Cardiopulmonary deconditioning and plasma volume loss are not sufficient to provoke orthostatic hypertension

Orthostatic hypertension, defined by an increase of systolic blood pressure (SBP) of ≥20 mmHg upon standing, harbors an increased cardiovascular risk. We pooled data from two rigorously conducted head-down tilt bedrest studies to test the hypothesis that cardiopulmonary deconditioning and hypovolemia predispose to orthostatic hypertension. With bedrest, peak VO2 decreased by 6 ± 4 mlO2/min/kg (p < 0.0001) and plasma volume by 367 ± 348 ml (p < 0.0001). Supine SBP increased from 127 ± 9 mmHg before to 133 ± 10 mmHg after bedrest (p < 0.0001). In participants with stable hemodynamics following head-up tilt, the incidence of orthostatic hypertension was 2 out of 67 participants before bedrest and 2 out of 57 after bedrest. We conclude that in most healthy persons, cardiovascular deconditioning and volume loss associated with long-term bedrest are not sufficient to cause orthostatic hypertension.

Effects of 30 days bed rest and exercise countermeasures on PBMC bioenergetics

AIM

Altered mitochondrial function across various tissues is a key determinant of spaceflight-induced physical deconditioning. In comparison to tissue biopsies, blood cell bioenergetics holds promise as a systemic and more readily accessible biomarker, which was evaluated during head-down tilt bed rest (HDTBR), an established ground-based analog for spaceflight-induced physiological changes in humans. More specifically, this study explored the effects of HDTBR and an exercise countermeasure on mitochondrial respiration in peripheral blood mononuclear cells (PBMCs).

METHODS

We subjected 24 healthy participants to a strict 30-day HDTBR protocol. The control group (n = 12) underwent HDTBR only, while the countermeasure group (n = 12) engaged in regular supine cycling exercise followed by veno-occlusive thigh cuffs post-exercise for 6 h. We assessed routine blood parameters 14 days before bed rest, the respiratory capacity of PBMCs via high-resolution respirometry, and citrate synthase activity 2 days before and at day 30 of bed rest. We confirmed PBMC composition by flow cytometry.

RESULTS

The change of the PBMC maximal oxidative phosphorylation capacity (OXPHOS) amounted to an 11% increase in the countermeasure group, while it decreased by 10% in the control group (p = 0.04). The limitation of OXPHOS increased in control only while other respiratory states were not affected by either intervention. Correlation analysis revealed positive associations between white blood cells, lymphocytes, and basophils with PBMC bioenergetics in both groups.

CONCLUSION

This study reveals that a regular exercise countermeasure has a positive impact on PBMC mitochondrial function, confirming the potential application of blood cell bioenergetics for human spaceflight.

Impact of daily artificial gravity on autonomic cardiovascular control following 60-day head-down tilt bed rest

Impaired cardiovascular autonomic control following space flight or immobilization may limit the ability to cope with additional hemodynamic stimuli. Head-down tilt bedrest is an established terrestrial analog for space flight and offers the opportunity to test potential countermeasures for autonomic cardiovascular deconditioning. Previous studies revealed a possible benefit of daily artificial gravity on cardiovascular autonomic control following head-down tilt bedrest, but there is a need for efficiency in a long-term study before an artificial gravity facility would be brought to space. We hypothesized that artificial gravity through short-arm centrifugation attenuates functional adaptions of autonomic function during head-down tilt bed rest. 24 healthy persons (8 women, 33.4 ± 9.3 years, 24.3 ± 2.1 kg/m2) participated in the 60-day head-down tilt bed rest (AGBRESA) study. They were assigned to three groups, 30 min/day continuous, or 6(5 min intermittent short-arm centrifugation, or a control group. We assessed autonomic cardiovascular control in the supine position and in 5 minutes 80° head-up tilt position before and immediately after bed rest. We computed heart rate variability (HRV) in the time (rmssd) and frequency domain, blood pressure variability, and baroreflex sensitivity (BRS). RR interval corrected rmssd was reduced supine (p = 0.0358) and during HUT (p = 0.0161). Heart rate variability in the high-frequency band (hf-RRI; p = 0.0004) and BRS (p < 0.0001) decreased, whereas blood pressure variability in the low-frequency band (lf-SBP, p = 0.0008) increased following bedrest in all groups. We did not detect significant interactions between bedrest and interventions. We conclude that up to daily 30 min of artificial gravity on a short-arm centrifuge with 1Gz at the center of mass do not suffice to prevent changes in autonomic cardiovascular control following 60-day of 6° head-down tilt bed rest. Clinical Trial Registration: https://drks.de/search/en/trial/DRKS00015677, identifier, DRKS00015677.

Effects of daily artificial gravity training on orthostatic tolerance following 60-day strict head-down tilt bedrest

PURPOSE

Orthostatic intolerance commonly occurs following immobilization or space flight. We hypothesized that daily artificial gravity training through short-arm centrifugation could help to maintain orthostatic tolerance following head-down tilt bedrest, which is an established terrestrial model for weightlessness.

METHODS

We studied 24 healthy persons (eight women; age 33.3 ± 9.0 years; BMI 24.3 ± 2.1 kg/m2) who participated in the 60-days head-down tilt bedrest (AGBRESA) study. They were assigned to 30 min/day continuous or 6 × 5 min intermittent short-arm centrifugation with 1Gz at the center of mass or a control group. We performed head-up tilt testing with incremental lower-body negative pressure until presyncope before and after bedrest. We recorded an electrocardiogram, beat-to-beat finger blood pressure, and brachial blood pressure and obtained blood samples from an antecubital venous catheter. Orthostatic tolerance was defined as time to presyncope. We related changes in orthostatic tolerance to changes in plasma volume determined by carbon dioxide rebreathing.

RESULTS

Compared with baseline measurements, supine and upright heart rate increased in all three groups following head-down tilt bedrest. Compared with baseline measurements, time to presyncope decreased by 323 ± 235 s with continuous centrifugation, by 296 ± 508 s with intermittent centrifugation, and by 801 ± 354 s in the control group (p = 0.0249 between interventions). The change in orthostatic tolerance was not correlated with changes in plasma volume.

CONCLUSIONS

Daily artificial gravity training on a short-arm centrifuge attenuated the reduction in orthostatic tolerance after 60 days of head-down tilt bedrest.

ACR White Paper on Magnetoencephalography and Magnetic Source Imaging: A Report from the ACR Commission on Neuroradiology

Magnetoencephalography, the extracranial detection of tiny magnetic fields emanating from intracranial electrical activity of neurons, and its source modeling relation, magnetic source imaging, represent a powerful functional neuroimaging technique, able to detect and localize both spontaneous and evoked activity of the brain in health and disease. Recent years have seen an increased utilization of this technique for both clinical practice and research, in the United States and worldwide. This report summarizes current thinking, presents recommendations for clinical implementation, and offers an outlook for emerging new clinical indications.

Effects of targeted therapy on blood gas analysis in pulmonary arterial hypertension – a retrospective analysis

Background

In pulmonary arterial hypertension (PAH), there is an excessive respiratory drive, which leads to inefficient ventilation with subsequent hypocapnia. Changes in blood gas analysis (BGA) may correlate with symptom severity and outcome. Data on impact of targeted PAH therapy on BGA are scarce and it remains unclear if these values can be used for risk stratification purposes.

Purpose

To assess capillary BGA in PAH at diagnosis and to evaluate the effect of targeted therapy on classical and calculated BGA parameters.

Methods

147 patients (62.3±17.1 years; female/male ratio: 66.7/33.3%) with newly diagnosed PAH were treated with targeted PAH therapy. 12-month follow-up included assessment of capillary blood gases and clinical variables. Patients underwent repeat RHC after 15.9±15.5 months.

Results

At diagnosis, both pcO2 (66.8±1.3 mmHg) and pcCO2 (32.7±0.5 mmHg) were slightly reduced. At 12-month follow-up, pcCO2 increased significantly to values within normal range (35.3±0.4 mmHg), while pcO2 showed no significant changes. After using the formula to calculate standard pcO2, baseline values were even lower, but there were significant improvements at 12-month follow-up, also reaching normal values. Changes in pcCO2 and standard pcO2 at diagnosis correlated with hemodynamics and survival at follow-up. Repeated RHC demonstrated significant reductions in mean PAP (48.9±1.2 to 39.9±1.0 mmHg; −18.4%), and PVR (11.3±0.7 to 6.2±0.3 WU; −45.1%), and an increase in cardiac index (2.1±0.04 to 2.6±0.1 ml/min/m2; +23.8%) (all p&lt;0.05). Hemodynamic improvements correlated with improved clinical parameters, including 6-minute walking distance (344±9 to 393±9 m), NTproBNP serum levels (2.163±219 to 772±84 ng/l, both p&lt;0.05) and WHO-FC at 12 months, resulting in improved risk status.

Conclusions

Targeted PAH therapy leads to significantly improved cardiopulmonary hemodynamics with subsequent increase in pcCO2, presumably due to less hyperventilation. Changes in pcCO2 and standard pcO2 (but not pcO2) correlate with hemodynamics and survival, potentially serving as non-invasive parameters for risk assessment and therapeutic response. The discrepancy between pcO2 and standard pcO2 at diagnosis suggests that pcO2 is upregulated by the hyperventilatory state. Standard pcO2 represents an easy-to-calculate parameter that can help more accurately identify PAH patients requiring O2 therapy in addition to targeted therapy. Further studies are needed in this context.

Funding Acknowledgement

Type of funding sources: None.

Associations between implicit and explicit affective inhibitory control, trait rumination and depressive symptoms

Introduction

Inhibitory control is the executive function component which underlies one’s ability to maintain goal-directed behavior by inhibiting prepotent responses or ignoring irrelevant information. Recent models suggest that impaired inhibition of negative information may contribute to depressive symptoms, and that this association is mediated by rumination. However, the exact nature of this association, particularly in non-clinical samples, is unclear.

Objectives

The goal of the current study was to assess the relationship between inhibitory control over emotional vs. non-emotional information, rumination and depressive symptoms.

Methods

A non-clinical sample of 119 participants (mean age: 36.44 ± 11.74) with various levels of depressive symptoms completed three variations of a Go/No-Go task online; two of the task variations required either explicit or implicit processing of emotional expressions, and a third variation contained no emotional expressions (i.e., neutral condition).

Results

We found that for participants who reported elevated depressive symptoms, their inhibitory control ability was reduced for all three task variations, relative to less depressed participants. However, for the task variation that required implicit emotion processing (rather than explicit), depressive symptoms were associated with inhibitory deficits for sad and neutral, but not for happy facial expressions. An exploratory analysis showed that the relationship between inhibition and depressive symptoms occurs in part through trait rumination for all three tasks, regardless of emotional content.

Conclusions

Collectively, these results indicate that elevated depressive symptoms are associated with both a general inhibitory control deficit, as well as affective interference from negative emotions, with implications for the assessment and treatment of mood disorders.

Disclosure

No significant relationships.

Transitions for older people with learning disabilities and behaviours that challenge others, and their family carers: a merged protocol for two rapid scoping reviews of evidence

BACKGROUND

There are over 1 million adults with a learning disability in the UK, of whom approximately 20% displaying behaviours that challenge others. Two thirds of people with learning disabilities live in the family home. As they and their family carers age, both are likely to face particular difficulties and stresses, but there is little understanding of their experiences and needs. To address this evidence gap, our main objective is to undertake two rapid scoping reviews that will collectively focus on the health and social care needs, experiences, service interventions and resources of older people with learning disabilities and behaviours that challenge others, and their family carers. Both reviews will focus on issues relating to forward planning and transitions to different care contexts. The study is part of a research project funded by the National Institute for Health Research No.129491.

METHODS

We propose to address the need for evidence via two rapid scoping reviews. We will include published and unpublished (grey) literature, encompassing empirical research, policy and practice guidance and lay resources to support decision-making. We will search multiple electronic databases, hand search references lists, and use expert guidance to identify potential evidence. The following databases were used for research and grey literature: CINAHL; Healthcare Management Information Consortium (HMIC); NHS Evidence; Scopus; Turning Evidence Into Practice (TRIP); Web of Science (WoS); Google (first 5 pages); and Google Scholar (first 5 pages). For RR2, additional intended databases are the Carer Research Knowledge Exchange Network (CAREN) and Social Care Institute for Excellence (SCIE). Two reviewers will independently screen all citations and full-text articles for inclusion. One reviewer will extract data, with an independent review undertaken by the research team. Critical appraisal will depend on the nature of included evidence. Narrative synthesis will be collaboratively developed, with descriptive information presented in tables summarising study characteristics and thematic analysis of findings presented in the main text. Dissemination will be through journal publication, conference presentations and written short-form, easy-read versions of articles and audio-video clips for lay audiences.

DISCUSSION

We will consider the strengths and limitations of our reviews, considering their impact on findings. We will summarise the main findings and provide an interpretation linked to the review questions and objectives. We will consider the implications of our findings for policy and practice, as well as future research addressing the support of older people with learning difficulties and behaviours that challenge others, and their family carers, in the context of transition to different care contexts in the UK. The protocol has been registered as Vseteckova, J., Jordan, J., Tilley, E., Larkin, M., Ryan, S., and Wallace, L. (2021, December 4). Transitions for older people with learning disabilities and behaviours that challenge others, and their family carers: a merged protocol for two rapid scoping reviews of evidence. Retrieved from osf.io/jzrn9.

[From human terrestrial models to new preventive measures for ocular changes in astronauts : Results of the German Aerospace Center studies]

BACKGROUND

Ocular changes in astronauts, particularly the spaceflight associated neuro-ocular syndrome (SANS), pose a medical challenge for which no suitable preventive measures exist. During long-duration spaceflight missions, e.g. to the Moon and Mars, SANS and radiation-induced cataract could affect the health and performance of crews and jeopardize the success of missions. Mechanistic studies and development of preventive measures require suitable terrestrial models.

OBJECTIVE

Overview on the most recent research and future plans in space medicine.

MATERIAL AND METHODS

Search for relevant publications using PubMed.

RESULTS

Bed rest studies at the German Aerospace Center (DLR) demonstrated that strict bed rest in a -6° head down tilt position reproduces changes just like SANS on Earth. This model including creation of optic disc edema is applied in human studies testing influences of artificial gravity through short arm centrifugation as a preventive method. The unique research facility :envihab provides the opportunity to also simulate the ambient conditions of the International Space Station during bed rest studies.

CONCLUSION

Future head down tilt bed rest studies will serve to systematically test preventive measures for SANS. Similar investigations would be difficult to realize under real space conditions. Through close collaboration between space medicine and terrestrial ophthalmology, this research can benefit patients on Earth.

OP0161 ASSOCIATION OF BASELINE CYTOTOXIC GENE EXPRESSION WITH USTEKINUMAB RESPONSE IN SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

Systemic Lupus Erythematous (SLE) is a clinically and biologically diverse disease, for which only one new therapy has been approved in the past 60 years. In a phase 2 trial on patients with mild-to-moderate SLE, ustekinumab (UST) improved clinical and laboratory measures of disease activity compared with placebo (PBO).1

Objectives:

We previously reported an association of IFN-γ reduction with response to UST,2suggesting an impact on the IL12/Th1 axis. To extend these findings, we performed unbiased transcriptomic analysis from baseline whole blood samples to identify genes that discriminate UST responders (UST-R) from non-responders (UST-NR) using the primary endpoint of Systemic Lupus Erythematosus Responder Index (SRI)-4 at week 24 to define response.

Methods:

UST was studied in a Ph2 PBO-controlled study of 102 patients with seropositive SLE and active disease despite standard therapy. Patients were randomized 3:2 to receive IV UST 6 mg/kg or placebo followed by subcutaneous injections of UST 90 mg or PBO every 8 weeks. Whole blood gene expression at baseline was measured via microarray using RNA samples from 100 patients, as samples from 2 patients failed quality control. An unbiased approach was used to identify gene signatures present at baseline that associate with UST response. Recombinant IL-12 or IL-23 was incubatedin vitrowith whole blood from 6 healthy donors for 24h and RNA-Seq was performed to determine the effect of these treatments on representative genes comprising the UST response signature.

Results:

A non-biased machine learning algorithm identified a 9-gene whole blood signature composed primarily of cytotoxic cell-associated transcripts (PRF1, KLRD1, GZMH, NKG7, GNLY, FGFBP2, TRGC2, TARP, TRGV2) that was enriched at baseline in UST-R vs UST-NR. By Gene Set Variation Analysis, the cytotoxic signature enrichment in UST-NR was less at baseline than both UST-R and a healthy control cohort (P=0.0087, P=0.056, respectively), whereas UST-R cytotoxic gene enrichment was similar to healthy controls (P=0.31). No significant difference in cytotoxic signature enrichment was observed at baseline between PBO responders and PBO non-responders or healthy controls (Figure). Enrichment levels of the cytotoxic gene signature remained stable over time in PBO and UST-NR groups while a trend of decreased cytotoxic signature was observed in UST-R, although never reaching levels seen in UST-NR. To begin to understand the relationship between IL-12 and IL-23, the targets of UST, and the cytotoxic signature, whole blood was stimulated with these cytokinesin vitro. Recombinant IL-12, but not IL-23, resulted in increased expression of representative members of this cytotoxic gene signature.

Conclusion:

We identified a novel cytotoxic signature in baseline blood samples that associated with UST response in SLE. The observation that IL-12 can increase this signaturein vitroand that IL-12 is a robust inducer of cytotoxic cell activity3as well as IFN-γ3suggests an important role of IL-12 blockade in the mechanism of action of UST in SLE.

References:

[1]van Vollenhoven RF. Lancet. 2018;392:1330-39

[2]Jordan. ACR 2018 Abstract # 2951

[3]G. Trinchieri. Nat Rev Immunol. 2003;3:133-46

Figure.

Disclosure of Interests:

Loqmane Seridi Employee of: Janssen Research & Development, LLC, Matteo Cesaroni Employee of: Janssen Research & Development, LLC, Matthew J Loza Employee of: Janssen Research & Development, LLC, Jessica Schreiter Employee of: Janssen Research & Development, LLC, Kristen Sweet Employee of: Janssen Research & Development, LLC, Yevgeniya Orlovsky Employee of: Janssen Research & Development, LLC, Spring House, PA, United States of America, Isabelle Baribaud Employee of: Janssen Research & Development, LLC, Ashley Orillion Employee of: Janssen Research & Development, LLC, Peter Lipsky Consultant of: Horizon Therapeutics, Ronald van Vollenhoven Grant/research support from: AbbVie, Amgen, Arthrogen, Bristol-Myers Squibb, GlaxoSmithKline (GSK), Janssen Research & Development, LLC, Lilly, Pfizer, Roche, and UCB, Consultant of: AbbVie, AstraZeneca, Biotest, Bristol-Myers Squibb, Celgene, Crescendo Bioscience, GSK, Janssen, Lilly, Medac, Merck, Novartis, Pfizer, Roche, UCB and Vertex, Speakers bureau: AbbVie, AstraZeneca, Biotest, Bristol-Myers Squibb, Celgene, Crescendo Bioscience, GlaxoSmithKline, Janssen, Lilly, Merck, Novartis, Pfizer, Roche, UCB, Vertex, Bevra H. Hahn Grant/research support from: Janssen Research & Development, LLC, George Tsokos Grant/research support from: Janssen Research & Development, LLC, Marc Chevrier Employee of: Janssen Research & Development, LLC, Shawn Rose Employee of: Janssen Research & Development, LLC, Frederic Baribaud Shareholder of: Janssen Research & Development, LLC, Employee of: Janssen Research & Development, LLC, Jarrat Jordan Employee of: Janssen Research & Development, LLC

[Eye changes in space : New insights into clinical aspects, pathogenesis and prevention]

BACKGROUND

More than ever research into changes in the eye caused by long-term space flight is becoming the focus of the international and national space agencies National Aeronautics and Space Administration (NASA), European Space Agency (ESA) and German Aerospace Center (DLR). In addition to space radiation-induced cataract formation considerable eye changes, summarized under space flight-associated neuro-ocular syndrome (SANS), can occur.

OBJECTIVE

This article gives an overview of the current state of research and future directions in the field of research concerned with ocular alterations in SANS and presents the relevance for terrestrial ophthalmological research.

MATERIAL AND METHODS

An analysis of existing publications on SANS in PubMed and reports on the risk of SANS published by the NASA of the USA was carried out.

RESULTS

The reasons for the development of the eye changes in space have not been clarified. Factors such as the increase in intracranial pressure, fluid shifts, hypercapnia and genetic factors are the subject of intensive research efforts. A terrestrial model for the induction of papilledema could be established (bed rest studies with -6° head-down tilt as a space analogue). Countermeasures for the development of eye changes, such as intermittent artificial gravity, are the subject of current research studies.

CONCLUSION

Research into SANS as part of bed rest studies will provide further important insights in the future for space research and also for terrestrial research. Clinical research projects can be derived from space research.

Characterization of coagulase-negative staphylococci from brining baths in Germany

Brining is an important step in cheese making, and using brine baths for this purpose is common practice in German dairies. Time of brining, brine concentration, and composition of the complex and heterogeneous microbiota, including coagulase-negative staphylococci (CNS), contribute to the ripening and taste of cheese. As well as producing staphylococcal enterotoxins, some CNS show antibiotic resistance; therefore, we isolated 52 strains of presumptive CNS from cheese brines from 13 factories in Germany. Species identification by sodA gene sequencing revealed that 50 isolates were CNS: 31 Staphylococcus saprophyticus, 4 Staphylococcus carnosus, 4 Staphylococcus equorum, 3 Staphylococcus sciuri, 2 Staphylococcus hominis, and 2 Staphylococcus warneri. One isolate each was identified as Staphylococcus epidermidis, Staphylococcus pasteurii, Staphylococcus succinus, and Staphylococcus xylosus. Further subtyping of the Staph. saprophyticus isolates to the subspecies level revealed the presence of 6 Staph. saprophyticus ssp. saprophyticus. Using pulsed-field gel electrophoresis with the identified Staph. saprophyticus strains, 12 independent clones were identified, resulting in the exclusion of 18 strains from further testing. In 19 of the remaining 32 CNS isolates, resistance to antibiotics was observed. Resistance was found against oxacillin (17), penicillin (5), and cefoxitin (1). Four isolates expressed resistance to both oxacillin and penicillin. No resistance was found to enrofloxacin, tetracycline, gentamicin, or erythromycin. Then, PCR analysis for antibiotic resistance genes was performed for 22 different genes. Only genes blaZ and bla_TEM were found in 7 isolates. These isolates were selected for challenge tests with different concentrations of lactic acid and NaCl to examine whether expression of antibiotic resistance was influenced by these stressors. An increase in the minimal inhibitory concentration from 0 to 2.0 µg/mL was seen for trimethoprim/sulfamethoxazole only in one isolate of Staph. saprophyticus at an increased lactic acid concentration. Finally, all isolates were tested for genetic determinants (entA, entB, entC, entD, and entE) of the most common staphylococcal enterotoxins; none of these genes were detected. We found no indication for unacceptable risks originating from the isolated CNS.

Relationships among organ damage, social support, and depression in African American women with systemic lupus erythematosus

OBJECTIVES

Systemic lupus erythematosus (SLE) disproportionately strikes African American women. Social support can potentially reduce disease impact. The purpose of this study is to understand the relationship between organ damage and depression in African American women and how social support influences this relationship.

METHODS

We used a mixed methods design, analyzing self-reported data on lupus-related organ damage, depression, and social support in 437 African American women with SLE recruited in the Georgians Organized Against Lupus (GOAL) cohort. Moreover, we conducted interviews among 15 GOAL participants to gather patients' perspectives about the role of social support in people who live with lupus.

RESULTS

We found a significant association between organ damage and depression ( r = 0.163, p = 0.001), as well as between depression and social support ( F = 17.574, p < 0.001). The quantitative analysis did not render social support as a significant moderator in the organ damage-depression relationship. Interviews, however, revealed that African American women with the most severe organ damage have the greatest need for support.

CONCLUSIONS

Social support is a key resource for lupus patients with high disease burden. Overall, these findings highlight the importance of monitoring depressive symptoms in this population and developing interventions aimed to increase social support available to lupus patients.

The effects of angiotensin receptor neprilysin inhibition by sacubitril/valsartan on adipose tissue transcriptome and protein expression in obese hypertensive patients

Increased activation of the renin-angiotensin system is involved in the onset and progression of cardiometabolic diseases, while natriuretic peptides (NP) may exert protective effects. We have recently demonstrated that sacubitril/valsartan (LCZ696), a first-in-class angiotensin receptor neprilysin inhibitor, which blocks the angiotensin II type-1 receptor and augments natriuretic peptide levels, improved peripheral insulin sensitivity in obese hypertensive patients. Here, we investigated the effects of sacubitril/valsartan (400 mg QD) treatment for 8 weeks on the abdominal subcutaneous adipose tissue (AT) phenotype compared to the metabolically neutral comparator amlodipine (10 mg QD) in 70 obese hypertensive patients. Abdominal subcutaneous AT biopsies were collected before and after intervention to determine the AT transcriptome and expression of proteins involved in lipolysis, NP signaling and mitochondrial oxidative metabolism. Both sacubitril/valsartan and amlodipine treatment did not significantly induce AT transcriptional changes in pathways related to lipolysis, NP signaling and oxidative metabolism. Furthermore, protein expression of adipose triglyceride lipase (ATGL) (P_time*group = 0.195), hormone-sensitive lipase (HSL) (P_time*group = 0.458), HSL-ser660 phosphorylation (P_time*group = 0.340), NP receptor-A (NPRA) (P_time*group = 0.829) and OXPHOS complexes (P_time*group = 0.964) remained unchanged. In conclusion, sacubitril/valsartan treatment for 8 weeks did not alter the abdominal subcutaneous AT transcriptome and expression of proteins involved in lipolysis, NP signaling and oxidative metabolism in obese hypertensive patients.

Branched-chain amino acid catabolism rather than amino acids plasma concentrations is associated with diet-induced changes in insulin resistance in overweight to obese individuals

BACKGROUND & AIMS

3-Hydroxyisobutyrate (3-HIB), a catabolic intermediate of the BCAA valine, which stimulates muscle fatty acid uptake, has been implicated in the pathogenesis of insulin resistance. We tested the hypothesis that circulating 3-HIB herald insulin resistance and that metabolic improvement with weight loss are related to changes in BCAAs and 3-HIB.

METHODS AND RESULTS

We analyzed plasma and urine in 109 overweight to obese individuals before and after six months on hypocaloric diets reduced in either carbohydrates or fat. We calculated the homeostasis model assessment index (HOMA-IR) and whole body insulin sensitivity from oral glucose tolerance tests and measured intramyocellular fat by magnetic resonance spectroscopy. BCAAs and 3-HIB plasma concentrations were inversely related to insulin sensitivity but not to intramyocellular fat content at baseline. With 7.4 ± 4.5% weight loss mean BCAA and 3-HIB plasma concentrations did not change, irrespective of dietary macronutrient content. Individual changes in 3-HIB with 6-month diet but not BCAAs were correlated to the change in whole body insulin sensitivity and HOMA-IR independently of BMI changes.

CONCLUSIONS

3-HIB relates to insulin sensitivity but is not associated with intramyocellular fat content in overweight to obese individuals. Moreover, changes in 3-HIB rather than changes in BCAAs are associated with metabolic improvements with weight loss. Registration number for clinical trials: ClinicalTrials.gov Identifier: NCT00956566.

Current Status of Companion and Complementary Diagnostics: Strategic Considerations for Development and Launch

US Food and Drug Administration (FDA)‐approved diagnostic assays play an increasingly common role in managing patients to prolong lifespan while also enhancing quality of life. Diagnostic assays can be essential for the safe and effective use of therapeutics (companion diagnostic), or may inform on improving the benefit/risk ratio without restricting drug access (complementary diagnostic). This tutorial reviews strategic considerations for drug and assay development resulting in FDA‐approved companion or complementary diagnostic status.

Sodium MRI in Multiple Sclerosis is Compatible with Intracellular Sodium Accumulation and Inflammation-Induced Hyper-Cellularity of Acute Brain Lesions

The cascade of inflammatory pathogenetic mechanisms in multiple sclerosis (MS) has no specific conventional MRI correlates. Clinicians therefore stipulate improved imaging specificity to define the pathological substrates of MS in vivo including mapping of intracellular sodium accumulation. Based upon preclinical findings and results of previous sodium MRI studies in MS patients we hypothesized that the fluid-attenuated sodium signal differs between acute and chronic lesions. We acquired brain sodium and proton MRI data of N = 29 MS patients; lesion type was defined by the presence or absence of contrast enhancement. N = 302 MS brain lesions were detected, and generalized linear mixed models were applied to predict lesion type based on sodium signals; thereby controlling for varying numbers of lesions among patients and confounding variables such as age and medication. Hierarchical model comparisons revealed that both sodium signals average tissue (χ²(1) = 27.89, p < 0.001) and fluid-attenuated (χ²(1) = 5.76, p = 0.016) improved lesion type classification. Sodium MRI signals were significantly elevated in acute compared to chronic lesions compatible with intracellular sodium accumulation in acute MS lesions. If confirmed in further studies, sodium MRI could serve as biomarker for diagnostic assessment of MS, and as readout parameter in clinical trials promoting attenuation of chronic inflammation.

Branched-chain and aromatic amino acids, insulin resistance and liver specific ectopic fat storage in overweight to obese subjects

BACKGROUND & AIMS

Amino acids may interfere with insulin action, particularly in obese individuals. We hypothesized that increased circulating branched-chain and aromatic amino acids herald insulin resistance and ectopic fat storage, particularly hepatic fat accumulation.

METHODS AND RESULTS

We measured fasting branched-chain and aromatic amino acids (tryptophan, tyrosine, and phenylalanine) by mass spectrometry in 111 overweight to obese subjects. We applied abdominal magnetic resonance imaging and spectroscopy to assess adipose tissue distribution and ectopic fat storage, respectively. Plasma branched-chain amino acids concentrations were related to insulin sensitivity and intrahepatic fat independent from adiposity, age and gender, but not to abdominal adipose tissue or intramyocellular fat.

CONCLUSIONS

In weight stable overweight and obese individuals, branched-chain amino acid concentrations are specifically associated with hepatic fat storage and insulin resistance.

No change in neuropsychological dysfunction or emotional processing during treatment of major depression with cognitive-behaviour therapy or schema therapy

BACKGROUND

Impaired neuropsychological functioning is a feature of major depression. Previous studies have suggested that at least some aspects of neuropsychological functioning improve with successful treatment of major depression. The extent to which medications may affect the degree of normalization of these functions is unclear. The aim of the current study was to examine the course of neuropsychological functioning during treatment of major depression with cognitive-behaviour therapy (CBT) or schema therapy (ST).

METHOD

A total of 69 out-patients with a primary diagnosis of major depression and 58 healthy controls completed mood ratings, neuropsychological measures, and measures of emotional processing at baseline and after 16 weeks. Participants were randomized after baseline assessment to a year-long course of CBT or ST. Patients reassessed at 16 weeks were medication-free throughout the study.

RESULTS

Significant neuropsychological impairment was evident at baseline in depressed participants compared with healthy controls. After 16 weeks of psychotherapy, mean depression rating scores fell more than 50%. However, no neuropsychological measures showed convincing evidence of significant improvement and emotional processing did not change.

CONCLUSIONS

Persisting impairment in neuropsychological functioning after the first 16 weeks of CBT or ST suggests a need to modify psychological treatments to include components targeting cognitive functioning.

[Pathophysiology of hypertension : What are our current concepts?]

In the year 2015, many questions regarding the pathophysiology of essential arterial hypertension remain unresolved. Substantial scientific progress has been made in various medical areas aided by novel molecular"omics" techniques. The findings could then be implemented in diagnostic and therapeutic procedures. In the field of hypertension research such methods have been applied in very large cohorts but have contributed less to pathophysiological understanding and clinical management than expected. The findings on the pathophysiological importance of baroreflex mechanisms, natriuretic peptides and osmotically inactive sodium storage discussed in this article all have something in common: all are based on small, carefully conducted human physiological investigations and often challenge current textbook knowledge. Nevertheless, these findings have opened up new research fields and are likely to affect clinical care.