61 research outputs found
Naloxone's Pentapeptide Binding Site on Filamin A Blocks Mu Opioid Receptor–Gs Coupling and CREB Activation of Acute Morphine
Chronic morphine causes the mu opioid receptor (MOR) to switch its coupling from Gi/o to Gs, resulting in excitatory signaling via both Gαs and its Gβγ dimer. Ultra-low-dose naloxone (NLX) prevents this switch and attenuates opioid tolerance and dependence. This protective effect is mediated via a high-affinity interaction of NLX to a pentapeptide region in c-terminal filamin A (FLNA), a scaffolding protein interacting with MOR. In organotypic striatal slice cultures, we now show that acute morphine induces a dose-dependent Go-to-Gs coupling switch at 5 and 15 min that resolves by 1 hr. The acute Gs coupling induced by 100 µM morphine was completely prevented by co-treatment with 100 pM NLX, (+)NLX, or naltrexone (NTX), or their pentapeptide binding site (FLNA2561–2565), which we show can act as a decoy for MOR or bind to FLNA itself. All of these co-treatments presumably prevent the MOR–FLNA interaction. Since ultra-low-dose NTX also attenuates the addictive properties of opioids, we assessed striatal cAMP production and CREB phosphorylation at S133. Correlating with the Gs coupling, acute morphine induced elevated cAMP levels and a several-fold increase in pS133CREB that were also completely blocked by NLX, NTX or the FLNA pentapeptide. We propose that acute, robust stimulation of MOR causes an interaction with FLNA that allows an initially transient MOR–Gs coupling, which recovers with receptor recycling but persists when MOR stimulation is repeated or prolonged. The complete prevention of this acute, morphine-induced MOR–Gs coupling by 100 pM NLX/NTX or 10 µM pentapeptide segment of FLNA further elucidates both MOR signaling and the mechanism of action of ultra-low-dose NLX or NTX in attenuating opioid tolerance, dependence and addictive potential
Resistive Exercise for Arthritic Cartilage Health (REACH): A randomized double-blind, sham-exercise controlled trial
<p>Abstract</p> <p>Background</p> <p>This article provides the rationale and methodology, of the first randomised controlled trial to our knowledge designed to assess the efficacy of progressive resistance training on cartilage morphology in women with knee osteoarthritis.</p> <p>Development and progression of osteoarthritis is multifactorial, with obesity, quadriceps weakness, joint malalignment, and abnormal mechanical joint forces particularly relevant to this study. Progressive resistance training has been reported to improve pain and disability in osteoarthritic cohorts. However, the disease-modifying potential of progressive resistance training for the articular cartilage degeneration characteristic of osteoarthritis is unknown. Our aim was to investigate the effect of high intensity progressive resistance training on articular cartilage degeneration in women with knee osteoarthritis.</p> <p>Methods</p> <p>Our cohort consisted of women over 40 years of age with primary knee osteoarthritis, according to the American College of Rheumatology clinical criteria. Primary outcome was blinded measurement of cartilage morphology via magnetic resonance imaging scan of the tibiofemoral joint. Secondary outcomes included walking endurance, balance, muscle strength, endurance, power, and velocity, body composition, pain, disability, depressive symptoms, and quality of life.</p> <p>Participants were randomized into a supervised progressive resistance training or sham-exercise group. The progressive resistance training group trained muscles around the hip and knee at 80% of their peak strength and progressed 3% per session, 3 days per week for 6 months. The sham-exercise group completed all exercises except hip adduction, but without added resistance or progression. Outcomes were repeated at 3 and 6 months, except for the magnetic resonance imaging scan, which was only repeated at 6 months.</p> <p>Discussion</p> <p>Our results will provide an evaluation of the disease-modifying potential of progressive resistance training for osteoarthritis.</p> <p>Trial Registration</p> <p>ANZCTR Reference No. 12605000116628</p
Non-nociceptive roles of opioids in the CNS: opioids' effects on neurogenesis, learning, memory and affect.
Mortality due to opioid use has grown to the point where, for the first time in history, opioid-related deaths exceed those caused by car accidents in many states in the United States. Changes in the prescribing of opioids for pain and the illicit use of fentanyl (and derivatives) have contributed to the current epidemic. Less known is the impact of opioids on hippocampal neurogenesis, the functional manipulation of which may improve the deleterious effects of opioid use. We provide new insights into how the dysregulation of neurogenesis by opioids can modify learning and affect, mood and emotions, processes that have been well accepted to motivate addictive behaviours
Withanolides and related steroids
Since the isolation of the first withanolides in the mid-1960s, over 600 new members of this group of compounds have been described, with most from genera of the plant family Solanaceae. The basic structure of withaferin A, a C28 ergostane with a modified side chain forming a δ-lactone between carbons 22 and 26, was considered for many years the basic template for the withanolides. Nowadays, a considerable number of related structures are also considered part of the withanolide class; among them are those containing γ-lactones in the side chain that have come to be at least as common as the δ-lactones. The reduced versions (γ and δ-lactols) are also known. Further structural variations include modified skeletons (including C27 compounds), aromatic rings and additional rings, which may coexist in a single plant species. Seasonal and geographical variations have also been described in the concentration levels and types of withanolides that may occur, especially in the Jaborosa and Salpichroa genera, and biogenetic relationships among those withanolides may be inferred from the structural variations detected. Withania is the parent genus of the withanolides and a special section is devoted to the new structures isolated from species in this genus. Following this, all other new structures are grouped by structural types.
Many withanolides have shown a variety of interesting biological activities ranging from antitumor, cytotoxic and potential cancer chemopreventive effects, to feeding deterrence for several insects as well as selective phytotoxicity towards monocotyledoneous and dicotyledoneous species. Trypanocidal, leishmanicidal, antibacterial, and antifungal activities have also been reported. A comprehensive description of the different activities and their significance has been included in this chapter. The final section is devoted to chemotaxonomic implications of withanolide distribution within the Solanaceae.
Overall, this chapter covers the advances in the chemistry and biology of withanolides over the last 16 years.Fil: Misico, Rosana Isabel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuÃmica Orgánica; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos FÃsicos Aplicados a la QuÃmica Orgánica (i); ArgentinaFil: Nicotra, V.. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Córdoba. Instituto Multidisciplinario de BiologÃa Vegetal (p); Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias QuÃmicas. Departamento de QuÃmica Orgánica; ArgentinaFil: Oberti, Juan Carlos MarÃa. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Córdoba. Instituto Multidisciplinario de BiologÃa Vegetal (p); Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias QuÃmicas. Departamento de QuÃmica Orgánica; ArgentinaFil: Barboza, Gloria Estela. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Córdoba. Instituto Multidisciplinario de BiologÃa Vegetal (p); Argentina. Universidad
Nacional de Córdoba. Facultad de Ciencias QuÃmicas. Departamento de Farmacia; ArgentinaFil: Gil, Roberto Ricardo. University Of Carnegie Mellon; Estados UnidosFil: Burton, Gerardo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuÃmica Orgánica; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos FÃsicos Aplicados a la QuÃmica Orgánica (i); Argentin
Physician Counseling on Colorectal Cancer Screening and Receipt of Screening among Latino Patients
BACKGROUND: Latinos have lower rates of colorectal cancer (CRC) screening and later stage diagnosis than Whites, which may be partially explained by physician communication factors. OBJECTIVE: We assessed associations between patient-reported physician counseling regarding CRC screening and receipt of CRC screening among Latino primary care patients. DESIGN: This was a cross-sectional telephone survey. PARTICIPANTS: The participants of this study were Latino primary care patients 50 years of age or older, with one or more visits during the preceding year. MAIN MEASURES: We developed patient-reported measures to assess whether physicians provided explanations of CRC risks and tests, elicited patients’ barriers to CRC screening, were responsive to patients’ concerns about screening, and encouraged patients to be screened. Outcomes were patient reports of receipt of endoscopy (sigmoidoscopy or colonoscopy) and fecal occult blood test (FOBT) within recommended guidelines. KEY RESULTS: Of 817 eligible patients contacted, 505 (62 %) completed the survey; mean age was 61 years (SD 8.4), 69 % were women, and 53 % had less than high school education. Forty-six percent reported obtaining endoscopy (with or without FOBT), 13 % reported FOBT only, and 41 % reported no CRC screening. In bivariate analyses, physician explanations, elicitation of barriers, responsiveness to concerns, and greater encouragement for screening were associated with receipt of endoscopy (p < 0.001), and explanations (p < 0.05) and encouragement (p < 0.001) were associated with FOBT. Adjusting for covariates, physician explanations (OR = 1.27; 95 % CI 1.03, 1.58) and greater physician encouragement (OR = 6.74; 95 % CI 3.57, 12.72) were associated with endoscopy; patients reporting quite a bit/a lot of physician encouragement had six times higher odds of obtaining the FOBT as those reporting none/a little encouragement (OR = 6.54; 95 % CI 2.76, 15.48). CONCLUSIONS: Among primarily lower-socioeconomic status Latino patients, the degree to which patients perceived that physicians encouraged CRC screening was more strongly associated with screening than with providing risk information, eliciting barriers, and responding to their concerns about screening
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A molecular, morphological and cytological investigation of the identity of non-native Ludwigia (Onagraceae) populations in Britain
A combined molecular, morphological and cytological analysis was used to study the identity and number of species of Ludwigia section Oligospermum occurring in British waterways. Only one taxon was identified for which the name L. grandiflora subsp. hexapetala (Hook. & Arn.) G.L. Nesom & Kartesz is preferred. A chromosome count of 2n = 80 was made for all plants tested and DNA evidence demonstrates that at least two clones are present in Britain. Morphological characters to differentiate L.grandiflora subsp. hexapetala and L. peploides subsp. montevidensis (Spreng.) P.H. Raven are provided. Though the production of fruit in Britain by apparently isolated populations is noted, repeated introduction into the wild from gardens is judged to be primarily responsible for the British distribution of the taxon. Legislative implications are considered and an amendment to Schedule 9 of the UK Wildlife and Countryside Act (1981) is strongly advocated
Sanitary quality of the public groundwater supply for the municipality of Belém in northern Brazil
Theoretical study on electronic spectra and interaction in [Au3]-L-[Au3] (L = C6F6,Ag+) complexes
Construction and comparative analyses of highly dense linkage maps of two sweet cherry intra-specific progenies of commercial cultivars.
Despite the agronomical importance and high synteny with other Prunus species, breeding improvements for cherry have been slow compared to other temperate fruits, such as apple or peach. However, the recent release of the peach genome v1.0 by the International Peach Genome Initiative and the sequencing of cherry accessions to identify Single Nucleotide Polymorphisms (SNPs) provide an excellent basis for the advancement of cherry genetic and genomic studies. The availability of dense genetic linkage maps in phenotyped segregating progenies would be a valuable tool for breeders and geneticists. Using two sweet cherry (Prunus avium L.) intra-specific progenies derived from crosses between 'Black Tartarian' × 'Kordia' (BT×K) and 'Regina' × 'Lapins'(R×L), high-density genetic maps of the four parental lines and the two segregating populations were constructed. For BT×K and R×L, 89 and 121 F(1) plants were used for linkage mapping, respectively. A total of 5,696 SNP markers were tested in each progeny. As a result of these analyses, 723 and 687 markers were mapped into eight linkage groups (LGs) in BT×K and R×L, respectively. The resulting maps spanned 752.9 and 639.9 cM with an average distance of 1.1 and 0.9 cM between adjacent markers in BT×K and R×L, respectively. The maps displayed high synteny and co-linearity between each other, with the Prunus bin map, and with the peach genome v1.0 for all eight LGs (LG1-LG8). These maps provide a useful tool for investigating traits of interest in sweet cherry and represent a qualitative advance in the understanding of the cherry genome and its synteny with other members of the Rosaceae family
Synapsin I is a spectrin-binding protein immunologically related to erythrocyte protein 4.1
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