Structural requirements of flavonoids to induce heme oxygenase-1 expression.

Population studies suggest cardiovascular health benefits of consuming fruits and vegetables rich in polyphenolic compounds such as flavonoids. We reported previously that the flavonoid quercetin protects arteries from oxidant-induced endothelial dysfunction and attenuates atherosclerosis in apolipoprotein E gene knockout mice, with induction of heme oxygenase-1 (Hmox1) playing a critical role. The present study investigated the structural requirements of flavonoids to induce Hmox1 in human aortic endothelial cells (HAEC). We identified ortho-dihydroxyl groups and an α,ß-unsaturated system attached to a catechol as the key structural requirements for Hmox1 induction. Active but not inactive flavonoids had a low oxidation potential and prevented ascorbate autoxidation, suggesting that Hmox1 inducers readily undergo oxidation and that oxidized, rather than reduced, flavonoids may be the biological inducer of Hmox1. To test this hypothesis, we synthesized stable derivatives of caffeic acid (3-(3,4-dihyroxyphenyl)-2-propenoic acid) containing either ortho-dihydroxy or ortho-dioxo groups. Compared with the dihydroxy compound, the quinone analog induced Hmox1 more potently in HAEC and also provided enhanced protection to arteries of wild type animals against oxidant-induced endothelial dysfunction. In contrast, the quinone analog failed to provide protection against oxidant-induced endothelial dysfunction in arteries of Hmox1-/- mice, establishing a key role for Hmox1 in vascular protection. These results suggest that oxidized forms of dietary polyphenols are the likely inducers of Hmox1 and may explain in part the protective cardiovascular effects of diets rich in these compounds.

Loss of Rearranged L-Myc Fusion (RLF) results in defects in heart development in the mouse.

Recently we reported that Rearranged L-Myc Fusion, RLF, acts as an epigenetic modifier maintaining low levels of DNA methylation at CpG island shores and enhancers across the genome. Here we focus on the phenotype of Rlf null mutant mice generated via an ENU mutagenesis screen, to identify genes required for epigenetic regulation. RLF is expressed in a range of fetal mouse tissues, including the fetal heart. Comprehensive timed-mating studies are consistent with our previously reported findings that Rlf homozygous mutant mice rarely survive to adulthood, with the majority dying shortly after birth. Histological analysis of two independent Rlf ENU mutant lines at E11.5-E14.5 showed heart defects resembling those present in humans with Left Ventricular Non-Compaction (LVNC). In situ hybridisation analysis localized expression of Rlf to the endocardium and epicardium of embryonic and postnatal hearts, and transiently to cardiomyocytes during heart looping and early chamber formation stages. RNA-seq analysis of Rlf mutant hearts highlighted defective NOTCH pathway signalling, recently describe as one cause of LVNC. This study provides the first evidence that RLF is required for normal heart development in the mouse. The heart morphological defects present at high penetrance in Rlf mutants are consistent with features of LVNC in humans, and molecular analysis identified attenuated JAGGED 1 expression and NOTCH signalling as likely contributors to these defects. Our study highlights the importance of RLF-dependent epigenetic modifications to DNA for maintaining correct gene regulatory network and intercellular signalling interactions during heart chamber and septal development. Further investigations are needed to define the biochemical role of RLF in the developing heart, and whether RLF mutations are a cause of heart defects in humans.

[Capitate Non-Union: One of the Causes of Carpal Tunnel Syndrome]. / Kapitatumpseudarthrose als mitauslösendes Moment eines Karpaltunnelsyndroms.

We report on a carpal tunnel syndrome in a 50-year-old woman, presumably caused in part by a 35-year-old asymptomatic capitate non-union. The carpal tunnel was released and a large exostosis removed. 3 weeks after the operation the patient was free of symptoms.

[Transposition of the Ring Finger after Severe Hand Injury]. / Ringfingertransposition nach schwerem Handtrauma.

We report a severe hand injury with a fracture of the third metacarpal bone, destruction of the metacarpophalangeal joint of the fourth finger, amputation of the little finger of the right hand and several tendon injuries, in an active musician. The fourth metacarpal bone was offset close to the base, the hand narrowed, and the ring finger transferred to the base of the little finger. The outcome was very favourable.

Proteasome inhibition and oxidative reactions disrupt cellular homeostasis during heme stress.

Dual control of cellular heme levels by extracellular scavenger proteins and degradation by heme oxygenases is essential in diseases associated with increased heme release. During severe hemolysis or rhabdomyolysis, uncontrolled heme exposure can cause acute kidney injury and endothelial cell damage. The toxicity of heme was primarily attributed to its pro-oxidant effects; however additional mechanisms of heme toxicity have not been studied systematically. In addition to redox reactivity, heme may adversely alter cellular functions by binding to essential proteins and impairing their function. We studied inducible heme oxygenase (Hmox1)-deficient mouse embryo fibroblast cell lines as a model to systematically explore adaptive and disruptive responses that were triggered by intracellular heme levels exceeding the homeostatic range. We extensively characterized the proteome phenotype of the cellular heme stress responses by quantitative mass spectrometry of stable isotope-labeled cells that covered more than 2000 individual proteins. The most significant signals specific to heme toxicity were consistent with oxidative stress and impaired protein degradation by the proteasome. This ultimately led to an activation of the response to unfolded proteins. These observations were explained mechanistically by demonstrating binding of heme to the proteasome that was linked to impaired proteasome function. Oxidative heme reactions and proteasome inhibition could be differentiated as synergistic activities of the porphyrin. Based on the present data a novel model of cellular heme toxicity is proposed, whereby proteasome inhibition by heme sustains a cycle of oxidative stress, protein modification, accumulation of damaged proteins and cell death.

Brain endothelial cells increase the proliferation of Plasmodium falciparum through production of soluble factors.

We here describe the novel finding that brain endothelial cells in vitro can stimulate the growth of Plasmodium falciparum through the production of low molecular weight growth factors. By using a conditioned medium approach, we show that the brain endothelial cells continued to release these factors over time. If this mirrors the in vivo situation, these growth factors potentially would provide an advantage, in terms of enhanced growth, for sequestered parasitised red blood cells in the brain microvasculature. We observed this phenomenon with brain endothelial cells from several sources as well as a second P. falciparum strain. The characteristics of the growth factors included: <3 kDa molecular weight, heat stable, and in part chloroform soluble. Future efforts should be directed at identifying these growth factors, since blocking their production or actions might be of benefit for reducing parasite load and, hence, malaria pathology.

Cell patterning with mucin biopolymers.

The precise spatial control of cell adhesion to surfaces is an endeavor that has enabled discoveries in cell biology and new possibilities in tissue engineering. The generation of cell-repellent surfaces currently requires advanced chemistry techniques and could be simplified. Here we show that mucins, glycoproteins of high structural and chemical complexity, spontaneously adsorb on hydrophobic substrates to form coatings that prevent the surface adhesion of mammalian epithelial cells, fibroblasts, and myoblasts. These mucin coatings can be patterned with micrometer precision using a microfluidic device, and are stable enough to support myoblast differentiation over seven days. Moreover, our data indicate that the cell-repellent effect is dependent on mucin-associated glycans because their removal results in a loss of effective cell-repulsion. Last, we show that a critical surface density of mucins, which is required to achieve cell-repulsion, is efficiently obtained on hydrophobic surfaces, but not on hydrophilic glass surfaces. However, this limitation can be overcome by coating glass with hydrophobic fluorosilane. We conclude that mucin biopolymers are attractive candidates to control cell adhesion on surfaces.

Plasma total bilirubin levels predict amputation events in type 2 diabetes mellitus: the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study.

AIMS/HYPOTHESIS: Bilirubin has antioxidant and anti-inflammatory activities. Previous studies demonstrated that higher bilirubin levels were associated with reduced prevalence of peripheral arterial disease (PAD). However, the relationship between bilirubin and lower-limb amputation, a consequence of PAD, is currently unknown. We hypothesised that, in patients with type 2 diabetes, bilirubin concentrations may inversely associate with lower-limb amputation. METHODS: The relationship between baseline plasma total bilirubin levels and amputation events was analysed in 9,795 type 2 diabetic patients from the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study. The analysis plan was pre-specified. Lower-limb amputation was adjudicated blinded to treatment allocation. Relevant clinical and biochemical data were available for analyses. Amputation was a pre-specified tertiary endpoint. RESULTS: Bilirubin concentrations were significantly inversely associated with lower-limb amputation, with a greater than threefold risk gradient across levels. Individuals with lower bilirubin concentrations had a higher risk for first amputation (HR 1.38 per 5 µmol/l decrease in bilirubin concentration, 95% CI 1.07, 1.79, p = 0.013). The same association persisted after adjustment for baseline variables, including age, height, smoking status, γ-glutamyltransferase level, HbA1c, trial treatment allocation (placebo vs fenofibrate), as well as previous PAD, non-PAD cardiovascular disease, amputation or diabetic skin ulcer, neuropathy, nephropathy and diabetic retinopathy (HR 1.38 per 5 µmol/l decrease in bilirubin concentration, 95% CI 1.05, 1.81, p = 0.019). CONCLUSIONS/INTERPRETATION: Our results identify a significant inverse relationship between bilirubin levels and total lower-limb amputation, driven by major amputation. Our data raise the hypothesis that bilirubin may protect against amputation in type 2 diabetes.

[Compression of the ulnar nerve at Guyon's canal caused by a pseudoaneurysm of the ulnar artery following trauma]. / Kompression des Nervus ulnaris in der Loge de Guyon durch ein traumatisches Aneurysma spurium der Arteria ulnaris.

We repor there on a 16-year-old patient who presented with pain and swelling in the hypothenar eminence as well as loss of sensibility in the fingers of the region innervated by the ulnar nerve; this happened 2-3 weeks after an injury by a glass splinter in his proximal palm. A pseudoaneurysm could be verified by duplex sonography. The patient wished to avoid any graft for arterial bridging for religious reasons. On the basis of an the Allen test preoperatively and the intraoperative findings, an adequate blood supply of the finger by the radial artery was expected. Thus, in respect to the patients wish, the aneurysm was resected without bridging. The patient recovered perfectly. 4 years later, an MR-angiography showed the deep and superficial transverse palmar arc to be supplied by a voluminous radial artery. The ulnar finger arteries originated from the deep arc, the radial finger arteries from the superficial arc. In this paper, the criteria pro and contra grafting the ulnar atery at Guyons's canal will be discussed.

Diversity, variability, and suboesophageal connectivity of antennal lobe neurons in D. melanogaster larvae.

Whereas the "vertical" elements of the insect olfactory pathway, the olfactory receptor neurons and the projection neurons, have been studied in great detail, local interneurons providing "horizontal" connections in the antennal lobe were ignored for a long time. Recent studies in adult Drosophila demonstrate diverse roles for these neurons in the integration of odor information, consistent with the identification of a large variety of anatomical and neurochemical subtypes. Here we focus on the larval olfactory circuit of Drosophila, which is much reduced in terms of cell numbers. We show that the horizontal connectivity in the larval antennal lobe differs largely from its adult counterpart. Only one of the five anatomical types of neurons we describe is restricted to the antennal lobe and therefore fits the definition of a local interneuron. Interestingly, the four remaining subtypes innervate both the antennal lobe and the suboesophageal ganglion. In the latter, they may overlap with primary gustatory terminals and with arborizations of hugin cells, which are involved in feeding control. This circuitry suggests special links between smell and taste, which may reflect the chemosensory constraints of a crawling and burrowing lifestyle. We also demonstrate that many of the neurons we describe exhibit highly variable trajectories and arborizations, especially in the suboesophageal ganglion. Together with reports from adult Drosophila, these data suggest that wiring variability may be another principle of insect brain organization, in parallel with stereotypy.

[Closed rupture of the intrinsic flexor tendon of the little finger]. / Gedeckte Ruptur der tiefen Beugesehne des Kleinfingers.

Closed ruptures of the deep flexor tendons are rare, even though they occur more often than those of the superficial flexor tendons. We report about a closed distal rupture of the deep flexor tendon of the little finger as experienced by a 50-year-old man who suffered an injury at work. The proximal stump allocated to the torn flexor tendon of zone I had noticeably pulled back to the middle of the palm of hand, and had come to rest around the tendon of the ring finger. We illustrate the problems linked with diagnosis, care and follow-up treatment of such a case.

Modafinil ameliorates excessive daytime sleepiness after traumatic brain injury.

BACKGROUND: Excessive daytime sleepiness (EDS) and fatigue are common symptoms after traumatic brain injury (TBI), but there is no specific treatment for affected patients. With this pilot study, we aimed at studying the effect of daily modafinil on posttraumatic EDS and fatigue. METHODS: We conducted a prospective, double-blind, randomized, placebo-controlled pilot study in 20 patients with TBI who had fatigue or EDS or both. After baseline examinations (questionnaires including the Epworth Sleepiness Scale to assess EDS and the Fatigue Severity Scale to assess fatigue, actigraphy, polysomnography, maintenance of wakefulness test, and psychomotor vigilance test), 10 patients received 100 to 200 mg modafinil every morning, and 10 patients were treated with placebo. After a 6-week treatment period, all examinations were repeated. RESULTS: EDS improved significantly in patients with TBI who were treated with modafinil, compared with the placebo group. Similarly, the ability to stay awake on the maintenance of wakefulness test improved only in the modafinil group. Modafinil, however, had no impact on posttraumatic fatigue. Clinically relevant side effects were not observed. CONCLUSION: This study indicates that modafinil is effective and well tolerated in the treatment of posttraumatic EDS but not of fatigue. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that modafinil (100-200 mg daily) improves posttraumatic EDS compared with placebo. This study provides Class I evidence that modafinil (100-200 mg daily) does not improve posttraumatic fatigue compared with placebo.

Stratlets: low Reynolds number point-force solutions in a stratified fluid.

We present fundamental solutions of low Reynolds number flows in a stratified fluid, including the case of a point force (Stokeslet) and a doublet. Stratification dramatically alters the flow by creating toroidal eddies, and velocity decays much faster than in a homogeneous fluid. The fundamental length scale is set by the competition of buoyancy, diffusion and viscosity, and is O(100 µm-1 mm) in aquatic environments. Stratification can therefore affect the swimming of small organisms and the sinking of marine snow particles, and diminish the effectiveness of mechanosensing in the ocean.

Insulin differentially influences brain glucose and lactate in traumatic brain injured patients.

BACKGROUND: Hypo- and hyperglycemia must be avoided to prevent additional brain damage following traumatic brain injury (TBI). However, the optimal blood glucose range requiring insulin remains unknown. Cerebral microdialysis is helpful in unmasking signs of metabolic impairment, thereby identifying deleterious blood glucose levels. METHODS: A retrospective analysis of prospectively collected cerebral microdialysis samples obtained from 20 non-diabetic patients with severe TBI treated at the trauma surgical intensive care unit at the University Hospital Zürich, Switzerland. RESULTS: The impact of different arterial blood glucose values and concomitant insulin administration on cerebral interstitial glucose and lactate levels was investigated. In addition, energetic impairment was determined by calculating lactate-to-glucose ratios. Insulin administration was associated with significantly reduced cerebral glucose concentrations and significantly increased lactate-to-glucose ratios with arterial blood glucose levels <5 mM. At arterial blood glucose levels >7 mM, insulin administration was associated with significantly increased interstitial glucose values, significantly decreased lactate concentrations, and markedly diminished lactate-to-glucose ratios. CONCLUSION: Insulin exerts differential effects that depend strongly on the underlying arterial blood glucose concentrations. To avoid energetic impairment, insulin should not be administered at arterial blood glucose levels <5 mM. However, at arterial blood glucose levels >7-8 mM, insulin administration appears to be encouraged to increase extracellular glucose concentrations and decrease energetic impairment reflected by reduced interstitial brain lactate and decreased lactate-to-glucose ratios. Nevertheless, frequent analysis is required to minimize the risk of inducing impaired brain metabolism.

Biochemical characteristics and inhibitor selectivity of mouse indoleamine 2,3-dioxygenase-2.

The first step in the kynurenine pathway of tryptophan catabolism is the cleavage of the 2,3-double bond of the indole ring of tryptophan. In mammals, this reaction is performed independently by indoleamine 2,3-dioxygenase-1 (IDO1), tryptophan 2,3-dioxygenase (TDO) and the recently discovered indoleamine 2,3-dioxygenase-2 (IDO2). Here we describe characteristics of a purified recombinant mouse IDO2 enzyme, including its pH stability, thermal stability and structural features. An improved assay system for future studies of recombinant/isolated IDO2 has been developed using cytochrome b (5) as an electron donor. This, the first description of the interaction between IDO2 and cytochrome b (5), provides further evidence of the presence of a physiological electron carrier necessary for activity of enzymes in the "IDO family". Using this assay, the kinetic activity and substrate range of IDO2 were shown to be different to those of IDO1. 1-Methyl-D-tryptophan, a current lead IDO inhibitor used in clinical trials, was a poor inhibitor of both IDO1 and IDO2 activity. This suggests that its immunosuppressive effect may be independent of pharmacological inhibition of IDO enzymes, in the mouse at least. The different biochemical characteristics of the mouse IDO proteins suggest that they have evolved to have distinct biological roles.

Smelling, tasting, learning: Drosophila as a study case.

Understanding brain function is to account for how the sensory system is integrated with the organism's needs to organize behaviour. We review what is known about these processes with regard to chemosensation and chemosensory learning in Drosophila. We stress that taste and olfaction are organized rather differently. Given that, e.g., sugars are nutrients and should be eaten (irrespective of the kind of sugar) and that toxic substances should be avoided (regardless of the kind of death they eventually cause), tastants are classified into relatively few behavioural matters of concern. In contrast, what needs to be done in response to odours is less evolutionarily determined. Thus, discrimination ability is warranted between different kinds of olfactory input, as any difference between odours may potentially be or become important. Therefore, the olfactory system has a higher dimensionality than gustation, and allows for more sensory-motor flexibility to attach acquired behavioural 'meaning' to odours. We argue that, by and large, larval and adult Drosophila are similar in these kinds of architecture, and that additionally there are a number of similarities to vertebrates, in particular regarding the cellular architecture of the olfactory pathway, the functional slant of the taste and smell systems towards classification versus discrimination, respectively, and the higher plasticity of the olfactory sensory-motor system. From our point of view, the greatest gap in understanding smell and taste systems to date is not on the sensory side, where indeed impressive advances have been achieved; also, a satisfying account of associative odour-taste memory trace formation seems within reach. Rather, we lack an understanding as to how sensory and motor formats of processing are centrally integrated, and how adaptive motor patterns actually are selected. Such an understanding, we believe, will allow the analysis to be extended to the motivating factors of behaviour, eventually leading to a comprehensive account of those systems which make Drosophila do what Drosophila's got to do.

Resource patch formation and exploitation throughout the marine microbial food web.

Exploitation of microscale (microm-mm) resource patches by planktonic microorganisms may influence oceanic trophodynamics and nutrient cycling. However, examinations of microbial behavior within patchy microhabitats have been precluded by methodological limitations. We developed a microfluidic device to generate microscale resource patches at environmentally realistic spatiotemporal scales, and we examined the exploitation of these patches by marine microorganisms. We studied the foraging response of three sequential levels of the microbial food web: a phytoplankton (Dunaliella tertiolecta), a heterotrophic bacterium (Pseudoalteromonas haloplanktis), and a phagotrophic protist (Neobodo designis). Population-level chemotactic responses and single-cell swimming behaviors were quantified. Dunaliella tertiolecta accumulated within a patch of NH4(+), simulating a zooplankton excretion, within 1 min of its formation. Pseudoalteromonas haloplanktis cells also exhibited a chemotactic response to patches of D. tertiolecta exudates within 30 s, whereas N. designis shifted swimming behavior in response to bacterial prey patches. Although they relied on different swimming strategies, all three organisms exhibited behaviors that permitted efficient and rapid exploitation of resource patches. These observations imply that microscale nutrient patchiness may subsequently trigger the sequential formation of patches of phytoplankton, heterotrophic bacteria, and protozoan predators in the ocean. Enhanced uptake and predation rates driven by patch exploitation could accelerate carbon flux through the microbial loop.

[Ossification in the carpal tunnel as a rare cause for untypical carpal tunnel syndrome]. / Ossifikation im Karpalkanal als seltene Ursache für ein atypisches Karpaltunnelsyndrom.

There are typical causes for carpal tunnel syndromes as well as a series of rare causes. Furthermore, the clinical image can also be untypical. This report is about a 59-year-old female patient with an untypical clinical symptomatology and with a rare cause: there was no major pain during the night or in the morning, no paraesthesias and no impairment of the fine motor skills, nevertheless, there were rapid paraesthesias and pain in the first three fingers of the right hand immediately after hyperextension of the wrist. Although the discomforts had already existed for 2 years they were not recognised properly because they were untypical and incomplete and neurography was negative. 3 years later in a renewed examination X-ray pictures of the carpus were taken and a 4 x 6 x 8 mm big ossicle on the ground of the carpal canal was found, the computed tomography and the intraoperative situs confirmed the image. The histology gave the diagnosis of a loose osteochondral body. Postoperatively the patient was quickly was free of the symptoms.