Mitochondrial complex I activity in microglia sustains neuroinflammation.

Sustained smouldering, or low-grade activation, of myeloid cells is a common hallmark of several chronic neurological diseases, including multiple sclerosis1. Distinct metabolic and mitochondrial features guide the activation and the diverse functional states of myeloid cells2. However, how these metabolic features act to perpetuate inflammation of the central nervous system is unclear. Here, using a multiomics approach, we identify a molecular signature that sustains the activation of microglia through mitochondrial complex I activity driving reverse electron transport and the production of reactive oxygen species. Mechanistically, blocking complex I in pro-inflammatory microglia protects the central nervous system against neurotoxic damage and improves functional outcomes in an animal disease model in vivo. Complex I activity in microglia is a potential therapeutic target to foster neuroprotection in chronic inflammatory disorders of the central nervous system3.

Mitochondrial reverse electron transport in myeloid cells perpetuates neuroinflammation.

Sustained smouldering, or low grade, activation of myeloid cells is a common hallmark of several chronic neurological diseases, including multiple sclerosis (MS) 1 . Distinct metabolic and mitochondrial features guide the activation and the diverse functional states of myeloid cells 2 . However, how these metabolic features act to perpetuate neuroinflammation is currently unknown. Using a multiomics approach, we identified a new molecular signature that perpetuates the activation of myeloid cells through mitochondrial complex II (CII) and I (CI) activity driving reverse electron transport (RET) and the production of reactive oxygen species (ROS). Blocking RET in pro-inflammatory myeloid cells protected the central nervous system (CNS) against neurotoxic damage and improved functional outcomes in animal disease models in vivo . Our data show that RET in myeloid cells is a potential new therapeutic target to foster neuroprotection in smouldering inflammatory CNS disorders 3 .

Endogenous CO2 ice mixture on the surface of Europa and no detection of plume activity.

Jupiter's moon Europa has a subsurface ocean beneath an icy crust. Conditions within the ocean are unknown, and it is unclear whether it is connected to the surface. We observed Europa with the James Webb Space Telescope (JWST) to search for active release of material by probing its surface and atmosphere. A search for plumes yielded no detection of water, carbon monoxide, methanol, ethane, or methane fluorescence emissions. Four spectral features of carbon dioxide (CO2) ice were detected; their spectral shapes and distribution across Europa's surface indicate that the CO2 is mixed with other compounds and concentrated in Tara Regio. The 13CO2 absorption is consistent with an isotopic ratio of 12C/13C = 83 ± 19. We interpret these observations as indicating that carbon is sourced from within Europa.

Viral rescue of magnocellular vasopressin cells in adolescent Brattleboro rats ameliorates diabetes insipidus, but not the hypoaroused phenotype.

Dysregulated arousal often accompanies neurodevelopmental disorders such as attention deficit hyperactivity disorder and autism spectrum disorder. Recently, we have found that adolescent homozygous Brattleboro (Hom) rats, which contain a mutation in the arginine vasopressin (AVP) gene, exhibit lower behavioral arousal than their heterozygous (Het) littermates in the open field test. This hypoaroused phenotype could be due to loss of AVP in magnocellular cells that supply AVP to the peripheral circulation and project to limbic structures or parvocellular cells that regulate the stress axis and other central targets. Alternatively, hypoarousal could be a side effect of diabetes insipidus - polydipsia and polyuria seen in Hom rats due to loss of AVP facilitation of water reabsorption in the kidney. We developed a viral-rescue approach to "cure" magnocellular AVP cells of their Brattleboro mutation. Infusion of a recombinant adeno-associated virus (rAAV) containing a functional Avp gene and promoter (rAAV-AVP) rescued AVP within magnocellular cells and fiber projections of the paraventricular nucleus of the hypothalamus (PVN) of male and female adolescent Hom rats. Furthermore, water intake was markedly reduced, ameliorating the symptoms of diabetes insipidus. In contrast, open field activity was unaffected. These findings indicate that the hyporaoused phenotype of adolescent Hom rats is not due to the loss of AVP function in magnocellular cells or a side effect of diabetes insipidus, but favors the hypothesis that central, parvocellular AVP mechanisms underlie the regulation of arousal during adolescence.

Otolaryngologist and pediatric oncologist perspectives on the role of fine needle aspiration in diagnosing pediatric head and neck masses.

OBJECTIVE: To determine how otolaryngologists and pediatric oncologists differ in their initial approach to diagnosing head and neck masses in children and adolescents. METHODS: We designed an electronic 28-question survey consisting of 4 clinical cases and one referral case varying by patient age, history, and physical exam findings. The survey was sent anonymously to pediatric oncologists and otolaryngologists at institutions in the United States and Canada. RESULTS: Two hundred and thirty one pediatric oncologists (29.4%) and 87 otolaryngologists (39.5%) completed the survey. Otolaryngologists were significantly more likely to recommend performing an FNA than oncologists in all four cases; less than 7% of pediatric oncologists recommended FNA for head and neck mass evaluation. Of providers who recommended FNA, otolaryngologists were more likely to do so because of diagnostic yield when compared to pediatric oncologists. However, when referred a patient with an FNA demonstrating non-Hodgkin lymphoma, the majority of pediatric oncologists (73.6%) and otolaryngologists (78.7%) would complete the staging work-up and begin treatment. If the same patient was referred with an FNA that demonstrated non-specific inflammation, most oncologists (91.0%) and otolaryngologists (94.4%) would biopsy the mass. CONCLUSION: Otolaryngologists and pediatric oncologists differ in their initial approach to diagnosing head and neck masses in children, yet they both would recommend treating a patient with a positive FNA. This highlights important differences in the diagnostic process depending on which provider sees the patient first. Further studies assessing the sensitivity and specificity are needed to determine the true diagnostic yield of FNAs in the assessment of head and neck masses in children and adolescents, especially with increasing need for molecular and genomic profiling.

Improved survival in metastatic germ-cell cancer.

Background: The prognostic score of the International Germ-Cell Cancer Collaborative Group (IGCCCG) in metastatic germ-cell cancers (mGCC) relies on treatments delivered before 1990. It is unclear, if this score is still relevant to contemporary cohorts of patients who receive modern-type chemotherapy and supportive care. Patients and methods: All patients who underwent cisplatin/etoposide-based first-line chemotherapy for mGCC at the University Hospital Zurich (USZ) between 1991 and 2016 were identified retrospectively. Clinical characteristics were extracted from medical charts and patients classified according to the IGCCCG score. International germ cell consensus classification: a prognostic factor-based staging system for metastatic germ cell cancers. J Clin Oncol 1997; 15: 594-603.). Progression-free survival (PFS) and overall survival (OS) probabilities at 5 years served as outcome parameters. Results: The study cohort consisted of 204 patients at a median age of 32 years and a median follow-up of 4.2 years. According to the IGCCCG score, PFS in the contemporary USZ cohort was 71% overall: 83% for good-risk, 69% for intermediate-risk and 30% for poor-risk patients, P < 0.001. OS for the entire cohort was 88%. In respect to OS, we observed no difference between good- and intermediate-risk patients (94% versus 91%, P = 0.62), but a statistically significant difference between those two risk groups and poor-risk patients, who had an OS of only 65%, P < 0.001. Conclusions: Within the contemporary USZ cohort of mGCC patients no improvements in PFS probabilities were observed compared with the ones predicted by the IGCCCG score for any prognostic category, but marked improvements in OS probabilities for intermediate- and poor-risk patients, possibly due to better salvage treatments.

A novel, blocking, Fc-silent anti-CD40 monoclonal antibody prolongs nonhuman primate renal allograft survival in the absence of B cell depletion.

CD40-CD154 pathway blockade prolongs renal allograft survival in nonhuman primates (NHPs). However, antibodies targeting CD154 were associated with an increased incidence of thromboembolic complications. Antibodies targeting CD40 prolong renal allograft survival in NHPs without thromboembolic events but with accompanying B cell depletion, raising the question of the relative contribution of B cell depletion to the efficacy of anti-CD40 blockade. Here, we investigated whether fully silencing Fc effector functions of an anti-CD40 antibody can still promote graft survival. The parent anti-CD40 monoclonal antibody HCD122 prolonged allograft survival in MHC-mismatched cynomolgus monkey renal allograft transplantation (52, 22, and 24 days) with accompanying B cell depletion. Fc-silencing yielded CFZ533, an antibody incapable of B cell depletion but still able to potently inhibit CD40 pathway activation. CFZ533 prolonged allograft survival and function up to a defined protocol endpoint of 98-100 days (100, 100, 100, 98, and 76 days) in the absence of B cell depletion and preservation of good histological graft morphology. CFZ533 was well-tolerated, with no evidence of thromboembolic events or CD40 pathway activation and suppressed a gene signature associated with acute rejection. Thus, use of the Fc-silent anti-CD40 antibody CFZ533 appears to be an attractive approach for preventing solid organ transplant rejection.

Fibrillin-1 impairment enhances blood-brain barrier permeability and xanthoma formation in brains of apolipoprotein E-deficient mice.

We recently reported that apolipoprotein E (ApoE)-deficient mice with a mutation in the fibrillin-1 gene (ApoE(-/-)Fbn1(C1039G+/-)) develop accelerated atherosclerosis with enhanced inflammation, atherosclerotic plaque rupture, myocardial infarction and sudden death. In the brain, fibrillin-1 functions as an attachment protein in the basement membrane, providing structural support to the blood-brain barrier (BBB). Here, we investigated whether fibrillin-1 impairment affects the permeability of the BBB proper and the blood-cerebrospinal fluid barrier (BCSFB), and whether this leads to the accelerated accumulation of lipids (xanthomas) in the brain. ApoE(-/-) (n=61) and ApoE(-/-)Fbn1(C1039G+/-) (n=73) mice were fed a Western-type diet (WD). After 14 weeks WD, a significantly higher permeability of the BBB was observed in ApoE(-/-)Fbn1(C1039G+/-) mice compared to age-matched ApoE(-/-) mice. This was accompanied by leukocyte infiltration, enhanced expression of pro-inflammatory cytokines, matrix metalloproteinases and transforming growth factor-ß, and by decreased expression of tight junction proteins claudin-5 and occludin. After 20 weeks WD, 83% of ApoE(-/-)Fbn1(C1039G+/-) mice showed xanthomas in the brain, compared to 23% of their ApoE(-/-) littermates. Xanthomas were mainly located in fibrillin-1-rich regions, such as the choroid plexus and the neocortex. Our findings demonstrate that dysfunctional fibrillin-1 impairs BBB/BCSFB integrity, facilitating peripheral leukocyte infiltration, which further degrades the BBB/BCSFB. As a consequence, lipoproteins can enter the brain, resulting in accelerated formation of xanthomas.

Human-directed social behaviour in dogs shows significant heritability.

Through domestication and co-evolution with humans, dogs have developed abilities to attract human attention, e.g. in a manner of seeking assistance when faced with a problem solving task. The aims of this study were to investigate within breed variation in human-directed contact seeking in dogs and to estimate its genetic basis. To do this, 498 research beagles, bred and kept under standardized conditions, were tested in an unsolvable problem task. Contact seeking behaviours recorded included both eye contact and physical interactions. Behavioural data was summarized through a principal component analysis, resulting in four components: test interactions, social interactions, eye contact and physical contact. Females scored significantly higher on social interactions and physical contact and age had an effect on eye contact scores. Narrow sense heritabilities (h(2) ) of the two largest components were estimated at 0.32 and 0.23 but were not significant for the last two components. These results show that within the studied dog population, behavioural variation in human-directed social behaviours was sex dependent and that the utilization of eye contact seeking increased with age and experience. Hence, heritability estimates indicate a significant genetic contribution to the variation found in human-directed social interactions, suggesting that social skills in dogs have a genetic basis, but can also be shaped and enhanced through individual experiences. This research gives the opportunity to further investigate the genetics behind dogs' social skills, which could also play a significant part into research on human social disorders such as autism.

Hypothalamic obesity.

Hypothalamic obesity represents a rare diagnosis applicable to only a small subset of obese patients. It is important to identify, diagnose, and treat these patients. This article reviews the physiology of the hypothalamus, focusing on its role in regulation of hunger, feeding, and metabolism. The causes of hypothalamic obesity are discussed including genetic, anatomic, and iatrogenic etiologies. The complex hormonal environment leading to obesity is explored for each etiology and treatment strategies are discussed. Reproductive consequences are also reviewed.

Heterogeneity of colorectal cancer (CRC) in reference to KRAS proto-oncogene utilizing WAVE technology.

BACKGROUND: New drugs targeting specific genes required for unregulated growth and metastases have improved survival rates for patients with metastatic colorectal cancer. Resistance to monoclonal antibodies specific for the epidermal growth factor receptor (EGFR) has been attributed to the presence of activating point mutations in the proto-oncogene KRAS. The use of EGFR inhibitor monotherapy in patients that have KRAS wild type has produced response rates of only 10-20%. The molecular basis for clinical resistance remains poorly understood. We propose two possible explanations to explain these low response rates; 1) levels of resistant CRC cells carrying mutated KRAS are below the sensitivity of standard direct sequencing modalities (<5%) or 2) the standard practice of analyzing a single area within a heterogeneous tumor is a practice that can overlook areas with mutated KRAS. METHODS: In a collaborative effort with the surgical and molecular pathology departments, 3 formalin fixed paraffin embedded tissue blocks of human CRC were obtained from the human tissue bank maintained by the Lifespan Pathology Department and/or the human tissue bank maintained by the Molecular Pathology Core of the COBRE for Cancer Research Development. The three specimens previously demonstrated KRAS mutations detected by the Applied Biosystems Kit. The Wave system 4500 (high performance ion-pairing liquid chromatography (IP-HPLC)) was utilized to evaluate tissue for the presence of KRAS proto-oncogene mutations at codons 12 and 13. RESULTS: Initially, the sensitivity of WAVE technology was compared with direct sequencing by evaluating a dilutional series. WAVE detected mutant alleles at levels of 2.5% compared to 20% performed with standard direct sequencing. Samples from three patients were evaluated by WAVE technology. Eight samples from patient 1 were analyzed. In two of eight samples, no mutations were detected at concentrations as low as 5%. In one sample a mutation was noted by WAVE and not by direct sequencing. All four samples from patient 2 tested positive for Exon 12/13 mutations. Of the seven samples from patient 3, five were positive for Exon 12/13 mutations and two were negative for Exon 12/13 mutations. CONCLUSION: In these studies the analysis of three patients' colorectal cancer tissues were analyzed utilizing the WAVE technology. Results demonstrated a greater degree of sensitivity in mutation detection when compared to standard sequencing. These studies also demonstrated heterogeneity of expression of KRAS mutations between areas of the tissue samples at a genomic level. The low clinical response rates to EGFR inhibition might be explained by the variation in mutation presence, which was dependent upon the region examined. The heterogeneity demonstrated in these studies provides another phenotypic variant that will impact clinical care.

Transtumoral targeting enabled by a novel neuropilin-binding peptide.

We have recently described a class of peptides that improve drug delivery by increasing penetration of drugs into solid tumors. These peptides contain a C-terminal C-end Rule (CendR) sequence motif (R/K)XX(R/K), which is responsible for cell internalization and tissue-penetration activity. Tumor-specific CendR peptides contain both a tumor-homing motif and a cryptic CendR motif that is proteolytically unmasked in tumor tissue. A previously described cyclic tumor-homing peptide, LyP-1 (sequence: CGNKRTRGC), contains a CendR element and is capable of tissue penetration. We use here the truncated form of LyP-1, in which the CendR motif is exposed (CGNKRTR; tLyP-1), and show that both LyP-1 and tLyP-1 internalize into cells through the neuropilin-1-dependent CendR internalization pathway. Moreover, we show that neuropilin-2 also binds tLyP-1 and that this binding equally activates the CendR pathway. Fluorescein-labeled tLyP-1 peptide and tLyP-1-conjugated nanoparticles show robust and selective homing to tumors, penetrating from the blood vessels into the tumor parenchyma. The truncated peptide is more potent in this regard than the parent peptide LyP-1. tLyP-1 furthermore improves extravasation of a co-injected nanoparticle into the tumor tissue. These properties make tLyP-1 a promising tool for targeted delivery of therapeutic and diagnostic agents to breast cancers and perhaps other types of tumors.

Measured comparison of the crossover periods for mid- and long-wave IR (MWIR and LWIR) polarimetric and conventional thermal imagery.

We report the results of a multi-day diurnal study in which polarimetric and conventional thermal imagery is recorded in the mid- and long-wave IR to identify and compare the respective time periods in which minimum target contrast is achieved. The data shows that the chief factors affecting polarimetric contrast in both wavebands are the amount of thermal emission from the objects in the scene and the abundance of MWIR and LWIR sources in the optical background. In particular, it has been observed that the MWIR polarimetric contrast was positively correlated to the presence of MWIR sources in the optical background, while the LWIR polarimetric contrast was negatively correlated to the presence of LWIR sources in the optical background.

Peptide-based interference of the transmembrane domain of neuropilin-1 inhibits glioma growth in vivo.

Angiogenesis in glioblastoma is largely dependent on vascular endothelial growth factor (VEGF) signalling. Consistently, the VEGF coreceptor NRP1 promotes angiogenesis and tumour growth in gliomas. Here, we provide data showing that an innovative peptidic tool targeting the transmembrane domain of NRP1 efficiently blocks rat and human glioma growth in vivo. We show both in vivo and in vitro that the antitumour effect results from the anti-proliferative, anti-migratory and anti-angiogenic properties of the compound. The proposed NRP1 antagonizing peptide is therefore a promising novel class of anti-angiogenic drugs that might prolong glioma patient survival. Our results finally show for the first time that the transmembrane domain of important signalling receptors can be antagonized in vivo thereby providing a new avenue towards the development of atypical antagonists with strong therapeutic potential.

Variation in physician reimbursement for endoscopy across Canada.

BACKGROUND: Endoscopy accounts for a significant proportion of income for physicians practicing gastroenterology. Fees are set provincially, and the consistency with regard to compensation for colonoscopy and gastroscopy across the provinces has yet to be established. OBJECTIVE: To compare and contrast provincial endoscopy fees across Canada and internationally. METHODS: Provincial and territorial ministries responsible for health care were contacted for their most current fee schedule. This was reviewed, and the billing amounts for colonoscopy and endoscopy collected. International contacts were made with regard to rates outside of Canada. RESULTS: The mean (+/- SD) national fee for gastroscopy was $114.19+/-$31.47 per procedure, with a range of $52.50 to $156.10. Physician billing nationally averaged $170.99+/-$33.49 per colonoscopy procedure, with a range of $105.00 to $223.00. The province of Quebec provided the least amount of compensation for both procedures, and the province of Nova Scotia provided the most for both procedures. CONCLUSION: Physician fees for gastroscopy and colonoscopy vary widely among the provinces, and, on average, seem to be less than international rates.

The many faces of semaphorins: from development to pathology.

The semaphorin family is a large group of proteins controlling cell migration and axonal growth cone guidance. These proteins are bi-functional signals capable of growth promotion or growth inhibition. Initially described in the nervous system, the majority of studies related to semaphorins and semaphorin signalling are nowadays performed in model systems outside the nervous system. Here, we provide an exhaustive review of the many faces of semaphorins both during developmental, regulatory and pathological processes. Indeed, because of their crucial fundamental roles, the semaphorins and their receptors represent important targets for the development of drugs directed at a variety of diseases.

The chemokine receptor Cxcr3 is not essential for acute cardiac allograft rejection in mice and rats.

Chemokine receptors have gained attention as potential targets for novel therapeutic strategies. We investigated the mechanisms of allograft rejection in chemokine receptor Cxcr3-deficient mice using a model of acute heart allograft rejection in the strain combination BALB/c to C57BL/6. Allograft survival was minimally prolonged in Cxcr3-deficient mice compared to wild-type (wt) animals (8 vs. 7 days) and treatment with a subtherapeutic dose of cyclosporine A (CsA) led to similar survival in Cxcr3-deficient and wt recipients (13 vs. 12 days). At rejection grafts were histologically indistinguishable. Microarray analysis revealed that besides Cxcr3 only few genes were differentially expressed in grafts or in spleens from transplanted or untransplanted animals. Transcript analysis by quantitative RT-PCR of selected cytokines, chemokines, or chemokine receptors or serum levels of selected cytokines and chemokines showed similar levels between the two groups. Furthermore, in a rat heart allograft transplantation model treatment with a small molecule CXCR3 antagonist did not prolong survival despite full blockade of Cxcr3 in vivo. In summary, Cxcr3 deficiency or pharmacologic blockade does not diminish graft infiltration, tempo and severity of rejection. Thus, Cxcr3 does not appear to play a pivotal role in the allograft rejection models described here.

The lakes of Titan.

The surface of Saturn's haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface. Initial visible and radar imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on the surface. Here we provide definitive evidence for the presence of lakes on the surface of Titan, obtained during the Cassini Radar flyby of Titan on 22 July 2006 (T16). The radar imaging polewards of 70 degrees north shows more than 75 circular to irregular radar-dark patches, in a region where liquid methane and ethane are expected to be abundant and stable on the surface. The radar-dark patches are interpreted as lakes on the basis of their very low radar reflectivity and morphological similarities to lakes, including associated channels and location in topographic depressions. Some of the lakes do not completely fill the depressions in which they lie, and apparently dry depressions are present. We interpret this to indicate that lakes are present in a number of states, including partly dry and liquid-filled. These northern-hemisphere lakes constitute the strongest evidence yet that a condensable-liquid hydrological cycle is active in Titan's surface and atmosphere, in which the lakes are filled through rainfall and/or intersection with the subsurface 'liquid methane' table.

Functional interaction between matrix metalloproteinase-3 and semaphorin-3C during cortical axonal growth and guidance.

In the developing cortex, axons and dendrites extend progressively in response to environmental cues attracting or repelling growing processes. Recent evidence suggests the existence of a functional link between guidance molecules and metalloproteinases. Here, we analyzed the putative functional interaction of matrix metalloproteinases (MMPs) with guidance cues of the semaphorin family during growth and guidance of cortical axons. Our results demonstrate that the expression pattern and the proteolytic activity of MMP-3 are consistent with a role of this particular MMP during cortical axon outgrowth. We found that MMP-3 is required for an optimal axon extension and is involved in the Sema3C-dependent chemoattraction of cortical axons by modulating both the growth capacity and the orientation of growth. Interestingly, the inhibitory Sema3A decreased both the expression and activity of MMP-3. Taken together, our results reveal a molecular interaction between MMPs and semaphorins providing new insight into the molecular mechanism allowing axonal growth cone to respond to environmental guidance cues in the context of cortical development.