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Methods in Molecular Biology (Clifton,... 2024N-methyl-D-aspartate receptors (NMDAR) are ligand-gated ion channels mediating excitatory neurotransmission and are important for normal brain development, cognitive... (Review)
Review
N-methyl-D-aspartate receptors (NMDAR) are ligand-gated ion channels mediating excitatory neurotransmission and are important for normal brain development, cognitive abilities, and motor functions. Pathogenic variants in the Glutamate receptor Ionotropic N-methyl-D-aspartate (GRIN) genes (GRIN1, GRIN2A-D) encoding NMDAR subunits have been associated with a wide spectrum of neurodevelopmental disorders and epilepsies ranging from treatable focal epilepsies to devastating early-onset developmental and epileptic encephalopathies. Genetic variants in NMDA receptor genes can cause a range of complex alterations to receptor properties resulting in various degrees of loss-of-function, gain-of-function, or mixtures thereof. Understanding how genetic variants affect the function of the receptors, therefore, represents an important first step in the ongoing development towards targeted therapies. Currently, targeted treatment options for GRIN-related diseases are limited. However, treatment with memantine has been reported to significantly reduce seizure frequency in a few individuals with developmental and epileptic encephalopathies harboring de novo gain-of-function GRIN2A missense variants, and supplementary treatment with L-serine has been associated with improved motor and cognitive performance as well as reduced seizure frequency in patients with GRIN2B loss-of-function missense variants as well as GRIN2A and GRIN2B null variants.
Topics: Receptors, N-Methyl-D-Aspartate; Humans; Neurodevelopmental Disorders; Epilepsy; Genetic Predisposition to Disease; Genetic Variation; Memantine
PubMed: 38727899
DOI: 10.1007/978-1-0716-3830-9_1 -
JACC. Clinical Electrophysiology Jun 2024
Topics: Humans; Atrial Fibrillation; Male; Aged; Propensity Score; Female; Atrial Flutter; Alzheimer Disease; Memantine; Aged, 80 and over; Incidence
PubMed: 38727659
DOI: 10.1016/j.jacep.2024.03.028 -
Journal of Feline Medicine and Surgery May 2024Chronic pain is a significant welfare concern in cats, and neuropathic pain, which arises from aberrant processing of sensory signals within the nervous system, is a... (Review)
Review
Chronic pain is a significant welfare concern in cats, and neuropathic pain, which arises from aberrant processing of sensory signals within the nervous system, is a subcategory of this type of pain. To comprehend this condition and how multimodal pharmacotherapy plays a central role in alleviating discomfort, it is crucial to delve into the anatomy of nociception and pain perception. In addition, there is an intricate interplay between emotional health and chronic pain in cats, and understanding and addressing the emotional factors that contribute to pain perception, and vice versa, is essential for comprehensive care.Clinical approach:Neuropathic pain is suspected if there is abnormal sensation in the area of the distribution of pain, together with a positive response to trial treatment with drugs effective for neuropathic pain. Ideally, this clinical suspicion would be supported by confirmation of a lesion at this neurolocalisation using diagnostic modalities such as MRI and neuroelectrophysiology. Alternatively, there may be a history of known trauma at that site. A variety of therapies, including analgesic, anti-inflammatory and adjuvant drugs, and neuromodulation (eg, TENS or acupuncture), can be employed to address different facets of pain pathways.Aim:This review article, aimed at primary care/ general practitioners, focuses on the identification and management of neuropathic pain in cats. Three case vignettes are included and a structured treatment algorithm is presented to guide veterinarians in tailoring interventions.Evidence base:The review draws on current literature, where available, along with the author's extensive experience and research.
Topics: Cats; Animals; Neuralgia; Cat Diseases; Pain Management; Analgesics; Combined Modality Therapy
PubMed: 38710218
DOI: 10.1177/1098612X241246518 -
Cureus Mar 2024Neuroleptic malignant syndrome (NMS) is a severe reaction to antipsychotic medications characterized by fever, muscle rigidity, altered mental status, and autonomic...
Neuroleptic malignant syndrome (NMS) is a severe reaction to antipsychotic medications characterized by fever, muscle rigidity, altered mental status, and autonomic dysfunction. Here, we describe the case of a 58-year-old female who presented with altered mental status two days after open reduction and internal fixation of the hip. A rapid response team was called when the patient appeared agitated with increased respiratory demand. After being intubated and moved to the ICU, she became febrile and rigid. A preliminary diagnosis of metabolic encephalopathy of unknown origin was made. Before being transported to the ICU, the patient was given multiple haloperidol doses in addition to her continued at-home medication, paroxetine, for major depressive disorder. The differential diagnosis included a workup for NMS, serotonin syndrome, and infectious processes. Once NMS was determined as the most likely etiology, all antipsychotic and serotonergic medications were discontinued. Then dantrolene and amantadine were administered, which resulted in clinically significant improvement. This case report demonstrates the importance of early identification of and intervention for NMS.
PubMed: 38686249
DOI: 10.7759/cureus.57276 -
World Journal of Clinical Cases Apr 2024Human immunodeficiency virus (HIV)-associated dementia (HAD) is a subcortical form of dementia characterized by memory deficits and psychomotor slowing. However, HAD...
BACKGROUND
Human immunodeficiency virus (HIV)-associated dementia (HAD) is a subcortical form of dementia characterized by memory deficits and psychomotor slowing. However, HAD often presents with symptoms similar to those of Creutzfeldt-Jakob disease (CJD), particularly in patients with acquired immune deficiency syndrome (AIDS).
CASE SUMMARY
We report the case of a 54-year-old male who exhibited cognitive dysfunction and secondary behavioral changes following HIV infection and suspected prion exposure. The patient was diagnosed with HIV during hospitalization and his cerebrospinal fluid tested positive for 14-3-3 proteins. His electroencephalogram showed a borderline-abnormal periodic triphasic wave pattern. Contrast-enhanced magnetic resonance imaging revealed moderate encephalatrophy and demyelination. Initially, symptomatic treatment and administration of amantadine were pursued for presumed CJD, but the patient's condition continued to deteriorate. By contrast, the patient's condition improved following anti-HIV therapy. This individual is also the only patient with this prognosis to have survived over 4 years. Thus, the diagnosis was revised to HAD.
CONCLUSION
In the diagnostic process of rapidly progressive dementia, it is crucial to rule out as many potential causes as possible and to consider an autopsy to diminish diagnostic uncertainty. The 14-3-3 protein should not be regarded as the definitive marker for CJD. Comprehensive laboratory screening for infectious diseases is essential to enhance diagnostic precision, especially in AIDS patients with potential CJD. Ultimately, a trial of diagnostic treatment may be considered when additional testing is not feasible.
PubMed: 38680258
DOI: 10.12998/wjcc.v12.i12.2065 -
Viruses Apr 2024This review article describes the current knowledge about the use of antiviral chemotherapeutics in avian species, such as farm poultry and companion birds. Specific... (Review)
Review
This review article describes the current knowledge about the use of antiviral chemotherapeutics in avian species, such as farm poultry and companion birds. Specific therapeutics are described in alphabetical order including classic antiviral drugs, such as acyclovir, abacavir, adefovir, amantadine, didanosine, entecavir, ganciclovir, interferon, lamivudine, penciclovir, famciclovir, oseltamivir, ribavirin, and zidovudine, repurposed drugs, such as ivermectin and nitazoxanide, which were originally used as antiparasitic drugs, and some others substances showing antiviral activity, such as ampligen, azo derivates, docosanol, fluoroarabinosylpyrimidine nucleosides, and novel peptides. Most of them have only been used for research purposes and are not widely used in clinical practice because of a lack of essential pharmacokinetic and safety data. Suggested future research directions are also highlighted.
Topics: Antiviral Agents; Animals; Birds; Virus Diseases; Bird Diseases; Poultry
PubMed: 38675934
DOI: 10.3390/v16040593 -
Nutrients Apr 2024The excessive activation of glutamate in the brain is a factor in the development of vascular dementia. γ-Oryzanol is a natural compound that has been shown to enhance...
The excessive activation of glutamate in the brain is a factor in the development of vascular dementia. γ-Oryzanol is a natural compound that has been shown to enhance brain function, but more research is needed to determine its potential as a treatment for vascular dementia. This study investigated if γ-oryzanol can delay or improve glutamate neurotoxicity in an in vitro model of differentiated HT-22 cells and explored its neuroprotective mechanisms. The differentiated HT-22 cells were treated with 0.1 mmol/L glutamate for 24 h then given γ-oryzanol at appropriate concentrations or memantine (10 µmol/L) for another 24 h. Glutamate produced reactive oxygen species and depleted glutathione in the cells, which reduced their viability. Mitochondrial dysfunction was also observed, including the inhibition of mitochondrial respiratory chain complex I activity, the collapse of mitochondrial transmembrane potential, and the reduction of intracellular ATP levels in the HT-22 cells. Calcium influx triggered by glutamate subsequently activated type II calcium/calmodulin-dependent protein kinase (CaMKII) in the HT-22 cells. The activation of CaMKII-ASK1-JNK MAP kinase cascade, decreased Bcl-2/Bax ratio, and increased Apaf-1-dependent caspase-9 activation were also observed due to glutamate induction, which were associated with increased DNA fragmentation. These events were attenuated when the cells were treated with γ-oryzanol (0.4 mmol/L) or the N-methyl-D-aspartate receptor antagonist memantine. The results suggest that γ-oryzanol has potent neuroprotective properties against glutamate excitotoxicity in differentiated HT-22 cells. Therefore, γ-oryzanol could be a promising candidate for the development of therapies for glutamate excitotoxicity-associated neurodegenerative diseases, including vascular dementia.
Topics: Glutamic Acid; Phenylpropionates; Animals; Neuroprotective Agents; Mice; Cell Line; Reactive Oxygen Species; Mitochondria; Oryza; Membrane Potential, Mitochondrial; Cell Differentiation; Cell Survival; Memantine; Apoptosis; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Neurons
PubMed: 38674927
DOI: 10.3390/nu16081237 -
How PBPK Can Help to Understand Old Drugs and Inform their Dosing in Elderly: Amantadine Case Study.Clinical Pharmacology and Therapeutics Jul 2024Amantadine, despite being on the market for 55 years, has several unknown aspects of its pharmacokinetics especially related to the influence of covariates such as...
Amantadine, despite being on the market for 55 years, has several unknown aspects of its pharmacokinetics especially related to the influence of covariates such as age, disease, or interactions linked to amantadine's renal elimination. As amantadine is used in Parkinson's disease and is considered a potential candidate in COVID treatment and other diseases, there is an unmet need for thorough understanding of its pharmacokinetic in special populations, such as the elderly. We aimed to mechanistically describe amantadine pharmacokinetics in healthy subjects and shed some light on the differences in drug behavior between healthy volunteers (18-65 years) and an elderly/geriatric population (65-98 years) using PBPK modeling and simulation. The middle-out PBPK model includes mechanistic description of drug renal elimination, specifically an organic cation transporter (OCT)2-mediated electrogenic bidirectional transport (basolateral) and multidrug and toxic compound extrusion (MATE)1-mediated efflux (apical). The model performance was verified against plasma and urine data reported after single and multiple dose administration in healthy volunteers and elderly patients from 18 independent studies. The ratios of predicted vs. observed maximal plasma concentration and area under the concentration-time curve values were within 1.25-fold. The model illustrates that renal transporter activity is expected to decrease in healthy elderly compared to healthy volunteers, which is in line with literature proteomic data for OCT2. The model was applied to assess the potential of reaching toxicity-related plasma concentrations in different age groups of geriatric subjects.
Topics: Humans; Aged; Amantadine; Adult; Middle Aged; Aged, 80 and over; Male; Young Adult; Models, Biological; Adolescent; Female; Organic Cation Transporter 2; Renal Elimination; Organic Cation Transport Proteins; COVID-19 Drug Treatment; Age Factors; Healthy Volunteers; Computer Simulation
PubMed: 38666589
DOI: 10.1002/cpt.3276 -
Medicine Apr 2024Alzheimer's disease (AD) is a progressive neurodegenerative disorder. Dementia severity was assessed mainly through cognitive function, psychobehavioral symptoms, and... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Alzheimer's disease (AD) is a progressive neurodegenerative disorder. Dementia severity was assessed mainly through cognitive function, psychobehavioral symptoms, and daily living ability. Currently, there are not many drugs that can be selected to treat mild to moderate AD, and the value of drugs remains controversial.
OBJECTIVE
The aim of this study is to quantitatively evaluate the efficacy and safety of cholinesterase inhibitors (ChEIs), memantine, and sodium oligomannate (GV-971) in the treatment of patients with AD. Additionally, molecular docking analysis will be used to investigate the binding affinities of donepezil, galantamine, rivastigmine, and memantine with key receptor proteins associated with AD, including beta-amyloid (Abeta), microtubule-associated protein (MAP), apolipoprotein E4 (APOE4), and Mitofusin-2 (MFN2), to further validate the results of the meta-analysis.
METHODS
We obtained clinical trials characterized by randomization, placebo control, and double-blinded methodologies concerning ChEIs, memantine, and GV-971. Statistical analysis was performed using Review Manager Version 5.4 software. Molecular docking was also conducted to evaluate the results.
RESULTS
All drugs improved the cognitive function, with the effect value ranging from -1.23 (95% CI -2.17 to -0.30) for 20 mg memantine to -3.29 (95% CI -4.14 to -2.45) for 32 mg galantamine. Although 32 mg galanthamine and GV-971 did not improve the clinicians' Global Impression of Change scale, other drugs showed significant results compared with placebo. On NPI, only 10 mg of donepezil and 24 mg of galantamine had improvement effects. On ADCS/ADL, only 20 mg memantine and 900 mg GV-971 had no significant difference from the placebo. Donepezil 5 mg and GV-971 900 mg did not increase the drug withdrawal rates due to various reasons or adverse reactions when compared to the placebo. Donepezil demonstrated superior binding to the protein and exhibited greater efficacy compared to other drugs.
CONCLUSION
ChEIs, memantine, and GV-971 all can slow the progression of AD but have different effects on respective assessments. Donepezil and GV-971 were relatively well tolerated.
Topics: Humans; Alzheimer Disease; Donepezil; Galantamine; Memantine; Molecular Docking Simulation; Cholinesterase Inhibitors; Rivastigmine
PubMed: 38640313
DOI: 10.1097/MD.0000000000037799