 200 (2008) 509–519]. Given the requirement of dopamine (DA) transmission in cocaine-induced behavioral sensitization and the interactions between NO and DA systems, the present study investigated the role of the neuronal nitric oxide synthase (nNOS) gene and the effect of cocaine on the expression of tyrosine hydroxylase (TH)-immunoreactive (-ir) neurons. Adult (postnatal day 80) wild type (WT) and nNOS knockout (KO) mice received saline or a sensitizing regimen of cocaine (20 mg/kg) for 5 days. After 24 h, TH immunoreactivity was assessed in the ventral tegmental area (VTA) and the dorsal striatum (dST) using stereology and Western blotting, respectively. We report that (a) nNOS KO mice express lower levels of TH-ir neurons in the VTA compared to WT counterparts, (b) cocaine administration to WT mice significantly increased striatal TH expression, and (c) the same cocaine administration to nNOS KO mice significantly decreased striatal TH expression. Thus, the nitrergic system may contribute to cocaine-induced behavioral sensitization by regulating dopaminergic neurotransmission.     

A proline-rich polypeptide complex (PRP) from ovine colostrum. Studies on the effect of PRP on nitric oxide (NO) production induced by LPS in THP-1 cells

A proline-rich polypeptide complex (PRP) isolated from ovine colostrum shows immunoregulatory activity. Similar activity was observed when PRP was replaced with a nonapeptide (NP) isolated from chymotryptic digest of PRP. The polypeptide complex also shows procognitive activity. In the form of orally administered tablets called Colostrinin®, containing 100 µg of PRP, it improves the outcome of Alzheimer's disease (AD) patients. The mechanism of action of PRP/Colostrinin® in AD is not yet clarified. Microglial cells involvement in AD has been related to amyloid β (Aβ) internalization, the release of inflammatory cytokines, overproduction of nitrogen oxide (NO) and superoxide anion (O₂^-), and the development of neuritic plaques. It has been previously found in our laboratory that PRP regulates the secretion of an array of cytokines. It also was shown, in preliminary experiments using human blood cells and murine macrophages, that PRP inhibits production of NO and O₂^- induced by LPS. In the present work, to study the effect of PRP and NP on the release of NO and O₂^- induced by LPS we applied THP-1 cells. The human monocyte/macrophage THP-1 cell line has been widely used as a model of human microglial cells. The results obtained showed that THP-1 cells release NO when activated with LPS. However, neither PRP nor NP induced production of NO. Although the nonapeptide, at higher concentration (100 µg/mL), showed an inhibitory activity on the release of NO induced by LPS, no inhibition was observed when PRP was used. THP-1 cells treated with LPS, PRP or NP did not release O₂^-.     

一氧化氮合酶阳性神经元在肝硬化大鼠中缝核的分布

目的研究肝硬化大鼠中缝核内一氧化氮合酶阳性神经元分布的变化。方法用四氯化碳建立肝硬化动物模型,NADPH-d组织化学方法观察大鼠脑干中缝核内神经元的变化,图像分析仪对神经元的形态及数量进行分析。结果①NOS阳性神经元及纤维广泛分布于脑干中缝核内,特别是中缝背核,且上段多于下段;②肝硬化大鼠NOS阳性神经元脑干中缝核内分布与正常组基本一致,但阳性反应物的密集度明显增高。结论肝硬化后脑干中缝核一氧化氮合酶较正常明显增多,其分布与兴奋性氨基酸分布相互重叠,可以推测它与一些神经递质在脑内共存并激发神经毒作用。     

Preparation and characterization of polyelectrolyte complex nanoparticles based on poly (malic acid), chitosan. A pH-dependent delivery system

The main objective of this work was to develop polyelectrolyte complex (PEC) nanoparticles based on poly (malic acid), chitosan (PMLA/CS) as pH-dependent delivery systems. The results indicated that the PMLA/CS Nps were successfully prepared. The prepared PMLA/CS Nps showed spherical morphology with a mean diameter of 212.81 nm and negative surface charge of ?24.60 mV, and revealing significant pH-sensitive properties as the mass ratio of PMLA to CS was 5:5. The prepared PMLA/CS Nps were characterized by FT-IR, TEM and DLS. The prepared PMLA/CS Nps remained stable over a temperature range of 4–53 °C. Doxorubicin (Dox) as a model drug was loaded on the nanoparticles through the physical adsorption method. The high drug loading efficiency (16.9%) and the sustained release patterns in acidic media were observed, and the release accelerated in alkaline solutions. MTT based cytotoxic analysis also depicted the non-toxic nature of PMLA/CS Nps, while Dox-PMLA/CS Nps showed dose-dependent cytotoxicity towards MDA-MB-231 cells. Hence, the nanoparticles could be potentially applied as pH sensitive drug vehicles for controlled release.     

A new pseudo-peptide of Arg-Gly-Asp (RGD) with inhibitory effect on tumor metastasis and enzymatic degradation of extracellular matrix

A series of pseudo-peptide analogs of the Arg-Gly-Asp (RGD) sequence of fibronectin have been synthe-sized, and their anti-metastatic effects in mice and inhibitory effects on tumor cell invasion in vitro have been examined. The partially modified retro pseudo-peptide of RGD, R_rev-COCH₂CO-D (FC-63), was more effective in inhibiting tumor metastasis than the original RGDS peptide. Replacement of the malonyl moiety of FC-63 with a carboxyethylene linkage (R_rev-COCH₂CH₂-D, FC-303 ) achieved more potent inhibition of lung metastasis of melanoma cells than FC-63. Among the analogs, FC-336, a p-xylylendiamine derivative having two FC-303 moieties, showed the most potent inhibitory effect on experimental lung metastasis produced by i.v. co-injection with B16-BL6 melanoma or colon 26 M3.1 cells in a dose-dependent manner. Multiple administrations of FC-336 after tumor inoculation also showed efficient therapeutic potency against spontaneous lung metastasis of B16-BL6 melanoma in mice. Furthermore, FC-336 effectively inhibited the invasion, migration and adhesion of tumor cells in vitro, but its inhibitory effects were not more than those of RGDS peptide. Zymography analysis revealed that FC-336 inhibited the degradation of gelatin substrate by matrix metalloproteinases (MMPs) produced by tumor cells, while the RGDS peptide did not affect the enzymatic degradation. These findings indicate that the pseudo-peptides of the RGD sequence, possessing the inhibitory property of the degradation by MMPs differently from original RGD-containing peptides, may be advantageous and useful in preventing tumor metastasis. © Rapid Science 1998     

The effect of medical treatment on nasal exhaled nitric oxide (NO) in patients with persistent allergic rhinitis: A randomized control study

PurposeThis study aimed to evaluate the role of nasal nitric oxide (NO) in the management of patients with persistent allergic rhinitis (PER).MethodsIt was a randomized and comparative study. The study subjects were classified as controls (healthy subjects) or patients with PER based on defined criteria. All clinical, functional and biological data were collected for analyzing. Nasal fractional exhaled nitric oxide (FENO) was measured by electroluminescence device. Patients with PER were randomized for treatment with antihistamine (ATH) combined with leukotriene receptor antagonists (LRA) or only with intranasal steroids (INS).ResultsDuring two years, 501 subjects were included: 234 control subjects and 267 patients with PER. The levels of nasal NO, total IgE, blood eosinophil counts, and apnea-hypopnea index (AHI) in patients with PER were higher than controls (P < 0.001; P < 0.05; P < 0.05; P < 0.01; respectively). There were statistically significant correlations between nasal NO, nasal peak flows, total IgE, and blood eosinophil counts in patients with PER (R = −0.687 and P = 0.0012; R = −0.643 and P = 0.0018; R = 0.432 and P = 0.0024; R = 0.445 and P = 0.002; respectively). After 6 months of treatment, patients treated with INS had greater improvement of clinical symptoms and reduction of nasal NO values than patients treated with ATH + LRA (985 ± 253 vs. 732 ± 298 ppb; P < 0.05).ConclusionNasal NO measurement is a useful tool for the follow-up of patients with PER. It also helps clinicians to estimate the level of response to treatment in patients with PER.     

高压氧治疗中、重度新生儿缺氧缺血性脑病（HIE）的临床研究（附53例疗效观察）

为了探索治疗新生儿缺氧缺血性脑病（ＨＩＥ）的有效疗法，我科新生儿专业组自１９９２年起应用高压氧治疗中、重度该病患儿５３例，结果显示，其临床疗效及预后随访情况均明显优于对照组，提示高压氧是治疗ＨＩＥ较理想的方法，但在选择病例时需注意，存在重症肺炎并心衰、呼衰或有脑实质、脑室内及较大量蛛网膜下腔出血者急性期不宜行高压氧治疗。     

唾液SIgA、溶菌酶含量与慢性支气管炎关系的探讨

目的：探讨了慢性支气管炎患者唾液SIgA和溶菌酶含量的变化及临床意义。方法：应用放射免疫分析检测38例慢性支气管炎患者唾液SIgA含量,免疫扩散法测定溶菌酶含量,并与35名正常人作比较。结果：慢性支气管炎患者唾液SIgA和溶菌酶含量非常显著地高于正常人组（P〈0．01）,经2周治疗后仍有显著性差异（P〈0．05）。结论：检测慢性支气管炎患者唾液SIgA和溶菌酶含量的变化对临床观察预后有重要的临床价值。     

Adsorption of proteins at physiological concentrations on pegylated surfaces and the compatibilizing role of adsorbed albumin with respect to other proteins according to optical waveguide lightmode spectroscopy (OWLS)

In literature, contacts between pegylated compounds and blood proteins are generally discussed in terms of excluded volume-related repulsions although adsorption and compatibility have been reported for some of these proteins occasionally. The major problem to investigate the behavior of blood in contact with pegylated surfaces is the complexity of the medium and especially the presence of albumin in large excess. In a model approach, optical waveguide lightmode spectroscopy (OWLS) was used to monitor the fate of albumin, fibrinogen, and γ-globulins at physiological concentrations in pH?=?7.4 isotonic HEPES buffer after contact with SiTiO₂ chips coated with diblock poly(DL-lactic acid)-block-poly(ethylene oxide)s and triblock poly(DL-lactic acid)-block-poly(ethylene oxide)-block-poly(DL-lactic acid) copolymers. Corresponding homopolymers were used as controls. The three protein systems were investigated separately, as a mixture and when added successively according to different orders of addition. OWLS gave access to the mass and the thickness of adhering protein layers that resist washing with HEPES buffer. Protein depositions were detected regardless of the presence of poly(ethylene glycol) segments on surfaces. Adsorption depended on the protein, on the surface and also on the presence of the other proteins. Unexpectedly any surface coated with a layer of adsorbed albumin prevented deposition of other proteins, including albumin itself. This outstanding finding suggests that it was the presence of albumin adsorbed on a surface, pegylated or not, that made that surface compatible with other proteins. As a consequence, dipping a device to be in contact with the blood of a patient in a solution of albumin could be a very simple means to avoid further protein deposition and maybe platelets adhesion after in vivo implantation.     

Quantitative trait loci (QTL) applications to substances of abuse: Physical dependence studies with nitrous oxide and ethanol in BXD mice

Recombinant inbred (RI) mouse strains were developed primarily as a tool to detect and provisionally map major gene loci—those with effects large enough to cause a bimodal distribution in the trait of interest. This implied that progress toward gene mapping was possible only for gene loci accounting for at least half of the genetic variance. More recently, QTL (quantitative trait loci) approaches have been advanced that do not require bimodal distributions and are thus applicable to a much wider range of phenotypes. They offer the prospect of meaningful progress toward detecting and mapping minor as well as major gene loci affecting any trait of interest, provided there is a significant degree of genetic determination among the RI strains. This paper presents a review of RI gene mapping efforts concerning phenotypes related to drug abuse and presents new data for studies now in progress for nitrous oxide and acute ethanol withdrawal intensity. These two studies exemplify several strengths and limitations of the RI QTL approach.     

Effect of chronic activation of 5-HT3 receptors on 5-HT3, 5-HT(1A) and 5-HT(2A) receptors functional activity and expression of key genes of the brain serotonin system

The dopamine D3 receptor gene (DRD3) is considered being one of the candidate genes contributing to the development of tardive dyskinesia (TD). In a recent meta-analysis with mixed ethnicities, only a barely positive association was found between the functional DRD3 Ser9Gly polymorphism and TD in patients with schizophrenia (OR = 1.17; 95% CI: 1.01-1.37; p = 0.041). To further evaluate the controversial association between the polymorphism and TD using only Japanese subjects, we tested the association in a case-control design. We also conducted a meta-analysis including 8 studies with 3 East Asian populations (Japanese, Chinese, and Korean). In our Japanese case-control sample (43 with TD/157 without TD), we found no association between the DRD3 Ser9Gly polymorphism in schizophrenia and TD (genotype: p = 0.92; allele: p = 1.00). Furthermore, no significant difference in the mean AIMS score among the three genotypic groups was observed in our sample. The meta-analysis comprising 1291 East Asian subjects also showed no association between the polymorphism and TD; the Mantel-Haenszel pooled OR for TD among carriers of the DRD3 Ser9Gly of the eight Asian studies was 0.94 (95% CI: 0.78-1.12). Overall, our results suggest that the DRD3 Ser9Gly polymorphism may not confer susceptibility to TD in East Asian populations. Given that the Ser9Gly variant may play a putative role in the DRD3 function, further studies on the DRD3 are warranted.     

Transfection and intracellular trafficking characteristics for poly(amidoamine)s with pendant primary amine in the delivery of plasmid DNA to bone marrow stromal cells

Poly(amidoamine)s with pendant primary amine (polymer 1a–1c) were evaluated as in vitro non-viral gene delivery vectors for bone marrow stromal cells (BMSCs). The cytotoxicity of these poly(amidoamine)s, measured by MTT assay, increased with increasing length of side chain, however, they were less toxic than branched polyethylenimine (PEI) 25 kDa. Using pGL-3 and pEGFP-C1 as luciferase gene and green fluorescent protein (GFP) gene, among all polycations including polymer 1a–1c and PEI, polymer 1b at optimal N/P ratio showed highest luciferase expression (1.92 × 10⁸ RLU/mg protein) as well as percentage of cells expressing GFP (29.01 ± 2.33%). For all polycations, intracellular trafficking of Cy3-labelled plasmid DNA (pDNA) was similar. Fluorescent particles attached to cell membrane at 0.5 h after adding the polycation/DNA complexes, aggregated in cytoplasm after 2 h, and then stayed around the perinuclear region after 4 h. pDNA nuclear localization appeared at 4 h post-transfection, but much more pDNA entered into nucleus at 24 h. At high N/P ratio, polymer 1a–1c could deliver pDNA into 70–80% of BMSCs after 24 h transfection, however, labelled pDNA was observed in only 4–25% of cells at the same time. Compared to PEI, polymer 1b showed comparable or even higher percentage of pDNA uptake and nuclear localization. We concluded that poly(amidoamine)s with pendant primary amine, especially polymer 1b, are new kind of promising candidates of less toxic and highly efficient non-viral gene delivery vectors for BMSCs.     

Involvement of the brain histaminergic system in addiction and addiction-related behaviors: A comprehensive review with emphasis on the potential therapeutic use of histaminergic compounds in drug dependence

Neurons that produce histamine are exclusively located in the tuberomamillary nucleus of the posterior hypothalamus and send widespread projections to almost all brain areas. Neuronal histamine is involved in many physiological and behavioral functions such as arousal, feeding behavior and learning. Although conflicting data have been published, several studies have also demonstrated a role of histamine in the psychomotor and rewarding effects of addictive drugs. Pharmacological and brain lesion experiments initially led to the proposition that the histaminergic system exerts an inhibitory influence on drug reward processes, opposed to that of the dopaminergic system. The purpose of this review is to summarize the relevant literature on this topic and to discuss whether the inhibitory function of histamine on drug reward is supported by current evidence from published results. Research conducted during the past decade demonstrated that the ability of many antihistaminic drugs to potentiate addiction-related behaviors essentially results from non-specific effects and does not constitute a valid argument in support of an inhibitory function of histamine on reward processes. The reviewed findings also indicate that histamine can either stimulate or inhibit the dopamine mesolimbic system through distinct neuronal mechanisms involving different histamine receptors. Finally, the hypothesis that the histaminergic system plays an inhibitory role on drug reward appears to be essentially supported by place conditioning studies that focused on morphine reward. The present review suggests that the development of drugs capable of activating the histaminergic system may offer promising therapeutic tools for the treatment of opioid dependence.     

时空扫描方法在北京市甲型H1N1流感聚集性探测中的应用

目的 探讨北京市2009年甲型H1N1流感发病时空分布特征,为传染病预防控制提供理论依据.方法 利用SaTScan8.0软件进行时空扫描分析,通过ArcGIS8.3软件呈现甲型H1N1流感时空聚集区域.结果 按照7天、14天、30天,50％的时间周期进行单纯时间扫描分析,结果显示甲型H1N1流感发病在9月4日-12月1...