Gel properties and interactions of hydrogels constructed with low acyl gellan gum and puerarin.

To develop composite hydrogels based on low acyl gellan gum (GG), the effect of puerarin (PUE) on the gel properties of GG was investigated. The results showed that the maximum storage modulus (G') of the 1.2 % GG/0.8 % PUE composite hydrogel was 377.4 Pa at 0.1 Hz, which was enhanced by 4.7-fold compared with that of 1.2 % GG. The melting temperature of this composite hydrogel increased from 74.1 °C to >80.0 °C. LF-NMR results showed that a significant amount of free water was present in the hydrogel matrix. The surface structure aggregation and the shrinkage of the honeycomb meshes in the composite hydrogel proved the cross-linking of PUE and GG. XRD, FTIR and molecular simulation results illustrated that hydrogen bonds were the most important factor controlling the interaction between GG and PUE. Thus, the GG/PUE composite hydrogel has good elasticity, thermal stability and water retention, which lays a good foundation for further application in the food industry.

Monovalent Salt and pH-Stimulated Gelation of Scallop (Patinopecten yessoensis) Male Gonad Hydrolysates/κ-Carrageenan.

The gelation of scallop Patinopecten yessoensis male gonad hydrolysates (SMGHs) and κ-carrageenan (KC) subjected to pH (2-8, 3-9) and NaCl/KCl stimuli-response was investigated. SMGHs/KC gels subjected to a NaCl response exhibited an increasing storage modulus G'from 2028.6 to 3418.4 Pa as the pH decreased from pH 8 to 2, with corresponding T23 fluctuating from 966.40 to 365.64 ms. For the KCl-treated group, SMGHs/KC gels showed an even greater G' from 4646.7 to 10996.5 Pa, with T23 fluctuating from 622.2 to 276.98 ms as the pH decreased from 9 to 3. The improved gel strength could be ascribed to the blueshift and redshift of hydroxyl groups and amide I peaks, enhanced enthalpy and peak temperature, and gathered characteristic diffraction peaks from SMGHs, KC, NaCl, and KCl. The CLSM and cryo-SEM images further reflected that SMGHs/KC gels showed more flocculation formation and denser and more homogeneous networks with smaller pore sizes in more acidic domains, especially when subjected to the KCl response. This research gives a theoretical and methodological understanding of the construction of salt- and pH-responsive SMGHs/KC hydrogels as novel functional soft biomaterials applied in food and biological fields.

Formation and microstructural characterization of scallop (Patinopecten yessoensis) male gonad hydrolysates/sodium alginate coacervations as a function of pH.

Studying the noncovalent interactions between proteins and polysaccharides is quite important mainly due to the wide number of applications such as developing pH-responsive complexes. Scallop Patinopecten yessoensis male gonad hydrolysates­sodium alginate (SMGHs-SA) was investigated as noncovalent complexes at pH from 1 to 10. The critical pH values pHC (around 6) and pHφ (around 4) were independent of the SMGHs-SA ratio, indicating the formation of soluble and insoluble complexes. The pH response of SMGHs-SA complexes was evaluated by investigating the rheological behavior, moisture distribution, functional group change and microstructure. Compared to the co-soluble and soluble complexes phases, the SMGHs-SA complexes had a higher storage modulus and viscosity as well as a lower relaxation time (T23) in the insoluble complexes phase (pHφ>3). Additionally, the amide I band and COO- stretching vibration peaks were redshifted and the amide A band vibration peaks were blueshifted by acidification. Electrostatic interactions and intermolecular/intramolecular hydrogen bonding led to SMGHs-SA agglomeration at pH 3, forming a uniform and dense gel network structure with strong gel strength and water-retention capacity. This study provides a theoretical and methodological basis for the design of novel pH-responsive complexes by studying SMGHs-SA complex coacervation.

Electroconvulsive therapy-induced neuroimaging alterations measured by cerebral blood flow in adolescents with major depressive disorder.

BACKGROUND: Electroconvulsive therapy (ECT) is a novel treatment strategy for adolescents with major depressive disorder (MDD). However, its related neurobiological changes associated with ECT remain undetermined. OBJECTIVE: To elucidate the impact of ECT on the regional cerebral blood flow (CBF), and to identify alterations in the CBF associated with clinical outcomes in adolescents with MDD. METHODS: Fifty-two treatment-naive adolescents who had experienced their first episode of MDD and 36 healthy controls (HCs) were recruited. To assess baseline parameters, all subjects were scanned with arterial spin labeling resting-state functional magnetic resonance imaging (ASL-fMRI) at the beginning of the study. Subsequently, 27 MDD adolescents were re-scanned after 2 weeks after ECT. CBF imaging was used for the prediction of specific clinical outcomes. Lastly, the associations between alterations seen on brain imaging alterations after ECT and ECT clinical efficacy (ΔHAMD scores) were determined. RESULTS: Relative to HCs, adolescents with MDD exhibited reduced CBF in the left medial superior frontal gyrus (SFGmed) (cluster = 243, peak t = -3.9373, and P < 0.001) and augmented CBF in the right percental gyrus (PerCG) (cluster = 321, peak t = 4.3332, and P < 0.001) at baseline. Following ECT, MDD adolescents exhibited reduced CBF in the right fusiform gyrus (FFG) (cluster = 309, peak t = -4.346, and P < 0.001) and left hippocampus (HIP) (cluster = 290, peak t = -4.706, and P < 0.001), and enhanced CBF in the left orbital part of the inferior frontal gyrus (ORBinf) (cluster = 214, peak t = 4.073, and P < 0.001). Correlation analysis suggested an inverse association between ΔHAMD scores and CBF values in the left ORBinf (R2 = 0.196, P = 0.021). CONCLUSIONS: It was found that ECT resulted in alterations in CBF in specific brain areas, highlighting the significance of ORBinf in ECT pathophysiology in MDD adolescents.

Alteration of microRNA-4474/4717 expression and CREB-binding protein in human colorectal cancer tissues infected with Fusobacterium nucleatum.

Colorectal cancer (CRC) is a common and highly lethal form of cancer. Although the etiologic role of Fusobacterium nucleatum (F. nucleatum) in the development of CRC has been elucidated, the specific tumor molecules involved in the progression of CRC induced by F. nucleatum have not been identified. This study investigated several miRNAs and genes involved in the progression of F. nucleatum-induced CRC by Affymetrix miRNA microarray technology and GeneChip Human Transcriptome Array 2.0. The results suggest that miR-4474 and miR-4717 are up-regulated in CRC tissues in response to F. nucleatum infection, compared with the control group (paracancerous tissues), while other genes associated with signaling pathways in cancer, including CREB-binding protein (CREBBP), STAT1, PRKACB, CAMK2B, JUN, TP53 and EWSR1, were dysregulated. Bioinformatic analysis identified CREBBP as the primary aberrantly expressed gene in F. nucleatum-induced CRC. Consistent with the microarray analysis results, real-time RT-PCR analysis demonstrated that the expression of miR-4474/4717 was upregulated while that of CREBBP mRNA was downregulated in CRC patients infected with F. nucleatum. Additionally, CREBBP was identified as a novel target of miR-4474/4717. The results of this study suggest that miR-4474 and miR-4717 are involved in the progression of F. nucleatum-induced CRC by posttranscriptionally regulating the target gene CREBBP.

Helicobacter pylori VacA induces autophagic cell death in gastric epithelial cells via the endoplasmic reticulum stress pathway.

The Helicobacter pylori vacuolating cytotoxin (VacA) can promote progressive vacuolation and gastric injury and may be associated with human gastric cancer. Increasing evidence indicates that autophagy is involved in the cell death induced by VacA, but the specific mechanisms need to be further elucidated. We show here that VacA could induce autophagy and increase cell death in human gastric cancer cell lines. Further investigations revealed that inhibition of autophagy could decrease the VacA-induced cell death in AGS cells. Furthermore, numerous dilated endoplasmic reticula (ER) were observed, and the phosphorylation of a subunit of eukaryotic translation initiation factor 2 subunit 1 also increased in the VacA-treated AGS cells, while repression of ER stress could reduce autophagy and cell death through knockdown of activating transcription factor 4 and DNA-damage-inducible transcript 3. In addition, the expression of pseudokinase tribbles homolog 3 (TRIB3) upon ER stress was triggered by VacA, and knockdown of TRIB3 could also decrease VacA-induced cell death. Finally, inhibition of autophagy could decrease VacA s1m1 -induced cell death and apoptosis, and apoptosis inhibitor Z-VAD had no significant effect on autophagy induced by VacA s1m1 . Thus, these results suggested that VacA causes autophagic cell death via ER stress in gastric epithelial cells.

TLR2/TLR4 activation induces Tregs and suppresses intestinal inflammation caused by Fusobacterium nucleatum in vivo.

Toll-like receptors (TLRs) 2 and 4 play critical roles in intestinal inflammation caused by Fusobacterium nucleatum (F. nucleatum) infection, but the role of TLR2/TLR4 in regulation of proinflammatory cytokines remains unknown. In this study, through microarray analysis and qRT-PCR, we showed that TLR2/TLR4 are involved in the F. nucleatum-induced inflammatory signaling pathway in Caco-2 cells, C57BL/6 mice and human clinical specimens. In TLR2-/- and TLR4-/- mice, F. nucleatum infection resulted in increased colonization of the bacteria and production of the proinflammatory cytokines IL-8, IL-1ß and TNF-α. In addition, the ratio of Foxp3+ CD4+ T cells in the total CD4+ T cells in TLR2-/- and TLR4-/- mice was less than that in wild-type mice, and the ratio in hybrid mice was more than that in knockout mice, which suggested that TLR2/TLR4 mediated the number of Tregs. Furthermore, it was observed that inflammatory cytokine levels were reduced in TLR2-/- mice after Treg transfer. Thus, these data indicate that TLR2/TLR4 regulate F. nucleatum-induced inflammatory cytokines through Tregs in vivo.

Fusobacterium nucleatum-Induced Impairment of Autophagic Flux Enhances the Expression of Proinflammatory Cytokines via ROS in Caco-2 Cells.

Fusobacterium nucleatum (F. nucleatum) plays a critical role in gastrointestinal inflammation. However, the exact mechanism by which F. nucleatum contributes to inflammation is unclear. In the present study, it was revealed that F. nucleatum could induce the production of proinflammatory cytokines (IL-8, IL-1ß and TNF-α) and reactive oxygen species (ROS) in Caco-2 colorectal) adenocarcinoma cells. Furthermore, ROS scavengers (NAC or Tiron) could decrease the production of proinflammatory cytokines during F. nucleatum infection. In addition, we observed that autophagy is impaired in Caco-2 cells after F. nucleatum infection. The production of proinflammatory cytokines and ROS induced by F. nucleatum was enhanced with either autophagy pharmacologic inhibitors (3-methyladenine, bafilomycin A1) or RNA interference in essential autophagy genes (ATG5 or ATG12) in Caco-2 cells. Taken together, these results indicate that F. nucleatum-induced impairment of autophagic flux enhances the expression of proinflammatory cytokines via ROS in Caco-2 Cells.

[Synthesis and Study on Adsorption Property of Congo Red Molecularly Imprinted Polymer Nanospheres].

Molecularly imprinted polymer nanospheres (MIP) were prepared with Congo red as the template, methacrylic acid (MAA) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross linker, azodiisobutyronitrile (AIBN) as an initiator, and acetonitrile as the porogen by precipitation polymerization. The morphology of MIP was characterized by SEM and TEM which showed that the diameter of MIP was nanometer grade (90 nm) and the shape was homogeneous. The specific surface area and pore volumes of MIP and NIP were examined through Brunauer-Emett-Teller method of nitrogen adsorption experiments. Then, the adsorption and selective recognition ability of MIPs were evaluated using the equilibrium rebinding experiments. The results indicated that the prepared MIP showed a good selectivity recognition ability to its template. It concluded that MIP could be employed as an effective material for removing Congo red from waste water.

[Synthesis and adsorption property of Cd(II) - 8-hydroxyquinoline molecularly imprinted polymer microspheres].

Cd(II) ion could form a stable complex with 8-hydroxyquinoline (molar rate = 1 : 1) in ethanol solution as revealed by ultraviolet spectrum analysis. Based on this molar rate of Cd(II) ions and 8-hydroxyquinoline, Cd(II) ions imprinting polymer microspheres were synthesized by water-in-oil-in-water (W/O/W) emulsions polymerization, using metal Cd(II) ions as template, 8-hydroxyquinoline as ligand, methacrylic acid as functional monomer, ethylene acrylic acid methyl ester as cross-linker, and azodiisobutyronitrile as initiator in aqueous phase. The influences of the dosage of emulsifier, porogen and outer aqueous phase on the morphology and adsorption property of MIP were studied. The morphology of MIP was characterized by SEM which showed that the diameter of MIP was of micrometer grade and the shape was homogeneous under some operating conditions. The adsorption properties of MIP synthesized under different conditions were compared. The influences of solution pH, adsorption time, initial concentration and temperature on MIP adsorbed Cd(II) ions were assessed. The results showed that MIP showed fast kinetics for adsorption and desorption of Cd(II) ions. It was concluded that MIP could be employed as an effective material for the selective removal of Cd(II) ions from waste water.

[Changes of glucose in the brains of monkeys with MPTP induced Parkinson's disease].

OBJECTIVE: To examine the metabolic and behavioral changes of monkeys with MPTP induced Parkinson's disease. METHODS: Four healthy monkeys were injected with diluted MPTP solution continuously through peripheral veins. The behavioral changes of the monkeys were monitored with the Parkinson disease scale for monkeys. 18FDG-PET-CT scans for the whole brain were obtained before and 3 months after the injection of MPTP. The pathological and glucose metabolic changes of the brains were examined. RESULTS: The animal model of Parkinson's disease was successfully established in all 4 monkeys, showing typical parkinsonian syndromes of bradykinesia, rigidity and hypokinesia. Changes in high nervous activities such as apathetic and less aggressive behaviors were also observed. Their scores of Parkinson disease scale exceeded 20. The parkinsonian syndromes were relieved after the administration of sinemet. The 18FDG-PET-CT scans showed significant glucose reduction after the MPTP injection within and outside of the basal ganglion area. CONCLUSION: The metabolic changes of brains in the monkeys with Parkinson's disease are not limited to the basal ganglion area, which may be an important mechanism for the non-motor symptoms.

[Control of tumor with gamma knife in patients with pituitary adenomas].

OBJECTIVE: To evaluate the effectiveness and complications of gamma knife surgery for treating pituitary adenomas. METHODS: Retrospective analyses of 217 cases of pituitary adenomas (from July 2004 to November 2008) were performed in Sichuan university's West China Hospital. The patients were treated with an average dose of 26.3 Gy (range 11-33 Gy) and 45%-75% isodose line. Data from serial saddle area MRI and blood endocrine hormone tests were examined. RESULTS: Of the 191 patients being followed up, 95.2% had their tumors effectively controlled. All non-functional pituitary adenoma were controlled, with the size of tumor shrinking significantly in an average of 11.4 months after gamma knife surgery. About functional pituitary adenoma were controlled, with the size of tumor shrinking significantly in an average of 18.6 months. Pituitary hypofunction occurred in 11.5% of patients after the surgery. No patient experienced exacerbation of poor eyesight and visual field after gamma knife surgery. CONCLUSION: Gamma knife can effectively control tumor growth and is a safe and effective treatment for pituitary adenoma.

A novel luminol-based chemiluminescence method for the determination of amikacin sulfate in serum by using trivalent copper-periodate complex.

A novel chemiluminescence (CL) reaction was based on the oxidizing reaction of luminol by the trivalent copper-periodate complex (K5[Cu(HIO6)2], DPC) in alkaline medium. The CL intensity could be enhanced in the presence of amikacin sulfate (AKS). A new CL method was developed for the determination of AKS by coupling with flow injection (FI) technology. Because of the distinctive oxidative effect of DPC, the luminol-based CL reaction could occur at a low concentration of 10-7 M. The relative CL intensity was proportional to the concentration of AKS in the range of 4.0×10-9-4.0×10-6 g/mL with the detection limit of 1.2×10-9 g/mL. The relative standard deviation was 2.1% for 8.0×10-9 g/mL AKS (n=9). The proposed method was successfully applied to the direct determination of AKS at the level of ng/mL in serum samples. The recovery varied from 97.0% to 106.3%. A possible mechanism of the CL reaction was discussed in detail by relating to the CL kinetic characteristics and electrochemical activities of the oxidant DPC.

Ectopically expressed IBP promotes cell proliferation in oral squamous cell carcinoma.

IFN regulatory factor 4 binding protein (IBP) has been shown to play an important role in the progression of malignant tumors such as breast cancer cells, but its function in oral squamous cell carcinoma (OSCC) remains unclear. We found that IBP ectopically expressed in some OSCC specimens but not in normal oral mucosa epithelium tissues. IBP expression was significantly correlated with tumor size, differentiation, clinical stage, and distant metastasis. Furthermore, IBP markedly promoted OSCC cell proliferation, shortened the G1 interval in the cell cycle, and increased cyclin D1 expression. These findings suggest that IBP may be a potential therapeutic target for OSCC.

An experimental study on the effects of curcumin on posterior capsule opacification in young rabbit eyes.

BACKGROUND: Posterior capsule opacification (PCO) compromises vision development in infants after cataract surgery and lead to amblyopia. To observe the effects of curcumin on PCO in infant rabbits, curcumin was injected under the capaule and into the anterior chamber during phacoemulsification. METHODS: Seventy-five 1-month-old healthy New Zealand white rabbits were randomized into 3 groups, one eye of each rabbit was randomly selected to be operated. The operation involved continuous circular capsulorhexis, followed by hydrodissection with 0.6 ml each of balanced salt solution (BSS, group A), hydroxypropyl-ß-dodextrin (HP-ß-CD, 90 µg/ml, group B) or CUR-HP-ß-CD (123 µg/ml, group C), respectively. After phacoemulsification, 0.4 ml of each drug solution was injected into the anterior chamber via an incision. The extent of corneal edema and the inflammatory response within the anterior chamber were considered as measures PCO and observed postoperatively. All eyes were examined 1 and 2 months postoperative by slit lamp microscopy and photography after pupil dilation. On the third day postoperative, 6 rabbits from each group were executed. Paraffin-embedded sections were stained with hematoxylin-eosin (HE) or terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL, indicative of apoptosis). Stained sections were observed under light microscopy. Proliferation of lens epithelial cells (LECs) was observed microscopically on day 3, day 7, month 1 and month 2 after the operation with HE staining. RESULTS: The remission of cornea edema occurred earlier in group C than in groups A and B (P < 0.05); there were no significant differences between groups A and B. The remission of anterior chamber exudation in group C was earlier than those in groups A and B (P < 0.05). No significant difference in the times when PCO occurred, was observed among groups. Compared to groups A and B, the extent of PCO was less severe (P < 0.05). Three days after the operation, LECs aggregated at the orbit. Meanwhile, minor apoptosis was observed in all groups. One month after the operation transparent, cortex and proliferating LECs were observed near the orbit in groups A and B. Two months postoperative, heavy cortex proliferation was observed in all groups: epithelial cells migrated and aggregated at the posterior capsule and rearranged under the anterior capsule in the control group. Proliferation was also observed in group C, but to a less severe extent than in the other two groups. CONCLUSION: CUR-HP-ß-CD exerts an inhibitory effect on PCO.

Quenching effect of nickel ions on fluorescent gold nanoparticles.

Herein, we reported the quenching effect of Ni(2+) on bovine serum albumin protected fluorescent gold nanoparticles (BSA-GNPs). The quenching mechanism was discussed and a static quenching mechanism was proposed. The number of binding sites (n), apparent stability constants (K) and corresponding thermodynamic parameters of BSA-GNPs-Ni(2+) complex were measured at different temperatures. Under optimum conditions, the fluorescence intensity of BSA-GNPs is linearly proportional to nickel concentration from 6.0x10(-8)mol/L to 8.0x10(-6)mol/L with a detection limit of 1.0x10(-8)mol/L. The result indicated that BSA-GNP was a potential Ni(2+) probe.

Photoluminescence from water-soluble BSA-protected gold nanoparticles.

The photoluminescence from water-soluble gold nanoparticles, each composed of a 5.1 nm gold core and a bovine serum albumin (BSA)-protected layer, has been observed. The maximal excitation and the maximal emission wavelength are at 320 and 404 nm, respectively. The photoluminescence quantum yield is estimated as 0.053+/-0.0070, at room temperature. The mechanism of the luminescence is hypothesized to be associated with interband transitions between the filled 5d(10) band and 6(sp)(1) conduction band. The photoluminescence is sensitive to pH, organic solvents and metal ions. These observations suggest that this nanoparticles are a viable alternative to organic fluorophores or semiconductor nanoparticles for biological labeling and imaging.

Determination of propylthiouracil and methylthiouracil in human serum using high-performance liquid chromatography with chemiluminescence detection.

Based on the sensitizing effect of formaldehyde on the chemiluminescence (CL) reaction of propylthiouracil (PTU) and methylthiouracil (MTU) with acidic potassium permanganate and the combination technique of high-performance liquid chromatography (HPLC), a sensitive, selective and simple post-column CL detection method for determining PTU and MTU is described. The optimal conditions for the CL detection and HPLC separation were carried out. The linear ranges were 0.1-20 microg mL(-1) for MTU and 0.1-10 microg mL(-1) for PTU, the detection limits were 0.03 microg mL(-1) for PTU, 0.03 microg mL(-1) for MTU and the quantification limits were 0.1 microg mL(-1) for PTU, 0.1 microg mL(-1) for MTU. The method has been satisfactorily applied for the determination of MTU and PTU in human serum samples.

[Quality standard for Xindi soft capsule].

OBJECTIVE: To establish the quality control standard of Xindi soft capsule. METHOD: Quercetin, kaempferol and isorhamnetin were isolated by TLC with chloroform-ethyl formate-formic acid (5:4:1). The chromatographic separation was performed on a Diamonsil C18 column (4.6 mm x 250 mm, 5 microm). Acetonitrile-water-phosphoric (30:70:0.1) as mobile phase. The flow rate was 1 mL x min(-1) and column temperature was set at 40 degrees C. The UV detection wavelength was set at 254 nm. RESULT: Quercetin, Kaempferol and Isorhamnetin could be identified by TLC. Quercetin showed a good linear relationship at a range of 0.412-1.648 microg, r = 0.999 9, the average recovery was 96.8%, and RSD was 0.9% (n = 6). Kaempferol showed a good linear relationship at a range of 0.021-0.083 microg, r = 0.999 8, the average recovery was 96.9%, and RSD was 2.0% (n = 6). Isorhamnetin showed a good linear relationship at a range of 0.183-0.732 microg, r = 0.999 9, the average recovery was 97.1%, and RSD was 1.6% (n = 6). CONCLUSION: The method is accurate with the good reproducibility and can be used for the quality control of Xindi soft capsule.

Adenoviral-mediated HGF expression inhibits germ cell apoptosis in rats with cryptorchidism.

BACKGROUND: Prior studies have shown that the hepatocyte growth factor (HGF), as known for its multiple biological effects, possibly regulates spermatogenesis or tubulogenesis in the testis. To clarify the effect of HGF on restoration of spermatogenesis, or testicular weight, we transferred the HGF gene into the testis of the rat experimental cryptorchid model. METHODS: Replication-deficient recombinant adenoviral vectors containing the CAG promoter driving rat HGF (pAxCAHGF) and LacZ (pAxCALacZ) were constructed. Sprague-Dawley rats surgically induced with unilateral cryptorchidism and subsequent orchidopexy were divided into three groups: control (PBS), pAxCALacZ and pAxCAHGF by intratesticular injection. At 2 and 4 weeks after subsequent orchidopexy, testes were removed and weighed. These specimens were analyzed histopathologically, and examined for cell apoptosis. HGF expression in these specimens associated with c-Met receptor-mediated signal molecules was examined by reverse transcription-polymerase chain reaction (RT-PCR), Western blot or immunohistochemical study. RESULTS: Adenovirus-mediated HGF gene transfer induced overexpression of HGF in some seminiferous epithelial cells and interstitial cells, increased the phosphorylation of ERK and Akt, and decreased numbers of apoptotic cells of germ cells. HGF transduction also significantly increased the numbers of germ cells and testicular weight by 4 weeks compared with the other control groups. CONCLUSIONS: Adenoviral-mediated HGF gene transfer into the testis in the cryptorchidism rats inhibited germ cell apoptosis and restored spermatogenesis.