Anti-biofilm dentin primer with quaternary ammonium and silver nanoparticles

Antibacterial bonding agents could combat recurrent caries at the tooth-composite margins. The objectives of this study were to develop novel antibacterial dentin primers containing quaternary ammonium dimethacrylate (QADM) and nanoparticles of silver (NAg), and to investigate the effects on dentin bond strength and dental plaque microcosm biofilms for the first time. Scotchbond Multi-Purpose ("SBMP") bonding agent was used. QADM and NAg were incorporated into SBMP primer, yielding 4 primers: SBMP primer (control), control + 10% QADM (mass), control + 0.05% NAg, and control + 10% QADM + 0.05% NAg. Human saliva was collected to grow microcosm biofilms. The NAg particle size (mean ± SD; n = 100) was 2.7 ± 0.6 nm. Dentin shear bond strengths (n = 10) with human third molars were approximately 30 MPa for all groups (p > 0.1). QADM-NAg-containing primer increased the bacteria inhibition zone by 9-fold, compared with control primer (p < 0.05). QADM-NAg-containing primer reduced lactic acid production and colony-forming units of total micro-organisms, total streptococci, and mutans streptococci by an order of magnitude. In conclusion, novel QADM-NAg-containing primers were strongly antibacterial without compromising dentin bond strength, and hence are promising to inhibit biofilms and secondary caries. The processing method of incorporating QADM and NAg together into the same primer produced the strongest antibacterial effect, which could have a wide applicability to other bonding systems.

Surgery is an Effective and Reasonable Treatment for Degenerative Scoliosis: A Systematic Review

OBJECTIVE: A systematic review to evaluate the role of surgery for treating degenerative scoliosis (DS) in terms of improved function (Oswestry Disability Index [ODI]) and correction of deformity (Cobb angle); safety outcomes included complication and repeat surgery rates. METHODS: A search of the MEDLINE, ISI Web of Knowledge and Cochrane Library databases was performed. The methodological quality of each study was assessed according to standardized criteria and data were extracted. RESULTS: A total of 16 studies including 553 patients with DS met the eligibility criteria for inclusion. The mean ODI score at final follow-up was 36.0 ± 7.8 (304 patients) and the mean decrease in ODI was 23.3 ± 11.3 (302 patients). Mean reduction in curve angle (as a percentage of the original curve) was 48.5 ± 21.0% (527 patients). The overall incidence of complications was 49.0% (171 in 349 patients) and the rate of repeat surgery was 15.3% (61 in 398 patients). CONCLUSIONS: Despite a high incidence of complications and reoperations, surgery was an effective and reasonable treatment for DS, providing significant functional improvement and deformity correction.

Extracting continuum electron dynamics from high harmonic emission from molecules

We show that high harmonic generation is the most sensitive probe of rotational wave packet revivals, revealing very high-order rotational revivals for the first time using any probe. By fitting high-quality experimental data to an exact theory of high harmonic generation from aligned molecules, we can extract the underlying electronic dipole elements for high harmonic emission and uncover that the electron gains angular momentum from the photon field.

Antibacterial nanocomposite with calcium phosphate and quaternary ammonium

Secondary caries is a frequent reason for restoration failure, resulting from acidogenic bacteria and their biofilms. The objectives of this study were to: (1) develop a novel nanocomposite containing nanoparticles of amorphous calcium phosphate (NACP) and quaternary ammonium dimethacrylate (QADM); and (2) investigate its mechanical and antibacterial durability. A spray-drying technique yielded NACP with particle size of 116 nm. The nanocomposite contained NACP and reinforcement glass fillers, with QADM in the resin. Two commercial composites were tested as controls. Composites were inoculated with Streptococcus mutans. After 180-day water-aging, NACP+QADM nanocomposite had flexural strength and elastic modulus matching those of commercial controls (p > 0.1). NACP+QADM nanocomposite reduced the biofilm colony-forming units (CFU) by 3-fold, compared with commercial composites (p < 0.05). Metabolic activity and lactic acid production of biofilms on NACP+QADM were much less than those on commercial composites (p < 0.05). The antibacterial properties of NACP+QADM were maintained after water-aging for 30, 90, and 180 d (p > 0.05). In conclusion, the novel NACP-QADM nanocomposite greatly decreased biofilm metabolic activity, CFU, and lactic acid, while matching the load-bearing capability of commercial composites without antibacterial properties. The NACP-QADM nanocomposite with strong and durable antibacterial properties, together with its previously reported Ca-PO(4) release capability, may render it useful for caries-inhibiting restorations.

Ribosomal protein S14 unties the MDM2-p53 loop upon ribosomal stress

The MDM2-p53 feedback loop is crucially important for restricting p53 level and activity during normal cell growth and proliferation, and is thus subjected to dynamic regulation in order for cells to activate p53 upon various stress signals. Several ribosomal proteins, such as RPL11, RPL5, RPL23, RPL26 or RPS7, have been shown to have a role in regulation of this feedback loop in response to ribosomal stress. Here, we identify another ribosomal protein S14, which is highly associated with 5q-syndrome, as a novel activator of p53 by inhibiting MDM2 activity. We found that RPS14, but not RPS19, binds to the central acidic domain of MDM2, similar to RPL5 and RPL23, and inhibits its E3 ubiquitin ligase activity toward p53. This RPS14-MDM2 binding was induced upon ribosomal stress caused by actinomycin D or mycophenolic acid. Overexpression of RPS14, but not RPS19, elevated p53 level and activity, leading to G1 or G2 arrest. Conversely, knockdown of RPS14 alleviated p53 induction by these two reagents. Interestingly, knockdown of either RPS14 or RPS19 caused a ribosomal stress that led to p53 activation, which was impaired by further knocking down the level of RPL11 or RPL5. Together, our results demonstrate that RPS14 and RPS19 have distinct roles in regulating the MDM2-p53 feedback loop in response to ribosomal stress.

No association between the G196A and C270T polymorphism of the brain-derived neurotrophic factor gene and male infertility

Brain-derived neurotrophic factor (BDNF) plays important roles in neuronal development and reproductive action. Abnormal expression of BDNF gene has been detected in human sperm and seminal serum. In the present study, we investigated the possible association of G196A and C270T polymorphism of BDNF gene with male infertility. The genotypes of the G196A and C270T polymorphisms were in Hardy-Weinberg equilibrium both in fertile and infertile group. The genotype distribution frequencies were similar between infertile and fertile group. The results showed that the G196A and C270T polymorphism of the BDNF gene is unrelated to the male infertility, at least in a Chinese population.

Pharmacokinetics, pharmacodynamics, and tolerability of a generic formulation of exenatide: a randomized, open-label, single- and multiple-dose study in healthy Chinese volunteers

A randomized, open-label, dose-escalating study was designed to assess the pharmacokinetics, pharmacodynamics and tolerability of single and multiple subcutaneous administrations of exenatide in 24 healthy Chinese volunteers. The effects of gender on the pharmacokinetics of exenatide were also evaluated. Subjects were randomized to receive a single and multiple subcutaneous doses of 5 or 10 μg of exenatide. Following the single dose subjects received exenatide twice daily on days 2-4 and once on day 5. Sequential blood samples were collected at regular intervals from 0 to 8 h after single administration. Concomitantly the serum glucose concentrations were measured in each sample. Tolerability was assessed using physical examination, vital signs, laboratory analysis, and by interview of subjects. Pharmacokinetic parameters for exenatide after subcutaneous administration of a single dose of 5-10 μg were as follows: Cmax=77.7 (13.9) and 136.1 (15.2) pg/mL; AUC0-t=184.2 (49.7) and 309.7 (52.3) pg·h/mL; AUC0-∞=225.8 (77.4) and 365.4 (68.8) pg·h/mL; tmax (median [range])=1.00 (0.75-1.50) and 1.00 (0.75-1.50) h; t1/2 (mean [range])=1.4 (0.7-3.2) and 1.8 (1.0-2.5) h, respectively. Because of its short t1/2, Css, min could not be detected in any plasma samples prior to daily dosing on days 3-5. Pharmacokinetic parameters for exenatide after administration of multiple doses of 5 or 10 μg were as follows: Cmax=81.2 (12.2) and 144.5 (13.3) pg/mL; AUC0-t=181.1 (39.4) and 275.6 (45.0) pg·h/mL; AUC0-∞=217.2 (44.8) and 313.3 (48.4) pg·h/mL; tmax=1.10 (0.75-1.25) and 1.00 (1.00-1.25) h; t1/2=1.6 (0.8-2.2) and 1.4 (0.9-2.7) h, respectively. Both doses of exenatide were associated with significant reductions in serum glucose concentrations (P<0.001) when compared to baseline levels. Mean percentage of maximal decline for serum glucose concentrations after single and multiple doses were 15.6% and 19.9% for 5 μg, respectively; as well as 26.3% and 28.7% for 10 μg, respectively. 12 of the 24 subjects reported a total of 75 adverse events. The rate increased with higher doses of exenatide: after 5 μg only one subject experienced at least 1 adverse event but following 10 μg 11 subjects were affected. 2 subjects receiving the higher dose of 10 μg exenatide dropped out because of adverse events (nausea and vomiting). The most common adverse events were of gastrointestinal origin (e. g. decreased appetite, nausea and vomiting) and of mild severity. In conclusion, in healthy Chinese subjects, AUC and Cmax increased in proportion to the dose, whereas t1/2 was independent of dose. The pharmacokinetic parameters after multiple dosing were consistent with those after single doses. No significant gender differences were noted for pharmacokinetic variables. Both exenatide doses were associated with significant reductions in serum glucose levels. Adverse events were mainly of gastrointestinal origin and their incidence was dose-dependent.

Agonist of 5-HT1A/7 receptors but not that of 5-HT2 receptors disinhibits tracheobronchial-projecting airway vagal preganglionic neurons of rats

The vagus nerves supply the major cholinergic tone to airway smooth muscles physiologically and play critical roles in the genesis of airway hyperreactivity under some pathological conditions. Postganglionic airway cholinergic tone relies largely on the ongoing activity of medullary airway vagal preganglionic neurons (AVPNs), of which the tracheobronchial-projecting ones are primarily located in the external formation of the nucleus ambiguus (eNA). AVPNs are regulated by 5-HT, and 5-HT(1A/7) and 5-HT(2) receptors have been indicated to be involved. But the mechanisms at synaptic level are unknown. In the present study, tracheobronchial-projecting AVPNs (T-AVPNs) were retrogradely labeled from the trachea wall; fluorescently labeled T-AVPNs in the eNA were recorded with whole-cell voltage patch clamp; and the effects of 5-HT(1A/7) receptor agonist (±)-8-Hydroxy-2-(dipropylamino) tetralin hydrobromide (8-OH-DPAT) (1 μmol L(-1)) and 5-HT(2) receptor agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) (10 μmol L(-1)) on the synaptic inputs were examined. 8-OH-DPAT significantly inhibited the GABAergic and glycinergic spontaneous inhibitory postsynaptic currents (sIPSCs) of T-AVPNs in both the frequency and amplitude but had no effect on the GABAergic and glycinergic miniature inhibitory postsynaptic currents (mIPSCs). The 8-OH-DPAT inhibition of the GABAergic and glycinergic sIPSCs was prevented by 5-HT(1A/7) receptor antagonist N-[2-[4-(2-Methoxyphenyl)-1-piperazinyl] ethyl]-N-2-pyridinylcyclohexanecarboxamide maleate salt (WAY-100635) (1 μmol L(-1)). 8-OH-DPAT had no effect on the glutamatergic spontaneous excitatory postsynaptic currents (sEPSCs) and caused no alterations in the baseline current and input resistance of T-AVPNs. DOI had no effect on any types of the synaptic inputs of T-AVPNs. These results suggest that 5-HT(1A/7) receptor agonist causes "disinhibition" of T-AVPNs, which might, in part, account for the reflex increase of airway resistance.

Characterization of nonrapid virologic response patients infected with HCV genotype 1 who may relapse after standard therapy with peginterferon plus ribavirin

Approximately 50% of patients with hepatitis C virus (HCV) genotype 1 treated with peginterferon alfa-2a/ribavirin discontinue treatment early or experience a suboptimal response despite 48 weeks of therapy. The objective of this analysis was to develop a model to identify nonrapid virologic response (non-RVR) patients who may be candidates for intensified therapy that would increase treatment response. The retrospective analysis included non-RVR patients from four trials of 48-week peginterferon alfa-2a/ribavirin treatment. Patients were grouped into those who cleared virus between weeks 5 and 12 (complete early virologic responders, cEVR) or between weeks 13 and 24 (slow responders). A model was developed to predict relapse at the end of follow-up (week 72). An optimal model was evaluated and compared with current practice by using receiver operating characteristic curves, sensitivity and specificity. In total, 539 non-RVR patients were eligible for analysis of which 72% experienced cEVR and 28% were slow responders. Variables associated with relapse included age, ethnicity, baseline HCV RNA and interval of time to HCV RNA undetectable. The optimal model was most accurate at predicting patients at risk for relapse. The practice of considering treatment intensification (e.g. extending treatment duration) in all slow responders was less accurate but likely most practical. A week 4 HCV <2-log reduction was the earliest but least accurate marker. We developed a model that could identify non-RVR patients at high risk for relapse after 48 weeks of peginterferon alfa-2a plus ribavirin and who may benefit from intensified therapy to reduce this risk of relapse.

High-dose preoperative fractionated radiotherapy does not affect the patency and healing of ePTFE vascular prosthesis after replacement of canine abdominal aorta and inferior vena cava

BACKGROUND

Fractionated radiotherapy allows for the safe administration of larger doses without the development of immediate or late toxicity. The influence of preoperative fractionated radiotherapy on neointima formation for expanded polytetrafluoroethylene (ePTFE) graft has not been determined.

METHODS

Twenty mongrel dogs were randomly divided into radiotherapy group (a total dose of 35 Gy) or control group (no radiation). The infrarenal abdominal aorta and inferior vena cava were replaced by ePTFE grafts at 3 months after irradiation in the radiotherapy group. Grafts were explanted at 4 weeks after surgery. Histopathological techniques were undertaken to evaluate graft neointima formation. The control group was managed the same as the radiotherapy group except for not receiving irradiation.

RESULTS

Four grafts implanted into inferior vena cava in the irradiated group and three in the control group were found to be completely occluded. None of the grafts implanted into abdominal aorta were obstructed. In the case of the inferior vena cava graft, the thickness of the graft neointima did not differ significantly between the irradiated and control groups. However, for the abdominal aorta graft, the neointima thickness in the irradiated groups was significantly thinner than that in the control group.

CONCLUSION

Preoperative fractionated radiotherapy affects vascular healing via suppressing the development of neointima formation in the abdominal aorta graft.

Synthesis and Interfacial Properties of Novel Imidazoline Gemini Surfactants

Two novel imidazoline gemini surfactants quaternary ammonium salts of di(2-undecyl (heptadecyl)-1-formyl aminoethyl imidazoline) hexanediamine (SUAEIHDI/SHAEIHDI) were synthesized in this article, and their interfacial properties were studied. It was found that SUAEIHDI had a higher CMC value than SHAEIHDI in distillated water at constant temperature (12 ± 2) °C, indicating that it was easier for SHAEIHDI to form micelles in water. The symmetrical molecular structure of SUAEIHDI/SHAEIHDI is composed of lipophilic group and hydrophilic group comprising many active elements i. e. O, N and two imidazoline rings. The novel imidazoline gemini surfactants can be viewed as block-like copolymers, whose surface-modifying effects on nanomaterials are promising.

A case of occult bowel perforation after a cycle of chemotherapy for advanced epithelial ovarian carcinoma

Occult bowel perforation is a rare complication in chemotherapy of advanced epithelial ovarian cancer (EOC). The authors present a case of a 75-year-old woman who had appendectomy due to suppurative appendicitis five years prior, that experienced an occult bowel perforation resulting in continuous decline of electrolytes after a single cycle of nedaplatin (NDP) and paclitaxel during neoadjuvant treatment of advanced EOC. To the authors' knowledge, this is the first reported case of an occult bowel perforation after neoadjuvant chemotherapy (NAC) for ovarian cancer. The complication was highly suggestive of a cell lysis mechanism for the perforation.

Vertebral fracture efficacy during risedronate therapy in patients using proton pump inhibitors

Recent evidence suggests that proton pump inhibitor (PPI) use may affect fracture risk, an important issue for patients being concurrently treated for osteoporosis. The results of our post hoc analysis showed that, regardless of PPI concomitant use, risedronate significantly reduced the risk of new vertebral fractures compared with placebo.

INTRODUCTION

Recent evidence suggests that PPI use may affect fracture risk, an important issue for patients being concurrently treated for osteoporosis. Moreover, data suggest that concomitant use of PPIs may wane the anti-fracture effect of bisphosphonates. We explored the relationship between concomitant use of PPIs and incident vertebral fractures among patients treated with risedronate or placebo. Bone mineral density (BMD) and upper gastrointestinal (UGI) adverse events (AEs) were also assessed.

METHODS

This study is a post hoc analysis of a subset of patients participating in three prospective, randomized, placebo-controlled clinical trials, with durations of up to 3 years, which evaluated the efficacy of risedronate in reducing fracture risk: Vertebral Efficacy with Risedronate Trial-MultiNational (VERT-MN); Vertebral Efficacy with Risedronate Trial-North America (VERT-NA); and the risedronate Hip Intervention Program (HIP).

RESULTS

Total enrollment included 2,729 risedronate and 2,725 placebo patients. Concomitant acid-suppressing drugs were used by 8.8% of the total population (n = 482). Regardless of PPI concomitant use, risedronate significantly reduced the risk of new vertebral fractures compared with placebo (risk reduction: PPI users 57%, p = 0.009; PPI non-users 38%, p < 0.001). BMD increased with risedronate, independent of PPI use. PPI users were at a 2.5-fold greater risk of experiencing at least one UGI AE compared with non-users.

CONCLUSIONS

Risedronate significantly reduced the risk of new vertebral fractures compared with placebo, regardless of PPI concomitant use.

A promoter polymorphism in the Per3 gene is associated with alcohol and stress response

The period homolog genes Per1, Per2 and Per3 are important components of the circadian clock system. In addition to their role in maintaining circadian rhythm, these genes have been linked to mood disorders, stress response and vulnerability to addiction and alcoholism. In this study, we combined high-resolution sequence analysis and quantitative trait locus (QTL) mapping of gene expression and behavioral traits to identify Per3 as a compelling candidate for the interaction between circadian rhythm, alcohol and stress response. In the BXD family of mouse strains, sequence variants in Per3 have marked effects on steady-state mRNA and protein levels. As a result, the transcript maps as a cis-acting expression QTL (eQTL). We found that an insertion/deletion (indel) variant in a putative stress response element in the promoter region of Per3 causes local control of transcript abundance. This indel results in differences in protein binding affinities between the two alleles through the Nrf2 transcriptional activator. Variation in Per3 is also associated with downstream differences in the expression of genes involved in circadian rhythm, alcohol, stress response and schizophrenia. We found that the Per3 locus is linked to stress/anxiety traits, and that the basal expression of Per3 is also correlated with several anxiety and addiction-related phenotypes. Treatment with alcohol results in increased expression of Per3 in the hippocampus, and this effect interacts with acute restraint stress. Our data provide strong evidence that variation in the Per3 transcript is causally associated with and also responsive to stress and alcohol.