First Time In Humans Research Articles

Palliative Potts shunt for the treatment of children with drug-refractory pulmonary arterial hypertension: updated data from the first 24 patients.

Palliative Potts shunt has been proposed in children with suprasystemic pulmonary arterial hypertension (PAH). A retrospective multicentre study was performed to assess short- and long-term outcomes after Potts shunt. From 2003 to 2014, 24 children underwent a Potts shunt [19 surgical, median age: 7.7 years (1.5-17 years), median weight: 19.5 kg (10.2-47 kg) and 5 transcatheter, median age: 8.1 years (2.3-9.7 years), median weight: 22 kg (12.5-31 kg)] for drug-refractory PAH. For the first time in humans, we performed an unidirectional valved Potts anastomosis in a child with infrasystemic PAH on intravenous epoprostenol who experienced repeated central line infections. Severe postoperative complications occurred in 6 patients (25.0%, all from the surgical group) including 3 early deaths (12.5%) related to low cardiac output. After a median follow-up (FU) of 2.1 years (range, 3 months to 14.3 years, ≥8 years in 7 patients), World Health Organization (WHO) functional class was dramatically improved in the 21 survivors, all being in WHO-functional class 1 or 2 (P < 0.05); none experienced syncope during the FU; none had overt right ventricular failure; mean 6-min walk distance improved from 42.3 ± 10.0% to 81.2 ± 9.7% of adjusted values for age and sex (P < 0.001), BNP/NT-proBNP levels normalized in all; and weaning of intravenous epoprostenol was obtained in all patients who received triple combination as pre-Potts anastomosis therapy. Finally, all survivors caught up to normal growth curves. Arterial oxygen saturation gradient between upper and lower limbs persisted at the last FU (94.7 ± 3.6% vs 81.6 ± 5.1%, P < 0.001). One patient required double lung transplantation 6 years after a surgical Potts shunt. Palliative Potts shunt allows prolonged survival and dramatic, long-lasting improvement in functional capacities in children with severe, drug-refractory PAH. The Potts shunt might be considered as a first surgical or interventional step in the management of children with severe, drug-refractory PAH, leaving the door open for further lung transplantation, if needed.

Periodontal disease associates with higher brain amyloid load in normal elderly

The accumulation of amyloid-β (Aβ) plaques is a central feature of Alzheimer's disease (AD). First reported in animal models, it remains uncertain if peripheral inflammatory and/or infectious conditions in humans can promote Aβ brain accumulation. Periodontal disease, a common chronic infection, has been previously reported to be associated with AD. Thirty-eight cognitively normal, healthy, and community-residing elderly (mean age, 61 and 68% female) were examined in an Alzheimer's Disease Research Center and a University-Based Dental School. Linear regression models (adjusted for age, apolipoprotein E, and smoking) were used to test the hypothesis that periodontal disease assessed by clinical attachment loss was associated with brain Aβ load using 11C-Pittsburgh compound B (PIB) positron emission tomography imaging. After adjusting for confounders, clinical attachment loss (≥3 mm), representing a history of periodontal inflammatory/infectious burden, was associated with increased PIB uptake in Aβ vulnerable brain regions (p = 0.002). We show for the first time in humans an association between periodontal disease and brain Aβ load. These data are consistent with the previous animal studies showing that peripheral inflammation/infections are sufficient to produce brain Aβ accumulations.

Effects of somatosensory stimulation on corticomotor excitability in patients with unilateral cerebellar infarcts and healthy subjects - preliminary results.

BackgroundIn healthy humans, somatosensory stimulation in the form of 2 h-repetitive peripheral afferent nerve stimulation (SS) increases excitability of the contralateral motor cortex. In this preliminary study, we explored effects of SS on excitability to transcranial magnetic stimulation (TMS) in patients with unilateral cerebellar infarcts and age-matched controls.MethodsTen patients with infarcts in one cerebellar hemisphere and six age-matched controls participated in the study. Each subject participated in one session of active, and one session of sham SS delivered to the median nerve ipsilateral to the cerebellar infarct in patients, and to the homologous nerve in controls. Before and after each session, the following TMS measures were performed: resting motor threshold (rMT), motor evoked potentials (MEPs), short-interval intracortical inhibition (SICI) and short-interval intracortical facilitation (SICF). Amplitudes of motor evoked potentials were normalized to amplitudes of supramaximal M responses (MEP/M ratios).ResultsIn the control group, there was a significant increase in rMT, and a significant increase in MEP/M ratios after active, but not after sham SS. There were no significant differences in rMT or MEP/M ratios in the group of patients after active or sham SS. There were no significant differences in SICI or SICF after active or sham SS in either group.ConclusionConsistent with results reported in rodents, these preliminary findings suggest for the first time in humans, that normal cerebellar activity is required so that SS can modulate excitability of the sensorimotor cortex.

Safety, tolerability, pharmacokinetics, and pharmacodynamics of single-dose antiinterleukin- 18 mAb GSK1070806 in healthy and obese subjects.

To investigate the safety, tolerability, pharmacokinetics, and pharmacodynamics of GSK1070806, a novel IgG1 mAb that neutralizes human interleukin (IL)-18. In this first-timein-human (FTIH) study, cohorts of healthy and obese subjects were randomly allocated to receive single doses of GSK1070806 (0.008 - 10 mg/kg) or placebo. Blood was sampled ≤ 274 days post-dosing, and safety monitored. GSK1070806 was generally well tolerated. The most common AEs were nasopharyngitis and headache, arising as frequently in the placebo as in the active drug groups; most AEs were mild to moderate and unrelated to dose level. There were no allergic, delayed-type hypersensitivity, or infusion-related reactions and the incidence of immunogenicity was low. GSK1070806 plasma pharmacokinetic profiles were comparable in healthy and obese subjects; there was no major deviation from dose proportionality for AUC(∞) and C(max) although a trend for dose-dependent increase in t(1/2) was observed. Serum drug-bound IL-18 levels increased post-dosing and were sustained for a long time-period following GSK1070806 administration. Ex-vivo whole blood assay demonstrated prolonged pharmacological activity of GSK1070806 as determined by its primary immunological mechanism of action, inhibition of IL-18-induced IFN-γ production. GSK1070806 warrants clinical investigation in patients.

Unfolded protein response activation in cataracts

To analyze the expression of 78 kDa glucose-regulated protein (GRP78) and activating transcription factor 6 (ATF6), 2 factors in the unfolded protein response (UPR), in age-related and diabetes-associated cataract. Universidad Autónoma de Aguascalientes, Aguascalientes, México. Experimental study. The qualitative and quantitative expression of GRP78 and ATF6 were measured in surgical samples from 11 senile cataracts, 9 diabetic-associated cataracts, and 3 normal lenses. Both proteins were detected by immunofluorescence and immunogold-conjugated antibodies. Quantitative morphometry was used to analyze the differences in GRP78 and ATF6 between samples. The Mann-Whitney test was used for statistical analysis. Scanning electron microscopy showed the characteristic organization of fibers in normal lenses with regular alignment and interdigitation between them. On the other hand, lenses from eyes with senile or diabetic cataract showed the same pattern of misalignment and disorganization of the fibers. Both proteins were detected through immunofluorescence in senile and diabetic cataracts, but not in normal lenses. Immunogold-conjugated antibodies and transmission electron microscopy showed that GRP78 and ATF6 grains were 30% higher and 35% higher, respectively, in diabetic cataracts than in senile cataracts (P<.05). These data show for the first time in humans that GRP78 and ATF6 are present in lens fibers of senile cataracts and diabetic cataracts, establishing that the UPR may be important in the process of cataractogenesis. No author has a financial or proprietary interest in any material or method mentioned.

Gender and functional CYP2C and NAT2 polymorphisms determine the metabolic profile of metamizole

Metamizole is a pain-killer drug that has been banned in some countries because of its toxicity, but it is still used in many countries due to its effective analgesic and antispasmodic properties. Although large variability in the biodisposition and adverse effects of metamizole are known, factors underlying this variability are poorly understood.We analyzed the urinary recovery of metabolites, as well as the association of these profiles with genetic and non-genetic factors, in a group of 362 healthy individuals.Gender and functional polymorphisms are strongly related to metabolic profiles. N-demethylation of the active metabolite MAA is diminished in carriers of the CYP2C19*2 allele and in NAT2-slow acetylators. Acetylation of the secondary metabolite AA is decreased in men, in drinkers and in NAT2-slow acetylators with a differential effect of NAT2*5 and NAT2*6 alleles. The formylation of MAA is diminished in older subjects and in carriers of defect CYP2C9 and CYP2C19 alleles. Two novel arachidonoyl metabolites were identified for the first time in humans. Women and NAT2-slow acetylators show higher concentrations, whereas the presence of the rapid CYP2C19*17 allele is associated with lower concentrations of these metabolites. All genetic associations show a gene-dose effect.We identified for the first time genetic and non-genetic factors related to the oxidative metabolism of analgesic drug metamizole, as well as new active metabolites in humans. The phenotypic and genetic factors identified in this study have a potential application as biomarkers of metamizole biotransformation and toxicity.

Bayesian adaptive designs in single ascending dose trials in healthy volunteers

Recent publications indicate a strong interest in applying Bayesian adaptive designs in first time in humans (FTIH) studies outside of oncology. The objective of the present work was to assess the performance of a new approach that includes Bayesian adaptive design in single ascending dose (SAD) trials conducted in healthy volunteers, in comparison with a more traditional approach. A trial simulation approach was used and seven different scenarios of dose-response were tested. The new approach provided less biased estimates of maximum tolerated dose (MTD). In all scenarios, the number of subjects needed to define a MTD was lower with the new approach than with the traditional approach. With respect to duration of the trials, the two approaches were comparable. In all scenarios, the number of subjects exposed to a dose greater than the actual MTD was lower with the new approach than with the traditional approach. The new approach with Bayesian adaptive design shows a very good performance in the estimation of MTD and in reducing the total number of healthy subjects. It also reduces the number of subjects exposed to doses greater than the actual MTD.

Cellular Metabolic Regulators

The Toll-like receptor 4 (TLR4) ligand endotoxin triggers robust systemic inflammatory responses in humans at doses equal to or greater than 1 ng/kg. In this study, we tested the hypothesis that evidence of TLR4-induced responses would be detectable in leukocytes challenged with endotoxin doses that are below the threshold needed to trigger a characteristic systemic inflammatory phenotype in humans. Subjects were challenged with endotoxin at 1, 0.5, or 0.1 ng/kg (n = 5 per dose). Systemic responses were monitored for 24 hours. Blood samples, collected at designated intervals, were used to determine plasma cytokines levels, total and differential leukocyte counts, expression of leukocyte cell surface receptors, and changes in the leukocyte transcriptome. Western blotting was used to determine changes in leukocyte protein expression. We found that in vivo endotoxin at doses below 1.0 ng/kg triggers weak and variable responses in humans. In marked contrast, we show that endotoxin at a concentration as low as 0.1 ng/kg triggers a transient decline in cellular ATP levels in leukocytes. This is associated with the appearance of a unique protein expression signature in leukocytes. The protein expression signature includes 3 prominent features: (i) AMP-activated protein kinase subunit α (AMPKα) degradation, (ii) increased hypoxia inducible factor-1 (HIF-1) α expression, and (iii) autophagy, collectively indicative of a regulated metabolic response. An indistinguishable response phenotype was observed in human leukocytes treated with endotoxin in vitro. These data demonstrate for the first time in humans that a TLR4 ligand concentration that is below the threshold needed to trigger clinically evident systemic inflammatory manifestations initiates a transient decline in ATP levels, AMPKα degradation, HIF-1α expression, and autophagy in leukocytes. This establishes that low-grade TLR4 activation exerts control over leukocyte metabolism in the absence of systemic inflammatory indicators.

Impact of metformin on endothelial ischemia-reperfusion injury in humans in vivo: a prospective randomized open, blinded-endpoint study.

IntroductionLarge prospective studies in patients with type 2 diabetes mellitus have demonstrated that metformin treatment improves cardiovascular prognosis, independent of glycemic control. Administration of metformin potently limits infarct size in murine models of myocardial infarction. This study examined, for the first time in humans, whether metformin limits ischemia-reperfusion (IR) injury in vivo using a well-validated forearm model of endothelial IR-injury.MethodsTwenty-eight healthy volunteers (age 41±6 years, 10 male/16 female) were randomized between pretreatment with metformin (500 mg three times a day for 3 days) or no treatment in a Prospective Randomized Open Blinded Endpoint study. Brachial artery flow mediated dilation (FMD) was measured before and after 20 minutes of forearm ischemia and 20 minutes of reperfusion. FMD analysis was performed offline by investigators blinded for the treatment arm.ResultsBaseline FMD did not differ between metformin pretreatment and no pretreatment (6.9±3.6% and 6.1±3.5%, respectively, p = 0.27, n = 26). FMD was significantly lower after forearm IR in both treatment arms (4.4±3.3% and 4.3±2.8%, respectively, P<0.001 in both conditions). A linear mixed model analysis revealed that metformin treatment did not prevent the decrease in FMD by IR.ConclusionA 3 day treatment with metformin in healthy, middle-aged subjects does not protect against endothelial IR-injury, measured with brachial artery FMD after forearm ischemia. Further studies are needed to clarify what mechanism underlies the cardiovascular benefit of metformin treatment.Trial Registration ClinicalTrials.gov NCT01610401

Skeletal muscle proteomic signature in pulmonary arterial hypertension (1158.8)

Introduction: Pulmonary arterial hypertension (PAH) is characterized by a progressive increase in pulmonary vascular resistance leading to right ventricular (RV) hypertrophy and ultimately failure. Numerous observations suggest that exercise limitation in pulmonary arterial hypertension (PAH) is not solely due to cardio‐pulmonary impairment, but that other determinants such as skeletal muscle abnormalities are involved. To better understand the exercise limitation origins in PAH, we studied the proteomic signature of skeletal muscle impairment in idiopathic PAH (iPAH) patients.Methods and results: Muscle proteins from 4 iPAH patients and 4 sex and age matched controls were extracted following quadriceps muscle biopsy. Fractioned peptides were then tagged using isobaric Tags for Relative and Absolute Quantitation (iTRAQ, ABsciex) specific for each patient. Tagged peptides were then mixed, fractioned, identified and quantified using mass spectrometry quantitative method. Over 900 proteins were identified, among them, 9 were under‐expressed and 7 were over‐expressed in all iPAH patient quadriceps. More than 75% of the under‐expressed proteins are involved in oxidative metabolism and most other highlighted proteins play a role in myogenesis. These findings were structurally associated with decreased mitochondrial density (citrate synthase assay) and impaired mitochondrial structure measured by electronic microscopy, while muscle fibers distribution was unchanged. Functionally, all these abnormalities resulted in decreases in oxidative metabolism (pyruvate dehydrogenases assay).Conclusions: For the first time in humans, we provide evidences that, as in lungs and the right ventricle, the impaired mitochondrial metabolism is also present in skeletal muscle suggesting that PAH might be considered as a global mitochondrial/metabolic disease.

The nature of the control of blood glucose in those with poorer glucose tolerance influences mood and cognition

The ability to control the levels of blood glucose was related to mood and cognition. 155 adults, aged 45-85 years, without a diagnosis of diabetes, were given an oral glucose tolerance test and cognitive tests. Participants were classified according to age (41-60/61-85 years), whether they had better or poorer glucose tolerance and whether blood glucose did or did not fall below baseline values. There were two main findings. Those with poorer glucose tolerance forgot more words and had slower decision times, but only if 61 years or older. Secondly as there are reports in animal studies that inducing low levels of blood glucose values benefited cognitive performance, for the first time in humans, individual differences in the tendency to develop low levels of blood glucose were considered. In those with poor glucose tolerance a tendency for blood glucose to fall below baseline values was associated with better mood and faster working memory.

Wet Cupping Therapy Restores Sympathovagal Imbalances in Cardiac Rhythm

A recent study showed that cupping had therapeutic effects in rats with myocardial infarction and cardiac arrhythmias. The current studyaimed to investigate the possible useful effects of cupping therapy on cardiac rhythm in terms of heart rate variability (HRV). Forty healthy participants were included. Classic wet cupping therapy was applied on five points of the back. Recording electrocardiography (to determine HRV) was applied 1 hour before and 1 hour after cupping therapy. All HRV parameters increased after cupping therapy compared with before cupping therapy in healthy persons. These results indicate for the first time in humans that cupping might be cardioprotective. In this study, cupping therapy restored sympathovagal imbalances by stimulating the peripheral nervous system.

No pain, no gain: somatosensation from skeletal muscle

No pain, no gain: somatosensation from skeletal muscle

The rise and control of the 2007–2012 human Q fever outbreaks in the Netherlands

Q fever is an almost ubiquitous zoonosis caused by Coxiella burnetii, which is able to infect several animal species, as well as people. Cattle, sheep and goats are the primary animal reservoirs. In small ruminants, an infection may result in abortion and stillbirth. Infected animals can shed the organism in faeces, milk and mainly in foetal membranes and foetal fluids. Transmission to humans mainly occurs through the aerosol route.Q fever was described as a febrile illness, which had started to occur in 1933 in abattoir workers in Brisbane, Australia. Since the first documented outbreaks, Q fever has been described in many countries all over the world, and in 1955 its existence was reported in 51 countries on five continents. In the Netherlands, Q fever was diagnosed for the first time in humans in 1956, and became a notifiable disease in 1978. Between 1978 and 2006, the average number of notifications per annum was seventeen. In 2007, the first year of what later turned out to be one of the largest recorded community outbreaks of Q fever, an outbreak occurred with 168 human patients notified, and in 2008 and 2009, 1000 and 2354 human Q fever patients were notified, respectively, and dairy goats were suspected to be the source.In 2005, C. burnetii was diagnosed for the first time as a cause of abortion at two dairy goat farms in the Netherlands. In 2006, 2007, 2008, and 2009, six, seven, seven, and six new abortion waves at dairy goat farms were confirmed, respectively. The infected dairy goat farms were mainly located in the same area where human cases occurred and they were considered the most plausible source of human infection. In the same period, cases of abortion caused by C. burnetii were confirmed at two dairy sheep farms.Since 2007, a large multidisciplinary research portfolio has started, aimed at generating better knowledge about this disease. In June 2008, Q fever in small ruminants kept for milk production became notifiable in the Netherlands for farms with an abortion rate of more than five per cent. In the autumn of 2008, a voluntary vaccination campaign in goats was made possible in the high-risk Q fever area in the south of the Netherlands with the so far unregistered phase I vaccine containing inactivated C. burnetii (Coxevac®, CEVA Santé Animale). From 2009 onwards, vaccination became compulsory for dairy sheep and dairy goat farms in the south of the country, and was compulsory in the whole country from January 2010 onwards for dairy sheep and dairy goat farms, and for small ruminant farms offering recreational activity. Since February 2009, a stringent hygiene protocol became mandatory for all dairy goat and dairy sheep farms, and on 1 October 2009, bulk milk monitoring became mandatory on farms with more than fifty dairy goats or dairy sheep, and C. burnetii PCR positive bulk milk has since been used as an additional criterion for veterinary notification of Q fever. At the end of 2009, it was decided to cull all pregnant animals on farms with a C. burnetii PCR positive bulk tank milk. Since 2010, there was a sharp decline in the number of notified human cases with 504, 81, and 66 cases notified in 2010, 2011, and 2012, respectively. In combination with a rise in the human population with antibodies against C. burnetii, the implemented control measures most likely have ended this large outbreak.

Evaluation Of Afuresertib, An Oral Pan-AKT Inhibitor, In Patients With Langerhans Cell Histiocytosis

▪ BackgroundLangerhans cell histiocytosis (LCH) is a heterogeneous disease whose myriad manifestations result from accumulation of Langerhans cells in a variety of organs most commonly including skin, bone, central nervous system, liver, lymph nodes, and bone marrow. The disease can affect people of any age. Treatment is primarily driven by disease extent and organ involvement and can range from focused radiation or surgery to multi-agent chemotherapy. There is a relatively high recurrence rate following complete remissions with conventional chemotherapy. In the first-time-in-human (FTIH) study of the oral pan-AKT inhibitor afuresertib (GSK2110183), in patients with hematologic malignancies, a patient with refractory multi-system LCH experienced a prolonged period (> 3 years) of clinical benefit on 125mg oral once daily afuresertib. This observation led to the evaluation of the use of afuresertib in patients with LCH. MethodsThis single-arm, open-label trial was designed to evaluate the efficacy and safety of afuresertib, administered at 125 mg once daily, in adults and adolescents with relapsed/refractory LCH and adults with treatment-naïve LCH. Secondary objectives included pharmacokinetics. Diagnosis of LCH was confirmed by pathology review of archival tissue. The Histiocyte Society criteria were used for response evaluation at three and six months with safety and pharmacokinetic assessments performed at pre-specified intervals. BRAF status from archival tissue was evaluated by Sanger sequencing. Results17 patients (16 adults, 10 females) were enrolled; median age was 38 years (15-75). 3/17 patients had isolated pulmonary disease, 1/17 had single-system multifocal-bone disease, 1/17 had single-system skin disease, and 12/17 had multi-system disease. Seven patients were treatment-naïve; 10 had relapsed/refractory disease, including the one adolescent. The most frequent (>20% of patients) adverse events (AEs), regardless of causality, were nausea (59%), fatigue (59%), upper respiratory infection (47%), diarrhea (47%), dyspepsia (35%), bone pain (39%), asthenia (24%), memory impairment (24%), decreased appetite (24%) and vomiting (24%). Most AEs were Grade 1 or 2 in severity; no Grade 4 AEs were reported and no Grade 3 AEs occurring in more than 1 subject were reported. 6/17 (35%) had afuresertib dose modifications (interruption or reduction). Afuresertib plasma concentrations in the adult patients were similar to values seen in adult patients with other hematologic malignancies in the FTIH study. Following a single dose, the concentration-time profile in the adolescent patient was similar to adults in the FTIH study (Tmax = 3h: Cmax 229 ng/ml: AUC24 = 3893 ng*h/mL). 15 patients had archival tissues collected for BRAF testing; 13 had DNA suitable for analysis. 2/13 was BRAF V600E mutant and 11/13 were BRAF wild type. Upon evaluation of the all-treated patient population, 5/17 (29%) patients were reported as better at the three and/or six month disease assessment. Among the 5 responders, three were treatment-naïve and two had relapsed/refractory disease. The median duration on study for all patients was 214 (44-426) days. For the 5 patients who responded, the median duration on study was 372 (255-426) days. ConclusionThe pharmacokinetic and safety profile of afuresertib in patients with LCH was consistent with that observed in patients with other hematologic malignancies evaluated in the FTIH study. Afuresertib was active in patients with both treatment-naïve and relapsed/refractory disease. Additional evaluation, including molecular profiling, may be warranted alone or in combination with BRAF inhibitors or established therapies for LCH to determine the optimal population of patients with LCH who might benefit from afuresertib Disclosures:Vassallo:GlaxoSmithKline: Research Funding. Oliff:GlaxoSmithKline: Employment. Morris:GlaxoSMithKline: Employment. Reedy:GlaxoSmithKline: Employment. Portnoy:GlaxoSmithKline: Stock, prior employee Other. Smith:GlaxoSmithKline: Employment, Equity Ownership. Noble:GlaxoSmithKline: Employment, stock Other. Murnane:GlaxoSmithKline: Employment, stock Other. Szabo:GlaxoSmithKline: Employment. Heaney:Novartis: Research Funding; Sanofi-Aventis: Consultancy, Research Funding; Onconova: Research Funding; Incyte: Consultancy, Research Funding.

Central 5-HT4 receptor binding as biomarker of serotonergic tonus in humans: a [11C]SB207145 PET study

Identification of a biomarker that can inform on extracellular serotonin (5-HT) levels in the brains of living humans would enable greater understanding of the way brain circuits are modulated by serotonergic neurotransmission. Substantial evidence from studies in animals and humans indicates an inverse relationship between central 5-HT tonus and 5-HT type 4 receptor (5-HT4R) density, suggesting that 5-HT4R receptor density may be a biomarker marker for 5-HT tonus. Here, we investigated whether a 3-week administration of a selective serotonin reuptake inhibitor, expected to increase brain 5-HT levels, is associated with a decline in brain 5-HT4R binding. A total of 35 healthy men were studied in a placebo-controlled, randomized, double-blind study. Participants were assigned to receive 3 weeks of oral dosing with placebo or fluoxetine, 40 mg per day. Brain 5-HT4R binding was quantified at baseline and at follow-up with [(11)C]SB207145 positron emission tomography (PET). Three weeks of intervention with fluoxetine was associated with a 5.2% reduction in brain 5-HT4R binding (P=0.017), whereas placebo intervention did not change 5-HT4R binding (P=0.52). Our findings are consistent with a model, wherein the 5-HT4R density adjusts to changes in the extracellular 5-HT tonus. Our data demonstrate for the first time in humans that the imaging of central 5-HT4R binding may be used as an in vivo biomarker of the central 5-HT tonus.

Dietary Sodium Restriction and Association with Urinary Marinobufagenin, Blood Pressure, and Aortic Stiffness

Systolic BP and large elastic artery stiffness both increase with age and are reduced by dietary sodium restriction. Production of the natriuretic hormone marinobufagenin, an endogenous α1 Na+,K+-ATPase inhibitor, is increased in salt-sensitive hypertension and contributes to the rise in systolic BP during sodium loading. The hypothesis was that dietary sodium restriction performed in middle-aged/older adults (eight men and three women; 60 ± 2 years) with moderately elevated systolic BP (139 ± 2/83 ± 2 mmHg) would reduce urinary marinobufagenin excretion as well as systolic BP and aortic pulse-wave velocity (randomized, placebo-controlled, and crossover design). This study also explored the associations among marinobufagenin excretion with systolic BP and aortic pulse-wave velocity across conditions of 5 weeks of a low-sodium (77 ± 9 mmol/d) and 5 weeks of a normal-sodium (144 ± 7 mmol/d) diet. Urinary marinobufagenin excretion (weekly measurements; 25.4 ± 1.8 versus 30.7 ± 2.1 pmol/kg per day), systolic BP (127 ± 3 versus 138 ± 5 mmHg), and aortic pulse-wave velocity (700 ± 40 versus 843 ± 36 cm/s) were lower during the low- versus normal-sodium condition (all P<0.05). Across all weeks, marinobufagenin excretion was related with systolic BP (slope=0.61, P<0.001) and sodium excretion (slope=0.46, P<0.001). These associations persisted during the normal- but not the low-sodium condition (both P<0.005). Marinobufagenin excretion also was associated with aortic pulse-wave velocity (slope=0.70, P=0.02) and endothelial cell expression of NAD(P)H oxidase-p47phox (slope=0.64, P=0.006). These results show, for the first time in humans, that dietary sodium restriction reduces urinary marinobufagenin excretion and that urinary marinobufagenin excretion is positively associated with systolic BP, aortic stiffness (aortic pulse-wave velocity), and endothelial cell expression of the oxidant enzyme NAD(P)H oxidase. Importantly, marinobufagenin excretion is positively related to systolic BP over ranges of sodium intake typical of an American diet, extending previous observations in rodents and humans fed experimentally high-sodium diets.

Diet-induced changes in the Lean Brain: Hypercaloric high-fat-high-sugar snacking decreases serotonin transporters in the human hypothalamic region

It is evident that there is a relationship between the brain's serotonin system and obesity. Although it is clear that drugs affecting the serotonin system regulate appetite and food intake, it is unclear whether changes in the serotonin system are cause or consequence of obesity. To determine whether obesogenic eating habits result in reduced serotonin transporter (SERT)-binding in the human hypothalamic region, we included 25 lean, male subjects who followed a 6-week-hypercaloric diet, which were high-fat-high-sugar (HFHS) or high-sugar (HS) with increased meal size or -frequency (=snacking pattern). We measured SERT-binding in the hypothalamic region with SPECT. All hypercaloric diets significantly increased body weight by 3-3.5%. Although there were no differences in total calories consumed between the diets, only a hypercaloric HFHS-snacking diet decreased SERT-binding significantly by 30%. We here show for the first time in humans that snacking may change the serotonergic system increasing the risk to develop obesity.

Perivascular adipose tissue supresses superoxide production in internal mammary artery grafts by regulating Rac1-mediated activation of vascular NADPH-oxidase

Background: Internal mammary artery (IMA) is used as a graft in bypass surgery (CABG), but it is unclear whether it should be harvested with or without its perivascular adipose tissue (PVAT). Given that PVAT produces the antiatherogenic adipokine adiponectin (AdN), we examined the role of AdN as a signalling molecule between PVAT and IMA grafts. Methods: In Study 1, IMA segments were obtained from 364 patients undergoing CABG and used to determine NADPH-oxidase activity by lucigenin chemiluminescence (+/-NADPH 100μM). Mesothoracic (Mt-AT), subcutaneous (Sc-AT) and PVAT were obtained for gene expression studies. In Study 2, IMA segments from 17 patients were exposed ex vivo to AdN (10 μg/ml) for 6 hours ± wortmannin (a PI3K/Akt inhibitor); changes to NADPH-stimulated and Vas2870 (specific NADPH-oxidase inhibitor)-inhibitable O2- as well as the activation and membrane translocation of Rac1 (NADPH-oxidase subunit responsible for its activation) were determined. Results: Elevated circulating AdN was related with reduced NADPH-stimulated O2- (A). Increased expression of ADIPOQ in Mt- and Sc-AT was related with reduced NADPH-oxidase activity, however in PVAT it was associated with increased NADPH-stimulated O2-(B). AdN directly suppressed NADPH-stimulated (C) and Vas2870-inihibitable (D) O2- in the IMA. This was due to reduced activation (E)/membrane translocation (F) of Rac1, which was reversed by wortmannin. ![Figure][1] Conclusions: We demonstrate for the first time in humans, that AdN directly suppresses NADPH-oxidase through an Akt-mediated reduction of Rac1 activation and translocation to the membrane. The observed increase of AdN expression in PVAT in the presence of high oxidative stress may represent a novel, local defence mechanism of IMA against oxidative stress, that warrants further investigation. [1]: pending:yes

Understanding the Links among neuromedin U Gene, beta2-adrenoceptor Gene and Bone Health: An Observational Study in European Children

Neuromedin U, encoded by the NMU gene, is a hypothalamic neuropeptide that regulates both energy metabolism and bone mass. The beta-2 adrenergic receptor, encoded by the ADRB2 gene, mediates several effects of catecholamine hormones and neurotransmitters in bone. We investigated whether NMU single nucleotide polymorphisms (SNPs) and haplotypes, as well as functional ADRB2 SNPs, are associated with bone stiffness in children from the IDEFICS cohort, also evaluating whether NMU and ADRB2 interact to affect this trait. A sample of 2,274 subjects (52.5% boys, age 6.2±1.8 years) from eight European countries, having data on calcaneus bone stiffness index (SI, mean of both feet) and genotyping (NMU gene: rs6827359, rs12500837, rs9999653; ADRB2 gene: rs1042713, rs1042714), was studied. After false discovery rate adjustment, SI was significantly associated with all NMU SNPs. rs6827359 CC homozygotes showed the strongest association (recessive model, Δ = −1.8, p = 0.006). Among the five retrieved haplotypes with frequencies higher than 1% (range 2.0–43.9%), the CCT haplotype (frequency = 39.7%) was associated with lower SI values (dominant model, Δ = −1.0, p = 0.04) as compared to the most prevalent haplotype. A non-significant decrease in SI was observed in in ADRB2 rs1042713 GG homozygotes, while subjects carrying SI-lowering genotypes at both SNPs (frequency = 8.4%) showed much lower SI than non-carriers (Δ = −3.9, p<0.0001; p for interaction = 0.025). The association was more evident in preschool girls, in whom SI showed a curvilinear trend across ages. In subgroup analyses, rs9999653 CC NMU or both GG ADRB2 genotypes were associated with either lower serum calcium or β-CrossLaps levels (p = 0.01). This study in European children shows, for the first time in humans, a role for NMU gene through interaction with ADRB2 gene in bone strength regulation, more evident in preschool girls.