Phenotypic screening platform identifies statins as enhancers of immune cell-induced cancer cell death.

BACKGROUND: High-throughput screening (HTS) of small molecule drug libraries has greatly facilitated the discovery of new cancer drugs. However, most phenotypic screening platforms used in the field of oncology are based solely on cancer cell populations and do not allow for the identification of immunomodulatory agents. METHODS: We developed a phenotypic screening platform based on a miniaturized co-culture system with human colorectal cancer- and immune cells, providing a model that recapitulates part of the tumor immune microenvironment (TIME) complexity while simultaneously being compatible with a simple image-based readout. Using this platform, we screened 1,280 small molecule drugs, all approved by the Food and Drug Administration (FDA), and identified statins as enhancers of immune cell-induced cancer cell death. RESULTS: The lipophilic statin pitavastatin had the most potent anti-cancer effect. Further analysis demonstrated that pitavastatin treatment induced a pro-inflammatory cytokine profile as well as an overall pro-inflammatory gene expression profile in our tumor-immune model. CONCLUSION: Our study provides an in vitro phenotypic screening approach for the identification of immunomodulatory agents and thus addresses a critical gap in the field of immuno-oncology. Our pilot screen identified statins, a drug family gaining increasing interest as repurposing candidates for cancer treatment, as enhancers of immune cell-induced cancer cell death. We speculate that the clinical benefits described for cancer patients receiving statins are not simply caused by a direct effect on the cancer cells but rather are dependent on the combined effect exerted on both cancer and immune cells.

Assessment in vitro of interactions between anti-cancer drugs and noncancer drugs commonly used by cancer patients.

Cancer patients often suffer from cancer symptoms, treatment complications and concomitant diseases and are, therefore, often treated with several drugs in addition to anticancer drugs. Whether such drugs, here denoted as 'concomitant drugs', have anticancer effects or interact at the tumor cell level with the anticancer drugs is not very well known. The cytotoxic effects of nine concomitant drugs and their interactions with five anti-cancer drugs commonly used for the treatment of colorectal cancer were screened over broad ranges of drug concentrations in vitro in the human colon cancer cell line HCT116wt. Seven additional tyrosine kinase inhibitors were included to further evaluate key findings as were primary cultures of tumor cells from patients with colorectal cancer. Cytotoxic effects were evaluated using the fluorometric microculture cytotoxicity assay (FMCA) and interaction analysis was based on Bliss independent interaction analysis. Simvastatin and loperamide, included here as an opioid agonists, were found to have cytotoxic effects on their own at reasonably low concentrations whereas betamethasone, enalapril, ibuprofen, metformin, metoclopramide, metoprolol and paracetamol were inactive also at very high concentrations. Drug interactions ranged from antagonistic to synergistic over the concentrations tested with a more homogenous pattern of synergy between simvastatin and protein kinase inhibitors in HCT116wt cells. Commonly used concomitant drugs are mostly neither expected to have anticancer effects nor to interact significantly with anticancer drugs frequently used for the treatment of colorectal cancer.

A longitudinal study on the impact of Internet gaming disorder on self-perceived health, academic performance, and social life of first-year college students.

BACKGROUND AND OBJECTIVES: Internet gaming disorder (IGD) is associated with health, social, and academic problems but whether these are consequences of the disorder rather than precursors or correlates is unclear. We aimed to evaluate whether IGD in the 1st year of university predicts health, academic and social problems 1 year later, controlling for baseline health, academic and social problems, demographics, and mental health symptoms. METHODS: In a prospective cohort study, 1741 university students completed both a baseline online survey in their 1st year and a follow-up survey 1 year later. Log-binomial models examined the strength of prospective associations between baseline predictor variables (IGD, baseline health, academic and social problems, sex, age, and mental health symptoms) and occurrence of health, academic and social problems at follow-up. RESULTS: When extensively adjusted by the corresponding outcome at baseline, any mental disorder symptoms, sex, and age, baseline IGD was associated only with severe school impairment and poor social life (risk ratio [RR] = 1.77; 95% confidence interval [CI] = 1.14-2.75, p = .011; RR = 1.22; 95% CI = 1.07-1.38, p = .002, respectively). CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE: University authorities and counselors should consider that incoming 1st-year students that meet criteria for IGD are likely to have increased academic and social impairments during their 1st year for which they may want to intervene. This study adds to the existing literature by longitudinally examining a greater array of negative outcomes of IGD than previously documented.

Compliance with recommendations limiting COVID-19 contagion among university students in Sweden: associations with self-reported symptoms, mental health and academic self-efficacy.

AIMS: The COVID-19 containment strategy in Sweden uses public health recommendations relying on personal responsibility for compliance. Universities were one of few public institutions subject to strict closure, meaning that students had to adapt overnight to online teaching. This study investigates the prevalence of self-reported recommendation compliance and associations with self-reported symptoms of contagion, self-experienced effects on mental health and academic self-efficacy among university students in Sweden in May-June 2020. METHODS: This was a cross-sectional 23 question online survey in which data were analysed by multinomial regression, taking a Bayesian analysis approach complemented by null hypothesis testing. RESULTS: A total of 4495 students consented to respond. Recommendation compliance ranged between 70% and 96%. Women and older students reported higher compliance than did men and younger students. Mild to moderate COVID-19 symptoms were reported by 30%, severe symptoms by fewer than 2%; 15% reported being uncertain and half of the participants reported no symptoms. Mental health effects were reported by over 80%, and changes in academic self-efficacy were reported by over 85%; in both these areas negative effects predominated. Self-reported symptoms and uncertainty about contagion were associated with non-compliance, negative mental health effects, and impaired academic self-efficacy. CONCLUSIONS: Students generally followed public health recommendations during strict closure of universities, but many reported considerable negative consequences related to mental health and academic self-efficacy. Digital interventions should be developed and evaluated to boost coping skills, build resilience and alleviate student suffering during the pandemic and future similar crises.

An International Comparison of a Web-Based Personalized Feedback Intervention for Alcohol use During the Transition out of High School in the United States and Sweden.

Young adult drinkers engage in a range of drinking patterns from abstaining to heavy drinking in both the United States and Sweden. Heavy drinking during young adulthood in both countries is associated with a variety of negative consequences. Personalized feedback interventions have been identified as effective prevention strategies to prevent or reduce heavy drinking in the United States. This study examined transitions in drinking profiles and compared the efficacy of a personalized feedback intervention for 3965 young adults in the United States (1,735) and Sweden (2230) during their transition out of high school. Using goodness-of-fit criteria, results indicated that three drinking profiles exist among young adults transitioning out of high school: very low drinkers/abstainers, moderate to heavy drinkers, and very heavy drinkers. Latent Markov models revealed a moderating effect of country on personalized feedback intervention such that intervention condition participants in the United States were more likely to belong to the light drinker/abstainer or moderate to heavy profile relative to the very heavy drinking profile at 6-month follow-up. There was no significant effect of personalized feedback intervention in Sweden. Future research could investigate the impact of when personalized feedback interventions are administered and could examine if personalized feedback interventions should be more intentionally culturally adapted in order to be more effective.

Hierarchical models for epidermal nerve fiber data.

While epidermal nerve fiber (ENF) data have been used to study the effects of small fiber neuropathies through the density and the spatial patterns of the ENFs, little research has been focused on the effects on the individual nerve fibers. Studying the individual nerve fibers might give a better understanding of the effects of the neuropathy on the growth process of the individual ENFs. In this study, data from 32 healthy volunteers and 20 diabetic subjects, obtained from suction induced skin blister biopsies, are analyzed by comparing statistics for the nerve fibers as a whole and for the segments that a nerve fiber is composed of. Moreover, it is evaluated whether this type of data can be used to detect diabetic neuropathy, by using hierarchical models to perform unsupervised classification of the subjects. It is found that using the information about the individual nerve fibers in combination with the ENF counts yields a considerable improvement as compared to using the ENF counts only.

Targeting tumor cells based on Phosphodiesterase 3A expression.

We and others have previously reported a correlation between high phosphodiesterase 3A (PDE3A) expression and selective sensitivity to phosphodiesterase (PDE) inhibitors. This indicates that PDE3A could serve both as a drug target and a biomarker of sensitivity to PDE3 inhibition. In this report, we explored publicly available mRNA gene expression data to identify cell lines with different PDE3A expression. Cell lines with high PDE3A expression showed marked in vitro sensitivity to PDE inhibitors zardaverine and quazinone, when compared with those having low PDE3A expression. Immunofluorescence and immunohistochemical stainings were in agreement with PDE3A mRNA expression, providing suitable alternatives for biomarker analysis of clinical tissue specimens. Moreover, we here demonstrate that tumor cells from patients with ovarian carcinoma show great variability in PDE3A protein expression and that level of PDE3A expression is correlated with sensitivity to PDE inhibition. Finally, we demonstrate that PDE3A is highly expressed in subsets of patient tumor cell samples from different solid cancer diagnoses and expressed at exceptional levels in gastrointestinal stromal tumor (GIST) specimens. Importantly, vulnerability to PDE3 inhibitors has recently been associated with co-expression of PDE3A and Schlafen family member 12 (SLFN12). We here demonstrate that high expression of PDE3A in clinical specimens, at least on the mRNA level, seems to be frequently associated with high SLFN12 expression. In conclusion, PDE3A seems to be both a promising biomarker and drug target for individualized drug treatment of various cancers.

Long-term enzyme replacement therapy improves neurocognitive functioning and hippocampal synaptic plasticity in immune-tolerant alpha-mannosidosis mice.

Alpha-mannosidosis is a glycoproteinosis caused by deficiency of lysosomal acid alpha-mannosidase (LAMAN), which markedly affects neurons of the central nervous system (CNS), and causes pathognomonic intellectual dysfunction in the clinical condition. Cognitive improvement consequently remains a major therapeutic objective in research on this devastating genetic error. Immune-tolerant LAMAN knockout mice were developed to evaluate the effects of enzyme replacement therapy (ERT) by prolonged administration of recombinant human enzyme. Biochemical evidence suggested that hippocampus may be one of the brain structures that benefits most from long-term ERT. In the present functional study, ERT was initiated in 2-month-old immune-tolerant alpha-mannosidosis mice and continued for 9months. During the course of treatment, mice were trained in the Morris water maze task to assess spatial-cognitive performance, which was related to synaptic plasticity recordings and hippocampal histopathology. Long-term ERT reduced primary substrate storage and neuroinflammation in hippocampus, and improved spatial learning after mid-term (10weeks+) and long-term (30weeks+) treatment. Long-term treatment substantially improved the spatial-cognitive abilities of alpha-mannosidosis mice, whereas the effects of mid-term treatment were more modest. Detailed analyses of spatial memory and spatial-cognitive performance indicated that even prolonged ERT did not restore higher cognitive abilities to the level of healthy mice. However, it did demonstrate marked therapeutic effects that coincided with increased synaptic connectivity, reflected by improvements in hippocampal CA3-CA1 long-term potentiation (LTP), expression of postsynaptic marker PSD-95 as well as postsynaptic density morphology. These experiments indicate that long-term ERT may hold promise, not only for the somatic defects of alpha-mannosidosis, but also to alleviate cognitive impairments of the disorder.

Interactive Voice Response with Feedback Intervention in Outpatient Treatment of Substance Use Problems in Adolescents and Young Adults: A Randomized Controlled Trial.

PURPOSE: Substance use disorders and problematic substance use are common problems in adolescence and young adulthood. Brief personalized feedback has been suggested for treatment of alcohol and drug problems and poor mental health. This repeated measurement randomized controlled trial examines the effect of an interactive voice response (IVR) system for assessing stress, depression, anxiety and substance use. METHODS: The IVR system was used twice weekly over 3 months after treatment initiation, with or without addition of a personalized feedback intervention on stress and mental health symptoms. Both IVR assessment only (control group) and IVR assessment including feedback (intervention group) were provided as an add-on to treatment-as-usual procedures (TAU) in outpatient treatment of substance use problems in adolescents and young adults (N = 73). RESULTS: By using a mixed models approach, differences in change scores were analyzed over the three-month assessment period. Compared to the control group, the intervention group demonstrated significantly greater improvement in the Arnetz and Hasson stress score (AHSS, p = 0.019), the total Symptoms Checklist 8 score (SCL-8D, p = 0.037), the SCL-8D anxiety sub-score (p = 0.017), and on a summarized feedback score (p = 0.026), but not on the depression subscale. There were no differences in global substance use scores between the intervention group (feedback on mental health symptoms) and the control group. CONCLUSION: In conclusion, IVR may be useful for follow-up and repeated interventions as an add-on to regular treatment, and personalized feedback could potentially improve mental health in adolescents and young adults with problematic substance use.

Skills Training via Smartphone App for University Students with Excessive Alcohol Consumption: a Randomized Controlled Trial.

PURPOSE: University students in a study on estimated blood alcohol concentration (eBAC) feedback apps were offered participation in a second study, if reporting continued excessive consumption at 6-week follow-up. This study evaluated the effects on excessive alcohol consumption of offering access to an additional skills training app. METHOD: A total of 186 students with excessive alcohol consumption were randomized to an intervention group or a wait list group. Both groups completed online follow-ups regarding alcohol consumption after 6 and 12 weeks. Wait list participants were given access to the intervention at 6-week follow-up. Assessment-only controls (n = 144) with excessive alcohol consumption from the ongoing study were used for comparison. RESULTS: The proportion of participants with excessive alcohol consumption declined in both intervention and wait list groups compared to controls at first (p < 0.001) and second follow-ups (p = 0.054). Secondary analyses showed reductions for the intervention group in quantity of drinking at first follow-up (-4.76, 95% CI [-6.67, -2.85], Z = -2.09, p = 0.037) and in frequency of drinking at both follow-ups (-0.83, 95% CI [-1.14, -0.52], Z = -2.04, p = 0.041; -0.89, 95% CI [-1.16, -0.62], Z = -2.12, p = 0.034). The odds ratio for not having excessive alcohol consumption among men in the intervention group compared to male controls was 2.68, 95% CI [1.37, 5.25] (Z = 2.88, p = 0.004); the figure for women was 1.71, 95% CI [1.11, 2.64] (Z = 2.41, p = 0.016). CONCLUSION: Skills training apps have potential for reducing excessive alcohol use among university students. Future research is still needed to disentangle effects of app use from emailed feedback on excessive alcohol consumption and study participation. TRIAL REGISTRATION: NCT02064998.

The anticancer effect of mebendazole may be due to M1 monocyte/macrophage activation via ERK1/2 and TLR8-dependent inflammasome activation.

Mebendazole (MBZ), a drug commonly used for helminitic infections, has recently gained substantial attention as a repositioning candidate for cancer treatment. However, the mechanism of action behind its anticancer activity remains unclear. To address this problem, we took advantage of the curated MBZ-induced gene expression signatures in the LINCS Connectivity Map (CMap) database. The analysis revealed strong negative correlation with MEK/ERK1/2 inhibitors. Moreover, several of the most upregulated genes in response to MBZ exposure were related to monocyte/macrophage activation. The MBZ-induced gene expression signature in the promyeloblastic HL-60 cell line was strongly enriched in genes involved in monocyte/macrophage pro-inflammatory (M1) activation. This was subsequently validated using MBZ-treated THP-1 monocytoid cells that demonstrated gene expression, surface markers and cytokine release characteristic of the M1 phenotype. At high concentrations MBZ substantially induced the release of IL-1ß and this was further potentiated by lipopolysaccharide (LPS). At low MBZ concentrations, cotreatment with LPS was required for MBZ-stimulated IL-1ß secretion to occur. Furthermore, we show that the activation of protein kinase C, ERK1/2 and NF-kappaB were required for MBZ-induced IL-1ß release. MBZ-induced IL-1ß release was found to be dependent on NLRP3 inflammasome activation and to involve TLR8 stimulation. Finally, MBZ induced tumor-suppressive effects in a coculture model with differentiated THP-1 macrophages and HT29 colon cancer cells. In summary, we report that MBZ induced a pro-inflammatory (M1) phenotype of monocytoid cells, which may, at least partly, explain MBZ's anticancer activity observed in animal tumor models and in the clinic.

Daily Assessment of Acute Dynamic Risk in Paroled Offenders: Prediction, Predictive Accuracy and Intervention Effect.

Few studies have assessed acute dynamic risk repeatedly among paroled offenders to investigate the relationship between changes in acute dynamic risk and recidivism in crime. The present study investigates whether one-month changes in ten stress-related acute dynamic risk factors, collected through automated telephony while the participants were still in prison and over 30 consecutive days following parole, predict one-year criminal recidivism, including its predictive accuracy. The study also investigates whether a brief feedback intervention in conjunction with the daily assessments reduces recidivism compared to an assessment-only control group. Changes in five risk factors were found to be associated with increased risk of criminal recidivism after controlling for the results in prison, the initial value after parole, and the intervention. The predictive accuracy is marginally accurate: Summary score (AUC) = .666; Level of stress (AHSS) = .644; Psychiatric symptoms (SCL-8D) = .641; Anxiety symptoms = .673; Severity of most stressful daily event = .690. No differences in one-year recidivism rates were established between the intervention group and the control group. The study shows that daily assessments can usefully be made of dynamic risk factors in paroled offenders.

Discovering early diabetic neuropathy from epidermal nerve fiber patterns.

Epidermal nerve fibre (ENF) density and morphology are used to study small fibre involvement in diabetic, HIV, chemotherapy induced and other neuropathies. ENF density and summed length of ENFs per epidermal surface area are reduced, and ENFs may appear more clustered within the epidermis in subjects with small fibre neuropathy than in healthy subjects. Therefore, it is important to understand the spatial structure of ENFs. In this paper, we compare the ENF patterns between healthy subjects and subjects suffering from mild diabetic neuropathy. The study is based on suction skin blister specimens from the right foot of 32 healthy subjects and eight subjects with mild diabetic neuropathy. We regard the ENF entry point (location where the trunks of a nerve enters the epidermis) and ENF end point (termination of the nerve fibres) patterns as realizations of spatial point processes, and develop tools that can be used in the analysis and modelling of ENF patterns. We use spatial summary statistics and shift plots and define a new tool, reactive territory, to study the spatial patterns and to compare the patterns of the two groups. We will also introduce a simple model for these data in order to understand the growth process of the nerve fibres. Copyright © 2016 John Wiley & Sons, Ltd.

Internet-based cognitive behaviour therapy and physical exercise - Effects studied by automated telephone assessments in mental ill-health patients; a randomized controlled trial.

OBJECTIVES: Mental ill-health has become a large health problem and it is important for caregivers to provide effective treatment alternatives. REGASSA is a randomized controlled study performed in primary care to study the effects of 12 weeks of Internet-based cognitive behaviour therapy (ICBT) and physical exercise (PE) compared with treatment as usual (TAU) in patients with mild-to-moderate mental ill-health. The present study aimed to examine the results of these treatment alternatives on psychological functioning, stress, and sleep disturbances. METHODS: The study comprised 879 patients with mental ill-health taking part in the REGASSA study. Data were collected by Interactive Voice Response (IVR), a computerized, automated telephone technique. The treatments were compared at baseline, twice during treatment, at the end of treatment and at three follow-ups after treatment. Measures used were the Outcome Questionnaire-45, the short versions of the Perceived Stress Scale, and the Karolinska Sleep Questionnaire. RESULTS: Linear mixed models showed that the patients in ICBT and PE had better results than in TAU on psychological functioning and sleep disturbances, p < .001, with weak-to-moderate effect sizes. On stress there were no differences; all groups made improvements. Women had stronger effects than men. More patients recovered on psychological functioning (OQ-45) in ICBT and PE than in TAU. CONCLUSIONS: Internet-based cognitive behaviour therapy and PE proved to be effective treatment alternatives for patients with mild-to-moderate mental ill-health in improving psychological functioning, stress, and sleep disturbances and could be useful alternatives in primary care. PRACTITIONER POINTS: Internet-based cognitive behaviour therapy and physical exercise proved to be effective treatment alternatives for mental ill-health patients in primary care. Automated techniques (Interactive Voice Response) could be useful for following treatment course in large groups of patients in the health care. It is important to use measures that capture different aspects of patients' health problems. The recruitment of participants was based on patients' interest and inclusion criteria which may have affect the generalizability.

Comparison of WEB and Interactive Voice Response (IVR) Methods for Delivering Brief Alcohol Interventions to Hazardous-Drinking University Students: A Randomized Controlled Trial.

UNLABELLED: This study evaluated automated techniques including personalized normative feedback and protective behavioral strategies, for brief interventions intended to reduce peak alcohol concentrations in university students. After completing baseline assessment, a total of 1,678 hazardous-drinking consumers were randomized to a single or a repeated Internet (WEB) or Interactive Voice Response (IVR) intervention, or to a control group (Single WEB: 323; Single IVR: 329; Repeated WEB: 318; Repeated IVR: 334; CONTROL GROUP: 374). At follow-up, six weeks after baseline, questionnaires were returned by 1,422 participants (Single WEB: 277; Single IVR: 286; Repeated WEB: 259; Repeated IVR: 279; CONTROL GROUP: 321). It was found that peak estimated BAC was reduced in the total group (b -0.14, 95% confidence interval (CI) -0.023; -0.005), in the total (b -0.17, 95% CI -0.027; -0.007) and single (b -0.021, 95% CI -0.032; -0.011) WEB group, and in the total (b -0.011, 95% CI -0.021; -0.015) and repeated (b -0.012, 95% CI -0.023; -0.000) IVR groups, compared to controls. The reduction in peak estimated BAC was greater in the single WEB group compared to the single IVR group (b -0.011, 95% CI -0.022; -0.000). This study concluded that both WEB and IVR interventions have a small but significant effect in reducing heavy episodic drinking, which may be due to the relatively large sample size. Repeated intervention may be needed if delivered by IVR.

Synthesis and Properties of Bis-Porphyrin Molecular Tweezers: Effects of Spacer Flexibility on Binding and Supramolecular Chirogenesis.

Ditopic binding of various dinitrogen compounds to three bisporphyrin molecular tweezers with spacers of varying conformational rigidity, incorporating the planar enediyne (1), the helical stiff stilbene (2), or the semi-rigid glycoluril motif fused to the porphyrins (3), are compared. Binding constants Ka = 104-106 M(-1) reveal subtle differences between these tweezers, that are discussed in terms of porphyrin dislocation modes. Exciton coupled circular dichroism (ECCD) of complexes with chiral dinitrogen guests provides experimental evidence for the conformational properties of the tweezers. The results are further supported and rationalized by conformational analysis.

Benchmarking study of parameter variation when using signature fingerprints together with support vector machines.

QSAR modeling using molecular signatures and support vector machines with a radial basis function is increasingly used for virtual screening in the drug discovery field. This method has three free parameters: C, γ, and signature height. C is a penalty parameter that limits overfitting, γ controls the width of the radial basis function kernel, and the signature height determines how much of the molecule is described by each atom signature. Determination of optimal values for these parameters is time-consuming. Good default values could therefore save considerable computational cost. The goal of this project was to investigate whether such default values could be found by using seven public QSAR data sets spanning a wide range of end points and using both a bit version and a count version of the molecular signatures. On the basis of the experiments performed, we recommend a parameter set of heights 0 to 2 for the count version of the signature fingerprints and heights 0 to 3 for the bit version. These are in combination with a support vector machine using C in the range of 1 to 100 and γ in the range of 0.001 to 0.1. When data sets are small or longer run times are not a problem, then there is reason to consider the addition of height 3 to the count fingerprint and a wider grid search. However, marked improvements should not be expected.

Characterizing changes in levan physicochemical properties in different pH environments using asymmetric flow field-flow fractionation.

The purpose of this study was to assess the stability of the polyfructan levan under different pH solution conditions by monitoring changes in the levan physicochemical properties, such as molar mass (M), root mean square radius (r(rms)), hydrodynamic radius (r(h)), structure factor (r(rms)/r(h)), and aggregation state with respect to solution pH and hydrolysis time. A commercial levan produced from Z. Mobilis was characterized using asymmetric flow field-flow fractionation (AF4) in combination with online multiangle light scattering (MALS) and differential refractive index (dRI) detection. Under neutral pH solution conditions the levan was found to have a M ranging from 10(5) to 5 × 10(7) g/mol, a r(rms) ranging from ~25 to 100 nm and a r(h) from ~3 to 151 nm. Two populations were observed in the sample. One population with a M less than 106 g/mol which represented ~60 % of the sample and a second population with an ultrahigh M up to 5 × 10(7) g/mol, which comprised ~40 % of the sample. The measured r(rms)/r(h) structure factor decreased from 1.8 to 0.65 across the AF4 fractogram indicating that early eluting low M levan species had a random coil configuration and late eluting high M species had more homogeneous spherical structures. The measured apparent density values decreased from 80 to 10 kg/m(3) across the elution profile and suggest that the observed second population also contains aggregates. The stability of levan in different pH conditions ranging from 1.3 to 8.5 was assessed by tracking changes in the average M and r(h), and monitoring the formation of fructose over 1 week. The onset of levan acid hydrolysis was observed to occur sooner at lower pH conditions and no hydrolysis was observed for pH 5.5 and higher.