MASLD is related to impaired alcohol dehydrogenase (ADH) activity and elevated blood ethanol levels: Role of TNFα and JNK

Elevated fasting ethanol levels in peripheral blood frequently found in metabolic dysfunction-associated steatohepatitis (MASLD) patients even in the absence of alcohol consumption are discussed to contribute to disease development. To test the hypothesis that besides an enhanced gastrointestinal synthesis a diminished alcohol elimination through alcohol dehydrogenase (ADH) may also be critical herein, we determined fasting ethanol levels and ADH activity in livers and blood of MASLD patients and in wild-type ± anti-TNFα antibody (infliximab) treated and TNFα-/- mice fed a MASLD-inducing diet. Blood ethanol levels were significantly higher in patients and wild-type mice with MASLD while relative ADH activity in blood and liver tissue was significantly lower compared to controls. Both alterations were significantly attenuated in MASLD diet-fed TNFα-/- mice and wild-type mice treated with infliximab. Moreover, alcohol elimination was significantly impaired in mice with MASLD. In in vitro models, TNFα but not IL-1β or IL-6 significantly decreased ADH activity. Our data suggest that elevated ethanol levels in MASLD patients are related to TNFα-dependent impairments of ADH activity.

Fructose: a modulator of intestinal barrier function and hepatic health?

PURPOSE

Consumption of fructose has repeatedly been discussed to be a key factor in the development of health disturbances such as hypertension, diabetes type 2, and non-alcoholic fatty liver disease. Despite intense research efforts, the question if and how high dietary fructose intake interferes with human health has not yet been fully answered.

RESULTS

Studies suggest that besides its insulin-independent metabolism dietary fructose may also impact intestinal homeostasis and barrier function. Indeed, it has been suggested by the results of human and animal as well as in vitro studies that fructose enriched diets may alter intestinal microbiota composition. Furthermore, studies have also shown that both acute and chronic intake of fructose may lead to an increased formation of nitric oxide and a loss of tight junction proteins in small intestinal tissue. These alterations have been related to an increased translocation of pathogen-associated molecular patterns (PAMPs) like bacterial endotoxin and an induction of dependent signaling cascades in the liver but also other tissues.

CONCLUSION

In the present narrative review, results of studies assessing the effects of fructose on intestinal barrier function and their impact on the development of health disturbances with a particular focus on the liver are summarized and discussed.

TNFα is a key trigger of inflammation in diet-induced non-obese MASLD in mice

Tumor necrosis factor alpha (TNFα) is thought to be a critical factor in the development of metabolic dysfunction-associated steatotic liver disease (MASLD). Here, we determined the effects of a treatment with the anti-TNFα antibody infliximab and a genetic deletion of TNFα, respectively, in the development of non-obese diet-induced early metabolic dysfunction-associated steatohepatitis (MASH) in mice. The treatment with infliximab improved markers of liver damage in mice with pre-existing early MASH. In TNFα-/- mice, the development of early signs of MASH and insulin resistance was significantly attenuated compared to wild-type animals. While mRNA expression of proinflammatory cytokines like interleukin 1β (Il1b) and interleukin 6 (Il6) were significantly lower in livers of MASH-diet-fed TNFα-/- mice compared to wild-type mice with early MASH, markers of intestinal barrier function were similarly impaired in both MASH-diet-fed groups compared to controls. Our data suggest that TNFα is a key regulator of hepatic inflammation and insulin resistance associated with the development of early non-obese MASH.

A Xanthohumol-Rich Hop Extract Diminishes Endotoxin-Induced Activation of TLR4 Signaling in Human Peripheral Blood Mononuclear Cells: A Study in Healthy Women

Infections with Gram-negative bacteria are still among the leading causes of infection-related deaths. Several studies suggest that the chalcone xanthohumol (XN) found in hop (Humulus lupulus) possesses anti-inflammatory effects. In a single-blinded, placebo controlled randomized cross-over design study we assessed if the oral intake of a single low dose of 0.125 mg of a XN derived through a XN-rich hop extract (75% XN) affects lipopolysaccharide (LPS)-induced immune responses in peripheral blood mononuclear cells (PBMCs) ex vivo in normal weight healthy women (n = 9) (clinicaltrials.gov: NCT04847193) and determined associated molecular mechanisms. LPS-stimulation of PBMCs isolated from participants 1 h after the intake of the placebo for 2 h resulted in a significant induction of pro-inflammatory cytokine release which was significantly attenuated when participants had consumed XN. The XN-dependent attenuation of proinflammatory cytokine release was less pronounced 6 h after the LPS stimulation while the release of sCD14 was significantly reduced at this timepoint. The LPS-dependent activation of hTLR4 transfected HEK293 cells was significantly and dose-dependently suppressed by the XN-rich hop extract which was attenuated when cells were co-challenged with sCD14. Taken together, our results suggest even a one-time intake of low doses of XN consumed in a XN-rich hop extract can suppress LPS-dependent stimulation of PBMCs and that this is related to the interaction of the hop compound with the CD14/TLR4 signaling cascade.

GW9662, a peroxisome proliferator-activated receptor gamma antagonist, attenuates the development of non-alcoholic fatty liver disease

BACKGROUND AND AIMS

Insulin resistance is among the key risk factors for the development of non-alcoholic fatty liver disease (NAFLD). Recently, it has been reported that GW9662, shown to be a potent peroxisome proliferator-activated receptor gamma (PPARγ) antagonist, may improve insulin sensitivity in settings of type 2 diabetes. Here, we determined the effects of GW9662 on the development of NAFLD and molecular mechanisms involved.

METHODS

Female C57BL/6J mice were pair-fed either a liquid control diet (C) or a fat-, fructose- and cholesterol-rich diet (FFC) for 8 weeks while either being treated with GW9662 (1 mg/kg body weight; C+GW9662 and FFC+GW9662) or vehicle (C and FFC) i.p. three times weekly. Indices of liver damage and inflammation, parameters of glucose metabolism and portal endotoxin levels were determined. Lipopolysaccharide (LPS)-challenged J774A.1 cells were treated with 10 μM GW9662.

RESULTS

Despite similar caloric intake the development of NAFLD and insulin resistance were significantly attenuated in FFC+GW9662-treated mice when compared to FFC-fed animals. Bacterial endotoxin levels in portal plasma were almost similarly increased in both FFC-fed groups while expressions of toll-like receptor 4 (Tlr4), myeloid differentiation primary response 88 (Myd88) and interleukin 1 beta (Il1b) as well as nitrite (NO₂^-) concentration in liver were significantly higher in FFC-fed mice than in FFC+GW9662-treated animals. In J774A.1 cells, treatment with GW9662 significantly attenuated LPS-induced expression of Il1b, interleukin 6 (Il6) and inducible nitric oxide synthase (iNos) as well as NO₂^- formation.

CONCLUSION

In summary, our data suggest that the PPARγ antagonist GW9662 attenuates the development of a diet-induced NAFLD and that this is associated with a protection against the activation of the TLR4 signaling cascade.

Midbody-Localized Aquaporin Mediates Intercellular Lumen Expansion During Early Cleavage of an Invasive Freshwater Bivalve

Intercellular lumen formation is a crucial aspect of animal development and physiology that involves a complex interplay between the molecular and physical properties of the constituent cells. Embryos of the invasive freshwater mussel Dreissena rostriformis are ideal models for studying this process due to the large intercellular cavities that readily form during blastomere cleavage. Using this system, we show that recruitment of the transmembrane water channel protein aquaporin exclusively to the midbody of intercellular cytokinetic bridges is critical for lumenogenesis. The positioning of aquaporin-positive midbodies thereby influences the direction of cleavage cavity expansion. Notably, disrupting cytokinetic bridge microtubules impairs not only lumenogenesis but also cellular osmoregulation. Our findings reveal a simple mechanism that provides tight spatial and temporal control over the formation of luminal structures and likely plays an important role in water homeostasis during early cleavage stages of a freshwater invertebrate species.

Teachers’ emotional well-being during the SARS-CoV-2 pandemic with long school closures: A large-scale cross-sectional survey in Northern Italy

Objectives

This study aimed to evaluate the magnitude of emotional burden on teaching staff during the SARS-CoV-2 pandemic in a significantly impacted region. In addition, the correlates of emotional burden were analysed to enable the design of targeted interventions.

Study design

This study was a cross-sectional survey.

Methods

An electronic survey was administered to the teaching staff at public schools and kindergartens in a specific geographical area. Cross-sectional assessments of pandemic-specific variables were performed using the Pandemic Fatigue Scale, the Depression Anxiety Stress Scale (DASS)-21, the Satisfaction with Life Scale, and the Resilient Coping Scale. DASS-21 results were compared with results from a parallel survey that was representative of the local general population.

Results

In total, 3251 teaching staff members participated in the survey. Teachers showed a higher emotional burden for depression, anxiety and stress than the general population during the pandemic. According to a linear regression model, this burden is correlated with the language in which the questionnaires were answered, mistrust towards institutions, specific SARS-CoV-2 anxiety, past infection with SARS-CoV-2, avoidance of information about the pandemic and pandemic fatigue; emotional burden was negatively correlated with measures for life satisfaction, resilience and team atmosphere. Some independent variables were shown to contribute differentially to the variance of depression, anxiety or stress.

Conclusions

Emotional distress during the pandemic among teachers is higher than in the general population and correlates with variables that could, at least in principle, be targeted for specific interventions.

Understanding frameworking for smart and sustainable city development: A configurational approach

In recent decades, frameworks combining rankings and indices for smart and sustainable city development have proliferated. Stakeholders respond to them in various ways for strategizing towards urban sustainability. We refer to this as frameworking, which we identify as focusing on how frameworks are commensurated. However, research on commensuration has concentrated mostly on reactivity towards metrics. Little is known about how stakeholders contemplate the quality of and reaction to rankings and indices. We examine this issue through a configurational analysis of a set of European cities that consistently appear in these frameworks. We unveil several configurations of smart city metrics that relate to sustainability. Based on these effects, we theorize frameworking as differences in the relative configurations of smart city metrics that can generate performance. These configurations relate to three underlying dimensions: smart city capability, reactivity and context. We show that when frameworking is studied configurationally, we can identify the previously under-researched response to the quality of indices and reactivity to metrics. Finally, we discuss the theoretical and practical implications of a complex account of frameworks relevant to boosting urban sustainability.

Markers of Intestinal Permeability Are Rapidly Improved by Alcohol Withdrawal in Patients with Alcohol-Related Liver Disease

Changes in intestinal microbiome and barrier function are critical in the development of alcohol-related liver disease (ALD). Here, we determined the effects of a one-week alcohol withdrawal on parameters of intestinal barrier function in heavy drinkers with ALD in comparison to healthy non-drinkers (controls). In serum samples of 17 controls (m = 10/f = 7) and 37 age-matched ALD patients (m = 26/f = 11) undergoing a one-week alcohol withdrawal, markers of liver health and intestinal barrier function were assessed. Liver damage, e.g., fibrosis and hepatic steatosis, were assessed using FibroScan. Before alcohol withdrawal, markers of liver damage, lipopolysaccharide binding protein (LBP) and overall TLR4/TLR2 ligands in serum were significantly higher in ALD patients than in controls, whereas intestinal fatty acid binding protein (I-FABP) and zonulin protein concentrations in serum were lower. All parameters, with the exception of LBP, were significantly improved after alcohol withdrawal; however, not to the level of controls. Our data suggest that one-week of abstinence improves markers of intestinal barrier function and liver health in ALD patients.

Long-term results and comparison of the Green-Anderson and multiplier growth prediction methods after permanent epiphysiodesis using Canale's technique

PURPOSE

The aim of the study was to evaluate the accuracy and radiographic outcomes of Canale's method in patients with idiopathic leg-length discrepancy (LLD) following percutaneous epiphysiodesis. The accuracy of two common growth prediction methods was assessed.

METHODS

A total of 18 patients with 26 affected bones (eight distal femur, two proximal tibia, five combined) were clinically and radiologically analyzed after reaching skeletal maturity. We compared the final effect of epiphysiodesis at maturity with the expected effect of epiphysiodesis before surgery; these measures were calculated using the Green-Anderson and multiplier methods, respectively. We furthermore compared pre- and postoperative frontal and lateral plane radiographs.

RESULTS

The average LLD was 21.2 mm before surgery and 7.9 mm after epiphysiodesis. The final effect of both methods was not significantly different compared with the expected effect of epiphysiodesis before surgery. However, the prediction by the Green-Anderson method was closer to the definitive epiphysiodesis effect. The frontal plane radiographic deformity parameters did not change significantly after epiphysiodesis. The postoperative sagittal plane radiographic deformity parameters were in the normal range.

CONCLUSION

The Canale technique is a reliable method to reduce LLD in children. With regards to growth prediction, the Green-Anderson method using bone age seems to be more accurate than the multiplier method using chronological age. However, a relative over-estimation was observed with both methods in several cases, which might result in an insufficient correction.

LEVEL OF EVIDENCE

IV, Therapeutic study.

Impact of proximal radiopaque coronary bypass graft markers on postbypass surgery coronary angiography

BACKGROUND

Implantation of radiopaque bypass graft markers during coronary artery bypass surgery (CABG) has the potential of facilitating subsequent coronary angiography. This study sought to investigate the impact of proximal coronary bypass graft markers on angiographic outcomes during subsequent coronary angiography in a large cohort.

METHODS AND RESULTS

Between 2005 and 2016, we enrolled 1378 patients (331 with and 1047 without bypass graft markers) with a history of CABG who underwent their first subsequent coronary angiography at our institution. Primary endpoints were radiation time and absolute amount of contrast media used. In unadjusted analyses, radiation time, duration of angiography, dose area product, and the amount of contrast agent were significantly lower in patients with proximal bypass graft markers (P < .001). After full adjustment, proximal coronary bypass graft markers remained a significant predictor for less radiation time and a lower consumption of contrast agent but not for dose area product, which was mainly associated with body mass index and sex. Bypass graft markers were not associated with a lower graft patency.

CONCLUSIONS

Radiopaque coronary bypass graft markers can improve the detection of bypass grafts during subsequent coronary angiography and are associated with a lower radiation time and less consumption of contrast agent. Thus, this easy and cost-efficient technique might significantly reduce the risk of coronary angiography after CABG.

Endpoint comparison for bone mineral density measurements in North Central Cancer Treatment Group cancer clinical trials N02C1 and N03CC (Alliance)

Bone mineral density (BMD) measurement can vary depending upon anatomical site, machine, and normative values used. This analysis compared different BMD endpoints in two clinical trials. Trial results differed across endpoints. Future clinical trials should consider inclusion of multiple endpoints in sensitivity analysis to ensure sound overall study conclusions.

INTRODUCTION

Methodological issues hamper efficacy assessment of osteoporosis prevention agents in cancer survivors. Osteoporosis diagnosis can vary depending upon which bone mineral density (BMD) anatomical site and machine is used and which set of normative values are applied. This analysis compared different endpoints for osteoporosis treatment efficacy assessment in two clinical studies.

METHODS

Data from North Central Cancer Treatment Group phase III clinical trials N02C1 and N03CC (Alliance) were employed involving 774 patients each comparing two treatments for osteoporosis prevention. Endpoints for three anatomical sites included raw BMD score (RawBMD); raw machine-based, sample-standardized, and reference population-standardized T scores (RawT, TSamp, TRef); and standard normal percentile corresponding to the reference population-standardized T score (TPerc). For each, treatment arm comparison was carried out using three statistical tests using change and percentage change from baseline (CB, %CB) at 1 year.

RESULTS

Baseline correlations among endpoints ranged from 0.79 to 1.00. RawBMD and TPerc produced more statistically significant results (14 and 19 each out of 36 tests) compared to RawT (11/36), TSamp (8/36), and TRef (7/36). Spine produced the most statistically significant results (26/60) relative to femoral neck (20/60) and total hip (13/60). Lastly, CB resulted in 44 statistically significant results out of 90 tests, whereas %CB resulted in only 15 significant results.

CONCLUSIONS

Treatment comparisons and interpretations were different across endpoints and anatomical sites. Transforming via sample statistics provided similar results as transforming via reference or machine-based norms. However, RawBMD and TPerc may be more sensitive to change as clinical trial endpoints.

Mitochondrial DNA copy number - but not a mitochondrial tandem CC to TT transition - is increased in sun-exposed skin

Mitochondrial DNA (mtDNA) mutations are causatively associated with photo-ageing and are used as biomarkers of UV exposure. The most prominent mitochondrial mutation is the common deletion (CD), which is induced in many tissues by oxidative stress. More photo-specific mutations might be CC to TT tandem transitions which arise from UV-induced cyclobutane pyrimidine dimers. As nucleotide excision repair is absent in mitochondria, this DNA damage can presumably not be repaired resulting in high mitochondrial mutation levels. Here, we analysed levels of the CD, a mitochondrial and a chromosomal tandem transition in epidermis and dermis from exposed and less UV-exposed skin. We also analysed mtDNA copy number, for which changes as a result of oxidative stress have been described in different experimental settings. Whereas mitochondrial tandem transition levels were surprisingly low with no discernible correlation with UV exposure, mtDNA copy number and CD were significantly increased in UV-exposed samples.

The Stability and Structure of Complex Species Formed in Equilibrium Reactions of Diethyltin(IV) with N-D-Gluconylamino Acids in Aqueous Solution

Complex formation equilibria of diethyltin(IV) with five N-D-gluconylamino acids in aqueous solution (I = 0.1 M, NaClO4) were studied and the stabilities of the species were determined by potentiometric titrations. Diethyltin(IV) complexes of α-amino acid derivatives are water-soluble in the physiological pH range, while in the presence of N-D-gluconyl-β-alanine a precipitate is formed, which dissolves with increasing pH. 13C NMR measurements showed that in the N-D-gluconyl-α-amino acid complexes the ligand is coordinated through its deprotonated carboxylate oxygen, amide nitrogen and C(2)-hydroxy group, while for the soluble N-D-gluconyl-β-alanine complex the ligand is coordinated via the deprotonated carboxylate and C(3)-, C(4)-, C(5)-hydroxy groups. Mössbauer measurements reflected the geometry of the complexes formed.

Turbulence Visualization at the Terascale on Desktop PCs

Despite the ongoing efforts in turbulence research, the universal properties of the turbulence small-scale structure and the relationships between small- and large-scale turbulent motions are not yet fully understood. The visually guided exploration of turbulence features, including the interactive selection and simultaneous visualization of multiple features, can further progress our understanding of turbulence. Accomplishing this task for flow fields in which the full turbulence spectrum is well resolved is challenging on desktop computers. This is due to the extreme resolution of such fields, requiring memory and bandwidth capacities going beyond what is currently available. To overcome these limitations, we present a GPU system for feature-based turbulence visualization that works on a compressed flow field representation. We use a wavelet-based compression scheme including run-length and entropy encoding, which can be decoded on the GPU and embedded into brick-based volume ray-casting. This enables a drastic reduction of the data to be streamed from disk to GPU memory. Our system derives turbulence properties directly from the velocity gradient tensor, and it either renders these properties in turn or generates and renders scalar feature volumes. The quality and efficiency of the system is demonstrated in the visualization of two unsteady turbulence simulations, each comprising a spatio-temporal resolution of 10244. On a desktop computer, the system can visualize each time step in 5 seconds, and it achieves about three times this rate for the visualization of a scalar feature volume.

Abstract P2-14-10: Self Reported Cognitive Function in Breast Cancer Survivors: A 12 Month Longitudinal Descriptive Study

Background: Changes in cognitive function are commonly reported in breast cancer (BC) survivors. Longitudinal studies have only recently been completed and are few. In particular, long term studies are lacking. The purpose of this abstract is to describe self-reported cognitive changes in women before the start, or after the first cycle of chemotherapy, through 12 months.

Methods: The data for this analysis were collected as part of a placebo-controlled randomized trial evaluating ginkgo biloba for the prevention of cognitive decline during adjuvant chemotherapy for BC. As there was no evidence that gingko biloba impacted cognitive function in any way, the sample was combined. Descriptive statistics were calculated to obtain the percent of women reporting worse perceived functioning or changes in their cognitive function at the start of chemotherapy, at the completion of treatment, and at 6, 12 and 24 months later (24 month data still being analyzed). 210 women, mostly white and mostly beginning anthracycline based chemotherapy, completed self report measures of cognition throughout the study. Women rated 10 areas of functioning by choosing a number from 1, signifying “functioning extremely less than normal”, to 7, signifying “extremely better than normal”. A score of 4 represented functioning perceived as “normal” for the respondent. Results: At baseline and after chemotherapy, the means for all 10 self reported cognitive items indicated “less than normal” functioning. Areas with the worst functioning included memory, ability to think clearly, staying focused, and planning ahead. At 6 and 12 months after chemotherapy, a percentage of participants reported worse functioning compared to baseline in every area. Changes in functioning are in the table below.

Table 1

At 12 months, the mean for only 4 items indicated these areas were at “normal” functioning. These were the ability to learn, solve problems, react quickly and balance a checkbook.

Discussion: For a subgroup of women, cognitive changes continue to worsen throughout 12 months and for many, perceived deficits remain.

Areas most negatively impacted relate to attention, memory and executive function. Future research should focus on identifying predictors of worse functioning and continued research is needed to elucidate targets for intervention research to prevent unwanted cognitive changes.

A modified fluorimetric host cell reactivation assay to determine the repair capacity of primary keratinocytes, melanocytes and fibroblasts

BACKGROUND

The Host Cell Reactivation Assay (HCRA) is widely used to identify circumstances and substances affecting the repair capacity of cells, however, it is restricted by the transfection procedure used and the sensitivity of the detection method. Primary skin cells are particularly difficult to transfect, and therefore sensitive methods are needed to detect any variations due to the cell-type or inter-individual differences or changes induced by diverse substances.A sensitive and repeatable method to detect the repair capacity of skin cells would be useful in two different aspects: On the one hand, to identify substances influencing the repair capacity in a positive manner (these substances could be promising ingredients for cosmetic products) and on the other hand, to exclude the negative effects of substances on the repair capacity (this could serve as one step further towards replacing or at least reducing animal testing).

RESULTS

In this paper, we present a rapid and sensitive assay to determine the repair capacity of primary keratinocytes, melanocytes and fibroblasts based on two wave-length Green Fluorescent Protein (GFP) and DsRed reporter technology in order to test different substances and their potential to influence the DNA repair capacity. For the detection of plasmid restoration, we used FACS technology, which, in comparison to luminometer technology, is highly sensitive and allows single cell based analysis.The usefulness of this assay and studying the repair capacity is demonstrated by the evidence that DNA repair is repressed by Cyclosporin A in fibroblasts.

CONCLUSIONS

The methodology described in this paper determines the DNA repair capacity in different types of human skin cells. The described transfection protocol is suitable for the transfection of melanocytes, keratinocytes and fibroblasts, reaching efficacies suitable for the detection of the restored plasmids by FACS technology. Therefore the repair capacity of different cell types can be compared with each other. The described assay is also highly flexible, and the activity of other repair mechanisms can be determined using modifications of this method.

BAL27862: A Unique Microtubule Destabilizer Active Against Chemorefractory Breast Cancers

Background: BAL27862, a novel, synthetic, small molecule, is a potent inhibitor of tubulin polymerization that induces cancer cell death. BAL27862 elicits a unique microtubule (MT) phenotype, distinct from paclitaxel, vinblastine and colchicine, has broad in vitro anti-proliferative activity against a diverse range of human tumor lines (low nM IC50s) and induces significant antitumor responses in a range of animal models of human cancer when administered orally (p.o.) or intravenously (i.v.). In this study, BAL27862 activity in a panel of experimental breast cancer models was assessed.Materials and Methods: Anti-proliferative activity was analyzed using a monolayer (crystal violet) or soft agar (clonogenic) assay. Effects on MT phenotypes were assessed by immunofluorescence for α-tubulin. Efficacy was assessed in mouse xenograft models bearing chemosensitive and multidrug resistant human breast tumors.Results: The unique BAL27862-associated MT phenotype in interphase cells consisted of a partially collapsed MT network without peripheral MTs. In dividing cells, tiny MT asters were found scattered within the nuclear region. Potent anti-proliferative activity was demonstrated against 8 breast cancer cell lines (crystal violet assay IC50 range: 6.5 – 22 nM for the SKBR3, MCF7, BT474, T47D, BT549, MDA-MB231, MDA-MB453 and MDA-MB468 lines), although one line (HCC1937) appeared relatively insensitive (IC50: &gt;1000 nM). Interestingly, two breast cancer lines were sensitive to BAL27862 treatment in a clonogenic assay (IC50/IC70: MAXF 401 = 13/18 nM; MAXF MX1 = 22/46 nM), despite one being relatively resistant to paclitaxel treatment (MAXF 401 = 11/48 nM; MAXF MX1 = 127/&gt;3500 nM). Moreover, using monolayer assays, BAL27862 activity was retained against five tumor lines overexpressing the Pgp efflux pump (including MT-3/ADR mammary adenocarcinoma cells), which were up to several thousand-fold resistant to paclitaxel and vinblastine. BAL27862 showed little activity against human stem cells or peripheral blood mononucleocytes.When administered p.o or i.v. to mice at well tolerated doses, BAL27862 treatment elicited statistically significant antitumor activity (p≤0.05) in three chemosensitive human breast tumor xenograft models (including MAXF 401, MaCa 4049 and MT-3); resulting in a final %T/C (ratio of mean tumor volume of treated and control group x 100) equivalent to that observed with comparator cytotoxics using MTD schedules (e.g. final %T/C in MT-3 model: 36% BAL27862, 35% paclitaxel, 50% doxorubicin). Strikingly, significant antitumor activity was maintained in the Pgp-overexpressing MT-3/ADR xenograft model, where paclitaxel and doxorubicin were ineffective (final %T/C: 37% BAL27862, 112% paclitaxel, 108% doxorubicin).Conclusions: BAL27862 is a new tubulin-interacting agent with an apparently novel mechanism of action. A potent antitumor activity in experimental models of breast cancer, including chemorefractory models, strongly support further development of BAL27862 as a novel breast cancer treatment modality with a possibility for both i.v. and p.o. administration.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2093.

The pilot European Alzheimer's Disease Neuroimaging Initiative of the European Alzheimer's Disease Consortium

BACKGROUND

In North America, the Alzheimer's Disease Neuroimaging Initiative (ADNI) has established a platform to track the brain changes of Alzheimer's disease. A pilot study has been carried out in Europe to test the feasibility of the adoption of the ADNI platform (pilot E-ADNI).

METHODS

Seven academic sites of the European Alzheimer's Disease Consortium (EADC) enrolled 19 patients with mild cognitive impairment (MCI), 22 with AD, and 18 older healthy persons by using the ADNI clinical and neuropsychological battery. ADNI compliant magnetic resonance imaging (MRI) scans, cerebrospinal fluid, and blood samples were shipped to central repositories. Medial temporal atrophy (MTA) and white matter hyperintensities (WMH) were assessed by a single rater by using visual rating scales.

RESULTS

Recruitment rate was 3.5 subjects per month per site. The cognitive, behavioral, and neuropsychological features of the European subjects were very similar to their U.S. counterparts. Three-dimensional T1-weighted MRI sequences were successfully performed on all subjects, and cerebrospinal fluid samples were obtained from 77%, 68%, and 83% of AD patients, MCI patients, and controls, respectively. Mean MTA score showed a significant increase from controls (left, right: 0.4, 0.3) to MCI patients (0.9, 0.8) to AD patients (2.3, 2.0), whereas mean WMH score did not differ among the three diagnostic groups (between 0.7 and 0.9). The distribution of both MRI markers was comparable to matched US-ADNI subjects.

CONCLUSIONS

Academic EADC centers can adopt the ADNI platform to enroll MCI and AD patients and older controls with global cognitive and structural imaging features remarkably similar to those of the US-ADNI.

A UVB fingerprint mutation on the p53 tumor suppressor gene decreases in vitro

The culture of tissue-derived human cells is an important aspect of tissue engineering. Prior to transplantation, the quality of the cultured cells/tissue should be routinely tested so that any enrichment of procarcinogenic cells can be excluded. On this account, a UVB-induced p53 fingerprint mutation would be a valuable quality control marker for skin cells cultured for use in tissue engineering. We developed an allele-specific real-time polymerase chain reaction assay based on SYBR Green which can quantitatively detect CC-TT transitions in the tumor suppressor gene p53. To analyze the transition 281/282, we used DNA from HaCaT cells, a keratinocyte cell line containing the investigated mutation, as a standard to determine the mutation frequency in cultured cutaneous cells. We analyzed a variety of skin cells grown in culture and found a notable decrease in the UVB fingerprint mutation in fibroblasts during proliferation. Furthermore, we quantified the total amount of mutated DNA in different cutaneous cells and detected a significantly higher level in melanocytes. These results are consistent with findings obtained in our laboratory concerning the common deletion, the most frequently reported mutation in the mitochondrial genome, which suggest a positive influence of prolonged in vitro cell proliferation on the quality of genomic DNA.

The influence of folic acid depletion on the Nucleotide Excision Repair capacity of human dermal fibroblasts measured by a modified Host Cell Reactivation Assay

Animal and human studies have shown that low levels of folic acid are associated with an impaired DNA Repair Capacity (DRC) and an increased cancer risk. However, the molecular evidence that folic acid enhances the DRC of cultured human cells is still limited because of a paucity of in vitro studies. We investigated the effect of folic acid depletion in vitro on the DRC of human dermal fibroblasts derived from 17 donors of different ages. To assess the cellular Nucleotide Excision DRC, we used a modified Host Cell-Reactivation Assay (HCRA), adapted to the Fluorescence Activated Cell Sorting (FACS)-technology, which is highly sensitive in comparison to luminometer-technology and allows single cell based analysis. We used DsRed as a reporter (irradiated with UVC light) and pEGFP to control the performance of the transformations. Folic acid had a statistically significant effect on the DRC in all of the 17 donors, however, the levels varied considerably between individuals (2.0-19.6%). When the effect of folic acid substituted on the DRC was compared to donor age, we observed that there was less DNA repair in old donors compared to the younger donors, although this was only significant at lower levels.

Domino reactions with fluorinated five-membered heterocycles. α-Trifluoromethyl α-amino acids with unsaturated side-chains

Alpha-trifluoromethyl alpha-amino acids with unsaturated side-chains have been prepared from 5-fluoro-4-trifluoromethyloxazole and allyl, propargyl as well as terpene alcohols in a one-pot procedure.

Synthesis of α-trifluoromethyl α-amino acids with aromatic, heteroaromatic and ferrocenyl subunits in the side chain

5-Benzyloxy-4-trifluoromethyl-1,3-oxazoles, obtained from 5-fluoro-4-trifluoromethyloxazoles and benzyl alcohols, are capable for rearrangements. A 1,3 shift of a benzyl group is the key step of a new general route toward alpha-trifluoromethyl substituted aromatic and heteroaromatic amino acids, demonstrating that 5-fluoro-4-trifluoromethyl-1,3-oxazole is a synthetic Tfm-Gly equivalent. On reaction with benzpinacol partially fluorinated oxazoles are transformed into bis(trifluoromethyl) substituted 2,5-diamino adipic acid and N-benzoyl-2-benzhydryl-3,3,3-trifluoroalanine.

Abbreviated nomenclature for cyclic and branched homo- and hetero-detic peptides

Amino acid sequences and linear or head-to-tail cyclopeptides can be represented conveniently in one-line text formulae using the three-letter symbols. However, other - but nonetheless important - topologies of peptides are 'side chain-to-head (or tail)', 'backbone-to-backbone', 'side chain-to-side chain' cyclopeptides, 'side chain-to-side chain' connected peptide strands, and branched peptides (like peptide dendrimers). In general, such structures cannot be described using the three-letter symbols in one-line text: a chemical structure editor is required for symbolic representations according to the IUPAC-IUBMB recommendations. The aim of this contribution is to offer an unambiguous and general nomenclature system that enables researchers to represent all cyclic and branched homo- and hetero-detic peptides in a coherent manner in one-line text - as long as their as constituents can be represented in (three)-letter codes. The application of this new nomenclature would overcome the existing difficulties and provide a way to express complex situations in the shortest way in order to highlight more clearly the salient points in a given scientific communication.

Hexafluoroacetone as protecting and activating reagent: Site-selective functionalization of iminodiacetic acid

Hexafluoroacetone was applied as a bidentate protecting and activating agent for the syntheses of RGD-peptide mimetics starting from iminodiacetic acid in solution and on solid phase.

Clinical decision-making in hypertension using an automated (BpTRU) measurement device

Mercury sphygmomanometers are being removed from clinical practice in the United States due to environmental concerns about mercury toxicity. Accurate blood pressure measurement is central to high-quality hypertension management. In this study of 106 patients, the BpTRU(TM) device was compared to nurse blood pressure measurements that complied with all the JNC VII/American Heart Association guidelines in evaluation of a random casual blood pressure. The intermethod difference in systolic blood pressure was +1.8+/-5.1 mmHg, and for diastolic blood pressure it was 4.8+/-5.1 mmHg (both P<0.001). For the primary study end point of clinical decision-making, there was 92% (97/106) agreement between the hypertension nurse specialist and the BpTRU (kappa 0.8280, 95% confidence interval, 0.721-0.9350). The oscillometric blood pressure measurement with the BpTRU is recommended as a replacement for poorly performed auscultatory blood pressure measurement in clinical practice.

Solvation phenomena of a tetrapeptide in water/trifluoroethanol and water/ethanol mixtures: a diffusion NMR, intermolecular NOE, and molecular dynamics study

Solvation of a tetrapeptide, NAc-Ser-Phe-Val-Gly-OMe (1), in water and in water/alcohol mixtures with 2,2,2-trifluoroethanol (TFE)/water or ethanol (ETH)/water has been studied by diffusion NMR and intermolecular NOE measurements. The experimental results were compared with those obtained from detailed Molecular Dynamics (MD) calculations. Independently, all three methods revealed preferential solvation on the surface of the peptide by TFE in the water/TFE mixtures, but not by ETH in the water/ETH mixtures. The MD calculations show that the TFE concentration coating the peptide is higher than that in the bulk, while for ethanol, the concentration is nearly equal to that in the bulk. Calculated site-specific preferential solvation data between TFE, ETH, and water with the different peptide groups have been compared with the NMR data and shown to be in general agreement with the experimental facts.

Evidence of complete hydrophobic coating of bombesin by trifluoroethanol in aqueous solution: an NMR spectroscopic and molecular dynamics study

Bombesin is a tetradecapeptide that possesses a random coil structure in pure water. In the presence of 30 % (v/v) 2,2,2-trifluoroethanol (TFE), it adopts a partial helical conformation involving the C-terminal amino acids 6-14. This conformational change, known as the TFE effect, is studied here in terms of the solvation state of the peptide at different TFE concentrations by means of intermolecular homo- and heteronuclear NOE measurements. When an aqueous solution of bombesin is titrated with TFE, a continual decrease in the water/peptide interactions and a concomitant increase in the TFE/peptide interactions is observed, and at 30 % (v/v) TFE no homonuclear NOEs between water and the peptide can be detected. The conformational transition of the bombesin molecule is thus accompanied by a complete surface covering with TFE. A parallel molecular dynamics (MD) study of the peptide in aqueous solution with the single-point charge (SPC) water model and in a 30 % (v/v) TFE/water mixture with a recently developed TFE model has also been performed. The 10 ns simulations were in agreement with the experimental data. The calculations indicate stabilisation of the alpha-helix in the H(2)O/TFE mixture, in contrast to the situation in pure water, and clustering of the TFE molecules around the peptide.

Subcellular localization of the human proto-oncogene protein DEK

Recent data revealed that DEK associates with splicing complexes through interactions mediated by serine/arginine-repeat proteins. However, the DEK protein has also been shown to change the topology of DNA in chromatin in vitro. This could indicate that the DEK protein resides on cellular chromatin. To investigate the in vivo localization of DEK, we performed cell fractionation studies, immunolabeling, and micrococcal nuclease digestion analysis. Most of the DEK protein was found to be released by DNase treatment of nuclei, and only a small amount by treatment with RNase. Furthermore, micrococcal nuclease digestion of nuclei followed by glycerol gradient sedimentation revealed that DEK co-sedimentates with oligonucleosomes, clearly demonstrating that DEK is associated with chromatin in vivo. Additional chromatin fractionation studies, based on the different accessibilities to micrococcal nuclease, showed that DEK is associated both with extended, genetically active and more densely organized, inactive chromatin. We found no significant change in the amount and localization of DEK in cells that synchronously traversed the cell cycle. In summary these data demonstrate that the major portion of DEK is associated with chromatin in vivo and suggest that it might play a role in chromatin architecture.

Metal ion coordination of macromolecular bioligands: formation of zinc(II) complex of hyaluronic acid

The coordination of zinc(II) ion to hyaluronate (Hya), a natural copolymer, in aqueous solution at pH 6 was investigated by potentiometric and circular dichroism (CD) spectroscopic methods, and by monitoring the changes in macroscopic properties by high-precision measurements. The zinc(II)-selective electrode, and CD measurements proved the binding of zinc(II) by Hya. A number of Hya fragments (Mr approximately 3.3 x 10(3)-1.4 x 10(6)) were studied to estimate the contributions of the polyelectrolyte effect, the solvation and host-guest interactions to the extra stabilization of the macromolecular zinc(II) complexes as compared with the monomeric unit. The zinc(II) ion activity increase reflected a stability decrease for the fragments with Mr < 4 x 10(4). This molecular weight differs from that where cleavage of the Hya skeleton starts (approximately 5 x 10(5), according to the size-exclusion gel, and anion-exchange chromatographic behavior of the Hya fragments) and from that where the polyelectrolyte effect stops (approximately 6 x 10(3)). The excess volumes and Bingham shear yield values of the solutions revealed the transformation of the coherent random coil structure stabilized by intermolecular association in the NaHya to an intramolecular association producing the globular structure of the ZnHya molecule, with a smaller but more strongly bound solvate water sheet.

First synthesis of totally orthogonal protected alpha-(trifluoromethyl)- and alpha-(difluoromethyl)arginines

The first synthesis of a series of totally orthogonal protected racemic alpha-(trifluoromethyl)- and alpha-(difluoromethyl)arginines is described. The key steps of the synthesis are the mild guanidinylation procedure and the selective hydrogenation of a CC triple bond in the presence of a Cbz-group.

Regulation of receptor function by cholesterol

Cholesterol influences many of the biophysical properties of membranes and is nonrandomly distributed between cellular organelles, subdomains of membranes, and leaflets of the membrane bilayer. In combination with the high dynamics of cholesterol distribution, this offers many possibilities for regulation of membrane-embedded receptors. Depending on the receptor, cholesterol can have a strong influence on the affinity state, on the binding capacity, and on signal transduction. Most important, cholesterol may stabilize receptors in defined conformations related to their biological functions. This may occur by direct molecular interaction between cholesterol and receptors. In this review, we discuss the functional dependence of the nicotinic acetylcholine receptor as well as different G protein-coupled receptors on the presence of cholesterol.