bluuebunny/crossref_metadata_2025 huggingface dataset:
Dominant-negative TLR5 polymorphism reduces adaptive immune response to flagellin and negatively associates with Crohn's disease
Authors: Gewirtz Andrew T. , Vijay-Kumar Matam , Brant Steven R. , Duerr Richard H. , Nicolae Dan L. , Cho Judy H.
Published: January 2006

Crohn's disease (CD) is associated with elevated adaptive immunity to commensal microbes, with flagellin being a dominant antigen. In light of heightened awareness of the importance of innate immunity in regulating adaptive immunity and ambiguity as to the role of CD-associated immune responses in CD pathophysiology, we sought to determine whether natural acquisition of immune responses to flagellin were regulated by the innate immune flagellin receptor toll-like receptor 5 (TLR5) and determine whether persons carrying a recently defined common dominant-negative TLR5 polymorphism (TLR5-stop) might be protected from developing CD. Carriage rates of a recently defined dominant-negative TLR5 polymorphism (TLR5-stop) and levels of serum immunoreactivity to bacterial products were measured in inflammatory bowel disease patients, first-degree relatives, and unrelated controls. We observed that, in healthy subjects, persons carrying TLR5-stop had significantly lower levels of flagellin-specific IgG and IgA but had similar levels of total and LPS-specific Ig. Moreover, we observed that, among Jewish subjects, the carriage rate of TLR5-stop (in heterozygous state) was significantly less in CD patients, but not ulcerative colitis (UC) patients, compared with unaffected relatives and unrelated controls (5.4, 0.9, 6.0, and 6.5% for unaffected relatives, CD, UC, and unrelated Jewish controls, respectively, n = 296, 215, 185, and 416, respectively; P = 0.037 by likelihood calculation for CD vs. controls), indicating that TLR5-stop can protect persons of Jewish ethnicity against CD. We did not observe a significant association of TLR5-stop with CD in a non-Jewish cohort (11.1, 10.4, and 11.7% for unaffected relatives, CD, and UC, respectively; n = 841, 543, and 300 for unaffected relatives, respectively). These results demonstrate that natural acquisition of immune responses to flagellin are regulated by TLR5 and suggest that immune responses to flagellin are not merely associated with CD but rather promote the pathogenic response.
Differential expression proteomics of human colon cancer
Authors: Mazzanti Roberto , Solazzo Michela , Fantappié Ornella , Elfering Sarah , Pantaleo Pietro , Bechi Paolo , Cianchi Fabio , Ettl Adam , Giulivi Cecilia
Published: January 2006

The focus of this study was to use differential protein expression to investigate operative pathways in early stages of human colon cancer. Colorectal cancer represents an ideal model system to study the development and progression of human tumors, and the proteomic approach avoids overlooking posttranslational modifications not detected by microarray analyses and the limited correlation between transcript and protein levels. Colon cancer samples, confined to the intestinal wall, were analyzed by expression proteomics and compared with matched samples from normal colon tissue. Samples were processed by two-dimensional gel electrophoresis, and spots differentially expressed and consistent across all patients were identified by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry analyses and by Western blot analyses. After differentially expressed proteins and their metabolic pathways were analyzed, the following main conclusions were achieved for tumor tissue: 1) a shift from β-oxidation, as the main source of energy, to anaerobic glycolysis was observed owed to the alteration of nuclear- versus mitochondrial-encoded proteins and other proteins related to fatty acid and carbohydrate metabolism; 2) lower capacity for Na+and K+cycling; and 3) operativity of the apoptosis pathway, especially the mitochondrial one. This study of the human colon cancer proteome represents a step toward a better understanding of the metabolomics of colon cancer at early stages confined to the intestinal wall.
HCl-induced inflammatory mediators in cat esophageal mucosa and inflammatory mediators in esophageal circular muscle in an in vitro model of esophagitis
Authors: Cheng Ling , Cao Weibiao , Fiocchi Claudio , Behar Jose , Biancani Piero , Harnett Karen M.
Published: January 2006

Platelet-activating factor (PAF) and interleukin-6 (IL-6) are produced in the esophagus in response to HCl and affect ACh release, causing changes in esophageal motor function similar to esophagitis (Cheng L, Cao W, Fiocchi C, Behar J, Biancani P, and Harnett KM. Am J Physiol Gastrointest Liver Physiol 289: G418–G428, 2005). We therefore examined HCl-activated mechanisms for production of PAF and IL-6 in cat esophageal mucosa and circular muscle. A segment of normal mucosa was tied at both ends, forming a mucosal sac (Cheng L, Cao W, Fiocchi C, Behar J, Biancani P, and Harnett KM. Am J Physiol Gastrointest Liver Physiol 289: G860–G869, 2005) that was filled with acidic Krebs buffer (pH 5.8) or normal Krebs buffer (pH 7.0) as control and kept in oxygenated Krebs buffer for 3 h. The supernatant of the acidic sac (MS-HCl) abolished contraction of normal muscle strips in response to electric field stimulation. The inhibition was reversed by the PAF antagonist CV3988 and by IL-6 antibodies. PAF and IL-6 levels in MS-HCl and mucosa were significantly elevated over control. IL-6 levels in mucosa and supernatant were reduced by CV3988, suggesting that formation of IL-6 depends on PAF. PAF-receptor mRNA levels were not detected by RT-PCR in normal mucosa, but were significantly elevated after exposure to HCl, indicating that HCl causes production of PAF and expression of PAF receptors in esophageal mucosa and that PAF causes production of IL-6. PAF and IL-6, produced in the mucosa, are released to affect the circular muscle layer. In the circular muscle, PAF causes production of additional IL-6 that activates NADPH oxidase to induce production of H2O2. H2O2causes formation of IL-1β that may induce production of PAF in the muscle, possibly closing a self-sustaining cycle of production of inflammatory mediators.
Antidipsogenic effects of a TRPV4 agonist, 4α-phorbol 12,13-didecanoate, injected into the cerebroventricle
Authors: Tsushima Hiromi , Mori Mayumi
Published: January 2006

Transient receptor potential vanilloid 4 (TRPV4) is one member of the TRP superfamily of nonselective cation channels. Recently, the possibility has been raised that TRPV4 is an osmoreceptor, because it is found in the circumventricular organs where osmoreceptors are supposed to be distributed and because it is sensitive to osmotic pressure in in vitro experiments. In addition, TRPV4 knockout mice have abnormal osmosensitivity. In this study, effects of 4α-phorbol 12,13-didecanoate (4α-PDD), a TRPV4 agonist, on drinking behavior were examined to investigate roles for TRPV4 as an osmoreceptor in vivo in wild-type animals. Intracerebroventricular injections of 4α-PDD inhibited water intake under normal conditions in both light and dark periods of the day, after food deprivation, and after administration of angiotensin II. However, this drug did not influence increased water intake after administration of a hypertonic solution or after water deprivation that significantly increased plasma osmolality. Locomotor activity of the 4α-PDD-injected group decreased slightly compared with that of the vehicle-injected group; however, sweet taste, food intake, and body temperature were not different between the two groups. The antidipsogenic effects of 4α-PDD were blocked by preinjection into the ventricle of TRPV4 antagonists such as ruthenium red or gadolinium. These findings suggest that TRPV4 regulates drinking behavior under certain conditions, and the regulation interacts with the angiotensin II pathway.
IGF-I and insulin receptor signal transduction in trout muscle cells
Authors: Castillo Juan , Ammendrup-Johnsen Ina , Codina Marta , Navarro Isabel , Gutiérrez Joaquim
Published: January 2006

In this study, primary cultures of trout skeletal muscle cells were used to investigate the main signal transduction pathways of insulin and IGF-I receptors in rainbow trout muscle. At different stages of in vitro development (myoblasts on day 1, myocytes on day 4, and fully developed myotubes on day 11), we detected in these cells the presence of immunoreactivity against ERK 1/2 MAPK and Akt/PKB proteins, components of the MAPK and the phosphatidylinositol 3-kinase-Akt pathways, respectively, two of the main intracellular transduction pathways for insulin and IGF-I receptors. Both insulin and IGF-I activated both pathways, although the latter provoked higher immunoreactivity of phosphorylated MAPKs and Akt proteins. At every stage, increases in total MAPK immunoreactivity levels were observed when cells were stimulated with IGF-I or insulin, while total Akt immunoreactivity levels changed little under stimulation of peptides. Total Akt and total MAPK levels increased as skeletal muscle cells differentiated in culture. Moreover, when cells were incubated with IGF-I or insulin, MAPK-P immunoreactivity levels showed greater increases over the basal levels on days 1 and 4, with no effect observed on day 11. Although Akt-P immunoreactivity displayed improved responses on days 1 and 4 as well, a stimulatory effect was still observed on day 11. In addition, the present study demonstrates that purified trout insulin receptors possess higher phosphorylative activity per unit of receptor than IGF-I receptors. In conclusion, these results indicate that trout skeletal muscle culture is a suitable model to study the insulin and IGF-I signal transduction molecules and that there is a different regulation of MAPK and Akt pathways depending on the developmental stage of the muscle cells.
Wavelength-dependent effects of evening light exposure on sleep architecture and sleep EEG power density in men
Authors: Münch Mirjam , Kobialka Szymon , Steiner Roland , Oelhafen Peter , Wirz-Justice Anna , Cajochen Christian
Published: January 2006

Light strongly influences the circadian timing system in humans via non-image-forming photoreceptors in the retinal ganglion cells. Their spectral sensitivity is highest in the short-wavelength range of the visible light spectrum as demonstrated by melatonin suppression, circadian phase shifting, acute physiological responses, and subjective alertness. We tested the impact of short wavelength light (460 nm) on sleep EEG power spectra and sleep architecture. We hypothesized that its acute action on sleep is similar in magnitude to reported effects for polychromatic light at higher intensities and stronger than longer wavelength light (550 nm). The sleep EEGs of eight young men were analyzed after 2-h evening exposure to blue (460 nm) and green (550 nm) light of equal photon densities (2.8 × 1013 photons·cm−2·s−1) and to dark (0 lux) under constant posture conditions. The time course of EEG slow-wave activity (SWA; 0.75–4.5 Hz) across sleep cycles after blue light at 460 nm was changed such that SWA was slightly reduced in the first and significantly increased during the third sleep cycle in parietal and occipital brain regions. Moreover, blue light significantly shortened rapid eye movement (REM) sleep duration during these two sleep cycles. Thus the light effects on the dynamics of SWA and REM sleep durations were blue shifted relative to the three-cone visual photopic system probably mediated by the circadian, non-image-forming visual system. Our results can be interpreted in terms of an induction of a circadian phase delay and/or repercussions of a stronger alerting effect after blue light, persisting into the sleep episode.
Impact of state of arousal and stress neuropeptides on urodynamic function in freely moving rats
Authors: Kiddoo Darcie A. , Valentino Rita J. , Zderic Stephen , Ganesh Arjunan , Leiser Steven C. , Hale Lance , Grigoriadis Dimitri E.
Published: January 2006

Corticotropin-releasing factor (CRF) is a neurotransmitter in Barrington’s nucleus neurons. These neurons can coregulate parasympathetic tone to the bladder (to modulate micturition) and brain noradrenergic activity (to affect arousal). To identify the role of CRF in the regulation of micturition, the effects of CRF agonists and antagonists on urodynamics in the unanesthetized rat were characterized. Rats were implanted with bladder and intrathecal or intraperitoneal catheters under isoflurane anesthesia. Cystometry was performed in the unanesthetized, unrestrained state at least 24 h later. In some cases, cortical electroencephalographic activity (EEG) was recorded simultaneously to assess arousal state. During cystometry, the state of arousal often shifted between waking and sleeping and urodynamic function changed depending on the state. Micturition threshold, bladder capacity, and micturition volume were all increased during sleep. The CRF1/CRF2receptor agonists CRF and urocortin 2 increased bladder capacity and micturition volume in awake but not in sleeping rats. Conversely, the CRF1receptor antagonists antalarmin and NBI-30775 increased urinary frequency and decreased bladder capacity in awake rats. The present results demonstrate a profound effect of the state of arousal on urodynamic function and suggest that simultaneous monitoring of EEG and cystometry may provide a useful model for studying nocturnal enuresis and other urinary disorders. In addition, the results provide evidence for an inhibitory influence of CRF in the spinal pathway on micturition. Targeting the CRF system in the spinal cord may provide a novel approach for treating urinary disorders.
Brief exposure to exogenous testosterone increases death signaling and adversely affects myocardial function after ischemia
Authors: Crisostomo Paul R. , Wang Meijing , Wairiuko George M. , Morrell Eric D. , Meldrum Daniel R.
Published: January 2006

Chronic endogenous testosterone exposure adversely affects proinflammatory and proapoptotic signaling after ischemia/reperfusion; however, it remains unknown whether a single acute testosterone exposure is equally detrimental. We hypothesized that acute exogenous testosterone infusion before ischemia would worsen myocardial functional recovery, increase the activation of MAPKs and caspase-3, and increase myocardial proinflammatory cytokine production. To study this, isolated-perfused rat hearts (Langendorff) from adult females and castrated males were subjected to 25-min ischemia and 40-min reperfusion with and without acute testosterone infusion (17β-hydroxy-4-androstenone, 10 ng·ml−1·min−1) before ischemia. Myocardial contractile function was continuously recorded. After ischemia/reperfusion, hearts were assessed for levels of testosterone (ELISA), expression of proinflammatory cytokines (ELISA), and activation of MAPKs and caspase-3 (Western blot analysis). Data were analyzed with two-way ANOVA or Student’s t-test; P < 0.05 was statistically significant. All indices of postischemic functional recovery were decreased with acute exogenous testosterone compared with the untreated groups. Acute testosterone infusion increased activation of MAPKs and caspase-3 following ischemia/reperfusion. However, there were no significant differences in the myocardial proinflammatory cytokine production after brief testosterone infusion. A single acute exposure to exogenous testosterone before ischemia worsens myocardial functional recovery and increases activation of MAPKs and caspase-3. These findings confirm the deleterious effects of testosterone on myocardium, elucidate the nongenomic mechanistic pathways of testosterone, and may have important clinical implications for patients who have acute exposure to exogenous testosterone.
Strategies for Developing Therapeutic Application of Human Embryonic Stem Cells
Authors: Raikwar Sudhanshu P. , Mueller Thomas , Zavazava Nicholas
Published: January 2006

The ongoing debate on human embryonic stem cells (hESC) is fuelled by ethical concerns but also by the legitimate hope that hESC could one day be used for the cure of presently untreatable human diseases. Here we discuss current approaches to and constraints upon hESC differentiation and describe their potential application in clinical medicine.
Calcium-Activated Potassium Channels and the Regulation of Vascular Tone
Authors: Ledoux Jonathan , Werner Matthias E. , Brayden Joseph E. , Nelson Mark T.
Published: January 2006

Different calcium signals in the endothelium and smooth muscle target different types of Ca2+-sensitive K+channels to modulate vascular function. These differential calcium signals and targets represent multilayered opportunities for prevention and/or treatment of vascular dysfunctions.
AMPK: A Key Sensor of Fuel and Energy Status in Skeletal Muscle
Authors: Hardie D. Grahame , Sakamoto Kei
Published: January 2006

Contraction induces marked metabolic changes in muscle, and the AMP-activated protein kinase (AMPK) is a good candidate to explain these effects. Recent work using a muscle-specific knockout of the upstream kinase, LKB1, has confirmed that the LKB1→AMPK cascade is the signaling pathway responsible for many of these effects.
The Developmental Origins of Insulin Resistance
Authors: Barker David J.P.
Published: January 2006

Until recently, the principal causes of degenerative disease were thought to act in adult life and to accelerate destructive processes, such as the formation of atheroma and rise in blood pressure. Recent observations that people who develop coronary heart disease grow differently to other people during fetal life and childhood have, however, led to a new ‘developmental’ model for the disease. Low birthweight has been shown to be associated with increased rates of coronary heart disease, type 2 diabetes mellitus and altered glucose tolerance. These associations with low birthweight extend across the normal range of birthweight and reflect slow fetal growth rather than premature birth. The associations are thought to be consequences of developmental plasticity, the phenomenon by which one genotype can give rise to a range of different physiological or morphological states in response to different environmental conditions during development. Recent observations suggest that low birthweight, thinness at 2 years of age and an increase in body mass index (BMI) after the age of 2 years are each associated with the development of insulin resistance in later life. The prevention of a substantial proportion of type 2 diabetes and other disorders linked to insulin resistance may, therefore, depend on interventions during development. These include protecting the growth of babies during the first 2 years after birth by good infant feeding practices and preventing a rapid increase in BMI after the age of 2 years. Improving fetal nutrition remains an important long-term goal.
Clamp Techniques in Paediatrics: What Have We Learned?
Authors: Arslanian Silva A.
Published: January 2006

The marked increase in conditions associated with insulin resistance in youth, including obesity, polycystic ovary syndrome, type 2 diabetes mellitus etc., has prompted the need to assess insulin sensitivity in this age group. Even though insulin resistance plays an important role in disorders of glucose metabolism and other pathological conditions, both insulin sensitivity and insulin secretion should be determined for a comprehensive evaluation of glucose homeostasis disorders. Insulin sensitivity and secretion are intricately coupled with a delicate feedback mechanism governing their relationship. This article will delineate our paediatric experience with the clamp technique, the hyperinsulinaemic-euglycaemic clamp in assessing in vivo insulin sensitivity, and the hyperglycaemic clamp in assessing insulin secretion.
Simple Fasting Methods to Assess Insulin Sensitivity in Childhood
Authors: Cutfield Wayne S. , Hofman Paul L.
Published: January 2006

The ‘gold standard’ techniques used to measure insulin sensitivity in children are the hyperinsulinaemic-euglycaemic clamp and Bergman’s minimal model. Although precise, these techniques are complex, invasive and time consuming. Alternative indirect measures of insulin sensitivity have been developed that utilize fasting glucose and insulin data in algorithms or computer programs. These methods include homeostatic model assessment (HOMA), the quantitative insulin sensitivity check index (QUICKI) and the glucose to insulin ratio (G:I). Each of these three fasting techniques has been developed and validated in adults, with little or no validation in children. Increasingly, HOMA and QUICKI are being used in childhood studies to assess insulin sensitivity. In a group of 79 pre-pubertal children, we found that the correlation between the minimal model and RHOMA (r = –0.4) was no better than that between the minimal model and fasting insulin (r = 0.4), with an even weaker correlation between the minimal model and QUICKI (r = 0.2). In addition, neither HOMA nor QUICKI were able to detect a reduction in insulin sensitivity with obesity or during growth hormone therapy, unlike the minimal model. In children with normal glucose levels, neither HOMA nor QUICKI was superior to fasting insulin. Validation of the derivation formulae for these methods in children is needed before they are more widely used. The potential benefits of these simple fasting techniques is that they are useful in large field studies. However, if the study groups are small or longitudinal changes in insulin sensitivity are sought, more precise techniques such as the clamp or minimal model should be used.
Use of Stable Isotopes to Assess Protein and Amino Acid Metabolism in Children and Adolescents: A Brief Review
Authors: Darmaun Dominique , Mauras Nelly
Published: January 2006

As protein accretion is a prerequisite for growth, studying the mechanisms by which nutrients and hormones promote protein gain is of the utmost relevance to paediatric endocrinology. Tracers are ideally suited for the assessment of protein and amino acid kinetics in vivo, as they provide an estimate of synthesis and turnover. Current tracer approaches in children and adolescents utilize stable isotopes, ‘heavier’ forms of elements that have one or several extra neutrons in the nucleus. Such isotopes are already present at low, but significant, levels in all tissues and foodstuffs, are not radioactive and are devoid of any known side-effects when present in small amounts. L-[1-13C] labelled leucine, given as a 4- to 6-h intravenous infusion, has become the method of choice to assess whole-body protein kinetics. After infusion, any 13C-leucinethat is oxidized appears in the breath as 13CO2, whereas the remainder is incorporated into body proteins through protein synthesis. The isotope enrichments are determined by isotope ratio mass spectrometry and gas chromatography mass spectrometry, and absolute rates of whole-body protein synthesis, oxidation, and breakdown can be extrapolated. This approach has been used extensively to investigate the regulation of protein kinetics by nutrients and by hormones. Attempts have also been made to measure amino acid/protein metabolism in selected body compartments, and to measure the kinetics of specific tissue proteins, for example, muscle, gut, or plasma proteins.
New Imaging Techniques of Fat, Muscle and Liver within the Context of Determining Insulin Sensitivity
Authors: Stefan Norbert , Machann Jürgen , Schick Fritz , Claussen Claus D. , Thamer Claus , Fritsche Andreas , Häring Hans-Ulrich
Published: January 2006

Body fat distribution and ectopic fat deposition are important determinants of insulin sensitivity. Fat deposition in muscle and the liver, in particular, has been found to impair insulin signalling in these insulin-sensitive tissues. Thus, exact quantification of fat content may help to distinguish between different sites of insulin resistance. Increased fat deposition in the visceral compartment compared with the subcutaneous depot also represents an important factor leading to insulin resistance. Recent data clearly showed that visceral fat is a strong determinant of liver fat content. Exact quantification of fat distribution by magnetic resonance imaging and magnetic resonance spectroscopy may help to define distinct ‘fat-distribution phenotypes’. This may allow a search for new candidate genes for type 2 diabetes mellitus and identify, at an early stage, individuals at risk for decline in insulin sensitivity.
Turner Syndrome, Insulin Sensitivity and Growth Hormone Treatment
Authors: Mazzanti Laura , Bergamaschi Rosalba , Castiglioni Laura , Zappulla Franco , Pirazzoli Piero , Cicognani Alessandro
Published: January 2006

Mild insulin resistance appears to be an early metabolic defect in girls with Turner syndrome (TS). Impaired glucose tolerance has been reported in 10–34% of patients with TS, and type 2 diabetes mellitus is 2–4 times more common and occurs at a younger age in girls with TS than in the general population. In a mixed longitudinal and cross-sectional study, we analysed carbohydrate tolerance and insulin sensitivity in 46 children and adolescents with TS who reached their final height after long-term treatment (mean 6.3 ± 2.5 years) with growth hormone (GH: 0.33 mg/kg/week [0.05 mg/kg/day]), and in 36 of these patients who were followed-up after the cessation of GH therapy (mean follow-up, 2.6 ± 2.5 years; range, 1–9.5 years). Patients with TS were compared with an age-matched female control group. Insulin sensitivity appeared to be lower in patients with TS than in controls, even before the start of GH therapy. As in controls, insulin sensitivity decreased with age in patients with TS, and levels were lower in those aged >12 years than in those aged <12 years. GH therapy resulted in good catch-up growth in patients with TS, with final height significantly higher than projected height evaluated before the initiation of GH therapy. Insulin sensitivity increased after 7–8 years of therapy and, on the cessation of GH therapy, returned to pre-treatment levels. The increase in insulin sensitivity seen on the cessation of GH therapy appeared to be influenced negatively by body mass index and triglyceride levels, and correlated positively with the number of years since cessation of GH therapy. As in the general population, excess weight and an abnormal lipid profile, in particular excess triglyceride levels, worsened insulin sensitivity. In conclusion, our study confirms that GH therapy reduces insulin sensitivity, but at its cessation there is a return to pre-therapy values. We therefore report a progressive improvement in carbohydrate tolerance and insulin function in patients with TS, despite an increase in age.
The Role of Growth Hormone in Neural Development
Authors: Scheepens Arjan , Möderscheim Tanja A.E. , Gluckman Peter D.
Published: January 2006

Growth hormone (GH) is integrally involved in the development of the central nervous system (CNS), as well as during its recovery from injury, two processes that share many similarities and may influence CNS functionality. This review discusses some of the most recent findings in the field and, in particular, the ontogeny, distribution, regulation and putative functions of GH and its receptor within the CNS, particularly during development. The relative roles of peripheral GH, acting in part through insulin-like growth factor-I, and of the autocrine/paracrine GH system within the brain are considered. The potential role of GH as a therapeutic agent to influence brain development and function is discussed.
Measuring Social-Cognitive Functions in Children with Somatotropic Axis Dysfunction
Authors: Skuse David , Lawrence Kate , Tang Joey
Published: January 2006

Growth hormone (GH) and insulin-like growth factor I (IGF-I) are expressed in specific regions of the central nervous system during early human development. They may consequently influence aspects of cognition, or emotional and behavioural adjustment from childhood to adulthood, in conditions associated with abnormalities of the somatotropic axis. GH receptors are relatively common within hippocampal and perihippocampal regions that are primarily involved in declarative memory for facts and events. They are also located in structures (e.g. the putamen) that are involved in the processing of social perceptions. IGF-I receptors have been discovered in the amygdala and prefrontal cortex, which contribute to the neural circuits known as the ‘social brain’. The evaluation of emotional, social and behavioural adjustment among children who have deficiencies in GH or IGF-I functional integrity requires the objective assessment of their social-cognitive competence. We describe a computerized test battery, the Schedules for the Assessment of Social Intelligence (SASI), which has been shown to possess excellent psychometric properties in terms of reliability and validity. The SASI, which can be used by both children and adults, may provide new evidence for deficits and treatment effects of GH/IGF-I on emotional, behavioural and cognitive functions.
Effects of Growth Hormone on Cognitive Function
Authors: Ross Judith L.
Published: January 2006

Whether growth hormone deficiency (GHD) and/or treatment in childhood and adolescence influences cognitive outcome in children with GHD or girls with Turner syndrome (TS) is controversial. Previous studies also suggest that quality of life (QoL) is reduced in adults with GHD, particularly in the areas of social isolation and fatigue. Baseline QoL scores were significantly lower in patients with GHD than in the general population of the same age, gender, and nationality. Unfortunately, few data are available describing QoL in children with GHD. TS is a genetic disorder characterized by short stature, gonadal dysgenesis, and a particular neurocognitive profile of normally developed language abilities (particularly verbal intelligence quotients) and impaired visual-spatial and/or visual-perceptual abilities. This study evaluated the effects of GH treatment on neurocognitive function in girls with TS who were enrolled in a long-term, double-blind, placebo-controlled trial of the effects of GH treatment on final adult height. Treatment duration ranged from 1 to 7 years. The major result of this study was the absence of GH treatment effects on cognitive function in girls with TS. GHD and/or treatment in childhood and adulthood influences cognitive and/or QoL outcomes in some but not all studies. This study did not support a role for GH in influencing the characteristic nonverbal neurocognitive deficits associated with TS. However, evaluation of QoL should be a part of the routine clinical management of patients with GHD or TS.
Neurocognitive Function in Adults with Growth Hormone Deficiency
Authors: van Dam P. Sytze
Published: January 2006

The clinical condition of growth hormone deficiency (GHD) as a consequence of pituitary or hypothalamic disease has been associated with reduced cognitive performance. In several studies, neuropsychological assessment has been performed in adults with GHD both before and after growth hormone (GH) replacement therapy. Interpretation of the available data is complicated by the variation in patient selection as well as the neuropsychological tests used in such studies. Most of the available studies indicate that GHD can lead to small, but clinically relevant changes in memory, processing speed and attention. Some of these changes may be reversed by GH replacement, although the number of reliable intervention studies is limited. In addition to the possible clinical relevance of neuropsychological improvement following GH replacement in patients with GHD, the observed findings may be of interest for studies in neurocognitive performance in other conditions associated with changes in the activity of the somatotrophic axis, and in the understanding of underlying pathophysiological mechanisms.
Glycosylation of Recombinant Proforms of Major House Dust Mite Allergens Der p 1 and Der f 1 Decelerates the Speed of Maturation
Authors: Takai Toshiro , Mizuuchi Eri , Kikuchi Yuko , Nagamune Teruyuki , Okumura Ko , Ogawa Hideoki
Published: January 2006

Background: The efficient manufacture of recombinant Der p 1 and Der f 1 has been an important bottleneck in the study of house dust mite allergies and the development of applications for allergen engineering. While Der f 1 has only one N-glycosylation motif in the mature sequence, Der p 1 has two motifs, one in the prosequence and the other in the mature sequence. To test whether inefficient maturation of a recombinant Pro-Der p 1 versus Pro-Der f 1 is due to N-glycosylation, the maturation speed of N-glycosylation motif mutants was compared. Methods: Expression vectors for the mutants, in which the motif in the Der p 1 prodomain was disrupted or a motif was created within the Der f 1 prodomain, were constructed by site-directed mutagenesis of preproforms with or without the motif within the mature portion. Culture supernatants of yeast Pichia pastoris transfectant cells containing proforms were buffer exchanged by gel filtration and incubated for maturation. Samples from the reactions were collected every 20 min and subjected to electrophoresis. The maturation speed was compared based on the band densities of the pro- and mature forms. Results: Disruption of the motif in the mature portion decreased the productivity and accelerated the maturation. Maturation was also accelerated by disruption of the other motif in the Der p 1 prodomain and slowed down by introduction of the motif into the Der f 1 prodomain. Conclusions: Maturation systems using Pro-Der p 1 without the prodomain glycosylation are useful for the efficient preparation of a recombinant mature allergen. In addition, these results demonstrated that the maturation of cysteine protease could be controlled through glycosylation of the prodomain.
Idiopathic Premature Ovarian Failure in 63 Young Women
Authors: Massin N. , Czernichow C. , Thibaud E. , Kuttenn F. , Polak M. , Touraine P.
Published: January 2006

Background: Premature ovarian failure (POF) in adolescents is defined as primary or secondary amenorrhea associated with high follicle-stimulating hormone (FSH) levels. In normal 46,XX patients, its etiology is most often unknown. We have evaluated the clinical, hormonal and ovarian phenotypes in patients with a normal karyotype who were diagnosed with POF before the age of 18. Methods: Sixty-three patients were included in this retrospective study. Results: The mean patient age was 20.4 years. The patients presented with three clinical patterns: lack of pubertal development (n = 23), primary amenorrhea with interrupted puberty (n = 18), and secondary amenorrhea with normal puberty (n = 22). Ten patients had a familial history of POF and 6 presented with hypothyroidism. The FSH, estradiol and inhibin B levels were not statistically different in the three clinical groups. Fifty percent of the patients presented small ovaries (length <2 cm) at ultrasonography. The presence of follicles was found at histology in only 7 of the 27 patients who underwent an ovarian biopsy. Conclusion: 46,XX patients presenting with early POF rarely presented a specific, identifiable disorder. We discuss the clinical management and different diagnosis strategies to improve our current knowledge of this syndrome.
A Phase II Trial with Cisplatin-Paclitaxel Cytotoxic Treatment and Concurrent External and Endocavitary Radiation Therapy in Locally Advanced or Recurrent Cervical Cancer
Authors: Miglietta L. , Franzone P. , Centurioni M.G. , Boni L. , Tacchini L. , Cosso M. , Boccardo F. , Ferrarini M. , Bruzzone M.
Published: January 2006

Background: Five randomized studies have demonstrated a beneficial effect of adding cisplatin-based chemotherapy to radiation therapy in the treatment of cervical carcinoma. In the present phase II study, we evaluated the response and toxicity of ciplatin-Taxol chemotherapy combined with concomitant radiotherapy in patients with locally advanced cervical carcinoma (LACC) and locally recurrent cervical carcinoma (LRCC). Patients and Methods: In 2000, this phase II study was initiated with a chemotherapy regimen of cisplatin (75 mg/m2) and Taxol (175 mg/m2) every 21 days, for four cycles, concomitant with external radiotherapy and high-dose-rate brachytherapy. Pelvic radiotherapy was started 2 weeks after the first chemotherapy cycle, while the first brachytherapy insertion was carried out during the fourth chemotherapy cycle. SCC marker was determined before treatment and after every chemotherapy cycle. Results: All of the 27 patients treated achieved a complete clinical response. Two patients with LACC experienced distant recurrence 22 and 24 months after complete response, respectively, and 1 patient with LRCC had local progression 6 months after the end of radiotherapy. Although generally tolerable, neutropenia grade 3–4 in 4 patients and anemia grade 3 in 2 patients were observed, and 1 patient experienced grade 2 neurotoxicity; toxicity due to radiotherapy was moderate. Conclusions: Concomitant cisplatin-Taxol chemoradiotherapy seems to be well tolerated, and results, even in this small series, are encouraging.
Proangiogenic Effects of Protease-Activated Receptor 2 Are Tumor Necrosis Factor-α and Consecutively Tie2 Dependent
Authors: Zhu Tang , Sennlaub Florian , Beauchamp Martin Hervé , Fan Li , Joyal Jean Sebastian , Checchin Daniella , Nim Satra , Lachapelle Pierre , Sirinyan Mirna , Hou Xin , Bossolasco Michela , Rivard Georges-Etienne , Heveker Nikolaus , Chemtob Sylvain
Published: January 2006

Objective—Angiogenesis is essential physiologically in growth and pathologically in tumor development, chronic inflammatory disorders, and proliferative retinopathies. Activation of protease-activated receptor 2 (PAR2) leads to a proangiogenic response, but its mechanisms have yet to be specifically described. Here, we investigated the mode of action of PAR2 in retinal angiogenesis.

Methods and Results—PAR2-activating peptide, SLIGRL, increased retinal angiogenesis associated with an induction of vascular endothelial growth factor and angiopoetin-2 and most notably tie2 in the retina in vivo as well as in cultured neuroretinal endothelial cells. SLIGRL also induced release of the proinflammatory and angiogenic mediator tumor necrosis factor-α (TNF-α) via the MEK/extracellular signal-regulated kinase (ERK) (MEK/ERK) pathway in these endothelial cells. TNF-α, in turn, elicited tie2 expression by activating the MEK/ERK pathway. PAR2-evoked tie2 expression, endothelium proliferation (in vitro), and retinal neovascularization (in vivo) were abrogated by selective TNF-α blockers (neutralizing antibody infliximab and soluble TNF-α receptor-Fc fusion protein etanercept) as well as the MEK inhibitor PD98059.

Conclusion—The proangiogenic properties of PAR2 are intertwined with its proinflammatory effects, such that in retinal vasculature, they depend on TNF-α and subsequent induction of tie2 via the MEK/ERK pathway.
Cholesteryl Ester Transfer Protein (CETP) Inhibition Beyond Raising High-Density Lipoprotein Cholesterol Levels
Authors: Klerkx Anke H.E.M. , Harchaoui Karim El , van der Steeg Wim A. , Boekholdt S. Matthijs , Stroes Erik S.G. , Kastelein John J.P. , Kuivenhoven Jan Albert
Published: January 2006

Raising high-density lipoprotein cholesterol (HDL-C) is a promising strategy in the struggle to prevent cardiovascular disease, and cholesteryl ester transfer protein (CETP) inhibitors have been developed to accomplish this. The first results are encouraging, and, in fact, in rabbits, inhibition of CETP reduces atherosclerosis. Because human data regarding the reduction of atheroma burden require more time, the biochemical mechanisms underlying the putative atheroprotection of CETP inhibitors are currently dissected, and several pathways have emerged. First, CETP inhibition increases HDL-C and reduces low-density lipoprotein cholesterol (LDL-C) levels consistent with CETP lipid transfer activity and its role in reverse cholesterol transport (RCT). This coincides with putative beneficial increases in both HDL and LDL size. However, many aspects regarding the impact of CETP inhibition on the RCT pathway remain elusive, in particular whether the first step concerning cholesterol efflux from peripheral tissues to HDL is influenced. Moreover, the relevance of scavenger receptor BI and consequently the central role of HDL in human RCT is still unclear. Second, CETP inhibition was shown recently to increase antioxidant enzymes associated with HDL, in turn associated with decreased oxidation of LDL. Atheroprotection in man is currently anticipated based on the improvement of these biochemical parameters known to influence atherosclerosis, but final confirmation regarding the impact of CETP inhibition on cardiovascular outcome will have to come from trials evaluating clinical end points.
Angiotensin II Attenuates Endothelium-Dependent Responses in the Cerebral Microcirculation Through Nox-2–Derived Radicals
Authors: Girouard Helene , Park Laibaik , Anrather Josef , Zhou Ping , Iadecola Costantino
Published: January 2006

Objective—Angiotensin II (Ang II) exerts deleterious effect on the cerebral circulation through production of reactive oxygen species (ROS). However, the enzymatic source of the ROS has not been defined. We tested the hypothesis that Ang II impairs endothelium-dependent responses in the cerebral microcirculation through ROS generated in cerebrovascular cells by the enzyme NADPH oxidase.

Methods and Results—Cerebral blood flow (CBF) was monitored by laser Doppler flowmetry in anesthetized mice equipped with a cranial window. Ang II (0.25±0.02 μg/kg per minute for 30 to 45 minutes) attenuated the CBF increase produced by the endothelium-dependent vasodilators acetylcholine (−42±5%;P<0.05), bradykinin (−53±5%;P<0.05), and A23187 (−43±4%;P<0.05), and induced cerebrovascular ROS production, assessed by hydroethidine fluoromicrography. These actions of Ang II were prevented by losartan, by the ROS scavenger Mn(III) tetrakis (4-benzoic acid) porphyrin chloride (100 μmol/L), or by the NADPH oxidase peptide inhibitor gp91ds-tat (1 μmol/L), and were not observed in mice lacking the NADPH oxidase subunit gp91phox(nox-2).

Conclusions—Ang II impairs the endothelial regulation of the cerebral microcirculation through AT1 receptor-mediated cerebrovascular oxidative stress. The source of the ROS is a nox-2-containing NADPH oxidase. These effects of Ang II could threaten the cerebral blood supply and contribute to the increased susceptibility to stroke and dementia associated with hypertension.
Upregulated TRPC1 Channel in Vascular Injury In Vivo and Its Role in Human Neointimal Hyperplasia
Authors: Kumar B. , Dreja K. , Shah S.S. , Cheong A. , Xu S.-Z. , Sukumar P. , Naylor J. , Forte A. , Cipollaro M. , McHugh D. , Kingston P.A. , Heagerty A.M. , Munsch C.M. , Bergdahl A. , Hultgårdh-Nilsson A. , Gomez M.F. , Porter K.E. , Hellstrand P. , Beech D.J.
Published: January 2006

Occlusive vascular disease is a widespread abnormality leading to lethal or debilitating outcomes such as myocardial infarction and stroke. It is part of atherosclerosis and is evoked by clinical procedures including angioplasty and grafting of saphenous vein in bypass surgery. A causative factor is the switch in smooth muscle cells to an invasive and proliferative mode, leading to neointimal hyperplasia. Here we reveal the importance to this process of TRPC1, a homolog of
Drosophila
transient receptor potential. Using 2 different in vivo models of vascular injury in rodents we show hyperplasic smooth muscle cells have upregulated TRPC1 associated with enhanced calcium entry and cell cycle activity. Neointimal smooth muscle cells after balloon angioplasty of pig coronary artery also express TRPC1. Furthermore, human vein samples obtained during coronary artery bypass graft surgery commonly exhibit an intimal structure containing smooth muscle cells that expressed more TRPC1 than the medial layer cells. Veins were organ cultured to allow growth of neointimal smooth muscle cells over a 2-week period. To explore the functional relevance of TRPC1, we used a specific E3-targeted antibody to TRPC1 and chemical blocker 2-aminoethoxydiphenyl borate. Both agents significantly reduced neointimal growth in human vein, as well as calcium entry and proliferation of smooth muscle cells in culture. The data suggest upregulated TRPC1 is a general feature of smooth muscle cells in occlusive vascular disease and that TRPC1 inhibitors have potential as protective agents against human vascular failure.
CD34
−
/CD133
+
/VEGFR-2
+
Endothelial Progenitor Cell Subpopulation With Potent Vasoregenerative Capacities
Authors: Friedrich Erik B. , Walenta Katrin , Scharlau John , Nickenig Georg , Werner Nikos
Published: January 2006

Our goal was to identify functionally important subpopulations within the heterogenous group of endothelial progenitor cells (EPC). Fluorescence-activated cell sorter analysis of CD133
+
progenitor cells revealed the presence of CD34
+
and CD34
−
subpopulations. CD34
−
/133
+
progenitors differentiate into CD34
+
/133
+
EPC, adhere more potently than these in response to SDF-1, and rapidly home to sites of limb ischemia in human volunteers. In human coronary atherectomy samples, fewer CD34
−
/133
+
than CD34
+
/133
+
EPC are present in stable plaques, whereas cell numbers increase with a reversion of the ratio in unstable lesions. In CD34
−
/133
+
EPC-injected nude mice, more transplanted cells coexpressing endothelial markers home to carotid artery lesion endothelium than in CD34
+
/133
+
-injected mice. In the former, lesions were smaller and reendothelialization higher than in the latter. We identified a new CD34
−
/133
+
EPC subpopulation, which is apparently a precursor of “classical” CD34
+
/133
+
EPC, and functionally more potent than these with respect to homing and vascular repair.
Exercise Can Prevent and Reverse the Severity of Hypertrophic Cardiomyopathy
Authors: Konhilas John P. , Watson Peter A. , Maass Alexander , Boucek Dana M. , Horn Todd , Stauffer Brian L. , Luckey Stephen W. , Rosenberg Paul , Leinwand Leslie A.
Published: January 2006

Hypertrophic cardiomyopathy (HCM) is the most common form of sudden death in young competitive athletes. However, exercise has also been shown to be beneficial in the setting of other cardiac diseases. We examined the ability of voluntary exercise to prevent or reverse the phenotypes of a murine model of HCM harboring a mutant myosin heavy chain (MyHC). No differences in voluntary cage wheel performance between nontransgenic (NTG) and HCM male mice were seen. Exercise prevented fibrosis, myocyte disarray, and induction of “hypertrophic” markers including NFAT activity when initiated before established HCM pathology. If initiated in older HCM animals with documented disease, exercise reversed myocyte disarray (but not fibrosis) and “hypertrophic” marker induction. In addition, exercise returned the increased levels of phosphorylated GSK-3β to those of NTG and decreased levels of phosphorylated CREB in HCM mice to normal levels. Exercise in HCM mice also favorably impacted components of the apoptotic signaling pathway, including Bcl-2 (an inhibitor of apoptosis) and procaspase-9 (an effector of apoptosis) expression, and caspase-3 activity. Remarkably, there were no differences in mortality between exercised NTG and HCM mice. Thus, not only was exercise not harmful but also it was able to prevent and even reverse established cardiac disease phenotypes in this HCM model.