"Uninformed consent" in clinical trials with cancer patients: A qualitative analysis of patients' and support persons' communication experiences and needs

OBJECTIVE

Cancer patients are often overwhelmed when being informed about clinical trials. However, there is a lack of evidence-based strategies to improve physician-patient communication in this area. This study assessed the experiences and needs of cancer patients and their support persons (SPs) during the informed consent (IC) process prior to participation in clinical trials.

METHODS

17 semi-structured interviews with cancer patients and their SP were conducted and analysed using a framework analysis.

RESULTS

Most respondents reported feeling well informed about the clinical trial. However, core aspects of the study were often not understood highlighting a dissonance between perceived and actual recall and understanding. Many participants trusted that the trial recommended was the best available care and only skimmed the consent form or did not read it at all.

CONCLUSIONS

This is the first German study to analyse both cancer patients' and SPs' perspectives on IC processes. Although many feel well informed, our results suggest a significant gap in recall and understanding of core components of clinical trials which hinders IC.

PRACTICE IMPLICATIONS

Further interventional research is required to improve the consent processes prior to clinical trials in order to provide optimal, patient-centred care.

Moderate differences in plasma leptin in mares have no effect on either the amino acid or the fatty acid composition of the uterine fluid

Female mammalian reproductive functions are closely linked to body condition and metabolic status. Energy homeostasis is regulated by endocrine hormones such as insulin, IGF-I, leptin and adiponectin via the hypothalamic-pituitary-adrenal axis. These metabolic hormones and their receptors are also expressed in reproductive tissues and the embryo. We investigated the relationship between circulating leptin and the fatty acid (FA) and amino acid (AA) composition of the equine uterine fluid (UF) and peripheral blood plasma (BP) by using a mass spectrometry-based approach. UF and BP were collected from ten broodmares on days 6 and 7 post ovulation, respectively. The mares were retrospectively assigned to two groups according to their BP leptin concentrations (high leptin (> 1.6 ng/ml) versus low leptin (<0.8 ng/ml)). Specific AA and FA compositions for BP and UF were found with different levels of respective metabolite abundances. The main FAs in BP were stearic, palmitic and linoleic acid. In UF, the three most abundant FAs were eicosapentaenoic, arachidonic and stearic acid. The AA profile of BP was dominated by glycine, glutamine, serine and alanine, which were likewise among the highly abundant AAs in UF. In UF, glutamic acid had by far the highest concentration. Therefore, BP leptin concentration within a physiological range do not seem to affect the specific FA nor the AA composition of the UF. The composition of the UF may therefore be mediated by local rather than by peripheral metabolic hormones.

Predictors and Barriers to Condom Use in the African Cohort Study

Consistent condom use is an inexpensive and efficacious HIV prevention strategy. Understanding factors associated with condom use and barriers to use can inform strategies to increase condom uptake. The ongoing African Cohort Study prospectively enrolls adults at 12 clinical sites in Uganda, Kenya, Tanzania, and Nigeria. At enrollment, participants are asked about condom use at last sex with a regular partner. Robust Poisson regression models were used to evaluate predictors of self-reported condom use. Participants who reported not using condoms were asked to provide reasons. From January 2013 to September 2019, 2482 participants reported having at least one regular sexual partner in the preceding 6 months. Of those, 1577 (63.5%) reported using a condom at last sex. Condom use was more common among older participants, males, HIV-infected participants, and those with an HIV-infected partner. Married participants, those with a partner of unknown HIV status, and those reporting alcohol use were less likely to report condom use at last sex. Condom use at last sex also varied significantly by clinical site. Partner disapproval or refusal to use a condom was a consistent driver of disparities in condom use among participants who were HIV infected, female, and aged 18-24 years. Effective HIV prevention programs should integrate condom education with the tools necessary to negotiate condom use with regular partners.

6 Decelerating embryo development? Characterisation of the uterine environment in European roe deer (Capreolus capreolus) during diapause

The early developing embryo faces a continuously changing microenvironment to supports its growth. In the European roe deer, this environment accompanies embryonic diapause, a period of up to 4 months in which fertilization and subsequent implantation are decoupled. Diapause is characterised by a deceleration of embryonic growth. In most ruminants such as cattle and sheep, interferon tau (IFNt) plays a major role in maternal recognition of pregnancy. Uniquely to ruminants, the roe deer embryo does not secrete IFNt. The roe deer was used as a model species to gain insights into the changing uterine environment devoid of IFNt that supports prolonged decelerated embryo development, resumption of developmental velocity, and subsequent implantation. Uterine fluid samples from 188 female does were collected during regular huntings between September and January, and 4 developmental stages-blastocysts at early, mid, and late diapause and elongated embryos (16, 57, 97, and 18 does per developmental stage, respectively)-were defined. The developmental stages were assigned based on morphological characteristics of the embryo and the embryonic genomic DNA content. For the analysis of amino acids (AA), all 188 uterine fluid samples were subjected to targeted liquid chromatography-tandem mass spectrometry. Almost all AA increased over the course of embryo development. Although most AA showed developmental stage-specific concentration peaks, serine, glycine, alanine, glutamate, and glutamine were most abundantly present irrespective of the developmental progression. For the analysis of the protein abundances in the uterine fluid in a selected subset of samples (n=5 per developmental stage), holistic liquid chromatography-tandem mass spectrometry identified and quantified a total of 819 proteins with a false discovery rate of &lt;1%. Comparison between the developmental stages revealed 106 differentially abundant proteins. Most changes in protein abundance that occurred related to embryo elongation. Interestingly, 713 proteins remained stable during embryo development, indicating that these proteins may contribute to prolonged embryo survival during embryonic diapause. The differentially abundant proteins were clustered with DAVID Bioinformatics Resources 6.8 (https://david.ncifcrf.gov/). The most enriched clusters were cell-cell adhesion, biosynthesis of AA and carbon metabolism, microtubule, structural molecule activity, and chaperone binding. The ongoing detailed identification of stably abundant proteins will advance our basic understanding of the embryos’ needs for sustained survival during prolonged decelerated development. In addition, a comparison with the protein abundances around the time of maternal recognition of pregnancy in other species could advance our knowledge on conserved proteins that support embryo development and establishment of pregnancy in mammals. Our findings may contribute to defining optimal in vitro embryo culture conditions in a species-independent manner and potentially identify factors capable of halting embryo development.

Hypothyroidism during second-line treatment of multidrug-resistant tuberculosis: a prospective study

SETTING

Hypothyroidism is an adverse effect of certain anti-tuberculosis drugs.

DESIGN

This is a prospective study of the frequency and possible pathomechanisms associated with hypothyroidism due to second-line treatment of multidrug-resistant tuberculosis. Fifty human immunodeficiency virus negative patients and 20 controls were included. All participants underwent ultrasonography of the thyroid and measurement of thyroid stimulating hormone (TSH). TSH levels were checked every 3 months. If hypothyroidism was present, T3, T4 and thyroid peroxidase autoantibodies were measured, and imaging extended to scintigraphy and repeated ultrasonography.

RESULTS

Before treatment, 7 patients (14%) and 1 control (5%) were hypothyreotic. During the first 6 months of treatment, TSH levels increased in 41 patients (82%), 39 (78%) had values above the normal range and 19 (38%) had overt hypothyroidism. As none of the patients had signs of autoimmune thyroiditis, interaction with anti-tuberculosis drugs was assumed to be the cause of hypothyroidism. Nine patients died during treatment, all of whom had developed hypothyroidism. In seven, the metabolic situation at their death was known, and they had become euthyreotic following levothyroxine substitution.

CONCLUSION

TSH levels should be checked before initiating anti-tuberculosis treatment and after 3 and 6 months to start timely replacement of levothyroxine. Further studies are needed to elucidate the exact pathomechanism involved in hypothyroidism and whether hypothyroidism can be used as predictor of treatment failure.

The Muon as a Tool for Scanning the Interior of the Human Body

A completely new technique for scanning the interior of the human body is proposed which is based on the following principle: muons from an accelerator pass through two spark chambers and are stopped in the body. The decay electrons leave the body and pass also two spark chambers. The trajectory co-ordinates read out from the spark chambers allow the determination of the point of decay with high precision. The truly three-dimensional picture obtained in this way is truly three-dimensionally displayed on a screen. Several modifications of the basic method are described, the most important ones being the simultaneous recording of the muonic X-rays (equivalent to a chemical analysis) or of the muon precession. The necessary dose is low. The most serious disadvantage is the need of a medium-energy accelerator. Quantitative figures on resolution, efficiency, and dose are given.

Informatics and Medicine

Objectives: To clarify challenges and research topics for informatics in health and to describe new approaches for interdisciplinary collaboration and education. Methods: Research challenges and possible solutions were elaborated by scientists of two universities using an interdisciplinary approach, in a series of meetings over several months. Results and Conclusion: In order to translate scientific results from bench to bedside and further into an evidence-based and efficient health system, intensive collaboration is needed between experts from medicine, biology, informatics, engineering, public health, as well as social and economic sciences. Research challenges can be attributed to four areas: bioinformatics and systems biology, biomedical engineering and informatics, health informatics and individual healthcare, and public health informatics. In order to bridge existing gaps between different disciplines and cultures, we suggest focusing on interdisciplinary education, taking an integrative approach and starting interdisciplinary practice at early stages of education.

* See more detailed authors´ affiliations at the end of the article.

Protective effects of soy-isoflavones in cardiovascular disease

Epidemiological studies indicate that the consumption of soy-containing food may prevent or slow-down the development of cardiovascular disease. In endothelial cells application of a soy extract or a combination of the most abundant soy isoflavones genistein and daidzein both inhibited apoptosis, a driving force in atherosclerosis development, when applied in combination with oxidized LDL or homocysteine. Proteome analysis revealed that the stressorinduced alteration of protein expression profile was reversed by the soy extract or the genistein/daidzein mixture. Only few protein entities that could be functionally linked to mitochondrial dysfunction were regulated in common by both application forms of isoflavones. A dietary intervention with isoflavone-enriched soy extract in postmenopausal women, who generally show strongly increased cardiovascular risk due to diminished estrogen production, led to significant alterations in the steady state levels of proteins from mononuclear blood cells. The proteins identified by proteome analysis revealed that soy isoflavones may increase the anti-inflammatory response in blood mononuclear cells thereby contributing to the atherosclerosispreventive activities of a soy-rich diet. Conclusion: By proteome analysis protein targets were identified in vitro in endothelial cells that respond to soy isoflavones and that may decipher molecular mechanisms through which soy products exert their protective effects in the vasculature.

Physical soil architectural traits are functionally linked to carbon decomposition and bacterial diversity

Aggregates play a key role in protecting soil organic carbon (SOC) from microbial decomposition. The objectives of this study were to investigate the influence of pore geometry on the organic carbon decomposition rate and bacterial diversity in both macro- (250–2000 μm) and micro-aggregates (53–250 μm) using field samples. Four sites of contrasting land use on Alfisols (i.e. native pasture, crop/pasture rotation, woodland) were investigated. 3D Pore geometry of the micro-aggregates and macro-aggregates were examined by X-ray computed tomography (μCT). The occluded particulate organic carbon (oPOC) of aggregates was measured by size and density fractionation methods. Micro-aggregates had 54% less μCT observed porosity but 64% more oPOC compared with macro-aggregates. In addition, the pore connectivity in micro-aggregates was lower than macro-aggregates. Despite both lower μCT observed porosity and pore connectivity in micro-aggregates, the organic carbon decomposition rate constant (Ksoc) was similar in both aggregate size ranges. Structural equation modelling showed a strong positive relationship of the concentration of oPOC with bacterial diversity in aggregates. We use these findings to propose a conceptual model that illustrates the dynamic links between substrate, bacterial diversity, and pore geometry that suggests a structural explanation for differences in bacterial diversity across aggregate sizes.

Associations between FTO genotype and total energy and macronutrient intake in adults: a systematic review and meta-analysis

Risk variants of fat mass and obesity-associated (FTO) gene have been associated with increased obesity. However, the evidence for associations between FTO genotype and macronutrient intake has not been reviewed systematically. Our aim was to evaluate the potential associations between FTO genotype and intakes of total energy, fat, carbohydrate and protein. We undertook a systematic literature search in OVID MEDLINE, Scopus, EMBASE and Cochrane of associations between macronutrient intake and FTO genotype in adults. Beta coefficients and confidence intervals (CIs) were used for per allele comparisons. Random-effect models assessed the pooled effect sizes. We identified 56 eligible studies reporting on 213,173 adults. For each copy of the FTO risk allele, individuals reported 6.46 kcal day(-1) (95% CI: 10.76, 2.16) lower total energy intake (P = 0.003). Total fat (P = 0.028) and protein (P = 0.006), but not carbohydrate intakes, were higher in those carrying the FTO risk allele. After adjustment for body weight, total energy intakes remained significantly lower in individuals with the FTO risk genotype (P = 0.028). The FTO risk allele is associated with a lower reported total energy intake and with altered patterns of macronutrient intake. Although significant, these differences are small and further research is needed to determine whether the associations are independent of dietary misreporting.

Well-differentiated neuroendocrine neoplasia: relapse-free survival and predictors of recurrence after curative intended resections

BACKGROUND

Resection with curative intention is the cornerstone of treatment in patients with neuroendocrine tumors. A proportion of patients will relapse after R0 resection, but the factors predictive of recurrence are not well understood.

METHODS

A database established 1998 at the University Hospital Marburg was queried for all patients with documented R0 resection. Recurrence-free survival and overall survival were estimated using the Kaplan-Meier method. Uni- and multivariate analyses were performed.

RESULTS

180 patients with a median age of 52 years entered the analysis. We observed 77 recurrences after a median time of 2.9 years. 24% of the recurrences occurred later than 5 years after operation. Median recurrence-free survival of the whole cohort was 101 months. In univariate analysis grade by Ki-67, stage, high lymph node ratio and microangioinvasion were significant predictors of recurrence. On multivariate analysis these parameters were confirmed as independent prognostic parameters with stage and microangioinvasion being the most important predictors.

CONCLUSIONS

After R0 resection of neuroendocrine tumors, postoperative surveillance should be extended to at least 10 years. Patients with distant metastases and microangioinvasion are at high risk of recurrence. Clinical trials of adjuvant treatment protocols are indicated in these patients.

Results of silicone oil injection into the vitreous

The long-therm follow-up of eyes after injection of silicone oil into the vitreous is reported.l The clinical findings, the results of the subjective examination of the retinal function as well as the ERG and the histological findings of the meanwhile enucleated eyes are very discouraging.

Transcriptome analysis of peripheral blood mononuclear cells in human subjects following a 36 h fast provides evidence of effects on genes regulating inflammation, apoptosis and energy metabolism

There is growing interest in the potential health benefits of diets that involve regular periods of fasting. While animal studies have provided compelling evidence that feeding patterns such as alternate-day fasting can increase longevity and reduce incidence of many chronic diseases, the evidence from human studies is much more limited and equivocal. Additionally, although several candidate processes have been proposed to contribute to the health benefits observed in animals, the precise molecular mechanisms responsible remain to be elucidated. The study described here examined the effects of an extended fast on gene transcript profiles in peripheral blood mononuclear cells from ten apparently healthy subjects, comparing transcript profiles after an overnight fast, sampled on four occasions at weekly intervals, with those observed on a single occasion after a further 24 h of fasting. Analysis of the overnight fasted data revealed marked inter-individual differences, some of which were associated with parameters such as gender and subject body mass. For example, a striking positive association between body mass index and the expression of genes regulated by type 1 interferon was observed. Relatively subtle changes were observed following the extended fast. Nonetheless, the pattern of changes was consistent with stimulation of fatty acid oxidation, alterations in cell cycling and apoptosis and decreased expression of key pro-inflammatory genes. Stimulation of fatty acid oxidation is an expected response, most likely in all tissues, to fasting. The other processes highlighted provide indications of potential mechanisms that could contribute to the putative beneficial effects of intermittent fasting in humans.

Zum Zerfall von Ga65

Der Zerfall von Ga65 (15,2 ± 0,2 min) wurde mit einem magnetischen Linsenspektrometer untersucht. Das β+-Kontinuum wurde in die folgenden Gruppen aufgelöst: (2,237 ± 0,015) MeV (15%); (2,113 ± 0,020) MeV (56%); (1,39 ± 0,04) MeV (19%) und (0,82 ± 0,08) MeV (10%). Eine Gruppe von 2,5 MeV wurde nicht gefunden (Intensität &lt; 0,2%).

Search for an Admixture of a 17 keV Neutrino in the β Decay of 35S

The β spectrum of a mass-separated thin 35S source has been measured with a small-volume Si photodiode. The energy-dependent response function of the total experimental set-up was calculated by the Monte Carlo method without any adjustable parameter. For an admixture of the hypothetical 17 keV neutrino, an upper limit of 0.59% (95% CL) was determined. Neglecting electron scattering on the spectrometer diaphragm was shown to generate a false 17 keV neutrino admixture of 0.3%.

Das kontinuierliche β -Spektrum des RaC

Das β-Kontinuum des RaC wurde mit einem magnetischen Doppellinsenspektrometer aufgenommen und in Gruppen von (3,26 ± 0,03) MeV (19%), (1,88 ± 0,08) MeV (9%), (1,51±0,05) MeV (40%), (1,02 ± 0,12) MeV (23%) und (0,42 ± 0,15) MeV (9%) zerlegt.

Carbon nanotube surface chemistry and its effects on interfacial nanomechanics

Individual multi-walled carbon nanotube pullout experiments were used to measure the adhesion strength at a nanotube-epoxy polymer interface. The interfacial strength was found, as expected, to increase when the nanotubes were chemically treated to induce strong bonding with the polymer matrix. At long nanotube embedment lengths within the polymer, the nanotubes were seen to fracture in preference to failure at their interface with the polymer. Interfacial mechanics models are applied to the data to describe interfacial adhesion at the nano-level.

Surface characteristics and wetting behavior of carbon nanotubes

The wetting properties and surface characteristics of individual carbon nanotubes are elucidated by immersing the nanotube into various organic liquid. The resultant force acting on the nanotube can be used to evaluate a liquid contact angle at the nanotube surface from classical methods. This technique was shown to be accurate enough to discern differences in wetting behavior due to both structural and chemical changes in the nanotube structure.

Functional expression of SLC15 peptide transporters in rat thyroid follicular cells

Peptide transport and expression of SoLute Carrier 15 (SLC15) peptide transporters was assessed in rat thyroid tissue and a rat thyroid cell line (PC Cl3 cells). Peptide transport was studied by monitoring the uptake of the fluorophore-conjugated dipeptide beta-Ala-Lys-N(epsilon)-7-amino-4-methyl-coumarin-3-acetic acid (Ala-Lys-AMCA). Expression of SLC15-specific mRNA transcripts was analyzed by RT-PCR. Of the two SLC15 transporters expressed in thyroid follicular cells, namely PEPT2 (SLC15A2) and PHT1 (SLC15A4), only PEPT2 was involved in peptide transport at the plasma membrane, with PHT1 most likely being intracellular. Interestingly, at the mRNA level PEPT2 was up-regulated under TSH stimulation. These findings represent the first evidence that peptide transport occurs in thyroid follicular cells. SLC15 transporters could participate to recycling of peptides derived from extracellular and lysosomal thyroglobulin proteolysis, both essential steps for thyroid hormone synthesis.

L-Proline transport into renal OK epithelial cells: a second renal proline transport system is induced by amino acid deprivation

Influx of [(3)H]-L-proline into renal OK cells revealed that basal transport was mediated by the transporter SIT1. When cells were submitted for 8 h to amino acid deprivation, uptake of L-proline was now dominated by a low-affinity system with an apparent K (m) of 4.4 +/- 0.6 mM and a V (max) of 10.2 +/- 0.6 nmol/mg of protein/min operating in addition to the high-affinity SIT1 system with a K (m) of 0.12 +/- 0.01 mM and a V (max) of 0.28 +/- 0.04 nmol/mg of protein/min. The low- and high-affinity proline transporting systems were sensitive to inhibitors of JNK and PI-3 kinases, whereas a GSK-3 inhibitor affected only the upregulated transport system. Ion-replacement studies and experiments assessing substrate specificities for both systems provided strong evidence that SNAT2, that showed two- to threefold increased mRNA levels, is the responsible transporter mediating the increased proline influx under conditions of amino acid deprivation.

Peptide transporters and their roles in physiological processes and drug disposition

1. The peptide transporters belong to the peptide transporter (PTR) family and serve as integral membrane proteins for the cellular uptake of di- and tripeptides in the organism. By their ability also to transport peptidomimetics and other substrates with therapeutic activities or precursors of pharmacologically active agents, they are of considerable importance in pharmacology. 2. PEPT1 is the low-affinity, high-capacity transporter and is mainly expressed in the small intestine, whereas PEPT2 is the high-affinity, low-capacity transporter and has a broader distribution in the organism. 3. Targeted mouse models have revealed PEPT2 to be the dominant transporter for the reabsorption of di- and tripeptides and its pharmacological substrates in the organism, and for the removal of these substrates from the cerebrospinal fluid. Moreover, the peptide transporters undergo physiological and pharmacological regulation and, of great interest, are present in disease states where PEPT1 exhibits ectopic expression in colonic inflammation. 4. The paper reviews the structural characteristics of the peptide transporters, the structural requirements for substrates, the distribution of the peptide transporters in the organism, and finally their regulation in the organism in healthy and pathological situations.

Protective effects of soy-isoflavones in cardiovascular disease. Identification of molecular targets

Epidemiological studies indicate that the consumption of soy-containing food may prevent or slow-down the development of cardiovascular disease. In endothelial cells application of a soy extract or a combination of the most abundant soy isoflavones genistein and daidzein both inhibited apoptosis, a driving force in atherosclerosis development, when applied in combination with oxidized LDL or homocysteine. Proteome analysis revealed that the stressor-induced alteration of protein expression profile was reversed by the soy extract or the genistein/daidzein mixture. Only few protein entities that could be functionally linked to mitochondrial dysfunction were regulated in common by both application forms of isoflavones. A dietary intervention with isoflavone-enriched soy extract in postmenopausal women, who generally show strongly increased cardiovascular risk due to diminished estrogen production, led to significant alterations in the steady state levels of proteins from mononuclear blood cells. The proteins identified by proteome analysis revealed that soy isoflavones may increase the anti-inflammatory response in blood mononuclear cells thereby contributing to the atherosclerosis-preventive activities of a soy-rich diet.

CONCLUSION

By proteome analysis protein targets were identified in vitro in endothelial cells that respond to soy isoflavones and that may decipher molecular mechanisms through which soy products exert their protective effects in the vasculature.

Informatics and medicine--from molecules to populations

OBJECTIVES

To clarify challenges and research topics for informatics in health and to describe new approaches for interdisciplinary collaboration and education.

METHODS

Research challenges and possible solutions were elaborated by scientists of two universities using an interdisciplinary approach, in a series of meetings over several months.

RESULTS AND CONCLUSION

In order to translate scientific results from bench to bedside and further into an evidence-based and efficient health system, intensive collaboration is needed between experts from medicine, biology, informatics, engineering, public health, as well as social and economic sciences. Research challenges can be attributed to four areas: bioinformatics and systems biology, biomedical engineering and informatics, health informatics and individual healthcare, and public health informatics. In order to bridge existing gaps between different disciplines and cultures, we suggest focusing on interdisciplinary education, taking an integrative approach and starting interdisciplinary practice at early stages of education.

Alteration of gene expression in rat colon mucosa after exercise

The development of colon cancer is highly influenced by lifestyle factors such as nutrition and physical inactivity. Detailed biological mechanisms are thus far unclear. The purpose of this study was to investigate the effects of regular treadmill exercise on gene expression in rat colon mucosa. For this purpose, 6-week-old male Wistar rats completed a stress-free voluntary treadmill exercise period of 12 weeks. Sedentary rats served as a control group. In the colon mucosa, steady-state mRNA expression levels of approximately 10,000 genes were compared between both groups by micro-array analysis (MWG rat 10K array). A total of 8846 mRNAs were detected above background level. Regular exercise led to a decreased expression of 47 genes at a threshold-factor of 2.0. Three genes were found to be up-regulated in the exercise group. The identified genes encode proteins involved in signal transduction (n=11), transport (n=8), immune system (n=7), cytoskeleton (n=6), protein targeting (n=6), metabolism (n=5), transcription (n=3) and vascularization (n=2). Among the genes regulated by regular exercise, the betaine-homocysteine methyltransferase 2 (BHMT2) seems to be of particular interest. Physical activity may protect against aberrant methylation by repressing the BHMT2 gene and thus contribute to a decreased risk of developing colon cancer. We have also identified vascular endothelial growth factor (VEGF), angiopoietin-2 (ANG-2) and calcium-independent phospholipase a2 (iPL-A2), all of them with markedly reduced transcript levels in the mucosa of active rats. In summary, our experiment presents the first gene expression pattern in rat colon mucosa following regular treadmill activity and represents an important step in understanding the molecular mechanisms responsible for the preventive effect of physical activity on the development of colon cancer.

Exercise Associated Genes in Rat Colon Mucosa: Upregulation of Ornithin Decarboxylase-1

Epidemiology has revealed that physical activity is an important lifestyle factor that reduces the risk of colon cancer. However, the underlying mechanisms of this protective effect have so far not been defined. The aim of this study was to identify molecular targets of physical activity in rat colon mucosa by employing our voluntary exercise model. Twenty male rats underwent a 12-week exercise program, with 9 additional rats serving as a control group. Running distances, body weights and heart weights as measures of physical adaptations were recorded, and changes in mRNA steady-state levels of marker genes involved in vascularization (VEGF, HIF-1 alpha, ODC-1), apoptosis (Bcl-2, PPAR gamma) and prostaglandin synthesis (COX-2) were determined by qRT-PCR. The four housekeeping genes GAPDH, beta-actin, 18S and ALDA served as reference genes. Recorded running distances showed great inter-individual differences resulting in three different groups of low (L-EX, < 2629 m/night; n=5), moderate (M-EX, 3003 - 7458 m/night; n=10) and high (H-EX, > 8314 m/night; n=5) physical activity. The M-EX and H-EX group revealed significant (p<0.05) adaptive changes with an increase in heart mass per kg body weight and a decrease in mean body weight. Amongst the marker genes studied by mRNA expression analysis only ODC-1 appears to be differentially expressed. Its 1.8-fold increased steady-state mRNA level in the H-EX group suggests that synthesis of polyamines may be increased by physical activity. This new finding could provide a link between extensive physical activity and its protective effects on colon cancer development.

Genomics and proteomics: importance for the future of nutrition research

A huge number of genes within the human genome code for proteins that mediate and/or control nutritional processes. Although a large body of information on the number of genes, on chromosomal localisation, gene structure and function has been gathered, we are far from understanding the orchestrated way of how they make metabolism. Nevertheless, based on the genetic information emerging on a daily basis, we are offered fantastic new tools that allow us new insights into the molecular basis of human metabolism under normal as well as pathophysiological conditions. Recent technological advancements have made it possible to analyse simultaneously large sets of mRNA and/or proteins expressed in a biological sample or to define genetic heterogeneity that may be important for the individual response of an organism to changes in its nutritional environment. Applications of the new techniques of genome and proteome analysis are central for the development of nutritional sciences in the next decade and its integration into the rapidly developing era of functional genomics.

The renal type H+/peptide symporter PEPT2: structure-affinity relationships

The H(+)/peptide cotransporter PEPT2 is expressed in a variety of organs including kidney, lung, brain, mammary gland, and eye. PEPT2 substrates are di- and tripeptides as well as peptidomimetics, such as beta-lactam antibiotics. Due to the presence of PEPT2 at the bronchial epithelium, the aerosolic administration of peptide-like drugs might play a major role in future treatment of various pulmonary and systemic diseases. Moreover, PEPT2 has a significant influence on the in vivo disposition and half-life time of peptide-like drugs within the body, particularly in kidney and brain. PEPT2 is known to have similar but not identical structural requirements for substrate recognition and transport compared to PEPT1, its intestinal counterpart. In this review we compiled available affinity constants of 352 compounds, measured at different mammalian tissues and expression systems and compare the data whenever possible with those of PEPT1.

Estimating the unknown components of nutrient mass balances for forestry plantations in mine rehabilitation, upper Hunter Valley, New South Wales, Australia

Commercial forestry plantations as a postmining land use in the Upper Hunter Valley of New South Wales, Australia are restricted by both the poor nutrient availability of mining substrates and low regional rainfall. An experiment was conducted to investigate whether municipal waste products and saline groundwater from coal mining operations could improve early tree growth without impacting on the environment through salt accumulation and/or nutrient enrichment and changes in groundwater quality. Potential impacts were investigated by quantifying the nutrient cycling dynamics within the plantation using an input-output mass balance approach for exchangeable calcium (Ca(2+)), exchangeable magnesium (Mg(2+)), exchangeable potassium (K(+)), exchangeable sodium (Na(+)), nitrogen (N), and phosphorus (P). Measured inputs to and outputs from the available nutrient pool in the 0-30 cm of the overburden subsystem were used to estimate the net effect of unmeasured inputs and outputs (termed "residuals"). Residual values in the mass balance of the irrigated treatments demonstrated large leaching losses of exchangeable Ca, Mg, K, and Na. Between 96% and 103% of Na applied in saline mine-water irrigation was leached below the 0-30-cm soil profile zone. The fate of these salts beyond 30 cm is unknown, but results suggest that irrigation with saline mine water had minimal impact on the substrate to 30 cm over the first 2 years since plantation establishment. Accumulations of N and P were detected for the substrate amendments, suggesting that organic amendments (particularly compost) retained the applied nutrients with very little associated losses, particularly through leaching.

Increased mitochondrial palmitoylcarnitine/carnitine countertransport by flavone causes oxidative stress and apoptosis in colon cancer cells

Cancer cell metabolism is characterized by limited oxidative phosphorylation in order to minimize oxidative stress. We have previously shown that the flavonoid flavone in HT-29 colon cancer cells increases the uptake of pyruvate or lactate into mitochondria, which is followed by an increase in O(2) (-.). production that finally leads to apoptosis. Similarly, a supply of palmitoylcarnitine in combination with carnitine induces apoptosis in HT-29 cells by increasing the mitochondrial respiration rate. Here we show that flavone-induced apoptosis is increased more than twofold in the presence of palmitoylcarnitine due to increased mitochondrial fatty acid transport and the subsequent metabolic generation of O(2) (-.) in mitochondria is the initiating factor for the execution of apoptosis.

Genistein affects the expression of genes involved in blood pressure regulation and angiogenesis in primary human endothelial cells

BACKGROUND

Several lines of evidence suggest that the dietary isoflavone genistein (Gen) has beneficial effects with regard to cardiovascular disease and in particular on aspects related to blood pressure and angiogenesis. The biological action of Gen may be, at least in part, attributed to its ability to affect cell signalling and response. However, so far, most of the molecular mechanisms underlying the activity of Gen in the endothelium are unknown.

METHODS AND RESULTS

To examine the transcriptional response to 2.5 microM Gen on primary human endothelial cells (HUVEC), we applied cDNA array technology both under baseline condition and after treatment with the pro-atherogenic stimulus, copper-oxidized LDL. The alteration of the expression patterns of individual transcripts was substantiated using either RT-PCR or Northern blotting. Gen significantly affected the expression of genes encoding for proteins centrally involved in the vascular tone such as endothelin-converting enzyme-1, endothelin-2, estrogen related receptor alpha and atrial natriuretic peptide receptor A precursor. Furthermore, Gen countered the effect of oxLDL on mRNA levels encoding for vascular endothelial growth factor receptor 165, types 1 and 2.

CONCLUSIONS

Our data indicate that physiologically achievable levels of Gen change the expression of mRNA encoding for proteins involved in the control of blood pressure under baseline conditions and reduce the angiogenic response to oxLDL in the endothelium.

alpha-Lipoic acid induces apoptosis in human colon cancer cells by increasing mitochondrial respiration with a concomitant O2-*-generation

The antioxidant alpha-lipoic acid (ALA) has been shown to affect a variety of biological processes associated with oxidative stress including cancer. We determined in HT-29 human colon cancer cells whether ALA is able to affect apoptosis, as an important parameter disregulated in tumour development. Exposure of cells to ALA or its reduced form dihydrolipoic acid (DHLA) for 24 h dose dependently increased caspase-3-like activity and was associated with DNA-fragmentation. DHLA but not ALA was able to scavenge cytosolic O2-* in HT-29 cells whereas both compounds increased O2-*-generation inside mitochondria. Increased mitochondrial O2-*-production was preceded by an increased influx of lactate or pyruvate into mitochondria and resulted in the down-regulation of the anti-apoptotic protein bcl-X(L). Mitochondrial O2-*-generation and apoptosis induced by ALA and DHLA could be prevented by the O2-*-scavenger benzoquinone. Moreover, when the lactate/pyruvate transporter was inhibited by 5-nitro-2-(3-phenylpropylamino) benzoate, ALA- and DHLA-induced mitochondrial ROS-production and apoptosis were blocked. In contrast to HT-29 cells, no apoptosis was observed in non-transformed human colonocytes in response to ALA or DHLA addition. In conclusion, our study provides evidence that ALA and DHLA can effectively induce apoptosis in human colon cancer cells by a prooxidant mechanism that is initiated by an increased uptake of oxidizable substrates into mitochondria.

Flavone initiates a hierarchical activation of the caspase-cascade in colon cancer cells

There is emerging evidence that dietary factors can prevent cancer by affecting the process of carcinogenesis. Flavonoids present in vegetarian food possess antioxidant activities, have scavenging effects on activated carcinogens and mutagens, affect cell cycle progression and alter gene and protein expression. We report here that flavone, the core structure of the flavone subgroup, potently inhibits proliferation and induces apoptosis in HCT-116 colon cancer cells. Flavone induces the activation of caspases 2, 3, 8, 9 and 10 and a decrease of mitochondrial anti-apoptotic Bcl(2) protein expression. Further analysis revealed that caspase 10 activation is mediated via caspase 1. Additionally, treatment with flavone results in release of the mitochondrial apoptosis-inducing factor (AIF), the key trigger of caspase-independent apoptosis, into the cytosol. In summary, our data show that flavone induces apoptosis in a caspase-dependent and -independent manner.