De l’activité pharmacologique à l’usage des drogues : la construction des connaissances sur les psychotropes

Les effets des drogues sont des événements complexes dans la vie des usagers. Que savons-nous des effets des plus importants psychotropes et comment en sommes-nous arrivés à ces connaissances ? Un exercice proposé aide le lecteur à évaluer l'état de ses connaissances. En examinant les niveaux d'expérience cellulaire, organique, comportemental et social de certaines drogues, l'exercice permet au lecteur d'explorer comment ses connaissances et celles des autres sont construites. Des exemples d'effets de cinq drogues, identifiés à partir de diverses sources, sont présentés et décrits dans le contexte de ces niveaux d'expérience.Drug effects are complex events in drug users' lives. What do we know about the effects of major psychotropic drugs, and how have we arrived at this knowledge? An exercise is presented herein that assists the reader in assessing the state of her or his knowledge about the effects of certain psychotropic drugs. The exercise format allows the reader to explore how their and others' knowledge about psychotropic drugs are constructed, by examining cellular, organal, behavioral, and social levels of experience for specific drugs. Examples of effects for five specific drugs, identified from a variety of sources, are presented and described in the context of these different levels of experience

Effect of Free Trade Agreements on Pharmaceutical Market Competition: The Case of the 2009 US-Peru Free Trade Agreement and Its Implementation as National Drug Policy

Free Trade Agreements (FTA) are controversial for threatening essential aspects of health, especially access to affordable medicines. The US-Peru FTA required changes in the Peruvian pharmaceutical legislation that resulted in the implementation of the National Drug Policy (NDP) of 2009. The NDP included more robust technical requirements for registration, a Peruvian Good Manufacturing Practices certificate, a longer timeline for drug registration, and an increase in registration fees. This study evaluated the impact of the FTA on the number of registrations and competition in the Peruvian pharmaceutical market. Data for the period January 2005 to April 2014 were provided by the Peruvian drug regulatory authority (Dirección General de Medicamentos, Insumos y Drogas, DIGEMID). A total of 31,114 pharmaceutical products with unique registration numbers were evaluated. Brand drug new registrations decreased from 1789 in 2005 to 455 in 2013, and the number of generic registrations decreased from 621 in 2005 to 114 in 2013. Brand re-registrations also decreased from 714 in 2005 to 58 in 2013. There were 228 brand products awaiting registration in 2009 and 1,908 in 2013. The proportion of products awaiting registration was three times greater for brand than for generic products in 2009–2013. Registration of brand and generic medicines significantly declined after the implementation of the US-Peru FTA in 2009. The decline in the number of registrations was associated with more robust technical requirements, a longer DIGEMID registration timeline, and an increase in registration fees. The stronger registration requirements are expected to increase the quality of the drugs marketed in the country, but also less competition and a reduction in domestic registrations

ALIX binds a YPX(3)L motif of the GPCR PAR1 and mediates ubiquitin-independent ESCRT-III/MVB sorting.

The sorting of signaling receptors to lysosomes is an essential regulatory process in mammalian cells. During degradation, receptors are modified with ubiquitin and sorted by endosomal sorting complex required for transport (ESCRT)-0, -I, -II, and -III complexes into intraluminal vesicles (ILVs) of multivesicular bodies (MVBs). However, it remains unclear whether a single universal mechanism mediates MVB sorting of all receptors. We previously showed that protease-activated receptor 1 (PAR1), a G protein-coupled receptor (GPCR) for thrombin, is internalized after activation and sorted to lysosomes independent of ubiquitination and the ubiquitin-binding ESCRT components hepatocyte growth factor-regulated tyrosine kinase substrate and Tsg101. In this paper, we report that PAR1 sorted to ILVs of MVBs through an ESCRT-III-dependent pathway independent of ubiquitination. We further demonstrate that ALIX, a charged MVB protein 4-ESCRT-III interacting protein, bound to a YPX(3)L motif of PAR1 via its central V domain to mediate lysosomal degradation. This study reveals a novel MVB/lysosomal sorting pathway for signaling receptors that bypasses the requirement for ubiquitination and ubiquitin-binding ESCRTs and may be applicable to a subset of GPCRs containing YPX(n)L motifs

AP-3 regulates PAR1 ubiquitin-independent MVB/lysosomal sorting via an ALIX-mediated pathway

The sorting of signaling receptors within the endocytic system is important for appropriate cellular responses. After activation, receptors are trafficked to early endosomes and either recycled or sorted to lysosomes and degraded. Most receptors trafficked to lysosomes are modified with ubiquitin and recruited into an endosomal subdomain enriched in hepatocyte growth factor–regulated tyrosine kinase substrate (HRS), a ubiquitin-binding component of the endosomal-sorting complex required for transport (ESCRT) machinery, and then sorted into intraluminal vesicles (ILVs) of multivesicular bodies (MVBs)/lysosomes. However, not all receptors use ubiquitin or the canonical ESCRT machinery to sort to MVBs/lysosomes. This is exemplified by protease-activated receptor-1 (PAR1), a G protein–coupled receptor for thrombin, which sorts to lysosomes independent of ubiquitination and HRS. We recently showed that the adaptor protein ALIX binds to PAR1, recruits ESCRT-III, and mediates receptor sorting to ILVs of MVBs. However, the mechanism that initiates PAR1 sorting at the early endosome is not known. We now report that the adaptor protein complex-3 (AP-3) regulates PAR1 ubiquitin-independent sorting to MVBs through an ALIX-dependent pathway. AP-3 binds to a PAR1 cytoplasmic tail–localized tyrosine-based motif and mediates PAR1 lysosomal degradation independent of ubiquitination. Moreover, AP-3 facilitates PAR1 interaction with ALIX, suggesting that AP-3 functions before PAR1 engagement of ALIX and MVB/lysosomal sorting

Blood-Brain Barrier Breakdown in the Aging Human Hippocampus

The blood-brain barrier (BBB) limits entry of blood-derived products, pathogens, and cells into the brain that is essential for normal neuronal functioning and information processing. Post-mortem tissue analysis indicates BBB damage in Alzheimer’s disease (AD). The timing of BBB breakdown remains, however, elusive. Using an advanced dynamic contrast-enhanced MRI protocol with high spatial and temporal resolutions to quantify regional BBB permeability in the living human brain, we show an age-dependent BBB breakdown in the hippocampus, a region critical for learning and memory that is affected early in AD. The BBB breakdown in the hippocampus and its CA1 and dentate gyrus subdivisions worsened with mild cognitive impairment that correlated with injury to BBB-associated pericytes, as shown by the cerebrospinal fluid analysis. Our data suggest that BBB breakdown is an early event in the aging human brain that begins in the hippocampus and may contribute to cognitive impairment

Porphyrostromium Trevisan (1848) Vs. Erythrotrichopeltis Kornmann (1984) (Rhodophyta)

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149702/1/tax02529.pd

Blood-brain barrier failure as a core mechanism in cerebral small vessel disease and dementia: evidence from a cohort study

Introduction: Small vessel disease (SVD) is a common contributor to dementia. Subtle blood-brain barrier (BBB) leakage may be important in SVD-induced brain damage. Methods: We assessed imaging, clinical variables, and cognition in patients with mild (i.e., nondisabling) ischemic lacunar or cortical stroke. We analyzed BBB leakage, interstitial fluid, and white matter integrity using multimodal tissue-specific spatial analysis around white matter hyperintensities (WMH). We assessed predictors of 1 year cognition, recurrent stroke, and dependency. Results: In 201 patients, median age 67 (range 34–97), BBB leakage, and interstitial fluid were higher in WMH than normal-appearing white matter; leakage in normal-appearing white matter increased with proximity to WMH (P , .0001), with WMH severity (P 5 .033), age (P 5 .03), and hypertension (P , .0001). BBB leakage in WMH predicted declining cognition at 1 year. Discussion: BBB leakage increases in normal-appearing white matter with WMH and predicts worsening cognition. Interventions to reduce BBB leakage may prevent SVD-associated dementia