The central nervous norepinephrine network links a diminished sense of emotional well-being to an increased body weight

OBJECTIVES

The neurobiological mechanisms linking obesity to emotional distress remain largely undiscovered.

METHODS

In this pilot study, we combined positron emission tomography, using the norepinephrine transporter (NET) tracer [(11)C]-O-methylreboxetine, with functional connectivity magnetic resonance imaging, the Beck depression inventory (BDI), and the impact of weight on quality of life-Lite questionnaire (IWQOL-Lite), to investigate the role of norepinephrine in the severity of depression (BDI), as well as in the loss of emotional well-being with body weight (IWQOL-Lite).

RESULTS

In a small group of lean-to-morbidly obese individuals (n=20), we show that an increased body mass index (BMI) is related to a lowered NET availability within the hypothalamus, known as the brain's homeostatic control site. The hypothalamus displayed a strengthened connectivity in relation to the individual hypothalamic NET availability to the anterior insula/frontal operculum, as well as the medial orbitofrontal cortex, assumed to host the primary and secondary gustatory cortex, respectively (n=19). The resting-state activity in these two regions was correlated positively to the BMI and IWQOL-Lite scores, but not to the BDI, suggesting that the higher the resting-state activity in these regions, and hence the higher the BMI, the stronger the negative impact of the body weight on the individual's emotional well-being was.

CONCLUSIONS

This pilot study suggests that the loss in emotional well-being with weight is embedded within the central norepinephrine network.

Interaction of thyroid hormone with brown adipose tissue

Brown adipose tissue (BAT) plays an important role in regulating core-body temperature in various species including man. [18F]FDGPET/ CT imaging first revealed the presence of metabolically active BAT depots and that decreased BAT function is associated with various metabolic conditions. Thyroid hormone (TH) in concert with sympathetic nervous system signalling (SNS) stimulates BAT thermogenesis and thyroid disorders result in dysfunctional BAT. Currently, research is focussing not only on BAT regulation but also on browning of white adipose tissue (WAT) to BAT beige adipose tissue (BeAT) in order to develop novel treatments for human obesity and related conditions. While [18F]FDG-PET/ CT imaging is continuing to provide valuable insights into BAT and BeAT function in health and disease, there is a pressing need to develop alternative radiotracers that reliably track their activity in vivo. As a result it is expected that preclinical micro PET/CT investigations of BAT and BeAT will gain in prominence.

The aim of this short review is to i) describe fundamentals in BAT biology, ii) highlight some of the clinical and preclinical studies performed on humans and rodents with a focus on TH, BAT and PET/CT, and iii) bridge these data with our own studies within the DFG thyroid transact priority program.

Interaction of thyroid hormone with brown adipose tissue. Lessons learned from PET-CT

Brown adipose tissue (BAT) plays an important role in regulating core-body temperature in various species including man. [18F]FDG-PET/CT imaging first revealed the presence of metabolically active BAT depots and that decreased BAT function is associated with various metabolic conditions. Thyroid hormone (TH) in concert with sympathetic nervous system signalling (SNS) stimulates BAT thermogenesis and thyroid disorders result in dysfunctional BAT. Currently, research is focussing not only on BAT regulation but also on browning of white adipose tissue (WAT) to BAT beige adipose tissue (BeAT) in order to develop novel treatments for human obesity and related conditions. While [18F]FDG-PET/CT imaging is continuing to provide valuable insights into BAT and BeAT function in health and disease, there is a pressing need to develop alternative radiotracers that reliably track their activity in vivo. As a result it is expected that preclinical micro PET/CT investigations of BAT and BeAT will gain in prominence. The aim of this short review is to i) describe fundamentals in BAT biology, ii) highlight some of the clinical and preclinical studies performed on humans and rodents with a focus on TH, BAT and PET/CT, and iii) bridge these data with our own studies within the DFG thyroid transact priority program.

Radioligand imaging of α4β2* nicotinic acetylcholine receptors in Alzheimer's disease and Parkinson's disease

The α4β2* nicotinic acetylcholine receptors (α4β2*-nAChR) are highly abundant in the human brain. As neuromodulators they play an important role in cognitive functions such as memory, learning and attention as well as mood and motor function. Post mortem studies suggest that abnormalities of α4β2*-nAChRs are closely linked to histopathological hallmarks of Alzheimer's disease (AD), such as amyloid aggregates/oligomers and tangle pathology and of Parkinson's disease (PD) such as Lewy body pathology and the nigrostriatal dopaminergic deficit. In this review we summarize and discuss nicotinic receptor imaging findings of 2-[18F]FA-85380 PET, [11C]nicotine PET and 5-[123I]IA-85380 SPECT studies investigating α4β2*-nAChR binding in vivo and their relationship to mental dysfunction in the brain of patients with AD and patients out of the spectrum of Lewy body disorders such as PD and Lewy body dementia (DLB). Furthermore, recent developments of novel α4β2*-nAChR-specific PET radioligands, such as (-)[18F]Flubatine or [18F]AZAN are summarized. We conclude that α4β2*-nAChR-specific PET might become a biomarker for early diagnostics and drug developments in patients with AD, DLB and PD, even at early or prodromal stages.

Dual-mode hydrodynamic railing and arraying of microparticles for multi-stage signal detection in continuous flow biochemical microprocessors

Continuous flow particulate-based microfluidic processors are in critical demand for emerging applications in chemistry and biology, such as point-of-care molecular diagnostics. Challenges remain, however, for accomplishing biochemical assays in which microparticle immobilization is desired or required during intermediate stages of fluidic reaction processes. Here we present a dual-mode microfluidic reactor that functions autonomously under continuous flow conditions to: (i) execute multi-stage particulate-based fluidic mixing routines, and (ii) array select numbers of microparticles during each reaction stage (e.g., for optical detection). We employ this methodology to detect the inflammatory cytokine, interferon-gamma (IFN-γ), via a six-stage aptamer-based sandwich assay.

Evidence of end-effector based gait machines in gait rehabilitation after CNS lesion

BACKGROUND

A task-specific repetitive approach in gait rehabilitation after CNS lesion is well accepted nowadays. To ease the therapists' and patients' physical effort, the past two decades have seen the introduction of gait machines to intensify the amount of gait practice. Two principles have emerged, an exoskeleton- and an endeffector-based approach. Both systems share the harness and the body weight support. With the end-effector-based devices, the patients' feet are positioned on two foot plates, whose movements simulate stance and swing phase.

OBJECTIVE

This article provides an overview on the end-effector based machine's effectiveness regarding the restoration of gait.

METHODS

For the electromechanical gait trainer GT I, a meta analysis identified nine controlled trials (RCT) in stroke subjects (n = 568) and were analyzed to detect differences between end-effector-based locomotion + physiotherapy and physiotherapy alone.

RESULTS

Patients practising with the machine effected in a superior gait ability (210 out of 319 patients, 65.8% vs. 96 out of 249 patients, 38.6%, respectively, Z = 2.29, p = 0.020), due to a larger training intensity. Only single RCTs have been reported for other devices and etiologies.

CONCLUSION

The introduction of end-effector based gait machines has opened a new succesful chapter in gait rehabilitation after CNS lesion.

Visualizing inflammation activity in rheumatoid arthritis with Tc-99 m anti-CD4-mAb fragment scintigraphy

PURPOSE

T-cell-located CD4 antigen represents one of the therapeutic targets in rheumatoid arthritis (RA). However, up to now there is no established imaging tool to visualize this target in vivo. The aim of our study was to assess the safety and tolerability of a technetium-99m labelled murine anti-human CD4 IgG1-Fab fragment ([(99m)Tc]-anti-CD4-Fab, [(99m)Tc]-EP1645) in patients with active synovitis due to RA, and to evaluate its potential as a marker of disease activity.

METHODS

In the present phase I proof of principle study five patients with RA were examined. Planar scans of the whole body, hands, and feet were taken 30 min up to 24h after application of 550 ± 150 MBq [(99m)Tc]-anti-CD4-Fab, followed by visual analyses, comparison with clinical data in 68 joints per patient and semiquantitative analysis of hand and wrist joints.

RESULTS

Neither infusion related adverse events nor adverse events during follow up were observed. No increase in human anti-murine antibody titres was seen. All patients had positive scans in almost 70% of clinically affected joints. Positive scans were also found in 8% of joints without evidence of swelling or tenderness.

CONCLUSION

Scintigraphy with [(99m)Tc]-anti-CD4-Fab is a promising technique for evaluation of inflammatory activity in patients with RA, pre-therapeutical evaluation of CD4 status and therapy control. Tracer uptake in clinically inconspicuous joints strongly indicates diagnostic potential of [(99m)Tc]-anti-CD4-Fab. Whether this technique is eligible as a prognostic factor in RA needs to be analysed in further studies as well as the pathophysiological background of clinically affected joints lacking tracer uptake.

[Mental distress and quality of life in tinnitus patients]

BACKGROUND

Tinnitus is a disease with a high prevalence that is often combined with psychiatric comorbidity. The aim of this study was to identify the dimensions of quality of life in which tinnitus patients are especially affected, and how these affections change during a therapy, including a hyperbaric oxygen therapy.

MATERIAL AND METHODS

120 patients suffering from tinnitus were examined at 3 time points: at the beginning (t1) and the end (t2) of a 2-week hyperbaric oxygen therapy, and 4 weeks later (t3). The following questionnaires were adopted: Hospital Anxiety and Depression Scale, Multidimensional Fatigue Inventory, and the quality of life instrument EORTC QLQ-C30.

RESULTS

Compared with the general population, tinnitus patients were impaired in all areas of quality of life. The greatest differences were found in the scales Social, Cognitive, Emotional and Role Functioning and in the field of financial difficulties with effect sizes of about 1.5. During the therapy, the scores improved, reaching roughly the middle between the initial patients' scores and the values of the general population. The directly assessed subjective improvement due to the therapy was only marginally correlated with the differences in the questionnaires.

CONCLUSION

Since there was no control group without hyperbaric oxygen therapy, the results do not justify conclusions about the effectiveness of this therapy. However, the findings document multiple impairments of the patients (especially psycho-social disturbances) and show hints for supportive offers.

Use of the robot assisted gait therapy in rehabilitation of patients with stroke and spinal cord injury

Difficulty in walking is a major feature of neurological disease, and loss of mobility is the activity of daily living on which patients place the greatest value. The impact on patients is enormous, with negative ramifications on their participation in social, vocational, and recreational activities. In current clinical practice the gait restoration with robotic device is an integral part of rehabilitation program. Robot therapy involves the use of a robot exoskeleton device or end-effector device to help the patient retrain motor coordination by performing well-focused and carefully directed repetitive practice. The exoskeleton, as an assistive device, is also an external structural mechanism with joints and links corresponding to those of the human body. These robots use joint trajectories of the entire gait cycle and offer a uniform (more or less) stiff control along this trajectory. In this field the new powered exoskeleton ReWalk (Argo Medical Technologies Ltd) was developed to have an alternative mobility solution to the wheelchair and rehabilitation treatment for individuals with severe walking impairments, enabling them to stand, walk, ascend/descent stairs and more. The end-effector-based robot is a device with footplates placed on a double crank and rocker gear system. Alternatives to powered exoskeletons are devices that use movable footplates to which the patient's feet are attached. All devices include some form of body weight support. Prominent goals in the field include: developing implementable technologies that can be easily used by patients, therapists, and clinicians; enhancing the efficacy of clinician's therapies and increasing the ease of activities in the daily lives of patients.

An early botulinum toxin A treatment in subacute stroke patients may prevent a disabling finger flexor stiffness six months later: a randomized controlled trial

OBJECTIVE

The study asked whether an early botulinum toxin A (BTX-A) injection in subacute stroke patients may prevent a disabling finger flexor stiffness six months later.

DESIGN

Single-blind, randomized pilot study.

SETTING

Inpatient rehabilitation centre.

SUBJECTS

Eighteen stroke patients, interval 4-6 weeks, non-functional arm, Fugl-Meyer arm score (0-66) <20, beginning elevated finger flexor tone, randomly allocated to group A or B.

INTERVENTIONS

In group A patients 150 units BTX-A (Xeomin) injected into the deep and superficial finger (100 units) and wrist flexors (50 units), no injection in group B patients. Comprehensive rehabilitation in both groups.

MAIN MEASURES

Primary variable was the Modified Ashworth Scale score (0-5) of the finger flexors; secondary variables were whole arm muscle tone with REPAS (a summary rating scale for resistance to passive movement), its motor control with the Fugl-Meyer arm score, and a disability scale, blindly assessed at T0 (start), T1 (four weeks) and T6 (six months).

RESULTS

Homogeneous groups at T0. Significantly less finger flexor stiffness in the BTX-A group at T1 and T6, the mean (SD) Modified Ashworth Scale scores in group A (B) were: 1.7 ± 0.5 (1.6 ± 0.5) at T0; 0.4 ± 0.5 (1.9 ± 0.7) at T1; and 1.4 ± 0.7 (2.4 ± 0.9) at T6. Among the secondary measures, the disability score, namely the items pain and passive nail trimming, was lower in group A at T1 and T6.

CONCLUSIONS

The results indicate an effect of early BTX-A injection on finger flexor stiffness six months later, presumably attributable to a reduced contracture development. Effect size calculation suggests inclusion of at least 17 patients per group excluding drop-outs in a warranted placebo-controlled trial.