Enamael Protection by Hydroxyapatite Toothpaste

Tooth enamel comprises ∼90% substituted hydroxyapatite (Ca10(PO4)6(OH)2), HAP, which is continually subjected to consecutive cycles of dissolution and recrystallisation. Initial dental caries is denoted by non-cavitated white spot lesions (WSLs) when net demineralisation occurs. Commercial products such as toothpastes, mouthwashes and chewing gums that release bioavailable calcium, phosphate and/or fluoride species have been shown to facilitate the remineralisation and repair of initial WSLs. In this respect, synthetic HAP particles can be incorporated into toothpastes to exploit both their abrasive and remineralising properties. The present study investigates the potential of a toothpaste containing micron-sized HAP particles (mirasensitive hap+®, Hager Werken, Germany) to repair WSLs in human enamel under optimum pH-neutral conditions and to protect the enamel exposed to an aggressive acid-challenge regime in vitro

Enamael Remineralisation by Arginine-Calcium Carbonate Toothpaste

White spot lesions (WSLs) are the first visual indication that the dynamic processes that maintain healthy tooth enamel have shifted in favour of demineralisation. It is possible to reverse this early stage of enamel caries with good oral hygiene and home-use products that enhance the bioavailability of salivary calcium, phosphate and fluoride species. Arginine (C6H14N4O2), a conditionally essential α-amino acid, is metabolised by oral bacteria to generate ammonia which protects enamel from acid-erosion. It also forms complexes with Ca2+ ions which increase the bioavailability of calcium and promote remineralisation. The present in vitro study investigates the potential of a commercial arginine- and calcium carbonate-bearing toothpaste (Colgate Sensitive Pro-Relief, Colgate-Palmolive (UK) Limited) to repair WSLs in human enamel under optimum and aggressive acid-challenge conditions

Antibacterial activity of a chitosan-PVA-Ag+-Tobermorite composite for periodontal repair

A polymer-mineral composite was prepared by solvent casting a mixture of chitosan, poly(vinyl alcohol), and Ag+-exchanged tobermorite in dilute acetic acid and characterised by scanning electron microscopy and Fourier transform infrared spectroscopy. The in vitro bioactivity of the CPTAg membrane was confirmed by the formation of hydroxyapatite on its surface in simulated body fluid. The alkaline dissolution products of the tobermorite lattice buffered the acidic breakdown products of the chitosan polymer and the presence of silver ions resulted in marked antimicrobial action against S. aureus, P. aeruginosa, and E. coli. The in vitro cytocompatibility of the CPTAg membrane was confirmed using MG63 osteosarcoma cells. The findings of this preliminary study have indicated that chitosan-poly(vinyl alcohol)-Ag+-tobermorite composites may be suitable materials for guided tissue regeneration applications

Hydrothermal synthesis of zeolites from green container glass

Landfilling and stockpiling unrecycled colored container glass represents a considerable failure in sustainability with respect to the conservation of energy and mineral resources. In this study, the single-step hydrothermal synthesis of low-silica zeolites from a mixture of waste green container glass and aluminum foil (Al:Si = 1) in 4 M NaOH(aq) at 125 °C was followed at 1, 3, 7 and 14 days. The principal phases, sodalite and cancrinite, appeared within 1 day accompanied by minor quantities of hydrogarnet and tobermorite arising from a stoichiometric excess of calcium ions in the parent glass. Products of 63, 67, 71 and 72% crystallinity were obtained at 1, 3, 7 and 14 days, respectively, with partial successive conversion of sodalite to cancrinite over time. Ion-exchange and catalytic applications of sodalite and cancrinite arise from the high anionic charge of the 1:1 ratio of alternating SiO44- and AlO45- units within their aluminosilicate frameworks. In this respect, the uptake capacity of the 14-day zeolitic product for Cu2+ and Cd2+ ions (1.58 meq g-1 and 1.66 meq g-1, respectively) was within the expected range for zeolites and compared favorably with those reported for other inorganic sorbents derived from industrial and municipal wastes. The 14-day product was also found to be an effective basic heterogeneous catalyst for the Knoevenagel condensation reaction

Plasminogen Alleles Influence Susceptibility to Invasive Aspergillosis

Invasive aspergillosis (IA) is a common and life-threatening infection in immunocompromised individuals. A number of environmental and epidemiologic risk factors for developing IA have been identified. However, genetic factors that affect risk for developing IA have not been clearly identified. We report that host genetic differences influence outcome following establishment of pulmonary aspergillosis in an exogenously immune suppressed mouse model. Computational haplotype-based genetic analysis indicated that genetic variation within the biologically plausible positional candidate gene plasminogen (Plg; Gene ID 18855) correlated with murine outcome. There was a single nonsynonymous coding change (Gly110Ser) where the minor allele was found in all of the susceptible strains, but not in the resistant strains. A nonsynonymous single nucleotide polymorphism (Asp472Asn) was also identified in the human homolog (PLG; Gene ID 5340). An association study within a cohort of 236 allogeneic hematopoietic stem cell transplant (HSCT) recipients revealed that alleles at this SNP significantly affected the risk of developing IA after HSCT. Furthermore, we demonstrated that plasminogen directly binds to Aspergillus fumigatus. We propose that genetic variation within the plasminogen pathway influences the pathogenesis of this invasive fungal infection

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Interactions of Cr3+, Ni2+, and Sr2+ with Crushed Concrete Fines

The underutilized cement-rich fine fraction of concrete-based demolition waste is a potential sorbent for aqueous metal ion contaminants. In this study, crushed concrete fines (CCF) were found to exclude 33.9 mg g−1 of Cr3+, 35.8 mg g−1 of Ni2+, and 7.16 mg g−1 of Sr2+ from ~1000 ppm single metal nitrate solutions (CCF:solution 25 mg cm−3) under static batch conditions at 20 °C after 3 weeks. The removal of Sr2+ followed a pseudo-second-order reaction (k2 = 3.1 × 10−4 g mg−1 min−1, R2 = 0.999), whereas a pseudo-first-order model described the removal of Cr3+ (k1 = 2.3 × 10−4 min−1, R2 = 0.998) and Ni2+ (k1 = 5.7 × 10−4 min−1, R2 = 0.991). In all cases, the principal mechanism of interaction was the alkali-mediated precipitation of solubility-limiting phases on the surface of the CCF. Four consecutive deionized water leaching procedures (CCF:water 0.1 g cm−3) liberated 0.53%, 0.88%, and 8.39% of the bound Cr3+, Ni2+, and Sr2+ species, respectively. These findings indicate that CCF are an effective sorbent for the immobilization and retention of aqueous Cr3+ and Ni2+ ions, although they are comparatively ineffectual in the removal and sustained exclusion of Sr2+ ions. As is commonly noted with Portland cement-based sorbents, slow removal kinetics, long equilibrium times, the associated release of Ca2+ ions, high pH, and the formation of loose floc may preclude these materials from conventional wastewater treatments. This notwithstanding, they are potentially suitable for incorporation into permeable reactive barriers for the containment of metal species in contaminated groundwaters, sediments, and soils

Interactions of Cr³⁺, Ni²⁺, and Sr²⁺ with Crushed Concrete Fines

The underutilized cement-rich fine fraction of concrete-based demolition waste is a potential sorbent for aqueous metal ion contaminants. In this study, crushed concrete fines (CCF) were found to exclude 33.9 mg g−1 of Cr3+, 35.8 mg g−1 of Ni2+, and 7.16 mg g−1 of Sr2+ from ~1000 ppm single metal nitrate solutions (CCF:solution 25 mg cm−3) under static batch conditions at 20 °C after 3 weeks. The removal of Sr2+ followed a pseudo-second-order reaction (k2 = 3.1 × 10−4 g mg−1 min−1, R2 = 0.999), whereas a pseudo-first-order model described the removal of Cr3+ (k1 = 2.3 × 10−4 min−1, R2 = 0.998) and Ni2+ (k1 = 5.7 × 10−4 min−1, R2 = 0.991). In all cases, the principal mechanism of interaction was the alkali-mediated precipitation of solubility-limiting phases on the surface of the CCF. Four consecutive deionized water leaching procedures (CCF:water 0.1 g cm−3) liberated 0.53%, 0.88%, and 8.39% of the bound Cr3+, Ni2+, and Sr2+ species, respectively. These findings indicate that CCF are an effective sorbent for the immobilization and retention of aqueous Cr3+ and Ni2+ ions, although they are comparatively ineffectual in the removal and sustained exclusion of Sr2+ ions. As is commonly noted with Portland cement-based sorbents, slow removal kinetics, long equilibrium times, the associated release of Ca2+ ions, high pH, and the formation of loose floc may preclude these materials from conventional wastewater treatments. This notwithstanding, they are potentially suitable for incorporation into permeable reactive barriers for the containment of metal species in contaminated groundwaters, sediments, and soils

Commonly Reported Adverse Events Associated With Pediatric Immunotherapy: A Systematic Review From the Children’s Oncology Group

Background:Immunotherapy is a new and promising approach to treating pediatric cancers. These types of therapies have unique mechanisms of action for identifying and fighting cancer, as compared with traditional chemotherapy, and therefore are associated with different therapy-related adverse events (AEs). The purpose of this systematic review was to review available evidence to: (a) identify commonly reported AEs associated with immunotherapy agents frequently used in pediatric oncology and (b) generate recommendations for nursing practice.Method:A clinical question was developed and used to guide the systematic literature review. Five immunotherapy agents (dinutuximab, blinatumomab, rituximab, inotuzumab ozogamicin, brentuximab vedotin) were selected for inclusion secondary to their high relevance to pediatric oncology. A literature search was conducted to locate articles published between January 1, 2003 and October 31, 2018.Results:Seventeen articles met eligibility criteria for inclusion and were evaluated using the Grading of Recommendations Assessment, Development, and Evaluation criteria. The most commonly reported AEs for the selected immunotherapy agents were identified and summarized. Strong recommendations are made for nurses to become familiar with the unique AE profiles associated with individual immunotherapy agents. Agent-specific recommendations for nursing practice regarding AEs associated with dinutuximab and rituximab were generated.Conclusions:Immunotherapy is rapidly emerging as an effective therapy for pediatric cancers. Nurses need to be aware of the breadth of agent-specific, immunotherapy-related AEs to appropriately monitor and manage patients receiving these therapies. Additional work is needed to confidently profile immunotherapy-related AEs in pediatric oncology and to develop agent-specific educational materials for patients/families

An Examination of Everyday Talk in Stepfamily Systems

This study explored frequencies of everyday talk in stepfamilies and the extent to which such frequencies of talk differed according to family relationship type. Participants included a parent, stepparent, and stepchild from 114 stepfamilies. Across relationship types, stepfamily members reported catching up, joking around, and recapping the day’s events most frequently and interrogating family members least frequently. Significant differences in frequencies of everyday talk across different relational dyads emerged for all three members of the stepfamily system. However, relatively few differences emerged in stepchildren’s reported frequencies of everyday talk with their stepparents and their nonresidential parents