Possible Role of Corticosteroids in Nervous System Plasticity: Improvement in Amblyopia After Optic Neuritis in the Fellow Eye Treated with Steroids

2001 ◽  
Vol 15 (3) ◽  
pp. 223-227 ◽  
Author(s):  
Cris S. Constantinescu ◽  
Irene Gottlob
Keyword(s):  
Visual System ◽  
Optic Neuritis ◽  
Neural Plasticity ◽  
Critical Period ◽  
Visual Stimulation ◽  
High Dose ◽  
Fellow Eye ◽  
Visual Improvement ◽  
Contralateral Eye

Objective: Amblyopia consists of reduced visual function in the absence of or ganic disease, caused by deficient visual stimulation, most commonly due to squint or refractive error. Amblyopia is thought to be reversible up until the age of ∼8 years (critical period) and is usually treated with occlusion of the fellow eye. There is re cent evidence for visual system plasticity extending beyond the critical period, sup ported by reports of improvement in visual acuity in the amblyopic eye after loss of vision in the contralateral eye. This suggests that the adult visual system exhibits suf ficient plasticity to allow such improvement. We describe here improvement in vi sual acuity in three amblyopic patients after they received high-dose intravenous glu cocorticoids for optic neuritis in the contralateral eye. Methods: Clinical and neurological evaluation added. Results: In all cases, the improvement was sustained, even after the recovery from the optic neuritis. Conclusions: Because steroids affect neural plasticity, we hypothesize that they facilitate and enhance visual improvement in amblyopia, a quality that may be tested in future controlled trials. Key Words: Am biyopia—Steroids—Plasticity—Glucocorticoids—Optic neuritis.

scholarly journals Improving the performance of the amblyopic visual system

2008 ◽  
Vol 364 (1515) ◽  
pp. 399-407 ◽  
Author(s):  
Dennis M Levi ◽  
Roger W Li
Keyword(s):  
Visual System ◽  
Perceptual Learning ◽  
Neural Plasticity ◽  
Time Course ◽  
Clinical Evidence ◽  
Sensory Function ◽  
Sensitive Period ◽  
Visual Improvement ◽  
Perceptual Performance ◽  
Effectiveness And Efficiency

Experience-dependent plasticity is closely linked with the development of sensory function; however, there is also growing evidence for plasticity in the adult visual system. This review re-examines the notion of a sensitive period for the treatment of amblyopia in the light of recent experimental and clinical evidence for neural plasticity. One recently proposed method for improving the effectiveness and efficiency of treatment that has received considerable attention is ‘perceptual learning’. Specifically, both children and adults with amblyopia can improve their perceptual performance through extensive practice on a challenging visual task. The results suggest that perceptual learning may be effective in improving a range of visual performance and, importantly, the improvements may transfer to visual acuity. Recent studies have sought to explore the limits and time course of perceptual learning as an adjunct to occlusion and to investigate the neural mechanisms underlying the visual improvement. These findings, along with the results of new clinical trials, suggest that it might be time to reconsider our notions about neural plasticity in amblyopia.

scholarly journals Modification of Peak Plasticity Induced by Brief Dark Exposure

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Alexander J. Lingley ◽  
Donald E. Mitchell ◽  
Nathan A. Crowder ◽  
Kevin R. Duffy
Keyword(s):  
Visual System ◽  
Neural Plasticity ◽  
Critical Period ◽  
Ocular Dominance ◽  
Monocular Deprivation ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Soma Size ◽  
Slow Progress ◽  
Dark Exposure ◽  
Central Visual System

The capacity for neural plasticity in the mammalian central visual system adheres to a temporal profile in which plasticity peaks early in postnatal development and then declines to reach enduring negligible levels. Early studies to delineate the critical period in cats employed a fixed duration of monocular deprivation to measure the extent of ocular dominance changes induced at different ages. The largest deprivation effects were observed at about 4 weeks postnatal, with a steady decline in plasticity thereafter so that by about 16 weeks only small changes were measured. The capacity for plasticity is regulated by a changing landscape of molecules in the visual system across the lifespan. Studies in rodents and cats have demonstrated that the critical period can be altered by environmental or pharmacological manipulations that enhance plasticity at ages when it would normally be low. Immersion in complete darkness for long durations (dark rearing) has long been known to alter plasticity capacity by modifying plasticity-related molecules and slowing progress of the critical period. In this study, we investigated the possibility that brief darkness (dark exposure) imposed just prior to the critical period peak can enhance the level of plasticity beyond that observed naturally. We examined the level of plasticity by measuring two sensitive markers of monocular deprivation, namely, soma size of neurons and neurofilament labeling within the dorsal lateral geniculate nucleus. Significantly larger modification of soma size, but not neurofilament labeling, was observed at the critical period peak when dark exposure preceded monocular deprivation. This indicated that the natural plasticity ceiling is modifiable and also that brief darkness does not simply slow progress of the critical period. As an antecedent to traditional amblyopia treatment, darkness may increase treatment efficacy even at ages when plasticity is at its highest.

Pre-emptive Analgesia for Postoperative Pain Relief in Children – Role of Paracetamol

2009 ◽  
pp. 9-16
Author(s):  
Rubina Yasmin ◽  
AKM Akhtaruzzaman ◽  
Paresh Chandra Sarker ◽  
Neaz Ahmed ◽  
Ranadhir Kumar Kundu ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Postoperative Pain ◽  
Diclofenac Sodium ◽  
Total Duration ◽  
Pain Scale ◽  
Prospective Clinical Study ◽  
High Dose ◽  
Induction Of Anaesthesia

This prospective clinical study was carried out in the Dept. of Anaesthesia, Analgesia and Intensive Care Medicine, BSMMU, Dhaka, during the period of May 2003 to July 2003. The study was done to emphasize the importance of giving analgesics preemptively instead of waiting for the child to complain of pain and to produce smooth recovery after surgery by decreasing immediate postoperative pain in children by a simple, safe acceptable drug. The children scheduled for tonsillectomy under general anaesthesia were recruited in this study. The analgesic efficiency of rectal paracetamol in two doses, 25 mg/kg bodywt.(Gr-P25) and 50 mg/kg. bodywt. (Gr-P50) were compared with Diclofenac Sodium suppository 1mg/ kg body weight (Gr-D) given half an hour before induction of anaesthesia. Pain scoring was done by TPPPS (Toddler Pre-schooler postoperative pain scale). Heart rate and blood pressure were stable in Gr-P50 and Gr-D. Time of first demand of analgesic was delayed in Gr-P50 and Gr-D. Total paracetamol consumption in 24 hours was less in Gr-P50(181±14.25) and Gr-D (212±25) than Gr-P25(318± 26.39). Total duration of analgesia in Gr- P50 (657±9.94) mins. and in Gr- D(502±10.63) mins. and in Gr-P25(288±23.17) mins. Pre-emptive high dose rectal paracetamol appears to be more effective than diclofenac sodium suppository for postoperative analgesia in children undergoing tonsillectomy. Journal of BSA, Vol. 18, No. 1 & 2, 2005 p.9-16

scholarly journals Adolescence as a “critical period” in the heritage language use. Polish in Germany

2021 ◽  
Vol 7 (1) ◽  
pp. 301-315
Author(s):  
Hanna Pułaczewska
Keyword(s):  
Role Models ◽  
Personal Development ◽  
Critical Period ◽  
Growing Up ◽  
Age Related ◽  
The Media ◽  
Role Of Parents ◽  
Qualitative Part ◽  
The Impact

Abstract In the article, we consider the impact of adolescence upon the usage of Polish in Polish-German bilinguals raised and living in Germany and demonstrate how adolescence surfaces as a socially based “critical period” in this usage using results from a survey and interviews conducted with 30 teenagers. In the quantitative part of the study, we seek to establish whether adolescents’ age affected the pattern and quantity of their usage of Polish in the media and contacts with age peers, whether the latter two facets of growing up with Polish were interrelated, and which other factors affected peer-relevant activities in Polish. Both age and peer contact turned out to significantly affect the use of the media in Polish, while peer contact in Polish was affected by the parental use of Polish in parent-child communication. The qualitative part presents the context and motivation for using Polish by the youths in peer-relevant activities. We integrate the results with insights provided by child development psychology from the perspective of language socialisation theory and interpret the age-related decline of interest in the Polish media as an effect of a diminishing role of parents and the increasing role of age peers as role models in personal development.

Possible Role of High-Dose Barbiturates and Early Administration of Parenteral Ketogenic Diet for Reducing Development of Chronic Epilepsy in Febrile Infection-Related Epilepsy Syndrome: A Case Report

2020 ◽  
Author(s):  
Shimpei Baba ◽  
Tohru Okanishi ◽  
Koichi Ohsugi ◽  
Rika Suzumura ◽  
Keiko Niimi ◽  
...  
Keyword(s):  
Continuous Infusion ◽  
Ketogenic Diet ◽  
Epilepsy Syndrome ◽  
High Dose ◽  
Early Administration ◽  
Chronic Epilepsy ◽  
Time Period ◽  
Irreversible Brain Damage ◽  
Electroencephalogram Eeg

AbstractWe describe the efficacy of high-dose barbiturates and early administration of a parenteral ketogenic diet (KD) as initial treatments for acute status epilepticus (SE) in an 8-year-old girl with febrile infection-related epilepsy syndrome (FIRES). The patient was admitted to our hospital with refractory focal SE. Abundant epileptic discharges over the left frontal region were observed on electroencephalogram (EEG). Treatment with continuous infusion of thiamylal for 4 hours, increased incrementally to 40 mg/kg/h, successfully ended the clinical SE, and induced a burst-suppression coma. The infusion rate was then gradually decreased to 4 mg/kg/h over the next 12 hours. Parenteral KD was administered from days 6 to 21 of illness. Continuous infusion of thiamylal was switched to midazolam on day 10 without causing seizures or EEG exacerbations. The patient has remained seizure free in the 15 months since hospital discharge. The effectiveness of KD for the treatment of FIRES has attracted attention amongst clinicians, but KD treatment may need to last for 2 to 4 days before it can stop SE, a time period that could cause irreversible brain damage. Considering the severity of SE in our patient and the dose of barbiturates needed to treat it, we consider this case to have had a good clinical outcome. The results suggest that rapid termination of seizure using high-dose barbiturates in conjunction with early administration of parenteral KD could reduce the development of chronic epilepsy in patients with FIRES.

scholarly journals Current Nanocarrier Strategies Improve Vitamin B12 Pharmacokinetics, Ameliorate Patients’ Lives, and Reduce Costs

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 743
Author(s):  
Marco Fidaleo ◽  
Stefano Tacconi ◽  
Carolina Sbarigia ◽  
Daniele Passeri ◽  
Marco Rossi ◽  
...  
Keyword(s):  
Side Effects ◽  
Vitamin B12 ◽  
Memory Performance ◽  
Oral Route ◽  
High Dose ◽  
Human Beings ◽  
Inborn Errors ◽  
Essential Nutrient

Vitamin B12 (VitB12) is a naturally occurring compound produced by microorganisms and an essential nutrient for humans. Several papers highlight the role of VitB12 deficiency in bone and heart health, depression, memory performance, fertility, embryo development, and cancer, while VitB12 treatment is crucial for survival in inborn errors of VitB12 metabolism. VitB12 is administrated through intramuscular injection, thus impacting the patients’ lifestyle, although it is known that oral administration may meet the specific requirement even in the case of malabsorption. Furthermore, the high-dose injection of VitB12 does not ensure a constant dosage, while the oral route allows only 1.2% of the vitamin to be absorbed in human beings. Nanocarriers are promising nanotechnology that can enable therapies to be improved, reducing side effects. Today, nanocarrier strategies applied at VitB12 delivery are at the initial phase and aim to simplify administration, reduce costs, improve pharmacokinetics, and ameliorate the quality of patients’ lives. The safety of nanotechnologies is still under investigation and few treatments involving nanocarriers have been approved, so far. Here, we highlight the role of VitB12 in human metabolism and diseases, and the issues linked to its molecule properties, and discuss how nanocarriers can improve the therapy and supplementation of the vitamin and reduce possible side effects and limits.

scholarly journals Early Consumption of Cannabinoids: From Adult Neurogenesis to Behavior

2021 ◽  
Vol 22 (14) ◽  
pp. 7450
Author(s):  
Citlalli Netzahualcoyotzi ◽  
Luis Miguel Rodríguez-Serrano ◽  
María Elena Chávez-Hernández ◽  
Mario Humberto Buenrostro-Jáuregui
Keyword(s):  
Young Adulthood ◽  
Adult Neurogenesis ◽  
Critical Period ◽  
Consumption Rate ◽  
Behavioral Outcomes ◽  
Endocannabinoid System ◽  
Illegal Drug ◽  
Adult Brain ◽  
As Stress

The endocannabinoid system (ECS) is a crucial modulatory system in which interest has been increasing, particularly regarding the regulation of behavior and neuroplasticity. The adolescent–young adulthood phase of development comprises a critical period in the maturation of the nervous system and the ECS. Neurogenesis occurs in discrete regions of the adult brain, and this process is linked to the modulation of some behaviors. Since marijuana (cannabis) is the most consumed illegal drug globally and the highest consumption rate is observed during adolescence, it is of particular importance to understand the effects of ECS modulation in these early stages of adulthood. Thus, in this article, we sought to summarize recent evidence demonstrating the role of the ECS and exogenous cannabinoid consumption in the adolescent–young adulthood period; elucidate the effects of exogenous cannabinoid consumption on adult neurogenesis; and describe some essential and adaptive behaviors, such as stress, anxiety, learning, and memory. The data summarized in this work highlight the relevance of maintaining balance in the endocannabinoid modulatory system in the early and adult stages of life. Any ECS disturbance may induce significant modifications in the genesis of new neurons and may consequently modify behavioral outcomes.

scholarly journals Understanding the Redox Biology of Selenium in the Search of Targeted Cancer Therapies

Antioxidants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 420 ◽  
Author(s):  
Jeffrey M. Stolwijk ◽  
Rohan Garje ◽  
Jessica C. Sieren ◽  
Garry R. Buettner ◽  
Yousef Zakharia
Keyword(s):  
Selenium Deficiency ◽  
Vital Role ◽  
High Dose ◽  
Specific Cell ◽  
Cancer Therapies ◽  
Selenium Compounds ◽  
Redox Biology ◽  
Selenium Treatment ◽  
Prevention Of Cancer

Selenium (Se) is an essential trace nutrient required for optimal human health. It has long been suggested that selenium has anti-cancer properties. However, clinical trials have shown inconclusive results on the potential of Se to prevent cancer. The suggested role of Se in the prevention of cancer is centered around its role as an antioxidant. Recently, the potential of selenium as a drug rather than a supplement has been uncovered. Selenium compounds can generate reactive oxygen species that could enhance the treatment of cancer. Transformed cells have high oxidative distress. As normal cells have a greater capacity to meet oxidative challenges than tumor cells, increasing the flux of oxidants with high dose selenium treatment could result in cancer-specific cell killing. If the availability of Se is limited, supplementation of Se can increase the expression and activities of Se-dependent proteins and enzymes. In cell culture, selenium deficiency is often overlooked. We review the importance of achieving normal selenium biology and how Se deficiency can lead to adverse effects. We examine the vital role of selenium in the prevention and treatment of cancer. Finally, we examine the properties of Se-compounds to better understand how each can be used to address different research questions.

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