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Background: Febuxostat is a BCS class-II drug, used in the treatment of gout. However, because of its lower solubility, a higher and more frequent dose of the drug is required in the treatment. Objective: The objective of this research was to develop and evaluate febuxostat-loaded floating beads as a gastro-retentive drug delivery system (GRDDS) to target drug release up to 24hr in order to enhance bioavailability. Methodology: Gastro-retentive floating beads were formulated using the ionotropic gelation method. Screening of lipids was carried out based on the shape and texture of floating beads. Drug-excipient compatibility study was done using DSC analysis. Further optimization of gastro-retentive floating beads of febuxostat was performed by Box-Behnken design using gelucire 43/01, lactose, and soluplus as independent variables and %drug entrapment and %drug release after 24 hr as dependent variables. Evaluation of the optimized batch was performed for in vitro buoyancy, %drug entrapment, %drug release, FTIR, and SEM study. Result and Discussion: In the ANOVA, contour plots, and 3D surface plots, the optimized batch showed 93.95±0.29 % drug entrapment and 88.14±0.58 % drug release after 24 hr with 98%±1% invitro buoyancy. Overlay plots and checkpoint batches were accompanied to confirm the optimization. Polynomial equations proved the positive effect of lipids on drug entrapment and drug release. SEM images explained porous and microstructures on beads. Conclusion: In conclusion, gastro-retentive febuxostat floating beads were successfully developed and characterized for once a daily dose with enhanced bioavailability and reduced cost of therapy.

Conventional drug delivery system for treating the angina and hypertension are not much effective as the drug do not reach the site of action in appropriate amounts. Thus potent and guarded therapy of this angina and hypertension disorder using specific drug delivery system is a challenging task to the pharmaceutical professionals. The study was aimed at increase the solubility of poorly soluble drug nifedipine and formulating it in sustained release dosage form. Solid dispersion of drug was prepared using Poly vinyl pyrrolidone (PVP) as inert hydrophilic carriers by solvent evaporation technique. A 17-fold increase in dissolution rate of nifedipine was observed with solid dispersion prepared with PVP (K30). Sustained release microcapsules of nifedipine were formulated using Eudragit RS 100 as a polymer, acetone as polymer solvent for Eudragit RS100, N-hexane as a non-solvent, liquid paraffin vehicle, with solid dispersion of nifedipine as core by emulsion solvent evaporation method and modified emulsion solvent evaporation method. Microcapsules from all the batches were found to discrete, spherical and free flowing and % entrapment efficiency was found to be in range of 96.01% to 97.87%. All the batches of microcapsules showed sustained release curve in pH 7.4 phosphate buffer up to 12hours with maximum release up to 97.22% after 12hrs was found to be in B2. SEM studies of the microcapsules showed the surface topography states that prepared microspheres were spherical in shape. Shiny and uniform covered surface with polymer. Keywords: Nifedipine, Poly vinyl pyrrolidone, Solid dispersion, Microcapsules, Emulsion solvent evaporation method

SF1:Super-enhancer profiling identifies three subtypes of LUSC. SF2: Brn2 is expressed in a subset of human primary LUSC tumors. SF3: Brn2 and Sox2 co-localize and collaborate in the 'neural' LUSC cells. SF4: DNp63 overexpression in the 'neural' LUSC cells suppresses Brn2 expression and induces phenotypic changes. SF5: Brn2 overexpression and p63 ablation in the 'classical' LUSC cells and Brn2 ablation in the 'neural' LUSC cells. SF6: DNp63 induces a classical squamous-cell transcriptional program and G1 phase arrest in the 'neural' LK2 cells. SF7: DNp63 suppresses the 'neural' lineage program and induces the classical squamous-cell transcriptional program. SF8: DNp63 alters ErbB family signaling in the 'neural' LK2 cells.

Molecular characterization of lung squamous cell carcinoma (LUSC), one of the major subtypes of lung cancer, has not sufficiently improved its nonstratified treatment strategies over decades. Accumulating evidence suggests that lineage-specific transcriptional regulators control differentiation states during cancer evolution and underlie their distinct biological behaviors. In this study, by investigating the super-enhancer landscape of LUSC, we identified a previously undescribed “neural” subtype defined by Sox2 and a neural lineage factor Brn2, as well as the classical LUSC subtype defined by Sox2 and its classical squamous partner p63. Robust protein–protein interaction and genomic cooccupancy of Sox2 and Brn2, in place for p63 in the classical LUSC, indicated their transcriptional cooperation imparting this unique lineage state in the “neural” LUSC. Forced expression of p63 downregulated Brn2 in the “neural” LUSC cells and invoked the classical LUSC lineage with more squamous/epithelial features, which were accompanied by increased activities of ErbB/Akt and MAPK–ERK pathways, suggesting differential dependency. Collectively, our data demonstrate heterogeneous cell lineage states of LUSC featured by Sox2 cooperation with Brn2 or p63, for which distinct therapeutic approaches may be warranted.Significance:Epigenomic profiling reveals a novel subtype of lung squamous cell carcinoma with neural differentiation.

ST1: Original sources for the cell lines used in this study. ST2: sgRNA sequences for CRISPR-Cas9 system and primers for quantitative reverse transcription PCR. ST3: Characteristics of human primary LUSC tumor specimens for immunohistochemistry. ST4: Gene loci for super-enhancers near transcriptional regulators shared by all the LUSC cell lines in 'classical' subgroup. ST5: Gene loci for super-enhancers with highest signals near transcriptional regulators in LK2 and NCI-H520 cells. ST6: Associations between gene signatures from DNp63-overexpressed LK2 model and those from human TCGA-LUSC dataset based on POU3F2/ TP63 expression.

Advancements in rational drug design over the past decades have consistently produced new cancer therapies, but such treatments are inevitably countered through an adaptive process that fosters therapy resistance. Malignant cells achieve drug resistance through intrinsic and acquired mechanisms, rooted in genetic and non-genetic determinants. In particular, recent work has highlighted the role of intrinsic cellular heterogeneity in the emergence of transient drug-tolerant persister cells that survive drug treatment, as well as non-genetically driven cell plasticity toward stable resistance. However, these models do not account for the role of dose and treatment duration as extrinsic forces in eliciting cancer cell adaptation. Here, we show that these two components together drive the resistance of ovarian cancer cells to targeted therapy along a trajectory of cellular adaptation, that we denote the ‘resistance continuum’. We report that gradual dose exposure and prolonged treatment promote a continuous increase in fitness, and show that this process is mediated by evolving transcriptional, epigenetic and genetic changes that promote multiple cell state transitions. The resistance continuum is underpinned by the assembly of gene expression programs and epigenetically reinforced stress response regulation. Using both in vivo and in vitro models, we found that this process involves widespread reprogramming of cell survival pathways, including interferon response, lineage reprogramming, metabolic rewiring and oxidative stress regulation. Together, the resistance continuum reveals the dynamic nature of cellular adaptation, and carries implications for cancer therapies, as initial exposure to lower doses primes cells over time for increased resistance to higher doses. Beyond cancer, such continuous adaptation exposes a basic aspect of cellular plasticity, which may also be deployed in other biological systems such as development, immune response and host-pathogen interactions.

Introduction: Cutaneous melanoma brain metastases (MBM) are a major cause of morbidity and mortality. While cytotoxic agents, interferon, or interleukin-2, have been used with some success in extra...

Objective: To discuss how the results of internal mammary lymph node biopsy at the time of autologous flap reconstruction in both the immediate and delayed setting may impact breast cancer treatment and the aesthetic outcome of autologous mastectomy reconstruction. Background: The internal mammary vessels are primary recipient vessels for autologous breast reconstruction with deep inferior epigastric artery perforator flaps. During exposure and preparation of recipient vessels, the internal mammary lymph nodes when discovered are submitted to pathology. We have found in some patients, these internal mammary lymph nodes return positive results in patients with clinically and histologically negative axillary nodes and negative preoperative MRI/PET scan imaging. We wished to examine if these results had an impact on the radiation or chemotherapy management of the patients post-operatively. We have also sought to provide long-term follow-up on patients who have been found to have positive internal mammary lymph nodes. Methods: We performed a retrospective review of patients with breast cancer who underwent autologous breast reconstruction with deep inferior epigastric artery perforator flaps. A specific chart review was performed on all patients found to have a positive result at the time of internal mammary lymph node biopsy. Results: Between 2008 and 2020 a total of 18 patients with positive internal mammary lymph nodes were identified after internal mammary recipient harvest and visible lymph node biopsy. In three cases the internal mammary lymph node was positive when the axilla was negative. In 3/18 (16%) cases the patient’s stage was changed based on the incidental findings of the internal mammary nodes. Positive results changed post-operative radiation management in all patients. In only 1/16 (6%) cases was there suspicion on preoperative MRI. There were no instances of pneumothorax or other serious complications associated with the internal mammary lymph node biopsy. Conclusions: Incidental internal mammary lymph node biopsy performed during microvascular autologous breast reconstruction may prove positive for metastatic spread despite negative pathology results of the axillary lymph nodes. This may be seen even in patients with a normal pre-op MRI. Internal mammary node biopsy is feasible without serious adverse events when performed at the time of recipient vessel dissection. If preoperative imaging or intraoperative direct examination of the internal mammary nodes raises suspicion, frozen section evaluation may change flap harvest selection to acquire more perforators and potentially alter flap inset to protect the autologous flap from the adverse effects of radiation.

Small cell lung cancers and squamous cell cancers can be epigenetically subtyped (Kong R et al 2022, Sato T et al, 2019) with focus on super-enhancer (SE) signals within or adjacent to transcription factors (TF). We reasoned that specific epigenomic subsets in lung adenocarcinomas (LUAD) operate with similar cellular programming showing TF dependency for lineage commitment and survival. We hypothesize that these dependencies on lineage programming are associated with a specific epigenomic landscape. Therefore, we investigated enrichment of SEs across the spectrum of LUADs to identify potential regulators for lineage commitment and survival. We obtained data for genome-wide H3K27ac enrichment by chromatin immunoprecipitation followed by sequencing (ChIP-seq) on a total of 53 LUAD cell lines. We performed unsupervised hierarchical clustering of signals on SEs at gene loci annotated with transcriptional regulation identified in two or more cell lines. To Uncover 3D contact information, we employed HiChIP, using antibody against SMC1, a cohesin complex, on NCI-H460. Three LUAD cell lines with distinct enhancer profiles were transfected with five enhancer segments of the SE at the PBX1 gene cloned into a Firefly luciferase plasmid. Lastly, four LUAD cell lines were treated with a PBX1 inhibitor, T417 for 72 hours in varying concentrations ranging from 20uM to 10nM and evaluated for sensitivity to the compound. Clustering analysis identified LUADs with differential enhancer enrichment for TFs. Among those, we focused on the PBX1 gene locus in LUADs harboring SEs proximal to its promoter. SMC1 HiChIP analysis on NCI-H460 suggest all enhancer segments are within a local topologically-associated domain with the PBX1 promoter. Luciferase reporter assay demonstrate activity of enhancer segments within the PBX1 SE, unique to each cell line (NCI-H460, PC-9 and NCI-H1437), with enhancers e4 and e5 rendered the highest level of activity while e2 being the most active in PC-9. The effects of these enhancer segments are congruent to H3K27ac enrichment patterns. Treatment with T417 showed reduction in cell proliferation at an IC50 of 2.5 uM and 0.97 uM for NCI-H460 and PC-9, respectively, whereas T417 did not affect cell viability in NCI-H1792 and NCI-H125. Data indicate a distinct subset of LUADs, enriched for the enhancer segments within the SE at the PBX1 gene locus, at which the HiChIP data displayed the enhancer segments lie within the same topologically-associated domain. The enhancer activity of enhancer segments correlated with H3K27ac enrichment pattern for each cell line, suggesting enrichment correlates with impact. Data with PBX1 T417 exposure suggests dependency of PBX1 in maintaining lineage state and survival for unique subsets of LUADs. Further investigation is needed to determine if T417 dependent inhibition is uniform to all PBX1 active LUADs and if other LUAD subsets are dependent on other TFs. Citation Format: Douglas M. Mansell, Maya Fridrich, Feng Jiang, Benjamin Chen, Ayushi Patel, Tian Li-Wang, Charles A. Powell, Hideo Watanabe. Epigenomic profiling uncovers distinct enrichment patterns of PBX1 super-enhancer among lung adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2231.

Introduction: In the treatment of advanced BRAF-mutated melanoma, selective regulation of the MAPK pathway with BRAF and MEK inhibition has emerged as one of the mainstays of therapy. Areas covered...

In the present work, a hybrid catalytic material of the class of tetravalent metal acid (TMA) salts has been synthesized by the sol–gel method, wherein solution of titanium tetrachloride is allowed to react with claw-type organic phosphonic acid, amino tris methylenephosphonic acid (ATMP) under appropriate reaction conditions of pH, temperature, time and ageing period. The resultant hybrid material (Ti-ATMP) was found to possess proton donating behaviour, and hence it was thought of interest to use it as solid acid catalyst to perform catalysed esterification reaction of biomass-derived levulinic acid with n-butanol to synthesize n-butyl levulinate. Various process parameters such as catalyst concentration % (X1), LA:n–butanol molar ratio (X2) and reaction time (min) (X3) were optimized by response surface methodology (RSM), using the Box–Behnken Design (BBD). Analysis of variance was performed in order to check the suitability of the quadratic model. The catalytic reusability study has been performed in order to have an idea about feasibility of its reuse. Ti- ATMP catalyst was found efficient and promising with satisfactory yields and excellent reusability. The results clearly indicate its potentiality as solid acid catalyst to catalyse other organic transformations.

We report a large epidemic (n = 126) of keratoconjunctivitis predominantly with two lineages of adenovirus (AdV) type D8 in patients seen in eye casualty between march and August 2019. Other AdV species identified by viral sequencing included B, C, and E. Despite various features of more severe eye disease being present, these were not significantly different between the different AdV species, with similar rates of pseudomembrane formation and keratitis observed in patients with AdV species B as for those with AdV species D.

The DNA repair scaffold SLX4 has multifaceted roles in genome stability, many of which depend on structure-selective endonucleases. SLX4 coordinates the cell cycle-regulated assembly of SLX1, MUS81-EME1, and XPF-ERCC1 into a tri-nuclease complex called SMX. Mechanistically, how the mitotic kinase CDK1 regulates the interaction between SLX4 and MUS81-EME1 remains unclear. Here, we show that CDK1-cyclin B phosphorylates SLX4 residues T1544, T1561, and T1571 in the MUS81-binding region (SLX4

Small cell lung cancer (SCLC), which comprises about 15% of lung cancer cases, is the most aggressive and deadliest type of lung cancer with extremely poor clinical outcomes (about 6% of 5-year overall survival). For about the last three decades, combinatory chemotherapy of etoposide and platinum (EP) treatment has been used as the standard first-line treatment for SCCL. While tumors are generally responsive to the EP treatment, in most cases, they rapidly relapse and acquire resistance after the treatment. However, detailed mechanisms underlying the acquired chemoresistance are not well understood. In this study, we constructed a SCLC comprehensive regulatory network using 135 SCLC tumors, projected chemo-resistant signature genes derived from patient-derived xenografts and genetically engineered mouse models on the network, and identified Granulin (GRN) as a key regulator of the chemo-resistant genes. In multiple independent SCLC datasets, expression levels of GRN and its associated genes increase with the EP treatment and show anti-correlation with neuroendocrine (NE) features of SCLC. Yap activation in a SCLC mouse model increases Grn expression suggesting Yap1 as a potential upstream regulator of Grn. But, on the other hand, the expression levels of GRN and its associated genes are up-regulated in EP treated patient-derived CDX models compared to treatment naïve ones, in which YAP1 expression is depleted in both groups, suggesting YAP1 independent GRN functions associated with chemoresistance. Our observations were validated using 4 SCLC cell lines having different GRN expressions (GRNhigh: SHP77 and H841 and GRNlow: H524 and H2081). The GRNlow showed better responses to the EP treatment compared to the GRNhigh cells (IC50: GRNhigh > 1𝜇M; GRNlow ≈ 1nM). Furthermore, the GRNlow cells with GRN over-expression acquired resistance to the treatment suggesting that GRN expression in SCLC is sufficient for chemo-resistance regardless of YAP1 activation. When we stratified SCLC patients using GRN and its associated genes, the patients in the GRN low group received clear benefits of the chemotherapy with better survival than ones without the treatment (LRT p=0.004) while there were no survival differences among patients regardless of the treatment in the GRN high group. Interestingly, immune checkpoint blockade marker genes were significantly up-regulated in patients from the GRN high group (p= 1.8×10-5, 4.8×10-5, 3.5×10-5, and 0.0002 for PDCD1, CD274, PDCD1LG2, and CTLA4, respectively). Combining this with an observation of that GRN and its associated genes were associated with high PDL1 expression in non-NE SCLC mouse models, immunotherapies might be a potentially effective treatment option for the GRN high group. Our study suggests GRN as a novel key regulator modulating chemo-resistance as well as a potential biomarker for immunotherapy response in SCLC and, hence, provide valuable information in the clinical decisions for better diagnosis, prognosis, and treatment for the purpose of precision medicine. Citation Format: Seungyeul Yoo, Ayushi Patel, Yi Zhong, Feng Jiang, Wenhui Wang, Hideo Watanabe, Jun Zhu. Molecular network analysis identifies GRN as a key regulator of chemotherapy resistance in small cell lung cancer [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr B53.

In the vast majority of cases, cutaneous melanoma presents as localized disease and is treated with wide excision and sentinel lymph node biopsy, with shared decision making regarding completion lymph node dissection and adjuvant systemic therapy. The treatment of recurrent and in-transit disease is more complex, with further options for regional and systemic therapies and multiple variables to be factored into decisions. Rates of overall and complete response to regional therapies can be quite high in carefully chosen patients, which limits the need for systemic therapies and their inherent side effects. Ongoing trials aim to assess the efficacy of combination regional and systemic therapies and assist in deciding among these options. This review discusses the treatment of primary melanoma and regional nodal disease and offers an in-depth discussion of options for the treatment of recurrent melanoma and in-transit melanoma.

siRNAs bearing a 3′-azobenzene derivative on the sense strand were evaluated for their gene silencing ability in mammalian cell culture and nuclease stability in nuclease-rich media. Azobenzene can be isomerized between cis and trans isomers through the incubation of UV (cis isomer) and visible light (trans isomer). It was demonstrated that subtle differences in nuclease stability and activity were observed. These small changes can be used to photochemically fine-tune the activity of an siRNA for gene-silencing applications.

Planktonic cultures, of a rationally designed consortium, demonstrated emergent properties that exceeded the sums of monoculture properties, including a >200% increase in cellobiose catabolism, a >100% increase in glycerol catabolism, a >800% increase in ethanol production, and a >120% increase in biomass productivity. The consortium was designed to have a primary and secondary-resource specialist that used crossfeeding with a positive feedback mechanism, division of labor, and nutrient and energy transfer via necromass catabolism. The primary resource specialist was Clostridium phytofermentans (a.k.a. Lachnoclostridium phytofermentans), a cellulolytic, obligate anaerobe. The secondary-resource specialist was Escherichia coli, a versatile, facultative anaerobe, which can ferment glycerol and byproducts of cellobiose catabolism. The consortium also demonstrated emergent properties of enhanced biomass accumulation when grown as biofilms, which created high cell density communities with gradients of species along the vertical axis. Consortium biofilms were robust to oxic perturbations with E. coli consuming O2, creating an anoxic environment for C. phytofermentans. Anoxic/oxic cycling further enhanced biomass productivity of the biofilm consortium, increasing biomass accumulation ~250% over the sum of the monoculture biofilms. Consortium emergent properties were credited to several synergistic mechanisms. E. coli consumed inhibitory byproducts from cellobiose catabolism, driving higher C. phytofermentans growth and higher cellulolytic enzyme production, which in turn provided more substrate for E. coli. E. coli necromass enhanced C. phytofermentans growth while C. phytofermentans necromass aided E. coli growth via the release of peptides and amino acids, respectively. In aggregate, temporal cycling of necromass constituents increased flux of cellulose-derived resources through the consortium. The study establishes a consortia-based, bioprocessing strategy built on naturally occurring interactions for improved conversion of cellulose-derived sugars into bioproducts.

Management of in-transit melanoma encompasses a variety of possible treatment pathways and modalities. Depending on the location of disease, number of lesions, burden of disease and patient preference and characteristics, some treatments may be more beneficial than others. After full body radiographic staging is performed to rule out metastatic disease, curative therapy may be performed through surgical excision, intraarterial regional perfusion and infusion therapies, intralesional injections, systemic therapies or various combinations of any of these. While wide excision is limited in indication to superficial lesions that are few in number, the other listed therapies may be effective in treating unresectable disease. Where intraarterial perfusion based therapies have been shown to successfully treat extremity disease, injectable therapies can be used in lesions of the head and neck. Although systemic therapies for in-transit melanoma have limited specific data to support their primary use for in-transit disease, there are patients who may not be eligible for any of the other options, and current clinical trials are exploring the use of concurrent and sequential use of regional and systemic therapies with early results suggesting a synergistic benefit for oncologic response and outcomes.

Nuclear reorganization, including the localization of proteins into discrete subnuclear foci, is a hallmark of the cellular response to DNA damage and replication stress. These foci are thought to represent transient environments or repair factories, in which the lesion is sequestered with molecules and co-factors that catalyze repair. For example, nuclear foci contain signaling proteins that recruit transducer proteins. One important class of transducers is the structure-selective endonucleases, such as SLX1-SLX4, MUS81-EME1, and XPF-ERCC1, which remove branched DNA structures that form during repair. The relocalization of structure-selective endonucleases into subnuclear foci provides a visual read-out for the presence of direct DNA damage, replication barriers, or DNA entanglements and can be monitored using fluorescence microscopy. By simultaneously probing for two or more fluorescent signals, fluorescence microscopy can also provide insights into the proximal association of proteins within a local environment. Here, we report an open-source and semi-automated method to detect and quantify subnuclear foci, as well as foci colocalization and the accompanying pixel-based colocalization metrics. We use this pipeline to show that pre-mitotic nuclei contain a basal threshold of foci marked by SLX1-SLX4, MUS81, or XPF. Some of these foci colocalize with FANCD2 and have a high degree of correlation and co-occurrence. We also show that pre-mitotic cells experiencing replication stress contain elevated levels of foci containing SLX1-SLX4 or XPF, but not MUS81. These results point towards a role for SLX1-SLX4 and XPF-ERCC1 in the early cellular response to replication stress. Nevertheless, most of the foci that form in response to replication stress contain either FANCD2 or one of the three endonucleases. Altogether, our work highlights the compositional heterogeneity of subnuclear foci that form in response to replication stress. We also describe a user-friendly pipeline that can be used to characterize these dynamic structures.

Efficient, large-scale conversion of plant-derived feedstocks to commodity chemicals remains a substantial technological challenge with enormous potential for societal benefits. Most research efforts have focused on metabolic engineering of model organisms for planktonic cell cultures in well-mixed suspension bioreactors. We utilized in silico metabolic modeling to explore the potential benefits of an alternative design strategy based on combining bacterial strains with complementary metabolic functions within high density, multispecies biofilms. We simulated four alternative system designs, each of which consisted of an anaerobic cellulolytic bacterium which degraded cellobiose to glucose, an aerobic Escherichia coli strain engineered for glucose-to-isobutanol conversion, and an aerobic or anaerobic byproduct consumer for metabolizing growth-inhibiting organic acids such as acetate secreted by the other two strains. Our simulations predicted dramatically different cellobiose-to-isobutanol conversion capabilities depending on the metabolic compatibility of the three bacteria. Important design considerations included glucose competition between the cellulolytic and isobutanol-producing bacteria, O2 competition between the isobutanol-producing and byproduct-consuming bacteria, organic acid matching between the cellulolytic and byproduct-consuming bacteria and the degree of metabolic redundancy between the community members. We believe that these design principles will be widely applicable to synthetic biofilm communities engineered to perform other bioconversion tasks.

The aqueous suspensions of gaseous microbubbles are currently being used as contrast enhancing agents for ultrasonic imaging and as potential vehicles for targeted drug delivery. The storage stability of microbubble suspensions is very important as for any possible application of microbubbles, a stable microbubble suspension is needed. A stable microbubble suspension is a suspension for which there is no drastic change in concentration (number of microbubbles/mL of storage solution) and microbubble size distribution during the period of storage. To characterize storage stability, half-life of the microbubble suspensions, which is the time required for the microbubble concentration (#/mL) to decrease by 50% during storage, was estimated using a simple model. The proposed model estimates the storage stability of aqueous microbubble suspensions and effect of material properties on their storage stability. It takes into account an inter-bubble mass transfer and combines it with a population balance equation to account for a change in concentration (#/mL) as well as size and size distribution of microbubbles in the aqueous suspensions. The calculations have been performed for microbubbles made of three gases, namely oxygen (O2), sulphur hexafluoride (SF6) and perfluorobutane (PFB). The variation in storage stability of microbubble suspensions was examined by varying microbubble shell properties such as shell elasticity, surface tension and shell resistance as well as the other parameters such as viscosity of the storage medium and the initial size distribution of the microbubbles. The analysis of the results show that, among the shell properties studied, the shell resistance influenced the suspension stability the most and shell elasticity influenced the stability the least. Similarly, a gas with the lower liquid phase diffusivity and lower Ostwald coefficient results in a stable microbubble suspension. Also, higher viscosity of storage solution and microbubbles with larger sizes tend to increase the storage stability. Overall, the increase in the total resistance (combination of shell resistance and resistance in the storage solution) to mass transfer of a gas increases the storage stability of the microbubble suspensions.

We report an unusually high number of cases (n = 26) of parechovirus infections in the cerebrospinal fluid (CSF) of neonates and infants admitted with sepsis in the United Kingdom during 8 May to 2 August 2016. Although such infections in neonates and infants are well-documented, parechovirus has not been routinely included in many in-house and commercial PCR assays for CSF testing. Clinicians should consider routine parechovirus testing in young children presenting with sepsis.