scholarly journals Time course of structural changes at identified sensory neuron synapses during long-term sensitization in Aplysia

1989 ◽  
Vol 9 (5) ◽  
pp. 1774-1780 ◽  
Author(s):  
CH Bailey ◽  
M Chen
Keyword(s):  
Sensory Neuron ◽  
Time Course ◽  
Structural Changes

scholarly journals A novel suprachoroidal microinvasive glaucoma implant: in vivo biocompatibility and biointegration

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Ian Grierson ◽  
Don Minckler ◽  
Marian K. Rippy ◽  
Andrew J. Marshall ◽  
Nathalie Collignon ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Time Course ◽  
Structural Changes ◽  
Ocular Tissues ◽  
Tissue Integration ◽  
Drainage Channels ◽  
Pressure Lowering ◽  
Over Time

Abstract Background A major challenge for any glaucoma implant is their ability to provide long-term intraocular pressure lowering efficacy. The formation of a low-permeability fibrous capsule around the device often leads to obstructed drainage channels, which may impair the drainage function of devices. These foreign body-related limitations point to the need to develop biologically inert biomaterials to improve performance in reaching long-term intraocular pressure reduction. The aim of this study was to evaluate in vivo (in rabbits) the ocular biocompatibility and tissue integration of a novel suprachoroidal microinvasive glaucoma implant, MINIject™ (iSTAR Medical, Wavre, Belgium). Results In two rabbit studies, no biocompatibility issue was induced by the suprachoroidal, ab-externo implantation of the MINIject™ device. Clinical evaluation throughout the 6 post-operative months between the sham and test groups were similar, suggesting most reactions were related to the ab-externo surgical technique used for rabbits, rather than the implant material itself. Histological analysis of ocular tissues at post-operative months 1, 3 and 6 revealed that the implant was well-tolerated and induced only minimal fibroplasia and thus minimal encapsulation around the implant. The microporous structure of the device became rapidly colonized by cells, mostly by macrophages through cell migration, which do not, by their nature, impede the flow of aqueous humor through the device. Time-course analysis showed that once established, pore colonization was stable over time. No fibrosis nor dense connective tissue development were observed within any implant at any time point. The presence of pore colonization may be the process by which encapsulation around the implant is minimized, thus preserving the permeability of the surrounding tissues. No degradation nor structural changes of the implant occurred during the course of both studies. Conclusions The novel MINIject™ microinvasive glaucoma implant was well-tolerated in ocular tissues of rabbits, with observance of biointegration, and no biocompatibility issues. Minimal fibrous encapsulation and stable cellular pore colonization provided evidence of preserved drainage properties over time, suggesting that the implant may produce a long-term ability to enhance aqueous outflow.

Coming Together Through Falling Apart

2019 ◽  
Vol 40 (2) ◽  
pp. 151-168
Author(s):  
Heather Churchill ◽  
Jeremy M. Ridenour
Keyword(s):  
Data Analysis ◽  
Qualitative Data ◽  
Structural Changes ◽  
Systematic Approach ◽  
Qualitative Approach ◽  
Psychological Assessments ◽  
Transference And Countertransference ◽  
Testing Data ◽  
Psychoanalytically Oriented Psychotherapy

Abstract. Assessing change during long-term psychotherapy can be a challenging and uncertain task. Psychological assessments can be a valuable tool and can offer a perspective from outside the therapy dyad, independent of the powerful and distorting influences of transference and countertransference. Subtle structural changes that may not yet have manifested behaviorally can also be assessed. However, it can be difficult to find a balance between a rigorous, systematic approach to data, while also allowing for the richness of the patient’s internal world to emerge. In this article, the authors discuss a primarily qualitative approach to the data and demonstrate the ways in which this kind of approach can deepen the understanding of the more subtle or complex changes a particular patient is undergoing while in treatment, as well as provide more detail about the nature of an individual’s internal world. The authors also outline several developmental frameworks that focus on the ways a patient constructs their reality and can guide the interpretation of qualitative data. The authors then analyze testing data from a patient in long-term psychoanalytically oriented psychotherapy in order to demonstrate an approach to data analysis and to show an example of how change can unfold over long-term treatments.

Economic Institutions and Growth Nexus: The Role of Governance and Democratic Institutions—Evidence from Time Varying Parameters’ (TVPs) Models

2016 ◽  
Vol 55 (4I-II) ◽  
pp. 675-688
Author(s):  
Ghulam Murtaza ◽  
Muhammad Zahir Faridi
Keyword(s):  
Structural Changes ◽  
Jel Classification ◽  
Economic Institutions ◽  
Time Varying ◽  
Democratic Institutions ◽  
Main Hypothesis ◽  
Dynamic Relationship ◽  
Rolling Window

The present study has investigated the channels through which the linkage between economic institutions and growth is gauged, by addressing the main hypothesis of the study that whether quality of governance and democratic institutions set a stage for economic institutions to promote the long-term growth process in Pakistan. To test the hypothesis empirically, our study models the dynamic relationship between growth and economic institutions in a time varying framework in order to capture institutional developments and structural changes occurred in the economy of Pakistan over the years. Study articulates that, along with some customary specifics, the quality of government and democracy are the substantial factors that affect institutional quality and ultimately cause to promote growth in Pakistan. JEL Classification: O40; P16; C14; H10 Keywords: Economic Institutions, Growth, Governance and Democracy, Rolling Window Two-stage Least Squares, Pakistan

Individual differences in white and grey matter structure associated with verbal habits of thought

2019 ◽  
Author(s):  
Justin C. Hayes ◽  
Katherine L Alfred ◽  
Rachel Pizzie ◽  
Joshua S. Cetron ◽  
David J. M. Kraemer
Keyword(s):  
Individual Differences ◽  
White Matter ◽  
Cognitive Processing ◽  
Grey Matter ◽  
Structural Changes ◽  
Structural Integrity ◽  
Diffusion Tensor ◽  
Self Report ◽  
White Matter Tracts

Modality specific encoding habits account for a significant portion of individual differences reflected in functional activation during cognitive processing. Yet, little is known about how these habits of thought influence long-term structural changes in the brain. Traditionally, habits of thought have been assessed using self-report questionnaires such as the visualizer-verbalizer questionnaire. Here, rather than relying on subjective reports, we measured habits of thought using a novel behavioral task assessing attentional biases toward picture and word stimuli. Hypothesizing that verbal habits of thought are reflected in the structural integrity of white matter tracts and cortical regions of interest, we used diffusion tensor imaging and volumetric analyses to assess this prediction. Using a whole-brain approach, we show that word bias is associated with increased volume in several bilateral language regions, in both white and grey matter parcels. Additionally, connectivity within white matter tracts within an a priori speech production network increased as a function of word bias. These results demonstrate long-term structural and morphological differences associated with verbal habits of thought.

Structural changes in the metal of welded joints of long-term operating steam pipelines

2020 ◽  
Vol 2020 (2) ◽  
pp. 24-28
Author(s):  
V.V. Dmytryk ◽  
◽  
. A.V. Glushko ◽  
S.P. Iglin ◽  
◽  
...  
Keyword(s):  
Welded Joints ◽  
Structural Changes ◽  
Operating Steam

A New Classification for Pathologies of Spinal Meninges, Part 1: Dural Cysts, Dissections, and Ectasias

Neurosurgery ◽  
2017 ◽  
Vol 81 (1) ◽  
pp. 29-44 ◽  
Author(s):  
Jörg Klekamp
Keyword(s):  
Structural Changes ◽  
Long Term Results ◽  
Type I ◽  
Type Ii ◽  
New Classification ◽  
Type Iii ◽  
Dural Sac ◽  
Spinal Cord Herniation ◽  
Dural Defects

Abstract BACKGROUND: The clinical significance of pathologies of the spinal dura is often unclear and their management controversial. OBJECTIVE: To classify spinal dural pathologies analogous to vascular aneurysms, present their symptoms and surgical results. METHODS: Among 1519 patients with spinal space-occupying lesions, 66 patients demonstrated dural pathologies. Neuroradiological and surgical features were reviewed and clinical data analyzed. RESULTS: Saccular dural diverticula (type I, n = 28) caused by defects of both dural layers, dissections between dural layers (type II, n = 29) due to defects of the inner layer, and dural ectasias (type III, n = 9) related to structural changes of the dura were distinguished. For all types, symptoms consisted of local pain followed by signs of radiculopathy or myelopathy, while one patient with dural ectasia presented a low-pressure syndrome and 10 patients with dural dissections additional spinal cord herniation. Type I and type II pathologies required occlusion of their dural defects via extradural (type I) or intradural (type II) approaches. For type III pathologies of the dural sac no surgery was recommended. Favorable results were obtained in all 14 patients with type I and 13 of 15 patients with type II pathologies undergoing surgery. CONCLUSION: The majority of dural pathologies involving root sleeves remain asymptomatic, while those of the dural sac commonly lead to pain and neurological symptoms. Type I and type II pathologies were treated with good long-term results occluding their dural defects, while ectasias of the dural sac (type III) were managed conservatively.

scholarly journals Visualizing the Bohr effect in hemoglobin: neutron structure of equine cyanomethemoglobin in the R state and comparison with human deoxyhemoglobin in the T state

2016 ◽  
Vol 72 (7) ◽  
pp. 892-903 ◽  
Author(s):  
Steven Dajnowicz ◽  
Sean Seaver ◽  
B. Leif Hanson ◽  
S. Zoë Fisher ◽  
Paul Langan ◽  
...  
Keyword(s):  
Structural Changes ◽  
Accurate Determination ◽  
Bohr Effect ◽  
Salt Bridges ◽  
Histidine Residues ◽  
Regions Of Stability ◽  
The Individual ◽  
T State

Neutron crystallography provides direct visual evidence of the atomic positions of deuterium-exchanged H atoms, enabling the accurate determination of the protonation/deuteration state of hydrated biomolecules. Comparison of two neutron structures of hemoglobins, human deoxyhemoglobin (T state) and equine cyanomethemoglobin (R state), offers a direct observation of histidine residues that are likely to contribute to the Bohr effect. Previous studies have shown that the T-state N-terminal and C-terminal salt bridges appear to have a partial instead of a primary overall contribution. Four conserved histidine residues [αHis72(EF1), αHis103(G10), αHis89(FG1), αHis112(G19) and βHis97(FG4)] can become protonated/deuterated from the R to the T state, while two histidine residues [αHis20(B1) and βHis117(G19)] can lose a proton/deuteron. αHis103(G10), located in the α1:β1dimer interface, appears to be a Bohr group that undergoes structural changes: in the R state it is singly protonated/deuterated and hydrogen-bonded through a water network to βAsn108(G10) and in the T state it is doubly protonated/deuterated with the network uncoupled. The very long-term H/D exchange of the amide protons identifies regions that are accessible to exchange as well as regions that are impermeable to exchange. The liganded relaxed state (R state) has comparable levels of exchange (17.1% non-exchanged) compared with the deoxy tense state (T state; 11.8% non-exchanged). Interestingly, the regions of non-exchanged protons shift from the tetramer interfaces in the T-state interface (α1:β2and α2:β1) to the cores of the individual monomers and to the dimer interfaces (α1:β1and α2:β2) in the R state. The comparison of regions of stability in the two states allows a visualization of the conservation of fold energy necessary for ligand binding and release.

Time-course of treatment-emergent adverse events in a long-term safety study of lisdexamfetamine dimesylate in children and adolescents with ADHD

2016 ◽  
Vol 33 (S1) ◽  
pp. S132-S132
Author(s):  
I. Hernández Otero ◽  
T. Banaschewski ◽  
P. Nagy ◽  
C.A. Soutullo ◽  
A. Zuddas ◽  
...  
Keyword(s):  
Adverse Events ◽  
Children And Adolescents ◽  
Time Course ◽  
Open Label ◽  
Lisdexamfetamine Dimesylate ◽  
Safety Population ◽  
First Onset ◽  
Stimulant Medications ◽  
Competing Interest

IntroductionThe long-term safety and efficacy of lisdexamfetamine dimesylate (LDX) in children and adolescents with attention deficit/hyperactivity disorder (ADHD) was evaluated in a European 2-year, open-label study (SPD489-404).ObjectiveTo evaluate the time-course of treatment-emergent adverse events (TEAEs) in SPD489-404.MethodsParticipants aged 6–17 years received open-label LDX (30, 50 or 70 mg/day) for 104 weeks (4 weeks dose-optimization; 100 weeks dose-maintenance).ResultsAll enrolled participants (n = 314) were included in the safety population and 191 (60.8%) completed the study. TEAEs occurred in 282 (89.8%) participants; most were mild or moderate. TEAEs considered by the investigators as related to LDX were reported by 232 (73.9%) participants with the following reported for ≥ 10% of participants: decreased appetite (49.4%), weight decreased (18.2%), insomnia (13.1%). TEAEs leading to discontinuation and serious TEAEs occurred in 39 (12.4%) and 28 (8.9%) participants, respectively. The median (range) time to first onset and duration, respectively, of TEAEs identified by the sponsor as being of special interest were: insomnia (insomnia, initial insomnia, middle insomnia, terminal insomnia), 17.0 (1–729) and 42.8 (1–739) days; weight decreased, 29.0 (1–677) and 225.0 (26–724) days; decreased appetite, 13.5 (1–653) and 169.0 (1–749) days; headache, 22.0 (1–718) and 2.0 (1–729) days. Reports of insomnia, weight decreased, decreased appetite and headache were highest in the first 4–12 weeks.ConclusionsTEAEs associated with long-term LDX treatment were characteristic of stimulant medications, with the greatest incidence observed during the first 4–12 weeks.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Sign in / Sign up

Export Citation Format

Share Document