Optimal administration of bronchodilators with valved holding chambers in preschool children: a review of literature

Our aim was to synthesize the published literature on factors that potentially affect the delivery of bronchodilators using valved holding chambers (VHC) in preschool children. We also aimed to identify those attributes that are not yet incorporated or clearly stated in the guidelines and those topics that are still lacking sufficient data. There is strong evidence supporting several recommendations in current guidelines. Based on present knowledge, bronchodilators should be delivered by VHC administering each puff separately. Face mask should be omitted as soon as the child can hold the mouthpiece of the VHC tightly between the lips and teeth. Based on the review, we suggest adding a specific note to current guidelines about the effect of chamber volume and the impact of co-operation during drug administration. Calming the child and securing a tight face-to-mask seal is critical for successful drug delivery. There is not enough evidence to make specific recommendations on the most reliable VHC and face mask for children. There is an urgent need for studies that evaluate and compare the effectiveness of VHCs in various clinical settings in wide age-groups and respiratory patterns. In addition, there is insufficient data on ideal chamber volume, material, and effective antistatic treatment. What is Known: Valved holding chambers (VHC) should not be considered interchangeable when used with pressurized metered dose inhalers (pMDI). Drug delivery is influenced by VHC volume, aerodynamic and electrostatic properties; mask fit; respiratory pattern and co-operation during inhalation; and the number of puffs actuated. What is New: The impact of co-operation, VHC volume, and good mask-to-face fit during drug inhalation is not stressed enough in the guidelines. Studies are urgently needed to evaluate the effectiveness of different VHCs in various clinical settings focusing on VHC electrostatic properties, respiratory patters, face masks, and ideal pMDI+VHC combinations.Peer reviewe

CDX2 and SATB2 loss are associated with myeloid cell infiltration and poor survival in colorectal cancer

Abstract Background: Caudal-type homeobox 2 (CDX2) and special AT-rich sequence-binding protein 2 (SATB2) are transcription factors playing important roles in intestinal homeostasis and participating in the regulation of intestinal inflammation. In colorectal cancer (CRC), reduced expression levels of CDX2 and SATB2 have been associated with poor differentiation and worse survival. However, their prognostic significance still needs further clarification, and the associations between CDX2 and SATB2 and immune cell infiltration into the CRC microenvironment are largely unknown. Methods: We analyzed CDX2 and SATB2 expression in two large cohorts of stages I–IV CRC patients (N = 2302) and analyzed their associations with clinicopathologic parameters, the density of local immune cells (determined with three multiplex immunohistochemistry panels and conventional immunohistochemistry), and survival. Results: In mismatch repair-proficient tumors, reduced CDX2 and SATB2 expression were associated with higher densities of immature monocytic cells, macrophages, and M2-like macrophages. Low expression of CDX2 was associated with shorter cancer-specific survival independent of conventional prognostic parameters in both cohorts. In the larger cohort, adjusted hazard ratio (HR) for negative (vs. high) CDX2 expression was 3.62 (95% CI 2.08–6.31, ptrend < 0.0001), and adjusted HR for negative (vs. high) SATB2 level was 1.61 (95% CI 0.97–2.67, ptrend = 0.002). Conclusion: This study indicates that reduced CDX2 and SATB2 expression levels are associated with myeloid cell infiltration in the CRC microenvironment and represent markers for poor outcome. These findings highlight the potential of CDX2 and SATB2 as biomarkers for classifying CRC patients and support their role in regulating the tumor microenvironment.Abstract Background: Caudal-type homeobox 2 (CDX2) and special AT-rich sequence-binding protein 2 (SATB2) are transcription factors playing important roles in intestinal homeostasis and participating in the regulation of intestinal inflammation. In colorectal cancer (CRC), reduced expression levels of CDX2 and SATB2 have been associated with poor differentiation and worse survival. However, their prognostic significance still needs further clarification, and the associations between CDX2 and SATB2 and immune cell infiltration into the CRC microenvironment are largely unknown. Methods: We analyzed CDX2 and SATB2 expression in two large cohorts of stages I–IV CRC patients (N = 2302) and analyzed their associations with clinicopathologic parameters, the density of local immune cells (determined with three multiplex immunohistochemistry panels and conventional immunohistochemistry), and survival. Results: In mismatch repair-proficient tumors, reduced CDX2 and SATB2 expression were associated with higher densities of immature monocytic cells, macrophages, and M2-like macrophages. Low expression of CDX2 was associated with shorter cancer-specific survival independent of conventional prognostic parameters in both cohorts. In the larger cohort, adjusted hazard ratio (HR) for negative (vs. high) CDX2 expression was 3.62 (95% CI 2.08–6.31, ptrend < 0.0001), and adjusted HR for negative (vs. high) SATB2 level was 1.61 (95% CI 0.97–2.67, ptrend = 0.002). Conclusion: This study indicates that reduced CDX2 and SATB2 expression levels are associated with myeloid cell infiltration in the CRC microenvironment and represent markers for poor outcome. These findings highlight the potential of CDX2 and SATB2 as biomarkers for classifying CRC patients and support their role in regulating the tumor microenvironment

Multimarker assessment of B cell and plasma cell subsets and their prognostic role in the colorectal cancer microenvironment

Abstract Purpose: Although the association between cytotoxic T lymphocytes and favorable prognosis in colorectal cancer is well established, the prognostic significance of B lymphocytes remains more ambiguous. This study aimed to assess the characteristics and significance of various B-cell and plasma cell subsets in colorectal tumors. Experimental Design: We designed a seven-plex IHC assay, combined with machine learning–based image analysis, to identify various B-cell and plasma cell populations and applied it to study a cohort of 912 colorectal tumors. We assessed the prognostic significance of B-cell and plasma cell densities using Kaplan–Meier estimators and Cox regression models. Additionally, we designed a more clinically applicable three-plex assay, which we used to study B-cell and plasma cell densities in a separate validation cohort of 737 patients. Results: High plasma cell density in the center of the tumor was associated with longer cancer-specific survival independent of disease stage, mismatch repair status, T-cell densities, and other covariates. In the study cohort, the multivariable HR for high (vs. low) plasma cell density was 0.48 (95% confidence interval, 0.32–0.72; Ptrend = 0.0005), whereas the corresponding HR in the validation cohort was 0.37 (95% confidence interval, 0.21–0.65; Ptrend = 0.0003). Of the specific subsets, IgG1–IgG2– plasma cells showed the strongest association with improved survival. High B-cell densities were not independently associated with a better prognosis. Conclusions: Plasma cell densities in the center of the tumor represent a relevant tumor-immune biomarker in colorectal cancer, complementing T-cell density measurements.Abstract Purpose: Although the association between cytotoxic T lymphocytes and favorable prognosis in colorectal cancer is well established, the prognostic significance of B lymphocytes remains more ambiguous. This study aimed to assess the characteristics and significance of various B-cell and plasma cell subsets in colorectal tumors. Experimental Design: We designed a seven-plex IHC assay, combined with machine learning–based image analysis, to identify various B-cell and plasma cell populations and applied it to study a cohort of 912 colorectal tumors. We assessed the prognostic significance of B-cell and plasma cell densities using Kaplan–Meier estimators and Cox regression models. Additionally, we designed a more clinically applicable three-plex assay, which we used to study B-cell and plasma cell densities in a separate validation cohort of 737 patients. Results: High plasma cell density in the center of the tumor was associated with longer cancer-specific survival independent of disease stage, mismatch repair status, T-cell densities, and other covariates. In the study cohort, the multivariable HR for high (vs. low) plasma cell density was 0.48 (95% confidence interval, 0.32–0.72; Ptrend = 0.0005), whereas the corresponding HR in the validation cohort was 0.37 (95% confidence interval, 0.21–0.65; Ptrend = 0.0003). Of the specific subsets, IgG1–IgG2– plasma cells showed the strongest association with improved survival. High B-cell densities were not independently associated with a better prognosis. Conclusions: Plasma cell densities in the center of the tumor represent a relevant tumor-immune biomarker in colorectal cancer, complementing T-cell density measurements

A surrogate method for comparison analysis of salivary concentrations of Xylitol-containing products

Background: Xylitol chewing gum has been shown to reduce Streptococcus mutans levels and decay. Two studies examined the presence and time course of salivary xylitol concentrations delivered via xylitol-containing pellet gum and compared them to other xylitol-containing products. Methods: A within-subjects design was used for both studies. Study 1, adults (N = 15) received three xylitol-containing products (pellet gum (2.6 g), gummy bears (2.6 g), and commercially available stick gum (Koolerz, 3.0 g)); Study 2, a second group of adults (N = 15) received three xylitol-containing products (pellet gum, gummy bears, and a 33% xylitol syrup (2.67 g). For both studies subjects consumed one xylitol product per visit with a 7-day washout between each product. A standardized protocol was followed for each product visit. Product order was randomly determined at the initial visit. Saliva samples (0.5 mL to 1.0 mL) were collected at baseline and up to 10 time points (~16 min in length) after product consumption initiated. Concentration of xylitol in saliva samples was analyzed using high-performance liquid chromatography. Area under the curve (AUC) for determining the average xylitol concentration in saliva over the total sampling period was calculated for each product. Results: In both studies all three xylitol products (Study 1: pellet gum, gummy bears, and stick gum; Study 2: pellet gum, gummy bears, and syrup) had similar time curves with two xylitol concentration peaks during the sampling period. Study 1 had its highest mean peaks at the 4 min sampling point while Study 2 had its highest mean peaks between 13 to 16 minutes. Salivary xylitol levels returned to baseline at about 18 minutes for all forms tested. Additionally, for both studies the total AUC for the xylitol products were similar compared to the pellet gum (Study 1: pellet gum - 51.3 [micro]g.min/mL, gummy bears - 59.6 [micro]g.min/mL, and stick gum - 46.4 [micro]g.min/mL; Study 2: pellet gum - 63.0 [micro]g.min/mL, gummy bears - 55.9 [micro]g.min/mL, and syrup - 59.0 [micro]g.min/mL). Conclusion: The comparison method demonstrated high reliability and validity. In both studies other xylitol-containing products had time curves and mean xylitol concentration peaks similar to xylitol pellet gum suggesting this test may be a surrogate for longer studies comparing various products.NIDCR-NIH U54 DE14254; Head Start, HRSA 90YD0188/03; and MCHB, HRSA R40MC03622-03

Prophage Spontaneous Activation Promotes DNA Release Enhancing Biofilm Formation in Streptococcus pneumoniae

Streptococcus pneumoniae (pneumococcus) is able to form biofilms in vivo and previous studies propose that pneumococcal biofilms play a relevant role both in colonization and infection. Additionally, pneumococci recovered from human infections are characterized by a high prevalence of lysogenic bacteriophages (phages) residing quiescently in their host chromosome. We investigated a possible link between lysogeny and biofilm formation. Considering that extracellular DNA (eDNA) is a key factor in the biofilm matrix, we reasoned that prophage spontaneous activation with the consequent bacterial host lysis could provide a source of eDNA, enhancing pneumococcal biofilm development. Monitoring biofilm growth of lysogenic and non-lysogenic pneumococcal strains indicated that phage-infected bacteria are more proficient at forming biofilms, that is their biofilms are characterized by a higher biomass and cell viability. The presence of phage particles throughout the lysogenic strains biofilm development implicated prophage spontaneous induction in this effect. Analysis of lysogens deficient for phage lysin and the bacterial major autolysin revealed that the absence of either lytic activity impaired biofilm development and the addition of DNA restored the ability of mutant strains to form robust biofilms. These findings establish that limited phage-mediated host lysis of a fraction of the bacterial population, due to spontaneous phage induction, constitutes an important source of eDNA for the S. pneumoniae biofilm matrix and that this localized release of eDNA favors biofilm formation by the remaining bacterial population

Streptococcus pneumoniae in Biofilms Are Unable to Cause Invasive Disease Due to Altered Virulence Determinant Production

It is unclear whether Streptococcus pneumoniae in biofilms are virulent and contribute to development of invasive pneumococcal disease (IPD). Using electron microscopy we confirmed the development of mature pneumococcal biofilms in a continuous-flow-through line model and determined that biofilm formation occurred in discrete stages with mature biofilms composed primarily of dead pneumococci. Challenge of mice with equal colony forming units of biofilm and planktonic pneumococci determined that biofilm bacteria were highly attenuated for invasive disease but not nasopharyngeal colonization. Biofilm pneumococci of numerous serotypes were hyper-adhesive and bound to A549 type II pneumocytes and Detroit 562 pharyngeal epithelial cells at levels 2 to 11-fold greater than planktonic counterparts. Using genomic microarrays we examined the pneumococcal transcriptome and determined that during biofilm formation S. pneumoniae down-regulated genes involved in protein synthesis, energy production, metabolism, capsular polysaccharide (CPS) production, and virulence. We confirmed these changes by measuring CPS by ELISA and immunoblotting for the toxin pneumolysin and the bacterial adhesins phosphorylcholine (ChoP), choline-binding protein A (CbpA), and Pneumococcal serine-rich repeat protein (PsrP). We conclude that biofilm pneumococci were avirulent due to reduced CPS and pneumolysin production along with increased ChoP, which is known to bind C-reactive protein and is opsonizing. Likewise, biofilm pneumococci were hyper-adhesive due to selection for the transparent phase variant, reduced CPS, and enhanced production of PsrP, CbpA, and ChoP. These studies suggest that biofilms do not directly contribute to development of IPD and may instead confer a quiescent mode of growth during colonization

Panel 7: otitis media:treatment and complications

Objective: We aimed to summarize key articles published between 2011 and 2015 on the treatment of (recurrent) acute otitis media, otitis media with effusion, tympanostomy tube otorrhea, chronic suppurative otitis media and complications of otitis media, and their implications for clinical practice. Data Sources: PubMed, Ovid Medline, the Cochrane Library, and Clinical Evidence (BMJ Publishing). Review Methods: All types of articles related to otitis media treatment and complications between June 2011 and March 2015 were identified. A total of 1122 potential related articles were reviewed by the panel members; 118 relevant articles were ultimately included in this summary. Conclusions: Recent literature and guidelines emphasize accurate diagnosis of acute otitis media and optimal management of ear pain. Watchful waiting is optional in mild to moderate acute otitis media; antibiotics do shorten symptoms and duration of middle ear effusion. The additive benefit of adenoidectomy to tympanostomy tubes in recurrent acute otitis media and otitis media with effusion is controversial and age dependent. Topical antibiotic is the treatment of choice in acute tube otorrhea. Symptomatic hearing loss due to persistent otitis media with effusion is best treated with tympanostomy tubes. Novel molecular and biomaterial treatments as adjuvants to surgical closure of eardrum perforations seem promising. There is insufficient evidence to support the use of complementary and alternative treatments. Implications for Practice: Emphasis on accurate diagnosis of otitis media, in its various forms, is important to reduce overdiagnosis, overtreatment, and antibiotic resistance. Children at risk for otitis media and its complications deserve special attention