Quantitative microchemical changes reflecting functional activity in supraoptic nerve cells of the rat

1. Neurones and nuclei, isolated from the supraoptic regions of the rat's hypothalamus, have been examined by phase contrast and interference microscopy and by ultraviolet absorption microspectrography, in a quantitative study of their metabolic response to stimulation. 2. Vhen isolated from rats dehydrated for up to five days, fresh supraoptic nuclei were larger and more likely to contain marginated nucleoli. The dry mass of fixed nuclei did not change. The mean dry mass and nucleic acid content of supra¬ optic nucleoli and cell bodies increased significantly with progressive osmotic stimulation. Nucleolar changes preceded those in the cell body by 24 to 48 hours. 3. The significance of these changes is discussed in relation to published data concerning neuronal responses to injury and prolonged stimulation. 4. The distribution of dry mass among supraoptic nucleol may be bimodal after moderate osmotic stress, but the presence of two populations of neurones within the supraoptic nucleus could not be confirmed. 5. The increases in dry mass and nucleic acid content of supraoptic nucleoli and cell bodies were both greater and faster during five days dehydration at a raised environmental temperature (24°C). Thus the metabolic response can be graded according to the functional load placed on the neurone. 6. Neurohypophyses which have been partially depleted of their "stores" of neurohormone contained some factor which, when injected into the lateral cerebral ventricle of normal rats, resulted in an increase in the mean dry mass and nucleic acid content of supraoptic nucleoli. These nucleolar changes seemed independent of neurohormone secretion or serum osmolality in the recipient animals. 7. Extracts of normal ("non-depleted") neurohypophyses significantly inhibited the dry mass response of supraoptic nucleoli to osmotic stress. 8. "Hormone-depleted" posterior lobe extracts did not alter the mean dry mass or nucleic acid content of nucleoli from the posterior part of the arcuate nucleus. 9. Extracts of tissue from the parietal cortex had no demonstrable effect on supraoptic nucleoli. 10. The possibility is discussed that "active" substances derived from the neurohypophysis may serve to match synthetic activity to secretory losses in supraoptic neurones. 11. The mean dry mass of pituicytes increases rapidly during the first 48 hours of dehydration. This response is as fast as any supraoptic changes detected in this investigation

Library-derived peptide aggregation modulators of Parkinson's disease early-onset alpha-synuclein variants.

[Image: see text] Parkinson’s Disease (PD) is characterized by the accumulation of Lewy bodies in dopaminergic neurons. The main protein component of Lewy bodies, α-synuclein (αS), is also firmly linked to PD through the identification of a number of single point mutations that are autosomal dominant for early-onset disease. Consequently, the misfolding and subsequent aggregation of αS is thought to be a key stage in the development and progression of PD. Therefore, modulating the aggregation pathway of αS is an attractive therapeutic target. Owing to the fact that all but one of the familial mutations is located in the preNAC 45–54 region of αS, we previously designed a semi-rational library using this sequence as a design scaffold. The 45–54 peptide library was screened using a protein-fragment complementation assay approach, leading to the identification of the 4554W peptide. The peptide was subsequently found to be effective in inhibiting primary nucleation of αS, the earliest stage of the aggregation pathway. Here, we build upon this previous work by screening the same 45–54 library against five of the known αS single-point mutants that are associated with early-onset PD (A30P, E46K, H50Q, G51D, and A53T). These point mutations lead to a rapid acceleration of PD pathology by altering either the rate or type of aggregates formed. All ultimately lead to earlier disease onset and were therefore used to enforce increased assay stringency during the library screening process. The ultimate aim was to identify a peptide that is effective against not only the familial αS variant from which it has been selected but that is also effective against WT αS. Screening resulted in five peptides that shared common residues at some positions, while deviating at others. All reduced aggregation of the respective target, with several also identified to be effective at reducing aggregation when incubated with other variants. In addition, our results demonstrate that a previously optimized peptide, 4554W(N6A), is highly effective against not only WT αS but also several of the single-point mutant forms and hence is a suitable baseline for further work toward a PD therapeutic

A downsized and optimised intracellular library-derived peptide prevents alpha-synuclein primary nucleation and toxicity without impacting upon lipid binding

Misfolding and aggregation of alpha-synuclein (αS) within dopaminergic neurons is a key factor in the development and progression of a group of age-related neurodegenerative diseases, termed synucleinopathies, that include Parkinson's disease (PD). We previously derived a peptide inhibitor from a 209,952-member intracellular library screen by employing the preNAC region (45–54) as a design template. At least six single-point mutations firmly linked to early-onset Parkinson's disease (E46K, H50Q, G51D, A53T/E/V) are located within this region, strongly implicating a pathogenic role within αS that leads to increased cytotoxicity. A library-derived ten residue peptide, 4554W, was consequently shown to block αS aggregation at the point of primary nucleation via lipid induction, inhibiting its conversion into downstream cytotoxic species. Here we couple truncation with a full alanine scan analysis, to establish the effect upon the αS aggregation pathway relative to 4554W. This revealed the precise residues responsible for eliciting inhibitory interaction and function, as well as those potentially amenable to modification or functionalisation. We find that modification N6A combined with N-terminal truncation results in a peptide of significantly increased efficacy. Importantly, our data demonstrate that the peptide does not directly disrupt αS lipid-binding, a desirable trait since antagonists of αS aggregation and toxicity should not impede association with small synaptic neurotransmitter vesicles, and thus not disrupt dopaminergic vesicle fusion and recycling. This work paves the way toward the major aim of deriving a highly potent peptide antagonist of αS pathogenicity without impacting on native αS function.</p

Just how much does it cost? A cost study of chronic pain following cardiac surgery

Objective: The study objective was to determine use of pain-related health care resources and associated direct and indirect costs over a two-year period in cardiac surgery patients who developed chronic post-surgical pain (CPSP). Methods: This multicentric observational prospective study recruited patients prior to cardiac surgery; these patients completed research assistant-administered questionnaires on pain and psychological characteristics at 6, 12 and 24 months post-operatively. Patients reporting CPSP also completed a one-month pain care record (PCR) (self-report diary) at each follow-up. Data were analyzed using descriptive statistics, multivariable logistic regression models, and generalized linear models with log link and gamma family adjusting for sociodemographic and pain intensity. Results: Out of 1,247 patients, 18%, 13%, and 9% reported experiencing CPSP at 6, 12, and 24 months, respectively. Between 16% and 28% of CPSP patients reported utilizing health care resources for their pain over the follow-up period. Among all CPSP patients, mean monthly pain-related costs were CAN$207 at 6 months and significantly decreased thereafter. More severe pain and greater levels of pain catastrophizing were the most consistent predictors of health care utilization and costs. Discussion: Health care costs associated with early management of CPSP after cardiac surgery seem attributable to a minority of patients and decrease over time for most of them. Results are novel in that they document for the first time the economic burden of CPSP in this population of patients. Longer follow-up time that would capture severe cases of CPSP as well as examination of costs associated with other surgical populations are warranted. Summary: Economic burden of chronic post-surgical pain may be substantial but few patients utilize resources. Health utilization and costs are associated with pain and psychological characteristics

Bis(\u3cem\u3eN\u3c/em\u3e-amidinohydrazones) and \u3cem\u3eN\u3c/em\u3e-(amidino)-\u3cem\u3eN\u3c/em\u3e\u27-aryl-bishydrazones: New Classes of Antibacterial/Antifungal Agents

The emergence of multidrug-resistant bacterial and fungal strains poses a threat to human health that requires the design and synthesis of new classes of antimicr obial agents. We evaluated bis(N-amidinohydrazones) and N-(amidino)-N\u27-aryl-bishydrazones for their antibacterial and antifungal activities against panels of Gram-positive/Gram-negative bacteria as well as fungi. We investigated their potential to develop resistance against both bacteria and fungi by a multi-step, resistance-selection method, explored their potential to induce the production of reactive oxygen species, and assessed their toxicity. In summary, we found that these compounds exhibited broad-spectrum antibacterial and antifungal activities against most of the tested strains with minimum inhibitory concentration (MIC) values ranging from \u3c 0.5- \u3e 500 μM against bacteria and 1.0- \u3e 31.3 μg/mL against fungi; and in most cases, they exhibited either superior or similar antimicrobial activity compared to those of the standard drugs used in the clinic. We also observed minimal emergence of drug resistance to these newly synthesized compounds by bacteria and fungi even after 15 passages, and we found weak to moderate inhibition of the human Ether-à-go-go-related gene (hERG) channel with acceptable IC50 values ranging from 1.12-3.29 μM. Overall, these studies sh ow that bis(N-amidinohydrazones) and N-(amidino)-N\u27-aryl-bishydrazones are potentially promising scaffolds for the discovery of novel antibacterial and antifungal agents

Early-life course factors and oral health among young Norwegian adults

Objective Using a national sample of young Norwegian adults, we examined whether unpleasant experience with dental care during childhood is associated with tooth loss and oral health–related quality of life in adulthood after accounting for early- and later-life socio-behavioural circumstances and dental avoidance behaviour. Methods 2433 individuals aged 25-35 years participated in an electronic survey. Oral quality of life was measured using the oral impact of daily performance (OIDP) inventory. Generalized linear models and negative binomial regression models were used to estimate the association of early unpleasant experiences with dental care and tooth loss and OIDP scores. Incidence rate ratio (IRR) and 95% confidence intervals (CI) were used to estimate the relative differences in prevalence of tooth loss and OIDP scores. Results Adjusting for early-life characteristics only, the prevalence of tooth loss was 1.42 (IRR = 1.42, 95% CI: 1.24-1.64) and 1.96 (IRR = 1.96, 95% CI: 1.70-2.26) times higher among individuals who reported unpleasant experiences a few times or several times, than in individuals who did not report unpleasant experiences with dental care in childhood. Adjusting further for educational level, smoking and tooth brushing attenuated the relative differences (IRR = 1.40, 95% CI: 1.22-1.62 and IRR = 1.88, 95% CI: 1.62-2.17, respectively). Lastly, when adjusting for dental avoidance behaviour, the prevalence of tooth loss was 1.29 (IRR = 1.29, 95% CI: 1.11-1.50) and 1.58 (IRR = 1.58, 95% CI: 1.32-1.88) times higher among individuals who reported unpleasant experiences a few times or several times than in those who did not. Corresponding associations of early unpleasant experience with OIDP were (IRR = 1.41 95% CI: 1.22-1.63) and (IRR = 1.69, 95% CI: 1.42-2.01) when adjusting for early-life characteristics, and (IRR = 1.39, 95% CI: 1.20-1.60) and (IRR = 1.51, 95% CI: 1.27-1.80) when adjusting for education, smoking and tooth brushing. When adjusting for dental avoidance behaviour, the association of early unpleasant experience with OIDP became nonsignificant. Conclusion Unpleasant dental care experiences during childhood are associated with poor oral health in adulthood, independent of later-life socio-behavioural characteristics including negative dental care seeking. This highlights the importance of tailoring regular contacts with dental healthcare services in childhood to build confidence in children and thus has implications for healthcare policy.publishedVersio

Shock wave apparatus for studying minerals at high pressure and impact phenomena on planetary surfaces

Shock wave and experimental impact phenomena research on geological and planetary materials is being carried out using two propellant (18 and 40 mm) guns (up to 2.5 km/sec) and a two‐stage light gas gun (up to 7 km/sec). Equation of state measurements on samples initially at room temperature and at low and high temperatures are being conducted using the 40 mm propellant apparatus in conjunction with Helmholtz coils, and radiative detectors and, in the case of the light gas gun, with streak cameras. The 18 mm propellant gun is used for recovery experiments on minerals, impact on cryogenic targets, and radiative post‐shock temperature measurements

Study protocol; thyroid hormone replacement for untreated older adults with subclinical hypothyroidism - a randomised placebo controlled trial (TRUST)

Background: Subclinical hypothyroidism (SCH) is a common condition in elderly people, defined as elevated serum thyroid-stimulating hormone (TSH) with normal circulating free thyroxine (fT4). Evidence is lacking about the effect of thyroid hormone treatment. We describe the protocol of a large randomised controlled trial (RCT) of Levothyroxine treatment for SCH. Methods: Participants are community-dwelling subjects aged ≥65 years with SCH, diagnosed by elevated TSH levels (≥4.6 and ≤19.9 mU/L) on a minimum of two measures ≥ three months apart, with fT4 levels within laboratory reference range. The study is a randomised double-blind placebo-controlled parallel group trial, starting with levothyroxine 50 micrograms daily (25 micrograms in subjects &lt;50Kg body weight or known coronary heart disease) with titration of dose in the active treatment group according to TSH level, and a mock titration in the placebo group. The primary outcomes are changes in two domains (hypothyroid symptoms and fatigue / vitality) on the thyroid-related quality of life questionnaire (ThyPRO) at one year. The study has 80% power (at p = 0.025, 2-tailed) to detect a change with levothyroxine treatment of 3.0% on the hypothyroid scale and 4.1% on the fatigue / vitality scale with a total target sample size of 750 patients. Secondary outcomes include general health-related quality of life (EuroQol), fatal and non-fatal cardiovascular events, handgrip strength, executive cognitive function (Letter Digit Coding Test), basic and instrumental activities of daily living, haemoglobin, blood pressure, weight, body mass index and waist circumference. Patients are monitored for specific adverse events of interest including incident atrial fibrillation, heart failure and bone fracture. Discussion: This large multicentre RCT of levothyroxine treatment of subclinical hypothyroidism is powered to detect clinically relevant change in symptoms / quality of life and is likely to be highly influential in guiding treatment of this common condition. Trial registration: Clinicaltrials.gov NCT01660126; registered 8th June 2012

Stratigraphy and age of the Eocene Igtertivâ Formation basalts, alkaline pebbles and sediments of the Kap Dalton Group in the graben at Kap Dalton, East Greenland

A NE–SW-trending graben at Kap Dalton on the Blosseville Kyst contains an at least 600 m thick succession of Eocene basalt lavas and sediments. The succession has been investigated by new field work, geochemical analysis and radiometric dating by the ⁴⁰Ar-³⁹Ar incremental heating method. The results show that the volcanic succession comprises about 220 m of the uppermost plateau basalt formation, the Skrænterne Formation. This is separated from the overlying lava flows of the Igtertivâ Formation by 7 m of sediments that represent a period of around six million years. The two formations can be distinguished by different trace element ratios. The Igtertivâ Formation comprises an at least 300 m thick main succession of flows dated to 49.09 ± 0.48 Ma, overlain by sediments of the Bopladsdalen Formation. A basal conglomerate in the sediments contains pebbles of alkaline igneous rocks of which three were dated at 49.17 ± 0.35 Ma, 47.60 ± 0.25 Ma, and 46.98 ± 0.24 Ma. The sediments are thus younger than 47 Ma. Above 30 m of sediments occur two Igtertivâ Formation lava flows dated to 43.77 ± 1.08 Ma. The overlying sediments of the Bopladsdalen and Krabbedalen Formations are therefore not older than about 44 Ma and palynological evidence shows that they are also not much younger than this. Use of the Geological Time Scale 2012 has resulted in good agreement between radiometric and palynological ages. The Igtertivâ Formation lava flows were fed from a regional coast-parallel dyke swarm indicating a new rifting episode at 49–44 Ma. This coincides with a major mid-Eocene plate reorganisation event in the North Atlantic and the start of northward-propagation of the Reykjanes Ridge through the continent. The Igtertivâ rift may have been directly instrumental for the initiation of this process.Keywords: Kap Dalton, Igtertivâ Formation, radiometric ages, alkaline pebbles, East Greenland, ridge propagation, plateau basalts, Bopladsdalen Formatio

Protrudin functions from the endoplasmic reticulum to support axon regeneration in the adult CNS

Funder: Bill and Melinda Gates Foundation (Bill & Melinda Gates Foundation); doi: https://doi.org/10.13039/100000865Funder: Christopher and Dana Reeve Foundation (Christopher & Dana Reeve Foundation); doi: https://doi.org/10.13039/100001305Funder: International Foundation for Research in Paraplegia (Internationale Stiftung für Forschung in Paraplegie); doi: https://doi.org/10.13039/501100001708Funder: Foundation for the National Institutes of Health (Foundation for the National Institutes of Health, Inc.); doi: https://doi.org/10.13039/100000009Funder: Christopher and Dana Reeve Foundation (Christopher & Dana Reeve Foundation)Abstract: Adult mammalian central nervous system axons have intrinsically poor regenerative capacity, so axonal injury has permanent consequences. One approach to enhancing regeneration is to increase the axonal supply of growth molecules and organelles. We achieved this by expressing the adaptor molecule Protrudin which is normally found at low levels in non-regenerative neurons. Elevated Protrudin expression enabled robust central nervous system regeneration both in vitro in primary cortical neurons and in vivo in the injured adult optic nerve. Protrudin overexpression facilitated the accumulation of endoplasmic reticulum, integrins and Rab11 endosomes in the distal axon, whilst removing Protrudin’s endoplasmic reticulum localization, kinesin-binding or phosphoinositide-binding properties abrogated the regenerative effects. These results demonstrate that Protrudin promotes regeneration by functioning as a scaffold to link axonal organelles, motors and membranes, establishing important roles for these cellular components in mediating regeneration in the adult central nervous system