Flavonoids dimers from the fruits of Psoralea corylifolia and their cytotoxicity against MCF-7 cells.

Nine new flavonoids dimers, psocorylins R-Z (1-9), were isolated from the fruits of Psoralea corylifolia L. (Psoraleae Fructus), a traditional Chinese medicine. The structures of these compounds were elucidated via multiple spectroscopic techniques and X-ray diffraction. Psocorylins R (1) and S (2) were rare cyclobutane-containing chalcone dimers, and psocorylins T-Z (3-9) were established by CC or COC bond of two flavonoid monomers. The structural-types, flavonoids dimers, were isolated from the plant for the first time, enriching the chemical diversity. The cytotoxicity assay suggested that compounds 1, 2, 4, 5, 6 and 8 exhibited cytotoxic activities against MCF-7 cells. Furthermore, compounds 1 and 8 significantly increased intracellular ROS levels, decreased MMP and induced apoptosis of MCF-7 cells. They markedly upregulated the expression of Bax and cleaved caspase-3, and suppressed Bcl-2 and caspase-3 levels, indicating their mechanism of Bcl-2/Bax/Cleaved caspase-3 pathway. Hence, our findings not only promoted the chemical investigation of Psoraleae Fructus, but also provided potential bioactive natural products for anti-cancer.

Cerebral hemorrhage caused by shaking adult syndrome? Evidence from biomechanical analysis using 3D motion capture and finite element models.

The present study combined three-dimensional (3D) motion capture with finite element simulation to reconstruct a real shaking adult syndrome (SAS) case and further explore the injury biomechanics of SAS. The frequency at which an adult male can shake the head of another person, head-shaking amplitude, and displacement curves was captured by the VICON 3D motion capture system. The captured shaking frequency and shaking curve were loaded on the total human model for safety (THUMS) head to simulate the biomechanical response of brain injury when a head was shaken in anterior-posterior, left-right, and left anterior-right posterior directions at frequencies of 4 Hz (Hz), 5 Hz, 6 Hz, and 7 Hz. The biomechanical response of the head on impact in the anterior, posterior, left, left anterior, and right posterior directions at the equivalent velocity of 6 Hz shaking was simulated. The violent shaking frequency of the adult male was 3.2-6.8 Hz; head shaking at these frequencies could result in serious cerebral injuries. SAS-related injuries have obvious directionality, and sagittal shaking can easily cause brain injuries. There was no significant difference between the brain injuries caused by shaking in the simulated frequency range (4-7 Hz). Impact and shaking at an equivalent velocity could cause brain injuries, though SAS more commonly occurred due to the cumulative deformation of brain tissue. Biomechanical studies of SAS should play a positive role in improving the accuracy of forensic identification and reducing this form of abuse and torture in detention or places of imprisonment.

Local infiltration of HYR-PB21, a sustained-release formulation of bupivacaine, provides analgesia and reduces opioid requirement after haemorrhoidectomy: a randomised controlled trial.

BACKGROUND: HYR-PB21 is a new sustained-release formulation of bupivacaine indicated for controlling postoperative pain. The objectives of this study were to investigate the analgesic efficacy and safety profile of HYR-PB21 in patients after haemorrhoidectomy. METHODS: This was a multicentre, randomised, double-blind, positive-controlled trial. Patients were assigned randomly to receive a single dose of HYR-PB21 (150 mg or 300 mg) or bupivacaine HCl (75 mg) after surgery for prolapsing haemorrhoids. Postoperative pain was evaluated using a numeric rating scale at rest to calculate a cumulative pain score. Total rescue opioid usage and the proportion of subjects receiving rescue opioid were also assessed. RESULTS: We enrolled 72 patients with haemorrhoidectomy, and 71 patients completed the study. The average cumulative pain score through 72 h after surgery in the 300 mg HYR-PB21 group (87 scores) was lower than in the bupivacaine HCl group (166 scores) in an intention-to-treat analysis (P<0.001). There was a dose-response effect in reducing total opioid usage and the proportion of rescue opioid use between the 150 mg and 300 mg HYR-PB21 groups, with bupivacaine HCl as a reference group. The HYR-PB21 groups did not show more adverse effects than the bupivacaine HCl group. CONCLUSIONS: Local infiltration of a single dose of HYR-PB21 sustained-release bupivacaine had better efficacy in controlling postoperative pain, with similar adverse effects, compared with a single dose of bupivacaine HCl in patients after haemorrhoidectomy. CLINICAL TRIAL REGISTRATION: ChiCTR2000041318 (Chinese Clinical Trial Registry).

A Two-Dimensional Metallacycle Cross-Linked Switchable Polymer for Fast and Highly Efficient Phosphorylated Peptide Enrichment.

The selective and efficient capture of phosphopeptides is critical for comprehensive and in-depth phosphoproteome analysis. Here we report a new switchable two-dimensional (2D) supramolecular polymer that serves as an ideal platform for the enrichment of phosphopeptides. A well-defined, positively charged metallacycle incorporated into the polymer endows the resultant polymer with a high affinity for phosphopeptides. Importantly, the stimuli-responsive nature of the polymer facilitates switchable binding affinity of phosphopeptides, thus resulting in an excellent performance in phosphopeptide enrichment and separation from model proteins. The polymer has a high enrichment capacity (165 mg/g) and detection sensitivity (2 fmol), high enrichment recovery (88%), excellent specificity, and rapid enrichment and separation properties. Additionally, we have demonstrated the capture of phosphopeptides from the tryptic digest of real biosamples, thus illustrating the potential of this polymeric material in phosphoproteomic studies.

Leaf functional traits differentiation in relation to covering materials of urban tree pits.

BACKGROUND: Understanding the ecological strategies of urban trees to the urban environment is crucial to the selection and management of urban trees. However, it is still unclear whether urban tree pit cover will affect plant functional traits. Here, we study the response of urban trees to different tree pit covers, analyzed the effects of different cover types on soil properties and their trade-off strategies based on leaf functional traits. RESULTS: We found that there were obvious differences in the physical properties of the soil in different tree pit covers. Under the different tree pit cover types, soil bulk density and soil porosity reached the maximum under cement cover and turf cover, respectively. We found that tree pit cover significantly affected the leaf properties of urban trees. Leaf thickness, chlorophyll content index and stomatal density were mainly affected by soil bulk density and non-capillary porosity in a positive direction, and were affected by soil total porosity and capillary porosity in a negative direction. Leaf dry matter content and stomata area were mainly negatively affected by soil bulk density and non-capillary porosity, and positively affected by soil total porosity and capillary porosity. Covering materials of tree pits promoted the functional adjustment of plants and form the best combination of functions. CONCLUSION: Under the influence of tree pit cover, plant have low specific leaf area, stomata density, high leaf thickness, chlorophyll content index, leaf dry matter content, leaf tissue density and stomata area, which belong to "quick investment-return" type in the leaf economics spectrum.

Decellularized nerve extracellular matrix/chitosan crosslinked by genipin to prepare a moldable nerve repair material.

Decellularized nerve extracellular matrix (NECM) composited with chitosan are moldable materials suitable for spinal cord repair. But the rapid biodegradation of the materials may interrupt neural tissue reconstruction in vivo. To improve the stability of the materials, the materials produced by NECM and chitosan hydrogels were crosslinked by genipine, glutaraldehyde or ultraviolet ray. Physicochemical property, degradation and biocompatibility of materials crosslinked by genipin, glutaraldehyde or ultraviolet ray were evaluated. The scaffold crosslinked by genipin possessed a porous structure, and the porosity ratio was 89.07 + 4.90%, the average diameter of pore was 85.32 + 5.34 µm. The crosslinked degree of the scaffold crosslinked by genipin and glutaraldehyde was 75.13 ± 4.87%, 71.25 ± 5.06% respectively; Uncrosslinked scaffold disintegrated when immerged in distilled water while the scaffold crosslinked by genipin and glutaraldehyde group retained their integrity. The scaffold crosslinked by genipin has better water absorption, water retention and anti-enzymatic hydrolysis ability than the other three groups. Cell cytotoxicity showed that the cytotoxicity of scaffold crosslinked by genipin was lower than that crosslinked by glutaraldehyde. The histocompatibility of scaffold crosslinked by genipin was also better than glutaraldehyde group. More cells grew well in the scaffold crosslinked by genipin when co-cultured with L929 cells. The decellularized nerve extracellular matrix/chitosan scaffold crosslinked by the genipin has good mechanical properties, micro structure and biocompatibility, which is an ideal scaffold for the spinal cord tissue engineering.

Acid-Activated Motion Switching of DB24C8 between Two Discrete Platinum(II) Metallacycles.

The precise operation of molecular motion for constructing complicated mechanically interlocked molecules has received considerable attention and is still an energetic field of supramolecular chemistry. Herein, we reported the construction of two tris[2]pseudorotaxanes metallacycles with acid-base controllable molecular motion through self-sorting strategy and host-guest interaction. Firstly, two hexagonal Pt(II) metallacycles M1 and M2 decorated with different host-guest recognition sites have been constructed via coordination-driven self-assembly strategy. The binding of metallacycles M1 and M2 with dibenzo-24-crown-8 (DB24C8) to form tris[2]pseudorotaxanes complexes TPRM1 and TPRM2 have been investigated. Furthermore, by taking advantage of the strong binding affinity between the protonated metallacycle M2 and DB24C8, the addition of trifluoroacetic acid (TFA) as a stimulus successfully induces an acid-activated motion switching of DB24C8 between the discrete metallacycles M1 and M2. This research not only affords a highly efficient way to construct stimuli-responsive smart supramolecular systems but also offers prospects for precisely control multicomponent cooperative motion.

INTRAOCULAR APPLICATION OF FIBRIN GLUE AS AN ADJUNCT TO PARS PLANA VITRECTOMY FOR RHEGMATOGENOUS RETINAL DETACHMENT.

PURPOSE: To evaluate the efficacy of intraocular application of fibrin glue to seal the retinal breaks during standard pars plana vitrectomy for primary rhegmatogenous retinal detachment. METHODS: Twenty-six eyes of 26 rhegmatogenous retinal detachment patients were included in the study. Fibrin glue was used to seal the retinal breaks during standard pars plana vitrectomy in all 26 eyes. Each eye was completely filled with a balanced saline solution at the end of the surgery. The success rate of the reattachment surgery, change in best-corrected visual acuity, intraocular pressure, and occurrence of intraoperative and postoperative complications were recorded and analyzed. RESULTS: All eyes, with a mean age of 45.1 ± 18.3 years, were treated with pars plana vitrectomy surgery. During pars plana vitrectomy surgery, the fibrin glue showed excellent adherence and compliance to the retina. The glue was no longer visible through ultrasound scan 14.85 ± 4.56 days after surgery. The retinal breaks were sealed completely, and retina attached in all 26 eyes with no occurrence of rhegmatogenous retinal detachment during the follow-up period. The best-corrected visual acuity at 6 months after operation was significantly improved from preoperation best-corrected visual acuity. After operation, two eyes (2/26) developed an epiretinal membrane. Although three eyes (3/26) had a transient increased intraocular pressure during the 1st week after surgery, the intraocular pressure lowered to the normal range after the application of timolol. One eye (1/26) required daily topical antiglaucoma drops to lower the intraocular pressure. No adverse effects of fibrin glue were observed. CONCLUSION: The fibrin glue provided a superior adhesive effect for sealing retinal breaks, while showing no additional adverse effects. It is a worthy alternative to gas tamponade for rhegmatogenous retinal detachment vitrectomy surgery.

PEG modification enhances the in vivo stability of bioactive proteins immobilized on magnetic nanoparticles.

OBJECTIVE: To increase the in vivo stability of bioactive proteins via optimized loading methods. RESULTS: ß-Glucosidase (ß-Glu), as a model protein, was immobilized on magnetic nanoparticles(denoted as MNP-ß-Glu) by chemical coupling methods and was further modified by poly(ethylene glycol) (PEG) molecules (denoted as MNP-ß-Glu-PEG) to increase its stability. The physicochemical properties of the as-prepared nanohybrids, including the particle size, zeta potential, and enzyme activity, were well characterized. The proper MNP/ß-Glu feed ratio was important for optimizing the particle size. Analysis of enzyme activity showed that the stability of immobilized ß-Glu compared with free ß-Glu was lower in deionized water and higher in blood serum at 37 °C. MNP-ß-Glu-PEG retained 77.9% of the initial activity within 30 days at 4 °C, whereas the free enzyme retained only 58.2%. Pharmacokinetic studies of Sprague-Dawley (SD) rats showed that the MNP-ß-Glu-PEG group retained a higher enzyme activity in vivo (41.46% after 50 min) than the MNP-ß-Glu group (0.03% after 50 min) and the ß-Glu group (0.37% after 50 min). Moreover, in contrast to the MNP-ß-Glu group, the enzyme activity was not fully synchronous with the decrease in the Fe concentration in the MNP-ß-Glu-PEG group. CONCLUSIONS: All findings indicated that the method of immobilization on magnetic nanoparticles and PEG modification is promising for the application of bioactive proteins in vivo.

Intestinal Epithelial Sirtuin 1 Regulates Intestinal Inflammation During Aging in Mice by Altering the Intestinal Microbiota.

BACKGROUND & AIMS: Intestinal epithelial homeostasis is maintained by complex interactions among epithelial cells, commensal gut microorganisms, and immune cells. Disruption of this homeostasis is associated with disorders such as inflammatory bowel disease (IBD), but the mechanisms of this process are not clear. We investigated how Sirtuin 1 (SIRT1), a conserved mammalian NAD+-dependent protein deacetylase, senses environmental stress to alter intestinal integrity. METHODS: We performed studies of mice with disruption of Sirt1 specifically in the intestinal epithelium (SIRT1 iKO, villin-Cre+, Sirt1flox/flox mice) and control mice (villin-Cre-, Sirt1flox/flox) on a C57BL/6 background. Acute colitis was induced in some mice by addition of 2.5% dextran sodium sulfate to drinking water for 5-9 consecutive days. Some mice were given antibiotics via their drinking water for 4 weeks to deplete their microbiota. Some mice were fed with a cholestyramine-containing diet for 7 days to sequester their bile acids. Feces were collected and proportions of microbiota were analyzed by 16S rRNA amplicon sequencing and quantitative PCR. Intestines were collected from mice and gene expression profiles were compared by microarray and quantitative PCR analyses. We compared levels of specific mRNAs between colon tissues from age-matched patients with ulcerative colitis (n=10) vs without IBD (n=8, controls). RESULTS: Mice with intestinal deletion of SIRT1 (SIRT1 iKO) had abnormal activation of Paneth cells starting at the age of 5-8 months, with increased activation of NF-κB, stress pathways, and spontaneous inflammation at 22-24 months of age, compared with control mice. SIRT1 iKO mice also had altered fecal microbiota starting at 4-6 months of age compared with control mice, in part because of altered bile acid metabolism. Moreover, SIRT1 iKO mice with defective gut microbiota developed more severe colitis than control mice. Intestinal tissues from patients with ulcerative colitis expressed significantly lower levels of SIRT1 mRNA than controls. Intestinal tissues from SIRT1 iKO mice given antibiotics, however, did not have signs of inflammation at 22-24 months of age, and did not develop more severe colitis than control mice at 4-6 months. CONCLUSIONS: In analyses of intestinal tissues, colitis induction, and gut microbiota in mice with intestinal epithelial disruption of SIRT1, we found this protein to prevent intestinal inflammation by regulating the gut microbiota. SIRT1 might therefore be an important mediator of host-microbiome interactions. Agents designed to activate SIRT1 might be developed as treatments for IBDs.

Enhanced intracellular delivery and controlled drug release of magnetic PLGA nanoparticles modified with transferrin.

Owing to the presence of multidrug resistance in tumor cells, conventional chemotherapy remains clinically intractable. To enhance the therapeutic efficacy of chemotherapeutic agents, targeting strategies based on magnetic polymeric nanoparticles modified with targeting ligands have gained significant attention in cancer therapy. In this study, we synthesized transferrin (Tf)-modified poly(D,L-lactic-co-glycolic acid) nanoparticles (PLGA NPs) loaded with paclitaxel (PTX) and superparamagnetic nanoparticle (MNP) using a solid-in-oil-in-water solvent evaporation method, followed by Tf adsorption on the surface of NPs. The Tf-modified magnetic PLGA NPs were characterized in terms of particle morphology and size, magnetic properties, encapsulation efficiency and drug release. Furthermore, the cytotoxicity and cellular uptake of the drug-loaded magnetic PLGA NPs were evaluated in both MCF-7 breast cancer and U-87 glioma cells in vitro. We found that Tf-modified PTX-MNP-PLGA NPs showed the highest cytotoxicity effect and cellular uptake efficiency under Tf receptor mediation in both MCF-7 and U-87 cells compared to unmodified PLGA NPs and free PTX. The cellular uptake efficiency of Tf-modified magnetic PLGA NPs appeared to be facilitated by the applied magnetic field, but the difference did not reach statistical significance. This study illustrates that this proposed formulation can be used as one new alternative treatment for patients bearing inaccessible tumors.

CCL17 combined with CCL19 as a nasal adjuvant enhances the immunogenicity of an anti-caries DNA vaccine in rodents.

AIM: CCL19 and its receptor CCR7 are essential molecules for facilitating the trafficking of mature dendritic cells (DCs) and helping to establish a microenvironment in lymphoid tissues to initiate primary immune responses, whereas CCL17 is required in the CCR7-CCL19-dependent migration of DCs. In this study we examined whether co-administration of CCL17 and CCL19 could enhance the immunogenicity of an anti-caries DNA vaccine, pCIA-P, in rodents. METHODS: Plasmids encoding CCL17 (pCCL17/VAX) and CCL19 (pCCL19/VAX) were constructed. BALB/c mice were intranasally administered pCCL17/VAX, pCCL19/VAX, or pCCL17/VAX plus pCCL19/VAX, the migration of DCs to the spleen and draining lymph nodes (DLNs) was assessed with flow cytometry. The mice were co-administered pCIA-P; and the anti-PAc antibodies in the serum and saliva were detected with ELISA. Wistar rats were orally challenged with Streptococcus mutans and then administered pCIA-P in combination with pCCL17/VAX, pCCL19/VAX, or pCCL17/VAX plus pCCL19/VAX. The amount of S mutans sustained on rat molar surfaces was assessed using a colony forming assay. Caries activity was scored with the Keyes method. RESULTS: Co-administration of the CCL17 and CCL19 genes in mice caused a greater increase in the number of mature DCs in the spleen and DLNs compared with administration of CCL17 or CCL19 genes alone. CCL17 and CCL19 double-adjuvant plus pCIA-P induced significantly higher levels of anti-PAc salivary IgA and anti-PAc serum IgG antibody in mice, and strengthened the ability of pCIA-P in inhibiting the colonization of S mutans on rat tooth surfaces. The caries activity of the combined adjuvant group was significantly lower than that of the pCCL17/VAX or the pCCL19/VAX group. CONCLUSION: A nasal adjuvant consisting of a combination of CCL17 and CCL19 attracts more mature DCs to secondary lymphoid tissues, inducing enhanced antibody responses against the anti-caries DNA vaccine pCIA-P and reducing S mutans infection in rodents.

Highly efficient, conjugated-polymer-based nano-photosensitizers for selectively targeted two-photon photodynamic therapy and imaging of cancer cells.

Two-photon photodynamic therapy (2P-PDT) is a promising noninvasive treatment of cancers and other diseases with three-dimensional selectivity and deep penetration. However, clinical applications of 2P-PDT are limited by small two-photon absorption (TPA) cross sections of traditional photosensitizers. The development of folate receptor targeted nano-photosensitizers based on conjugated polymers is described. In these nano-photosensitizers, poly{9,9-bis[6''-(bromohexyl)fluorene-2,7-ylenevinylene]-co-alt-1,4-(2,5-dicyanophenylene)}, which is a conjugated polymer with a large TPA cross section, acts as a two-photon light-harvesting material to significantly enhance the two-photon properties of the doped photosensitizer tetraphenylporphyrin (TPP) through energy transfer. These nanoparticles displayed up to 1020-fold enhancement in two-photon excitation emission and about 870-fold enhancement in the two-photon-induced singlet oxygen generation capability of TPP. Surface-functionalized folic acid groups make these nanoparticles highly selective in targeting and killing KB cancer cells over NIH/3T3 normal cells. The 2P-PDT activity of these nanoparticles was significantly improved, potentially up to about 1000 times, as implied by the enhancement factors of two-photon excitation emission and singlet oxygen generation. These nanoparticles could act as novel two-photon nano-photosensitizers with combined advantages of low dark cytotoxicity, targeted 2P-PDT with high selectivity, and simultaneous two-photon fluorescence imaging capability; these are all required for ideal two-photon photosensitizers.

Conjugated-polymer-based red-emitting nanoparticles for two-photon excitation cell imaging with high contrast.

Two-photon fluorescence microscopy is a widely used noninvasive bioimaging technique because of unique advantages such as a large penetration depth and 3D mapping capability. Ideal two-photon fluorophores require large two-photon absorption cross sections and red emission with high quantum yields. Here we report red-emitting-dye-doped conjugated polymer nanoparticles that display high two-photon excitation brightness. In these nanoparticles, conjugated polymer (PFV) was chosen as a two-photon light-harvesting material, and red-emitting dyes (MgPc and Nile red) were chosen as the energy acceptors and red-emitting materials. Two-photon excitation fluorescence of MgPc and Nile red was enhanced by up to ∼53 and ∼240 times, respectively. We have successfully demonstrated the application of these conjugated polymer-based nanoparticles in two-photon excitation cancer cell imaging with an excellent contrast ratio. This concept could become a general approach to the preparation of two-photon excitation red-emitting materials for deep-tissue live-cell imaging with high contrast.

Intranasal co-delivery of IL-6 gene enhances the immunogenicity of anti-caries DNA vaccine.

AIM: To investigate the effects of co-delivering IL-6 expressing plasmid pCI-IL-6 on the immunogenicity of the anti-caries DNA vaccine pCIA-P, which encodes the surface protein antigen PAc of Streptococcus mutans. METHODS: Plasmid pCI-IL-6 was constructed by inserting the murine IL-6 gene into the pCI vector. Expression of IL-6 in vitro was assessed using Western blot analysis. BALB/c mice were intranasally co-immunized with pCIA-P plus pCI-IL-6 on d 0 and 14. Anti-PAc IgG and secretory IgA (sIgA) were assessed by ELISA. Splenocytes from the mice were re-stimulated with the PAc protein, and IFN-γ and IL-4 production was measured using ELISA. Splenocyte proliferation was analyzed with flow cytometry. Rats were similarly immunized, and dental caries scores were determined using the Keyes method. RESULTS: Marked expression of IL-6 was found in COS-7 cells transfected with pCI-IL-6. In the pCI-IL-6 co-immunized mice, the specific IgG antibodies in serum and sIgA antibodies in saliva were significantly higher than those in the control mice at weeks 4 and 8. Moreover, the secretion of IFN-γ from splenocytes in response to re-stimulation with PAc protein was significantly higher in the pCI-IL-6 co-immunized mice than that in the control mice, whereas the secretion of IL-4 had no significant difference. The proliferation of splenocytes from the pCI-IL-6 co-immunized mice was significantly higher than that from the mice immunized with pCIA-P and pCI vector. In the rat caries model, the pCI-IL-6 co-immunization rats displayed lower caries scores than the control rats. CONCLUSION: Intranasal co-delivery of IL-6 gene significantly enhances the immunogenicity of the anti-caries DNA vaccine.

Optimizing invasive plant biomass valorization: Deep eutectic solvents pre-treatment coupled with ZSM-5 catalyzed fast pyrolysis for superior bio-oil quality.

The primary objective of this study is to explore the application of a deep eutectic solvent, synthesized from lactic acid and choline chloride, in combination with a pre-treatment involving ZSM-5 catalytic fast pyrolysis, aimed at upgrading the quality of bio-oil. Characterization results demonstrate a reduction in lignin content post-treatment, alongside a significant decrease in carboxyls and carbonyls, leading to an increase in the C/O ratio and noticeable enhancement in crystallinity. During catalytic fast pyrolysis experiments, the pre-treatment facilitates the production of oil fractions, achieving yields of 54.53% for total hydrocarbons and 39.99% for aromatics hydrocarbons under optimized conditions. These findings validate the positive influence of the deep eutectic solvent pre-treatment combined with ZSM-5 catalytic fast pyrolysis on the efficient production of bio-oil and high-value chemical derivatives. .

Efficacy of pegylated interferon α2a in patients without HBeAg loss after the withdrawal of long-term lamivudine therapy.

BACKGROUND: Improving the HBe seroconversion rate of patients without HBeAg loss after long-term lamivudine therapy has become an urgent clinical problem that we have to face. Unfortunately, there is no consensus on the mananement of these patients. The aim of this study was to evaluate the efficacy of pegylated interferon (PEG-IFN) α2a in patients without HBeAg loss after the withdrawal of long-term lamivudine therapy. METHODS: Fifty patients with chronic hepatitis B without the loss of HBeAg after ≥96 weeks of lamivudine treatment were enrolled to withdraw from treatment to induce a biochemical breakthrough. Patients who achieved a biochemical breakthrough within 24 weeks received 48-weeks of PEG-IFN α2a therapy, and were then assessed during a subsequent 24-week follow-up period. RESULTS: Forty-three (86.0%) patients achieved a biochemical breakthrough within 24 weeks of lamivudine withdrawal. The rates of combined response (both undetectable HBV DNA and HBeAg loss) and HBsAg loss were alone 51.2% and 20.9%, respectively after 48 weeks of PEG-IFN α2a therapy, and 44.2% and 18.6%, respectively, at 24 weeks after treatment cessation. The end-of-treatment combined response rate was 65.4% among patients with a baseline HBsAg <20,000 IU/mL, which was significantly higher than 29.4% of patients with HBsAg ≥20,000 IU/mL (P=0.031). For patients with HBsAg levels <1,500 IU/mL at 12 and 24 weeks therapy, the end-of-treatment combined response rate was 68.2% and 69.0%, which were both significantly higher than patients with HBsAg ≥1,500 IU/mL (33.3% and 14.3%; P=0.048 and 0.001). The end-of-treatment combined response rate was significantly higher among patients with HBV DNA<105 copies/mL (76.2%) compared to patients with HBV DNA ≥105 copies/mL (27.3%) after 24 weeks of therapy (P=0.004). CONCLUSION: Retreatment with PEG-IFN α2a was effective and safe for patients without HBeAg loss after the withdrawal of long-term lamivudine therapy. HBsAg levels at the baseline, 12 and 24 weeks of therapy, and HBV DNA levels at 24 weeks of therapy, can predict the effect of PEG-IFN α2a after 48 weeks of therapy.

Anti-caries DNA vaccine-induced secretory immunoglobulin A antibodies inhibit formation of Streptococcus mutans biofilms in vitro.

AIM: To investigate the effects of anti-caries DNA vaccine-induced salivary secretory immunoglobulin A (S-IgA) antibodies on Streptococcus mutans (S. mutans) adherence and biofilms formation in vitro. METHODS: Adult female Wistar rats were intranasally immunized with the anti-caries DNA vaccine pGJA-P/VAX. Their saliva samples were collected at different times after the immunization, and S-IgA antibody level in the saliva and its inhibition on S. mutans adherence were examined. The effects of S-IgA in the saliva with the strongest inhibitory effects were examined at 3 different stages, ie acquired pellicles, biofilm formation and production of mature biofilms. The number of viable bacteria and depth of the biofilm at 16 h in each stage were determined using counting colony forming units and using a confocal laser scanning microscopy (CLSM). The participation of S-IgA in acquired pellicles and its aggregation with S. mutans were also observed under CLSM. RESULTS: The S-IgA titer in saliva reached its peak and exhibited the strongest inhibition on S. mutans adhesion at 10 weeks after the immunization. The colonies and depth of the biofilm in the saliva-pretreated group were 41.79% and 41.02%, respectively, less than the control group. The colonies and depth of the biofilm in the co-culture group were 27.4% and 22.81% less than the control group. The assembly of S. mutans and S-IgA was observed under CLSM after co-cultivation. In the mature-stage biofilm, no differences were observed between the different groups. CONCLUSION: These results demonstrate that the anti-caries DNA vaccine induces the production of specific S-IgA antibodies that may prevent dental caries by inhibiting the initial adherence of S. mutans onto tooth surfaces, thereby reducing the accumulation of S. mutans on the acquired pellicles.

Co-delivery of ccl19 gene enhances anti-caries DNA vaccine pCIA-P immunogenicity in mice by increasing dendritic cell migration to secondary lymphoid tissues.

AIM: To investigate how co-delivery of the gene encoding C-C chemokine ligand-19 (CCL-19) affected the systemic immune responses to an anti-caries DNA vaccine pCIA-P in mice. METHODS: Plasmid encoding CCL19-GFP fusion protein (pCCL19/GFP) was constructed by inserting murine ccl19 gene into GFP-expressing vector pAcGFP1-N1. Chemotactic effect of the fusion protein on murine dendritic cells (DCs) was assessed in vitro and in vivo using transwell and flow cytometric analysis, respectively. BALB/c mice were administered anti-caries DNA vaccine pCIA-P plus pCCL19/GFP (each 100 µg, im) or pCIA-P alone. Serum level of anti-PAc IgG was assessed with ELISA. Splenocytes from the mice were stimulated with PAc protein for 48 h, and IFN-γ and IL-4 production was measured with ELISA. The presence of pCCL19/GFP in spleen and draining lymph nodes was assessed using PCR. The expression of pCCL19/GFP protein in these tissues was analyzed under microscope and with flow cytometry. RESULTS: The expression level of CCL19-GFP fusion protein was considerably increased 48 h after transfection of COS-7 cells with pCCL19/GFP plasmids. The fusion protein showed potent chemotactic activity on DCs in vitro. The level of serum PAc-specific IgG was significantly increased from 4 to 14 weeks in the mice vaccinated with pCIA-P plus pCCL19/GFP. Compared to mice vaccinated with pCIA-P alone, the splenocytes from mice vaccinated with pCIA-P plus pCCL19/GFP produced significantly higher level of IFN-γ, but IL-4 production had no significant change. Following intromuscular co-delivery, pCCL19/GFP plasmid and fusion protein were detected in the spleen and draining lymph nodes. Administration of CCL19 gene in mice markedly increased the number of mature DCs in secondary lymphoid tissues. CONCLUSION: CCL19 serves as an effective adjuvant for anti-caries DNA vaccine by inducing chemotactic migration of DCs to secondary lymphoid tissues.

A new gcrR-deficient Streptococcus mutans mutant for replacement therapy of dental caries.

BACKGROUND: gcrR gene acts as a negative regulator related to sucrose-dependent adherence in S. mutans. It is constructive to test the potential capacity of mutans with gcrR gene deficient in bacteria replacement therapy. METHODS: In this study, we constructed the mutant by homologous recombination. The morphological characteristics of biofilms were analyzed by confocal laser scanning microscopy. S. mutans UA159 and the mutant MS-gcrR-def were inoculated, respectively, or together for competitive testing in vitro and in rat model. RESULTS: Adhesion assay showed that the adhesion ability of the mutant increased relative to the wild type, especially in the early stage. MS-gcrR-def out-competed S. mutans UA159 in vitro biofilm, and correspondingly coinfection displayed significantly fewer caries in vivo. The former possessed both a lower level of acid production and a stronger colonization potential than S. mutans UA159. CONCLUSION: These findings demonstrate that MS-gcrR-def appears to be a good candidate for replacement therapy.