Immunomodulatory leptin receptor+ sympathetic perineurial barrier cells protect against obesity by facilitating brown adipose tissue thermogenesis.

Adipose tissues (ATs) are innervated by sympathetic nerves, which drive reduction of fat mass via lipolysis and thermogenesis. Here, we report a population of immunomodulatory leptin receptor-positive (LepR+) sympathetic perineurial barrier cells (SPCs) present in mice and humans, which uniquely co-express Lepr and interleukin-33 (Il33) and ensheath AT sympathetic axon bundles. Brown ATs (BATs) of mice lacking IL-33 in SPCs (SPCΔIl33) had fewer regulatory T (Treg) cells and eosinophils, resulting in increased BAT inflammation. SPCΔIl33 mice were more susceptible to diet-induced obesity, independently of food intake. Furthermore, SPCΔIl33 mice had impaired adaptive thermogenesis and were unresponsive to leptin-induced rescue of metabolic adaptation. We therefore identify LepR+ SPCs as a source of IL-33, which orchestrate an anti-inflammatory BAT environment, preserving sympathetic-mediated thermogenesis and body weight homeostasis. LepR+IL-33+ SPCs provide a cellular link between leptin and immune regulation of body weight, unifying neuroendocrinology and immunometabolism as previously disconnected fields of obesity research.

Immune-mediated denervation of the pineal gland underlies sleep disturbance in cardiac disease.

Disruption of the physiologic sleep-wake cycle and low melatonin levels frequently accompany cardiac disease, yet the underlying mechanism has remained enigmatic. Immunostaining of sympathetic axons in optically cleared pineal glands from humans and mice with cardiac disease revealed their substantial denervation compared with controls. Spatial, single-cell, nuclear, and bulk RNA sequencing traced this defect back to the superior cervical ganglia (SCG), which responded to cardiac disease with accumulation of inflammatory macrophages, fibrosis, and the selective loss of pineal gland-innervating neurons. Depletion of macrophages in the SCG prevented disease-associated denervation of the pineal gland and restored physiological melatonin secretion. Our data identify the mechanism by which diurnal rhythmicity in cardiac disease is disturbed and suggest a target for therapeutic intervention.

Local sympathetic denervation attenuates myocardial inflammation and improves cardiac function after myocardial infarction in mice.

Aims: Cardiac inflammation has been suggested to be regulated by the sympathetic nervous system (SNS). However, due to the lack of methodology to surgically eliminate the myocardial SNS in mice, neuronal control of cardiac inflammation remains ill-defined. Here, we report a procedure for local cardiac sympathetic denervation in mice and tested its effect in a mouse model of heart failure post-myocardial infarction. Methods and results: Upon preparation of the carotid bifurcation, the right and the left superior cervical ganglia were localized and their pre- and postganglionic branches dissected before removal of the ganglion. Ganglionectomy led to an almost entire loss of myocardial sympathetic innervation in the left ventricular anterior wall. When applied at the time of myocardial infarction (MI), cardiac sympathetic denervation did not affect acute myocardial damage and infarct size. In contrast, cardiac sympathetic denervation significantly attenuated chronic consequences of MI, including myocardial inflammation, myocyte hypertrophy, and overall cardiac dysfunction. Conclusion: These data suggest a critical role for local sympathetic control of cardiac inflammation. Our model of myocardial sympathetic denervation in mice should prove useful to further dissect the molecular mechanisms underlying cardiac neural control.

Cerebral MRI and EEG studies in the initial management of pediatric headaches.

BACKGROUND AND STUDY PURPOSE: High resolution imaging modalities and electroencephalographic studies (EEG) are used in the assessment of children with headaches. We evaluated the role of cerebral MRI (cMRI) and EEG in the initial assessment of children with headache as the chief complaint of initial presentation. METHODS: A retrospective chart analysis was performed at a tertiary University Hospital. RESULTS: 209 patients were included in this study [mean age 11.3 years; male 91 (43.5%); female 118 (56.5%)]. The following types of headaches were seen: Unclassified headache: 23.4%; probable migraine 17.2%, migraine without aura 13.4%, complicated migraine 12.4%, migraine with aura 1.0%; tension-type 15.3%, and cluster headaches 0.5%, and secondary headaches 16.7%. In 93 children (44.5%) abnormal physical/neurological findings were noted (multiple entries possible). On cMRI studies the following findings were seen: Infection of sinuses (7.2%), pineal cysts (2.4%), arachnoidial cyst and Chiari malformation (1.9%), unspecified signal enhancement (1.0%), and pituitary enlargement, inflammatory lesion, angioma, cerebral ischaemia, and intra-cerebral cyst (each 0.5%). Electroencephalographic findings included both focal and generalised abnormal slowing (5.3%) and Spike-wave complexes (3.3%). CONCLUSIONS: Despite abnormal findings on neurological/physical examination in a substantial number of children with headaches, the yield of pathological cMRIs was low. The use of EEG recordings was not contributory to the diagnostic and therapeutic approach. More research is needed to better define those patients who are likely to have an intracranial pathology.

Diagnostic approach to children with minor traumatic brain injury.

STUDY PURPOSE: To analyse the management of minor traumatic brain injury (MTBI) in paediatric hospitals in Germany. METHODS: An electronic survey was sent to 72 children hospitals. RESULTS: All participating (45/72; 62.5 %) hospitals had facilities to perform an electroencephalogram (EEG), 98 % cranial ultrasonography, 94 % MRI studies, and 87 % a CT scan. The initial Glasgow Coma Scale, the clinical presentation/neurological deficits, the intensity of the trauma and external/visible injuries were most important for initial assessment. The main reason for in-patient monitoring was initial clinical neurologic presentation (44 %). X-ray scans were used routinely in only 2.2 %, cMRI scans in 6.7 % and cCT scans in 13.3 %; approximately one third employed ultrasonography. In 22.2 % was an EEG part of the routine diagnostic work-up. Inpatient monitoring for 24-48 h was done in 80 %. CONCLUSIONS: Children with MTBI are often monitored clinically without resorting to potentially harmful and expensive diagnostic procedures (cCT scans).

Diagnosis and treatment of patients with stroke in a mobile stroke unit versus in hospital: a randomised controlled trial.

BACKGROUND: Only 2-5% of patients who have a stroke receive thrombolytic treatment, mainly because of delay in reaching the hospital. We aimed to assess the efficacy of a new approach of diagnosis and treatment starting at the emergency site, rather than after hospital arrival, in reducing delay in stroke therapy. METHODS: We did a randomised single-centre controlled trial to compare the time from alarm (emergency call) to therapy decision between mobile stroke unit (MSU) and hospital intervention. For inclusion in our study patients needed to be aged 18-80 years and have one or more stroke symptoms that started within the previous 2·5 h. In accordance with our week-wise randomisation plan, patients received either prehospital stroke treatment in a specialised ambulance (equipped with a CT scanner, point-of-care laboratory, and telemedicine connection) or optimised conventional hospital-based stroke treatment (control group) with a 7 day follow-up. Allocation was not masked from patients and investigators. Our primary endpoint was time from alarm to therapy decision, which was analysed with the Mann-Whitney U test. Our secondary endpoints included times from alarm to end of CT and to end of laboratory analysis, number of patients receiving intravenous thrombolysis, time from alarm to intravenous thrombolysis, and neurological outcome. We also assessed safety endpoints. This study is registered with ClinicalTrials.gov, number NCT00153036. FINDINGS: We stopped the trial after our planned interim analysis at 100 of 200 planned patients (53 in the prehospital stroke treatment group, 47 in the control group), because we had met our prespecified criteria for study termination. Prehospital stroke treatment reduced the median time from alarm to therapy decision substantially: 35 min (IQR 31-39) versus 76 min (63-94), p<0·0001; median difference 41 min (95% CI 36-48 min). We also detected similar gains regarding times from alarm to end of CT, and alarm to end of laboratory analysis, and to intravenous thrombolysis for eligible ischaemic stroke patients, although there was no substantial difference in number of patients who received intravenous thrombolysis or in neurological outcome. Safety endpoints seemed similar across the groups. INTERPRETATION: For patients with suspected stroke, treatment by the MSU substantially reduced median time from alarm to therapy decision. The MSU strategy offers a potential solution to the medical problem of the arrival of most stroke patients at the hospital too late for treatment. FUNDING: Ministry of Health of the Saarland, Germany, the Werner-Jackstädt Foundation, the Else-Kröner-Fresenius Foundation, and the Rettungsstiftung Saar.

A putative alpha-helical porin from Corynebacterium glutamicum.

The cell wall of Corynebacterium glutamicum contains a mycolic acid layer, which is a protective nonpolar barrier similar to the outer membrane of Gram-negative bacteria. The exchange of material across this barrier requires porins. Porin B (PorB) is one of them. Recombinant PorB has been produced in Escherichia coli, purified, crystallized and analyzed by X-ray diffraction, yielding 16 independent molecular structures in four different crystal forms at resolutions up to 1.8 A. All 16 molecules have the same globular core, which consists of 70 residues forming four alpha-helices tied together by a disulfide bridge. The 16 structures vary greatly with respect to the 29 residues in the N- and C-terminal extensions. Since corynebacteria belong to the group of mycolata that includes some prominent human pathogens, the observed structure may be of medical relevance. Due to the clearly established solid structure of the core, the native porin has to be oligomeric, and the reported structure is one of the subunits. An alpha-helical porin in a bacterial outer envelope is surprising because all presently known structures of such porins consist of beta-barrels. Since none of the four crystal packing arrangements was compatible with an oligomeric membrane channel, we constructed a model of such an oligomer that was consistent with all available data of native PorB. The proposed model is based on the required polar interior and nonpolar exterior of the porin, on a recurring crystal packing contact around a 2-fold axis, on the assumption of a simple C(n) symmetry (a symmetric arrangement around an n-fold axis), on the experimentally established electric conductivity and anion selectivity and on the generally observed shape of porin channels.

Ganglianeuroma: radiological and metabolic features in 4 children.

Ganglioneuroma constitutes a benign and surgically treatable tumor. The authors studied 4 patients with histopathologically proven ganglioneuroma focusing on radiological and metabolic features. The results confirm previous investigations that have shown metabolic activity in ganglioneuroma and characteristic patterns in imaging studies. Although for definite diagnosis tissue investigation is required, certain clinical and radiological features are suggestive of ganglioneuroma.