There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Probability Distributions.- Linear Models for Regression.- Linear Models for Classification.- Neural Networks.- Kernel Methods.- Sparse Kernel Machines.- Graphical Models.- Mixture Models and EM.- Approximate Inference.- Sampling Methods.- Continuous Latent Variables.- Sequential Data.- Combining Models.

Pattern Recognition and Machine Learning

Two types of cannabinoid receptor have been discovered so far, CB(1) (2.1: CBD:1:CB1:), cloned in 1990, and CB(2) (2.1:CBD:2:CB2:), cloned in 1993. Distinction between these receptors is based on differences in their predicted amino acid sequence, signaling mechanisms, tissue distribution, and sensitivity to certain potent agonists and antagonists that show marked selectivity for one or the other receptor type. Cannabinoid receptors CB(1) and CB(2) exhibit 48% amino acid sequence identity. Both receptor types are coupled through G proteins to adenylyl cyclase and mitogen-activated protein kinase. CB(1) receptors are also coupled through G proteins to several types of calcium and potassium channels. These receptors exist primarily on central and peripheral neurons, one of their functions being to inhibit neurotransmitter release. Indeed, endogenous CB(1) agonists probably serve as retrograde synaptic messengers. CB(2) receptors are present mainly on immune cells. Such cells also express CB(1) receptors, albeit to a lesser extent, with both receptor types exerting a broad spectrum of immune effects that includes modulation of cytokine release. Of several endogenous agonists for cannabinoid receptors identified thus far, the most notable are arachidonoylethanolamide, 2-arachidonoylglycerol, and 2-arachidonylglyceryl ether. It is unclear whether these eicosanoid molecules are the only, or primary, endogenous agonists. Hence, we consider it premature to rename cannabinoid receptors after an endogenous agonist as is recommended by the International Union of Pharmacology Committee on Receptor Nomenclature and Drug Classification. Although pharmacological evidence for the existence of additional types of cannabinoid receptor is emerging, other kinds of supporting evidence are still lacking.

https://pharmrev.aspetjournals.org/content/pharmrev/54/2/161.full.pdf

International Union of Pharmacology. XXVII. Classification of Cannabinoid Receptors

http://www.back-in-business-physiotherapy.com/images/files/DescendingControl.pdf

Descending control of pain.

The endogenous cannabinoid receptor agonist anandamide is a powerful vasodilator of isolated vascular preparations, but its mechanism of action is unclear. Here we show that the vasodilator response to anandamide in isolated arteries is capsaicin-sensitive and accompanied by release of calcitonin-gene-related peptide (CGRP). The selective CGRP-receptor antagonist 8-37 CGRP, but not the cannabinoid CB1 receptor blocker SR141716A, inhibited the vasodilator effect of anandamide. Other endogenous (2-arachidonylglycerol, palmitylethanolamide) and synthetic (HU 210, WIN 55,212-2, CP 55,940) CB1 and CB2 receptor agonists could not mimic the action of anandamide. The selective 'vanilloid receptor' antagonist capsazepine inhibited anandamide-induced vasodilation and release of CGRP. In patch-clamp experiments on cells expressing the cloned vanilloid receptor (VR1), anandamide induced a capsazepine-sensitive current in whole cells and isolated membrane patches. Our results indicate that anandamide induces vasodilation by activating vanilloid receptors on perivascular sensory nerves and causing release of CGRP. The vanilloid receptor may thus be another molecular target for endogenous anandamide, besides cannabinoid receptors, in the nervous and cardiovascular systems.

Vanilloid receptors on sensory nerves mediate the vasodilator action of anandamide

We studied the discriminating capacity of NMR spectroscopy-based metabolomics of exhaled breath condensate (EBC) in asthma and COPD patients, who were either steroid-naive or treated with inhaled corticosteroids (ICS) [fluticasone (500-1000 μg/day) for at least 2 months], and healthy subjects. Twenty-seven steroid-naive COPD patients (21/6, males/females, age 67±2 years, mean±SEM, FEV1 68±2.9% predicted value), 20 COPD patients on ICS (16/4, males/females, age 70±2 years, FEV1 73±4.2% predicyed value), 21 steroid-naive asthmatics (16/5, males/females, age 32±3.9 years, FEV1 99±4.9% predicted value), 19 asthmatics on ICS (14/5, males/females, age 31±4.0 years, FEV1 85±5.0% predicted value), and 15 healthy subjects (8/7, males/females, age 28±1 years, FEV1 116±2.6% predicted value) were included in a cross-sectional study. Asthma and healthy subjects were nonsmokers, COPD patients were exsmokers. EBC was collected after 20 min of tidal breathing (Ecoscreen, Jaeger, Hoechberg, Germany). 1H-NMR spectra (Bruker Avance spectrometer) were data reduced to buckets (AMIX 3.6 package, Bruker Biospin, Rheinstetten, Germany) and normalized to total spectral area. Good reproducibility and no salivary contamination was previously reported (Montuschi P et al, Thorax, 2012). PLS-DA showed all study groups were separated (R2=0.79, Q2=0.80), suggesting an effect of ICS on EBC metabolites which has to be investigated in prospective controlled studies.

![Figure][1] [1]: pending:yes

Metabolomic analysis of exhaled breath condensate in patients with asthma and COPD

NMR spectroscopy-based metabolomics of exhaled breath condensate in inflammatory respiratory diseases

Abstract The maintenance of human health is dependent on a symbiotic relationship between humans and associated bacteria. The diversity and abundance of each habitat’s signature microbes vary widely among body areas and among them the oral microbiome plays a key role. Significant changes in the oral cavity, predominantly at salivary and periodontal level, have been associated with changes in estrogen levels. However, whether the oral microbiome is affected by hormonal level alterations is understudied. Hence the main objective pursued by AMICA project was to characterize the oral microbiome (saliva) in healthy women through: profiling studies using "omics" technologies (NMR-based metabolomics, targeted lipidomics by LC–MS, metagenomics by NGS); SinglePlex ELISA assays; glycosidase activity analyses and bioinformatic analysis. For this purpose, thirty-nine medically healthy women aged 26–77 years (19 with menstrual cycle and 20 in menopause) were recruited. Participants completed questionnaires assessing detailed medical and medication history and demographic characteristics. Plasmatic and salivary levels of sexual hormones were assessed (FSH, estradiol, LH and progesteron) at day 3 and 14 for women with menstrual cycle and only once for women in menopause. Salivary microbiome composition was assessed through meta-taxonomic 16S sequencing and overall, the salivary microbiome of most women remained relatively stable throughout the menstrual cycle and in menopause. Targeted lipidomics and untargeted metabolomics profiling were assessed through the use of LC–MS and NMR spectroscopy technologies, respectively and significant changes in terms of metabolites were identified in saliva of post-menopausal women in comparison to cycle. Moreover, glycosyl hydrolase activities were screened and showed that the β-D-hexosaminidase activity was the most present among those analyzed. Although this study has not identified significant alterations in the composition of the oral microbiome, multiomics analysis have revealed a strong correlation between 2-AG and α-mannosidase. In conclusion, the use of a multidisciplinary approach to investigate the oral microbiome of healthy women provided some indication about microbiome-derived predictive biomarkers that could be used in the future for developing new strategies to help to re-establish the correct hormonal balance in post-menopausal women. 

/pdf/analysis-of-the-oral-microbiome-during-hormonal-cycle-and-35nknpdf.pdf

Analysis of the oral microbiome during hormonal cycle and its alterations in menopausal women: the “AMICA” project

By using NMR spectroscopy, a non-invasive investigation technique, we performed in vivo experiments aimed at uncovering the metabolic pathways involved in the early response of Fabrea salina cells to ultraviolet (UV) radiation. This hypersaline ciliate was chosen as a model organism because of its well-known high resistance to UV radiation. Identical cell samples were exposed to visible radiation only (control samples, CS) and to UV-B + UV-A + visible radiation (treated samples, TS), and NMR spectra of in vivo cells were collected at different exposure times. Resonances were identified through one- and two-dimensional experiments. To compare experiments performed at variable irradiation times on different culture batches, metabolite signals affected by the UV exposure were normalized to corresponding intensity at τ = 0, the zero exposure time. The most affected metabolites are all osmoprotectants, namely, choline, glycine-betaine, betaines, ectoine, proline, α-trehalose and sucrose. The time course of these signals presents qualitative differences between CS and TS, and most of these osmoprotectants tend to accumulate significantly in TS in a UV dose-dependent manner. A picture of the immediate stress response of F. salina against UV radiation in terms of osmoprotection, water retention and salting-out prevention is described.

Dominique Melck

Papers

Metabolomic analysis of exhaled breath condensate in patients with asthma and COPD

NMR spectroscopy-based metabolomics of exhaled breath condensate in inflammatory respiratory diseases

Analysis of the oral microbiome during hormonal cycle and its alterations in menopausal women: the “AMICA” project

Understanding UV-driven metabolism in the hypersaline ciliate Fabrea salina