Induction of ebolavirus cross-species immunity using retrovirus-like particles bearing the Ebola virus glycoprotein lacking the mucin-like domain.

BACKGROUND: The genus Ebolavirus includes five distinct viruses. Four of these viruses cause hemorrhagic fever in humans. Currently there are no licensed vaccines for any of them; however, several vaccines are under development. Ebola virus envelope glycoprotein (GP1,2) is highly immunogenic, but antibodies frequently arise against its least conserved mucin-like domain (MLD). We hypothesized that immunization with MLD-deleted GP1,2 (GPΔMLD) would induce cross-species immunity by making more conserved regions accessible to the immune system. METHODS: To test this hypothesis, mice were immunized with retrovirus-like particles (retroVLPs) bearing Ebola virus GPΔMLD, DNA plasmids (plasmo-retroVLP) that can produce such retroVLPs in vivo, or plasmo-retroVLP followed by retroVLPs. RESULTS: Cross-species neutralizing antibody and GP1,2-specific cellular immune responses were successfully induced. CONCLUSION: Our findings suggest that GPΔMLD presented through retroVLPs may provide a strategy for development of a vaccine against multiple ebolaviruses. Similar vaccination strategies may be adopted for other viruses whose envelope proteins contain highly variable regions that may mask more conserved domains from the immune system.

Attitudes and practices of nurses on a pediatric cancer and stem cell transplant ward: adaptation of an oral care protocol.

This study evaluated nurses' current practices and understanding of oral health for hematology and oncology patients. A written questionnaire administered to 33 nurses on the pediatric cancer and blood disorders unit of Children's Medical Center of Dallas included questions on oral evaluation, oral hygiene, and case-based questions. Information gathered was used to develop an oral care protocol. The study found that nurses were proficient in diagnosing obvious conditions including mucositis and pseudomembranous candidiasis, but they were less than proficient when diagnosing less easily recognizable conditions such as xerostomia. The nurses were found to have inadequate knowledge of the treatment and oral hygiene protocols for conditions that they could and could not diagnose. The protocol based on the questionnaire results included information gathering, oral hygiene protocol, evaluation of viral infection, evaluation of fungal infection, oral assessment guide, and treatment protocol. Through information gathering, an oral health care policy may be developed and implemented to aid in the treatment of children undergoing care for malignancies.

Genetic biomarkers associated with response to palliative radiotherapy in patients with painful bone metastases.

BACKGROUND: Palliative radiotherapy (RT) is effective in patients with painful bone metastases. Genetic factors may identify subgroup of patients who responded to RT. To identify DNA biomarkers associated with response to palliative RT. METHODS: Patients who received a single 8 Gy dose of RT for painful bone metastases were categorised into responders (n=36), non-responders (NR) (n=71). Saliva samples were sequenced to identify single-nucleotide variants (SNVs) in genes with known disease-causing variants from inflammation, radiation response, and DNA damage pathways. In univariate analysis, Cochran-Armitage trend tests were used to identify SNVs that associated with pain response (P<0.005), and the Penalized LASSO method with minimum Bayesian Information Criterion was used to identify multi-SNVs that jointly predict pain response to RT. The corresponding estimated effect of the multi-SNVs were used to drive the prognostic score for each patient. Based on it, patients were divided into 3 equal size risk groups. RESULTS: Forty-one significant variants were identified in univariate analysis. Multivariable analysis selected 14 variants to generate prognostic scores, adjusting for gender and primary cancer site. Eighty-nine percent of patients in the high prognostic group responded to palliative radiation therapy (P=0.0001). Estimated effect sizes of the variants ranged from 0.108-2.551. The most statistically significant variant was a deletion at position 111992032 in the ataxin gene ATXN2 (P=0.0001). Five variants were non-synonymous, including AOAH rs7986 (P=0.0017), ZAN rs539445 (P=0.00078) and rs542137 (P=0.00078), RAG1 rs3740955 (P=0.0014), and GBGT1 rs75765336 (P=0.0026). CONCLUSIONS: SNVs involved in mechanisms including DNA repair, inflammation, cellular adhesion, and cell signalling have significant associations with radiation response. SNVs with predictive power may stratify patient populations according to likelihood of responding to treatment, therefore enabling more efficient identification of beneficial strategies for pain management and improved resource utilisation.

Genetic biomarkers associated with changes in quality of life and pain following palliative radiotherapy in patients with bone metastases.

BACKGROUND: Patients with bone metastases undergoing palliative radiation therapy (RT) may experience changes in both the functional and symptomatic aspects of quality of life (QOL). The European Organization of Cancer Research and Treatment (EORTC) QOL Questionnaire Core-15 Palliative (QLQ-C15-PAL) is a validated questionnaire employed to assess QOL specifically in palliative patients. Our study aimed to identify single-nucleotide variant (SNV) genetic biomarkers associated with changes in QOL and pain. METHODS: Fifty-two patients who received a single 8-Gy RT for painful bone metastases completed the EORTC QOL-C15-PAL questionnaire prior to randomization and at 42-day post RT. Saliva samples obtained at day of RT were sequenced, and SNVs from genes involved in inflammation, radiation response, immune response, DNA damage, or QOL were assessed for association with changes in global QOL or the pain scale items using the Cochran-Armitage trend test. The penalized LASSO method with minimum Bayesian information criterion was used to select a multi-SNV model out of significant SNVs (P<0.005) and to produce prognostic scores for patients that categorized them into risk groups of low, middle, and high. RESULTS: The multivariable model predicting global QOL included 14 SNVs, of which HS1BP3 rs35579164 G:C and ABCA1 rs2230805 C>T had the largest positive and negative effect sizes, respectively (HS1BP3: 8.21, ABCA1: -3.44). The model for the response of QOL pain item included 8 SNVs, of which PLAUR rs4760 A>G and ELAC2rs11545302 had the largest positive and negative effect sizes, respectively (PLAUR: 5.23; ELAC: -3.84). The patients' risk groups were highly predictive of QOL response (P<0.0001) and pain item response (P<0.0001). In logistic regression analysis accounting for baseline factors of gender and primary cancer site, the global QOL risk group predicts pain response after RT [OR: 2.1, 95% confidence interval (CI): 1.2-3.9, P=0.015], but the QOL pain item risk group did not (OR: 0.93; 95% CI: 0.5-1.6, P=0.79). The multi-SNVs model included SNVs from genes involved in metabolism, membrane transport, cell cycle control, ciliary structure, and gene expression regulation. CONCLUSIONS: SNVs were significantly associated with changes in global QOL of global domain and pain item in patients with bone metastases. Identification of genetic biomarkers predictive of QOL items may allow patients and health care providers anticipate and better address the needs of the palliative cancer patient population.

Genetic biomarkers associated with pain flare and dexamethasone response following palliative radiotherapy in patients with painful bone metastases.

BACKGROUND: In patients who receive palliative radiation therapy (RT) for painful bone metastases, 40% experience a transient increase in pain known as a pain flare. Prophylactic dexamethasone has been shown to reduce pain flare incidence to 25%. We aimed to identify DNA biomarkers associated with pain flare and dexamethasone response. METHODS: Daily pain levels were recorded by 81 patients who received a single 8 Gy RT for painful bone metastases, of which 50 also received prophylactic dexamethasone. To identify single-nucleotide variants (SNVs), patient saliva samples obtained at day of RT were sequenced for 4,813 disease-associated genes, then filtered for genes associated with inflammation, radiation or immune response, and DNA damage. Significant SNVs (P<0.005) identified by the Cochran-Armitage trend test underwent the Penalized LASSO method with minimum Bayesian Information Criterion to select a multi-SNV model that jointly predicted pain flare, and pain flare despite prophylactic dexamethasone (dexamethasone response). The corresponding estimated effects of the multi-SNVs were used to drive the prognostic score of developing pain flare for each patient, who were divided into three risk groups of roughly equal sizes. RESULTS: Risk groups were significantly predictive of pain flare (P<0.0001) and dexamethasone response (P<0.0001). The high-risk patient groups had a 78% chance of developing pain flare, and pain flare despite dexamethasone [OR =24.6, 95% confidence interval (CI): 1.8-342.7, P=0.02]. The multivariable model for pain flare included 15 variants, with effect sizes ranging from -4.97 (NBPF1 rs3872309 C>T) to 5.54 (DNM2 10940838 A>C). The multivariable model for dexamethasone response included 6 variants, with effect sizes ranging from -1.03 (NBPF1 rs3872309 C>T) to 0.85 (TSEN54 rs62088470 C>G). CONCLUSIONS: Significant SNVs associated with pain flare were found in genes with functions in biosynthesis (DHODH, PECR), lipid excretion and metabolism (UGT2A1/2, VLDLR), and intracellular signalling (DNM2, SEC23A). Significant SNVs associated with dexamethasone response were from genes involved in extracellular matrix (HAS1, ADAMTS16) and cytoskeleton regulation (GAS2L2). Identification of SNVs predictive of pain flare and dexamethasone response enables targeted prophylactic therapy according to a patient's predisposed response.

A comparison of two meperidine/hydroxyzine sedation regimens for the uncooperative pediatric dental patient.

PURPOSE: The purpose of this study was to compare the safety and efficacy of submucosal-administered meperidine (SM) and oral-administered meperidine (OM). Both regimens were used in conjunction with oral hydroxyzine for the sedation of children for dental treatment. METHODS: Twenty preschool-age children, with previous histories of uncooperative behavior, were randomly assigned to first receive a sedation regimen of either SM (0.5 mg/ lb), or OM (1 mg/lb), both with oral hydroxyzine (0.5 mg/lb). A cross-over design was utilized so that each child received both regimens. Safety was monitored through vital signs and side effects. Efficacy was measured with Houpt and Frankl behavior ratings. RESULTS: Vital signs remained stable during both treatments. Differences noted were clinically insignificant. The major side effects reported during submucosal injection included pain (58%) and edema (26%). All blinded behavior ratings, in both sedation regimens, significantly improved from presedation Frankl ratings. No significant differences existed between treatments. Success was 63% in the SM group and 80% in the OM group. The percentages were not statistically significant (P=.219). CONCLUSIONS: Both methods of administration were found to be safe and effective for sedating uncooperative pediatric dental patients. Neither was significantly more effective or safer than the other.

In vitro and ex vivo intestinal tissue models to measure mucoadhesion of poly (methacrylate) and N-trimethylated chitosan polymers.

PURPOSE: The adhesion of a range of polymers based on poly(2-(dimethylamino-ethyl) methacrylate (pDMAEMA) was assessed using human mucus-secreting and non mucus-secreting intestinal cell monolayers, HT29-MTX-E12 (E12) and HT29 monolayers, as well as excised non-everted intestinal sacs from rats. Differentiation of mucoadhesion from bioadhesion was achieved by pre-treatment with the mucolytic agent, N-acetyl cysteine (NAC). Adherence of pDMAEMA polymers was compared to that obtained with the mucoadhesive, N-trimethylated chitosan (TMC). METHODS: The quantity of adherent coumarin 343-conjugated polymers to HT29, E12, and intestinal sacs was measured by fluorescence. Confocal laser scanning microscopy (CLSM), light microscopy, and fluorescent microscopy were used to provide direct evidence. Measurements of transepithelial electrical resistance (TEER), permeability to FITC-dextran 4000 (FD-4), and the release of lactate dehydrogenase (LDH) were used to assess potential cytotoxicity of polymers. RESULTS: Adherence of unquaternized and of 10%, 24%, and 32% methyl iodide-quaternized pDMAEMA polymers was measured in E12, HT29, and sacs. All pDMAEMA polymers showed significantly higher levels of adhesion to mucus (mucoadhesion) than to epithelium (bioadhesion). Colocalization of pDMAEMA with mucus was confirmed in E12 by microscopy. TMC showed equally high levels of mucoadhesion as unquaternized and 24% quaternized pDMAEMA, but displayed higher levels of bioadhesion. pDMAEMA-based polymers demonstrated lower levels of adherence to E12 and rat sacs in the presence of NAC, whereas adherence of TMC was unchanged. pDMAEMA significantly decreased the permeability of FD-4 across E12 monolayers and sacs and was less cytotoxic in E12 than in HT29. In contrast, TMC increased the permeability of FD-4 across E12 and sacs and was less cytotoxic in E12 than in HT29. CONCLUSIONS: Human mucus-producing E12 monolayers can be used to assess polymer mucoadhesion and give similar data to isolated rat intestinal sacs. pDMAEMA displayed similar levels of mucoadhesion and lower levels of bioadhesion than a chitosan derivative and it was not cytotoxic. pDMAEMA decreased FD-4 flux in the presence of mucus, whereas TMC increased it. The combination of mucus and methacrylate polymers appears to increase barrier function of the apical membrane.

Toward targeted oral vaccine delivery systems: selection of lectin mimetics from combinatorial libraries.

PURPOSE: Various lectins bind specifically to oligosaccharides on intestinal cells. Exploiting this specificity, Ulex europaeus agglutinin I (UEA1) has been used as a ligand for targeted oral vaccine delivery to M cells (antigen-presenting cells) in follicle-associated epithelium. In this study we characterized compounds identified from mixture-based positional scanning synthetic combinatorial libraries, which mimic UEA1 and, thus, may have properties applicable to targeted drug delivery. METHODS: Two UEA1 mimetics were synthesized and their activity was verified on live cells. The ability of the lead compound, a tetragalloyl D-Lysine amide construct (4-copy gallic acid construct), to deliver dye-loaded polystyrene particles to M cells was assessed in an in situ mouse gut loop model. RESULTS: The 4-copy gallic acid construct inhibited UEA1 binding to Caco-2 cell membranes with an IC50 of 3 microM, a 650- to 5000-fold increase over the natural UEA1 substrate alpha-L-fucose. The biotin-labeled derivative of this construct demonstrated comparable binding activity as verified on live cells by fluorescence-activated cell sorting. Preclinical studies confirmed its ability to mediate M cell-specific delivery of streptavidin-coated particles in vivo. CONCLUSIONS: Polyphenolic compounds, D-Lysine scaffolds with multiple galloyl groups, can mimic functional activities of UEA1. Properties of such molecules, including low molecular weight, stability, ease of synthesis and low cost, highlight their potential for application in targeted vaccine delivery.