Synthesis of carboxylic block copolymers via reversible addition fragmentation transfer polymerization for tooth erosion prevention

Dental professionals are seeing a growing population of patients with visible signs of dental erosion. The approach currently being used to address the problem typically leverages the enamel protection benefits of fluoride. In this report, an alternative new block copolymer with a hydrophilic polyacrylic acid (PAA) block and a hydrophobic poly(methyl methacrylate) (PMMA) block was developed to similarly reduce the mineral loss from enamel under acidic conditions. This series of PMMA-b-PAA block copolymers was synthesized by reversible addition fragmentation transfer (RAFT) polymerization. Their structures were characterized by gel permeation chromatography (GPC) and (1)H nuclear magnetic resonance (NMR) spectra. The molar fractions of acrylic acid (AA) in the final block copolymer were finely controlled from 0.25 to 0.94, and the molecular weight (Mn) of PMMA-b-PAA was controlled from 10 kDa to 90 kDa. The binding capability of the block copolymer with hydroxyapatite (HAP) was investigated by ultraviolet-visible spectroscopy (UV-Vis) and Fourier transform infrared (FTIR) spectroscopy. FTIR spectra confirmed that the PMMA-b-PAA block copolymer could bind to HAP via bridging bidentate bonds. Both UV-Vis and FTIR spectra additionally indicated that a high polymer concentration and low solution pH favored the polymer binding to HAP. The erosion-preventing efficacy of the PMMA-b-PAA block copolymer in inhibiting HAP mineral loss was quantitatively evaluated by atomic absorption spectroscopy (AAS). Based on the results, polymer treatment reduced the amount of calcium released by 27% to 30% in comparison with the unprotected samples. Scanning electron microscope (SEM) observations indicated that PMMA-b-PAA polymer treatment protected enamel from acid erosion. This new amphiphilic block copolymer has significant potential to be integrated into dentifrices or mouthrinses as an alternative non-fluoride ingredient to reduce tooth erosion.

A new variable for SRS plan quality evaluation based on normal tissue sparing: the effect of prescription isodose levels

OBJECTIVE

A new dosimetric variable, dose-dropping speed (DDS), was proposed and used to evaluate normal tissue sparing among stereotactic radiosurgery (SRS) plans with different prescription isodose lines.

METHODS

40 plans were generated for 8 intracranial SRS cases, prescribing to isodose levels (IDLs) ranging from 50% to 90% in 10% increments. Whilst maintaining similar coverage and conformity, plans at different IDLs were evaluated in terms of normal tissue sparing using the proposed DDS. The DDS was defined as the greater decay coefficient in a double exponential decay fit of the dose drop-off outside the planning target volume (PTV), which models the steep portion of the drop-off. Provided that the prescription dose covers the whole PTV, a greater DDS indicates better normal tissue sparing.

RESULTS

Among all plans, the DDS was found to be the lowest for the prescription at 90% IDL and the highest for the prescription at 60% or 70%. The beam profile slope change in the penumbra and its field size dependence were explored and given as the physical basis of the findings.

CONCLUSION

A variable was proposed for SRS plan quality evaluation. Using this measure, prescriptions at 60% and 70% IDLs were found to provide best normal tissue sparing.

ADVANCES IN KNOWLEDGE

A new variable was proposed based on which normal tissue sparing was quantitatively evaluated, comparing different prescription IDLs in SRS.

Associations of blood glucose and prevalent diabetes with risk of cardiovascular disease in 500 000 adult Chinese: the China Kadoorie Biobank

AIMS

To examine the relationship of self-reported diabetes, and of random blood glucose levels among individuals without known diabetes, with the prevalence of cardiovascular disease in Chinese adults.

METHODS

We examined cross-sectional data from the China Kadoorie Biobank of 0.5 million people aged 30-79 years recruited from 10 diverse regions of China in the period 2004-2008. Logistic regression was used to estimate the odds ratios of prevalent cardiovascular disease associated with self-reported diabetes, and with measured random blood glucose levels among participants with no history of diabetes, adjusting simultaneously for age, sex, area, education, smoking, alcohol, blood pressure and physical activity.

RESULTS

A total of 3.2% of participants had self-reported diabetes (men 2.9%; women 3.3%) and 2.8% had screen-detected diabetes (men 2.6%; women 2.8%), i.e. they had no self-reported history of diabetes but a blood glucose level suggestive of a diagnosis of diabetes. Compared with individuals without a history of diabetes, the odds ratios associated with self-reported diabetes were 2.18 (95% CI 2.06-2.30) and 1.88 (95% CI 1.75-2.01) for prevalent ischaemic heart disease and stroke/transient ischaemic attack, respectively. Among participants without self-reported diabetes there was a positive association between random blood glucose and ischaemic heart disease and stroke/transient ischaemic attack prevalence (P for trend <0.0001). Below the diabetic threshold (<11.1 mmol/l) each additional 1 mmol/l of random blood glucose was associated with 4% (95% CI 2-5%) and 5% (95% CI 3-7%) higher odds of prevalent ischaemic heart disease and stroke/transient ischaemic attack, respectively.

CONCLUSIONS

In this adult Chinese population, self-reported diabetes was associated with a doubling of the odds of prevalent cardiovascular disease. Below the threshold for diabetes there was still a modest, positive association between random blood glucose and prevalent cardiovascular disease.

Inhibition of ANKRD1 sensitizes human ovarian cancer cells to endoplasmic reticulum stress-induced apoptosis

High expression of Ankyrin Repeat Domain 1 (ANKRD1) in ovarian carcinoma is associated with poor survival, and in ovarian cancer cell lines is associated with platinum resistance. Importantly, decreasing ANKRD1 expression using siRNA increases cisplatin sensitivity. In this study, we investigated possible mechanisms underlying the association of ANKRD1 with cisplatin response. We first demonstrated that cisplatin-induced apoptosis in ovarian cancer cell lines was associated with endoplasmic reticulum (ER) stress, evidenced by induction of Glucose-Regulated Protein 78 (GRP78), growth arrest- and DNA damage-inducible gene 153 (GADD153) and increased intracellular Ca(2+) release. The level of sensitivity to cisplatin-induced apoptosis was associated with ANKRD1 protein levels and poly (ADP-ribose) polymerase (PARP) cleavage. COLO 316 ovarian cancer cells, which express high ANKRD1 levels, were relatively resistant to cisplatin, and ER stress-induced apoptosis, whereas OAW42 and PEO14 cells, which express lower ANKRD1 levels, are more sensitive to ER stress-induced apoptosis. Furthermore, we show that overexpression of ANKRD1 attenuated cisplatin-induced cytotoxicity, and conversely siRNA knockdown of ANKRD1 sensitized ovarian cancer cells to cisplatin and ER stress-induced apoptosis associated with induction of GADD153, and downregulation of BCL2 and BCL-XL. Taken together, these results suggest that ANKRD1 has a significant role in the regulation of apoptosis in human ovarian cancer cells, and is a potential molecular target to enhance sensitivity of ovarian cancer to chemotherapy.

Myocardial infarction caused by coronary artery dissection due to blunt injury: is thromboaspiration an appropriate treatment?

The present study reports a case of myocardial infarction (MI) resulting from blunt trauma-induced coronary artery injury. After falling from a 5-meter-tall building, a man suffered multiple fractures of the arms and legs. Percutaneous coronary intervention (PCI) was performed 48 hours after successful repair of the limb fractures. Coronary angiography revealed an occlusion of the left anterior descending artery, without significant lesions of other arteries. Intravascular ultrasound showed obvious signs of coronary artery dissection at the calcium point of the intimal layer, intramural hematoma, and intimal stripping. The intimal lesion itself may have been responsible for the MI, by causing mechanical obstruction. Use of a thrombectomy device to remove the thrombus caused coronary artery spasm and no blood flow. Sodium nitroprusside and tirofiban were injected into the coronary artery three times, and the coronary blood flow was restored. The patient was again returned to the care unit. One week later, balloon angioplasty without thromboaspiration was performed, and a rapamycin-eluting stent was placed at the point of the intimal lesion. The patient was discharged uneventfully 7 days after stent placement. The patient was asymptomatic and doing well at the outpatient follow-up visit 1 year after PCI.

First Report of Sclerotinia sclerotiorum Causing Sclerotinia Blight on Peanut (Arachis hypogaea) in Northeastern China

Peanut, Arachis hypogaea L., is an important source of vegetable oil and protein in China with a planting area of 5 million ha and annual production of 16.2 million metric tons. In September of 2012, typical symptoms of Sclerotinia blight were first observed on peanut in Shuangcheng, Heilongjiang Province, China. Approximately 50% of the plants in a field were infected. Symptoms began as a chlorotic wilt on the foliage and developed into necrosis of basal stems and developed very quickly in the field. In advanced stages of the disease, stems and branches became bleached and eventually died. White, fluffy mycelium and black irregular sclerotia (3.5 to 5.4 mm diameter) were observed on the infected stems. Infected branches and pegs were shredded, and most pods dropped on the soil during harvest. To isolate the causal agent of the disease, sclerotia were collected from the field. Twenty sclerotia were surface disinfected in 1% NaOCl for 3 min, rinsed three times with sterile water, placed on potato sucrose agar (PSA) with 100 μg/ml streptomycin, and then incubated at 22°C in the dark for 10 days. Fungal DNA was extracted from mycelia with a TIANGEN DNAsecure Plant Kit (Beijing) and amplified by PCR with the universal fungal primer ITS1 and ITS4. PCR products of five replicates were sequenced and subjected to an NCBI BLAST search. The BLAST search revealed that our sequences (GenBank Accession No. KC935388) had 100% identity with reported sequences of Sclerotinia sclerotiorum. The isolates were identified as S. sclerotiorum (Lib.) de Bary based on mycelia, sclerotia, and rDNA sequence analysis. To conduct pathogenicity tests, nine potted peanut plants (1 month old) were each inoculated with a 5-mm-diameter disk of colonized PSA by placing the inoculum on the base of the stem. Plants were inoculated with a plug of non-colonized PSA as controls. All inoculated plants were covered with a plastic bag for 5 days to maintain high humidity and incubated at 22 to 24°C in the growth chamber with a 12-h photoperiod. After 2 days, the inoculated plants showed water-soaked brown symptoms on the stem base and whole plants wilted after 5 days under high moisture conditions. The symptoms were identical to those observed on peanut plants in Shuangcheng, Heilongjiang Province, whereas the control plants remained symptom-free. Re-isolation of the fungus from the inoculated plants confirmed that the causal agent was S. sclerotiorum. S. sclerotiorum has been reported on peanut in the United States and Argentina (1,2,3). To our knowledge, this is the first report of S. sclerotiorum as a pathogen causing Sclerotinia blight on peanut in northeastern China. References: (1) A. Marinelli et al. Int. J. Pest Manage. 44:251, 1998. (2) J. E. Woodward et al. Plant Dis. 90:111, 2006. (3) J. E. Woodward et al. Plant Dis. 92:1468, 2008.

Abstract 098: Blocking Cardiac Gq-Receptor Coupling Prevents Adverse Remodeling and Preserves Myocardial Function after Ischemic Injury in Mice and Promotes Repair via Cardiac Regeneration

Background: Studies have shown that the heterotrimeric G protein, Gq, is a critical molecule in the development of myocardial hypertrophy and heart failure (HF). In the present study, we examined whether Gq signaling is also a critical pathological trigger for adverse remodeling and HF after ischemic injury. Using cardiac-specific transgenic mice with expression of a specific Gq inhibitory peptide (GqI) that blocks Gq-GPCR coupling allowed us to investigate whether Gq inhibition can alter cardiac structure and functional changes after myocardial infarction (MI).

Methods and Results: Cardiac-specific GqI transgenic (TG) and non-transgenic littermate control (NLC) mice were subjected to MI. Serial echocardiography performed before ischemia as well as 2, 4, 8 weeks after MI injury show that TG mice develop less progressive LV enlargement and dysfunction. The % LV EF and FS were significantly improved in the TG compared to NLC mice at 8 weeks post-MI. Consistently, cardiac contractility (+dP/dt) and relaxation (-dP/dt) were significantly improved in TG mice also when stimulated with isoproterenol. The LVEDP, the heart weight to body weight (BW) and lung to BW ratios were significantly less in TG mice, indicating that HF was limited with GqI expression. Moreover, TG mice have smaller infarcts, less LV dimensions and lower fibrosis in both the border zone and remote area with clearly more viable tissue in the scar region. Constantly, there are more micro-vessel and more BrdU(+) cardiomyocytes in the scar area and border zone at the 2 week post-MI in TG group. Western blot shows a consistent decrease in phosphorylated PKC substrates and higher levels of activated Akt in TG mice. Over expression of the GqI in cultured H9c2 myoblasts did lead to higher level of Ki67 positive cells (38.06±2.46%) than a control group (21.78±2.64%) and FACS analysis showed that Gq inhibition increased the % of H9c2 cells in S phase and G2/M phase compared to control cells.

Conclusion: These data indicate cardiac specific Gq inhibition protects the heart against adverse LV remodeling and HF progression after MI. Mechanisms attributed to GqI expression appear to include improved myocyte survival, less fibrosis, and promotion of angiogenesis and cardiac repair through regeneration.

PD-1/PDL1 and CD28/CD80 pathways modulate natural killer T cell function to inhibit hepatitis B virus replication

α-Galactosylceramide (α-GalCer)-activated natural killer T (NKT) cells have antiviral properties against hepatitis B virus (HBV). However, α-GalCer activation of NKT cells can induce anergy. We hypothesized that this effect may be overcome by a treatment strategy that includes manipulation of CD28/CD80 costimulatory and PD-1/PDL1 coinhibitory signals of NKT cells, thereby enhancing the anti-HBV effect of α-GalCer. We established a transgenic mouse model of chronic HBV infection and investigated hepatic NKT cell frequencies, functions and expression of immunomodulatory factors. Our results showed that compared with uninfected control mice, hepatic NKT cells from HBV transgenic mice displayed lower frequencies (7.91% vs 16.74%, P < 0.05), impaired capabilities to produce interferon (IFN)-γ (5.6% vs 1.4%, P < 0.05) and interleukin (IL)-4 (6.8% vs 0.3%, P < 0.05), higher expression of PD-1 (9.64% vs 6.36%, P < 0.05) and lower expression of CD28 (5.05% vs 28.88%, P < 0.05). However, when hepatic mononuclear cells (MNCs) were isolated from HBV transgenic mice, α-GalCer exposure in culture remarkably upregulated both PD-1(+) NKT cells (P < 0.05) and CD28(+) NKT cells (P < 0.05). Furthermore, when HBV transgenic mice were treated with combination therapies consisting of α-GalCer and anti-PDL1 monoclonal antibody (mAb) and/or anti-CD80/anti-CD28 mAbs, IFN-γ(+) NKT cell frequency was selectively increased (P < 0.05) and HBV replication was suppressed; these effects were accompanied by varying degrees and types of liver damage. Surprisingly, activating CD28/CD80 signal in HBV transgenic mice was more effective but caused less liver injury than blocking PD-1/PDL1 signal in modulating αGalCer-activated NKT cell function to inhibit HBV infection. Our findings also show that combined therapy with blocking PD-1/PDL1 and activating CD28/CD80 signal in the presence of aGalCer cannot superimpose the effect of antivirus. α-GalCer combination therapy that modulates the CD28/CD80 pathways of NKT cells may represent a promising approach to inhibit HBV replication in chronically infected patients.

The impact of intensifying acid suppression on sleep disturbance related to gastro-oesophageal reflux disease in primary care

BACKGROUND

Sleep disturbance is common in patients with GERD but there has been little evaluation of this problem in primary care in patients already taking therapy.

AIM

To evaluate the impact of administering a questionnaire (PASS test) to identify patients with sleep problems and evaluate the efficacy of esomeprazole to improve sleep disturbance in patients with GERD.

METHODS

This was a primary care based cluster-randomised, open-label study where practices were assigned to intervention or control groups. PASS test failures continued current therapy (control) or were switched to 4 weeks' once-daily esomeprazole 20 or 40 mg (intervention). Patients were evaluated at the end of 4 weeks and the outcomes that were assessed were the sleep questions from the Quality of Life in Reflux and Dyspepsia (QOLRAD) questionnaire and the presence or absence of sleep disturbance from the PASS test questionnaire.

RESULTS

A total of 1388 patients with evaluable data at 4 weeks were included in the analysis and 825 reported GERD-related sleep disturbance at baseline. At 4 weeks, 161 of 291 of control patients (55%) reported continued sleep disturbance compared to 120 of 534 (22.5%) of intervention patients [number needed to treat of 3: 95% confidence intervals (CI): 2.5-4]. There was a mean improvement in QOLRAD scores related to sleep in the intervention patients compared to control patients (mean improvement = 4.91; 95% CI: 3.73-6.09).

CONCLUSION

A PASS strategy identifies GERD patients with sleep disturbance in primary care that will benefit from a change in acid-suppressive therapy. ClinicalTrials.gov identifier: NCT00392002; study code: D9612L00096.

Zoledronate inhibits phosphate and bone morphogenetic protein 2-induced extracellular calcification of vascular smooth muscle cells in vitro

The aim of this study was to explore the effects of the bisphosphonate zoledronate on calcification induced by inorganic phosphate (Pi) and/or bone morphogenetic protein 2 (BMP-2) and the underlying mechanisms. Primary vascular smooth muscle cells (VSMCs) from rats were treated with 3 mM Pi or 3 mM Pi/BMP-2, with and without addition of zoledronate; 1.4 mM Pi served as a control. Calcium deposits, expression of core binding factor α-1 (Cbfa-1), osteopontin (OPN), parathyroid pituitary-specific transcription factor (Pit)-1 and Pit-2, and Pi uptake of VSMCs was determined. The calcification of VSMCs induced by elevated Pi or Pi/BMP-2 was significantly inhibited by zoledronate. The expression of Cbfa-1, OPN and Pit-1 was increased significantly after treatment with an elevated level of Pi or Pi/BMP-2, and this expression was significantly suppressed by addition of zoledronate. Pi uptake of VSMCs increased following treatment with elevated Pi and significantly decreased by addition of zoledronate. These results indicated that zoledronate effectively inhibited calcification induced by Pi/BMP-2, and this may have been achieved by means of the downregulation of expression of calcification-related proteins and uptake of Pi.

ASC-dependent RIP2 kinase regulates reduced PGE2 production in chronic periodontitis

Levels of prostaglandin E(2) (PGE(2)) and its processing enzyme, prostaglandin-endoperoxide-synthase-2/ cyclooxygenase-2 (PTGS2/COX-2), are elevated in actively progressing periodontal lesions, but suppressed in chronic disease. COX-2 expression is regulated through inflammatory signaling that converges on the mitogen-activated protein kinase (MAPK) pathway. Emerging evidence suggests a role for the inflammatory adaptor protein, ASC/Pycard, in MAPK activation. We postulated that ASC may represent a mediator of the MAPK-mediated regulatory network of PGE(2) production. Using RNAi-mediated gene slicing, we demonstrated that ASC regulates COX-2 expression and PGE(2) production in THP1 monocytic cells following infection with Porphyromonas gingivalis (Pg). Production of PGE(2) did not require the inflammasome adaptor function of ASC, but was dependent on MAPK activation. Furthermore, the MAP kinase kinase kinase CARD domain-containing protein RIPK2 was induced by Pg in an ASC-dependent manner. Reduced ASC and RIPK2 levels were revealed by orthogonal comparison of the expression of the RIPK family in ASC-deficient THP1 cells with that in chronic periodontitis patients. We show that pharmacological inhibition of RIPK2 represses PGE(2) secretion, and RNAi-mediated silencing of RIPK2 leads to diminished MAPK activation and PGE(2) secretion. These findings identify a novel ASC-RIPK2 axis in the generation of PGE(2) that is repressed in patients diagnosed with chronic adult periodontitis.