Browsing by Author "Greig, Nigel H."

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A Comprehensive Review on Neuroendocrine Neoplasms
(MDPI, 2023-08-05) Sultana, Qamar; Kar, Jill; Verma, Amogh; Sanghvi, Shreya; Kaka, Nirja; Patel, Neil; Sethi, Yashendra; Chopra, Hitesh; Kamal, Mohammad Amjad; Greig, Nigel H.
Neuroendocrine neoplasms (NENs) are a group of heterogeneous tumors with neuroen- docrine differentiation that can arise from any organ. They account for 2% of all malignancies in the United States. A significant proportion of NEN patients experience endocrine imbalances consequent to increased amine or peptide hormone secretion, impacting their quality of life and prognosis. Over the last decade, pathologic categorization, diagnostic techniques and therapeutic choices for NENs—both well-differentiated neuroendocrine tumors (NETs) and poorly differen- tiated neuroendocrine carcinomas (NECs)—have appreciably evolved. Diagnosis of NEN mostly follows a suspicion from clinical features or incidental imaging findings. Hormonal or non-hormonal biomarkers (like serum serotonin, urine 5-HIAA, gastrin and VIP) and histology of a suspected NEN is, therefore, critical for both confirmation of the diagnosis and classification as an NET or NEC. Therapy for NENs has progressed recently based on a better molecular understanding, including the involvement of mTOR, VEGF and peptide receptor radionuclide therapy (PRRT), which add to the growing evidence supporting the possibility of treatment beyond complete resection. As the incidence of NENs is on the rise in the United States and several other countries, physicians are more likely to see these cases, and their better understanding may support earlier diagnosis and tailoring treatment to the patient. We have compiled clinically significant evidence for NENs, including rele- vant changes to clinical practice that have greatly updated our diagnostic and therapeutic approach for NEN patients.
Codon Usage Bias Correlates With Gene Length in Neurodegeneration Associated Genes
(Daffodil International University, 2022-07-22) Khandia, Rekha; Saeed, Mohd.; Alharbi, Ahmed M.; Ashraf, Ghulam Md.; Greig, Nigel H.; Kamal, Mohammad Amjad
Codon usage analysis is a crucial part of molecular characterization and is used to determine the factors affecting the evolution of a gene. The length of a gene is an important parameter that affects the characteristics of the gene, such as codon usage, compositional parameters, and sometimes, its functions. In the present study, we investigated the association of various parameters related to codon usage with the length of genes. Gene expression is affected by nucleotide disproportion. In sixty genes related to neurodegenerative disorders, the G nucleotide was the most abundant and the T nucleotide was the least. The nucleotide T exhibited a significant association with the length of the gene at both the overall compositional level and the first and second codon positions. Codon usage bias (CUB) of these genes was affected by pyrimidine and keto skews. Gene length was found to be significantly correlated with codon bias in neurodegeneration associated genes. In gene segments with lengths below 1,200 bp and above 2,400 bp, CUB was positively associated with length. Relative synonymous CUB, which is another measure of CUB, showed that codons TTA, GTT, GTC, TCA, GGT, and GGA exhibited a positive association with length, whereas codons GTA, AGC, CGT, CGA, and GGG showed a negative association. GC-ending codons were preferred over AT-ending codons. Overall analysis indicated that the association between CUB and length varies depending on the segment size; however, CUB of 1,200–2,000 bp gene segments appeared not affected by gene length. In synopsis, analysis suggests that length of the genes correlates with various imperative molecular signatures including A/T nucleotide disproportion and codon choices. In the present study we additionally evaluated various molecular features and their correlation with different indices of codon usage, like the Codon Adaptation Index (CAI) and Relative Dynonymous Codon Usage (RSCU) of codons. We also considered the impact of gene fragment size on different molecular features in genes related to neurodegeneration. This analysis will aid our understanding of and in potentially modulating gene expression in cases of defective gene functioning in clinical settings.
Current Intellectual Glance Over Nanoparticles in Cancer and Neurodegenerative Research
(Bentham Science Publishers Ltd., 2022-11-21) Bhattacharya, Tanima; Shen, Bairong; Greig, Nigel H.; Kamal, Mohammad Amjad
Nanoparticles are highly fascinating technologically and are fundamentally important particles due to their large surface area in relation to their volume. They provide numerous advantages in their application to the life- and envi- ronmental-sciences consequent to their particle size (1-100 nm), which can be smaller than the size of a virus; thereby allowing them to potentially strongly adhere to surfactant and other biological materials. In this regard, na- noparticles represent promising agents for attaching biological entities to without changing their functions. There are numerous areas across the sciences where these engineered particles could be hugely beneficial; many of them inadequately explored. To aid understand the fuller potential and efficacies of these particles, more research is needed, and the results are brought into the limelight to allow them to be more fully and rapidly applied. Their eval- uation in the areas of anticancer, antimicrobial, antiviral, anti-carcinogenic, sensory agents with newer techniques, and environmental applications encouraged.
Effect of Smartphone Use on Sleep in Undergraduate Medical Students
(MDPI Publications, 2023-11-02) Goel, Ashish; Moinuddin, Arsalan; Tiwari, Rajesh; Sethi, Yashendra; Suhail, Mohammed K.; Mohan, Aditi; Kaka, Nirja; Sarthi, Parth; Dutt, Ravi; Ahmad, Sheikh F.; Attia, Sabry M.; Emran, Talha Bin; Chopra, Hitesh; Greig, Nigel H.
Smartphone use, particularly at night, has been shown to provoke various circadian sleep–wake rhythm disorders such as insomnia and excessive daytime tiredness. This relationship has been mainly scrutinized among patient groups with higher rates of smartphone usage, particularly adolescents and children. However, it remains obscure how smartphone usage impacts sleep parameters in adults, especially undergraduate college students. This study sought to (1) investigate the association between smartphone use (actual screen time) and four sleep parameters: Pittsburgh sleep quality score (PSQI), self-reported screen time, bedtime, and rise time; (2) compare the seven PSQI components between good and poor sleep quality subjects. In total, 264 undergraduate medical students (aged 17 to 25 years) were recruited from the Government Doon Medical College, Dehradun, India. All participants completed a sleep questionnaire, which was electronically shared via a WhatsApp invitation link. Hierarchical and multinomial regression analyses were performed in relation to (1) and (2). The average PSQI score was 5.03 ± 0.86, with approximately one in two respondents (48.3%) having a poor sleep index. Smartphone use significantly predicted respondents’ PSQI score (β = 0.142, p = 0.040, R2 = 0.027), perceived screen time (β = 0.113, p = 0.043, R2 = 343), bedtime (β = 0.106, p = 0.042, R2 = 045), and rise time (β = 0.174, p = 0.015, R2 = 0.028). When comparing poor-quality sleep (PSQI ≥ 5) to good-quality sleep (PSQI < 5), with good-quality sleep as the reference, except sleep efficiency and sleep medications (p > 0.05), five PSQI components declined significantly: subjective sleep quality (β = −0.096, p < 0.001); sleep latency (β = −0.034, p < 0.001); sleep duration (β = −0.038, p < 0.001); sleep disturbances (β = 1.234, p < 0.001); and sleep dysfunction (β = −0.077, p < 0.001). Consequently, public health policymakers should take this evidence into account when developing guidelines around smartphone use—i.e., the when, where, and how much smartphone use—to promote improved sleep behaviour and reduce the rate of sleep–wake rhythm disorders.
Exploring the Recent Trends in Management of Dementia and Frail-ty
(Daffodil International University, 2022-09-05) Rahman, Md. Mominur; Mim, Sadia Afsana; Islam, Md. Rezaul; Parvez, Anwar; Islam, Fahadul; Uddin, Mohammad Borhan; Rahaman, Md. Saidur; Shuvo, Pollob Ahmed; Ahmed, Muniruddin; Greig, Nigel H.; Kamal, Mohammad Amjad
Dementia and frailty increase health adversities in older adults, which are topics of growing research interest. Frailty is considered to correspond to a biological syndrome associated with age. Frail patients may ultimately develop multiple dysfunctions across several systems, including stroke, transient ischemic attack, vascular dementia, Parkinson's disease, Alzheimer's disease, frontotemporal dementia, dementia with Lewy bodies, cortico-basal degeneration, multiple system atrophy, amyotrophic lateral sclerosis, and Creutzfeldt-Jakob disease. Patients with dementia and frailty often develop malnutrition and weight loss. Rigorous nutritional, pharmacological, and non-pharmacological interventions generally are required for these patients, which is a challenging issue for healthcare providers. A healthy diet and lifestyle instigated at an early age can reduce the risk of frailty and dementia. For optimal treatment, accurate diagnosis involving clinical evaluation, cognitive screening, essential laboratory evaluation, structural imaging, functional neuroimaging, and neuropsychological testing is necessary. Diagnosis procedures best apply the clinical diagnosis, identifying the cause(s) and the condition(s) appropriate for treatment. The patient's history, caregiver's interview, physical examination, cognitive evaluation, laboratory tests, and structural imaging should best be involved in the diagnostic process. Varying types of physical exercise can aid the treatment of these disorders. Nutrition maintenance is a particularly significant factor, such as exceptionally high-calorie dietary supplements and a Mediterranean diet to support weight gain. The core purpose of this article is to investigate trends in the management of dementia and frailty, focusing on improving diagnosis and treatment. Substantial evidence builds the consensus that a combination of balanced nutrition and good physical activity is an integral part of treatment. Notably, more evidence-based medicine knowledge is required.
In Silico and Ex Vivo Analyses of the Inhibitory Action of the Alzheimer Drug Posiphen and Primary Metabolites With Human Acetyl- and Butyrylcholinesterase Enzymes
(Daffodil International University, 2022-02-11) Batool, Sidra; Furqan, Tiyyaba; Mahmood, Muhammad Sibte Hasan; Tweedie, David; Kamal, Mohammad A.; Greig, Nigel H.
Alzheimer’s disease (AD) is the most common neurodegenerative disorder worldwide. Ongoing research to develop AD treatments has characterized multiple drug targets including the cholinergic system, amyloid-β peptide, phosphorylated tau, and neuroinflammation. These systems have the potential to interact to either drive or slow AD progression. Promising agents that simultaneously impact many of these drug targets are the AD experimental drug Posiphen and its enantiomer phenserine that, currently, are separately being evaluated in clinical trials. To define the cholinergic component of these agents, the anticholinesterase activities of a ligand dataset comprising Posiphen and primary metabolites ((+)-N1-norPosiphen, (+)-N8-norPosiphen, and (+)-N1,N8-bisnorPosiphen) were characterized and compared to those of the enantiomer phenserine. The “target” dataset involved the human cholinesterase enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Binding interactions between the ligands and targets were analyzed using Autodock 4.2. The computationally determined inhibitory action of these ligands was then compared to ex vivo laboratory-measured values versus human AChE and BChE. While Posiphen lacked AChE inhibitory action, its major and minor metabolites (+)-N1-norPosiphen and (+)-N1,N8-bisnorPosiphen, respectively, possessed modest AChE inhibitory activity, and Posiphen and all metabolites lacked BChE action. Phenserine, as a positive control, demonstrated AChE-selective inhibitory action. In light of AChE inhibitory action deriving from a major and minor Posiphen metabolite, current Posiphen clinical trials in AD and related disorders should additionally evaluate AChE inhibition; particularly if Posiphen should be combined with a known anticholinesterase, since this drug class is clinically approved and the standard of care for AD subjects, and excessive AChE inhibition may impact drug tolerability.
Inhibition of Caspase 3 and Caspase 9 Mediated Apoptosis: A Multimodal Therapeutic Target in Traumatic Brain Injury
(Bentham Science Publishers Ltd., 2023-05-22) Unnisa, Aziz; Greig, Nigel H.; Kamal, Mohammad Amjad
Traumatic brain injury (TBI) is one of the significant causes of death and morbidity, and it is hence a focus of translational research. Apoptosis plays an essential part in the pathophysiology of TBI, and its inhibition may help overcome TBI's negative consequences and improve functional recovery. Although physiological neuronal death is necessary for appropriate embryologic development and adult cell turnover, it can also drive neurodegeneration. Caspases are principal mediators of cell death due to apoptosis and are critical for the required cleavage of intracellular proteins of cells committed to die. Caspase-3 is the major executioner Caspase of apoptosis and is regulated by a range of cellular components during physiological and pathological conditions. Activation of Caspase-3 causes proteolyzation of DNA repair proteins, cytoskeletal proteins, and the inhibitor of Caspase-activated DNase (ICAD) during programmed cell death, resulting in morphological alterations and DNA damage that define apoptosis. Caspase-9 is an additional crucial part of the intrinsic pathway, activated in response to several stimuli. Caspases can be altered post-translationally or by modulatory elements interacting with the zymogenic or active form of a Caspase, preventing their activation. The necessity of Caspase-9 and -3 in diverse apoptotic situations suggests that mammalian cells have at least four distinct apoptotic pathways. Continued investigation of these processes is anticipated to disclose new Caspase regulatory mechanisms with consequences far beyond apoptotic cell death control. The present review discusses various Caspase-dependent apoptotic pathways and the treatment strategies to inhibit the Caspases potentially.
Modelling the Interplay Between Neuron-Glia Cell Dysfunction and Glial Therapy in Autism Spectrum Disorde
(Bentham Science Publishers Ltd., 2023-04-15) Unnisa, Aziz; Greig, Nigel H.; Kamal, Mohammad Amjad
Autism spectrum disorder (ASD) is a complicated, interpersonally defined, static condition of the underdeveloped brain. Although the aetiology of autism remains unclear, disturbance of neuronglia interactions has lately been proposed as a significant event in the pathophysiology of ASD. In recent years, the contribution of glial cells to autism has been overlooked. In addition to neurons, glial cells play an essential role in mental activities, and a new strategy that emphasises neuron-glia interactions should be applied. Disturbance of neuron-glia connections has lately been proposed as a significant event in the pathophysiology of ASD because aberrant neuronal network formation and dysfunctional neurotransmission are fundamental to the pathology of the condition. In ASD, neuron and glial cell number changes cause brain circuits to malfunction and impact behaviour. A study revealed that reactive glial cells result in the loss of synaptic functioning and induce autism under inflammatory conditions. Recent discoveries also suggest that dysfunction or changes in the ability of microglia to carry out physiological and defensive functions (such as failure in synaptic elimination or aberrant microglial activation) may be crucial for developing brain diseases, especially autism. The cerebellum, white matter, and cortical regions of autistic patients showed significant microglial activation. Reactive glial cells result in the loss of synaptic functioning and induce autism under inflammatory conditions. Replacement of defective glial cells (Cell-replacement treatment), glial progenitor cell-based therapy, and medication therapy (inhibition of microglia activation) are all utilised to treat glial dysfunction. This review discusses the role of glial cells in ASD and the various potential approaches to treating glial cell dysfunction.
Nanotechnology: A Promising Targeted Drug Delivery System for Brain Tumours and Alzheimer's Disease
(Bentham Science Publishers Ltd., 2022-06-10) Unnisa, Aziz; Greig, Nigel H.; Kamal, Mohammad A.
is the process of modulating shape and size at the nanoscale to design and manufacture structures, devices, and systems. Nanotechnology's prospective breakthroughs are incredible, and some cannot even be comprehended right now. The blood-brain barrier, which is a prominent physiological barrier in the brain, limits the adequate elimination of malignant cells by preventing the concentration of therapeutic drugs at the target tissue. Nanotechnology has sparked interest in recent years as a way to solve these issues and improve drug delivery. Inorganic and organic nanomaterials were found to be beneficial for bioimaging approaches and controlled drug delivery systems. Brain cancer (BC) and Alzheimer’s disease (AD) are two of the prominent disorders of the brain. Even though the pathophysiology and pathways for both disorders are different, nanotechnology with common features can deliver drugs over the BBB, advancing the treatment of both disorders. This innovative technology could provide a foundation for combining diagnostics, treatments, and delivery of targeted drugs to the tumour site, with further supervising the response, by designing and delivering materials by employing atomic and molecular elements. There is currently limited treatment for Alzheimer's disease, and reversing further progression is difficult. Recently, various nanocarriers have been investigated to improve the bioavailability and efficacy of many AD treatment drugs. Nanotechnology-assisted drugs can penetrate the BBB and reach the target tissue. However, further research is required in this field, to ensure the safety and efficacy of drug-loaded nanoparticles. The application of nanotechnology in the diagnosis and treatment of brain tumours and Alzheimer's disease is briefly discussed in this review.
Relative synonymous codon usage and codon pair analysis of depression associated genes
(Scopus, 2024-02-12) Khandia, Rekha; Gurjar, Pankaj; Kamal, Mohammad Amjad; Greig, Nigel H.
Depression negatively impacts mood, behavior, and mental and physical health. It is the third leading cause of suicides worldwide and leads to decreased quality of life. We examined 18 genes available at the genetic testing registry (GTR) from the National Center for Biotechnological Information to investigate molecular patterns present in depression-associated genes. Different genotypes and differential expression of the genes are responsible for ensuing depression. The present study, investigated codon pattern analysis, which might play imperative roles in modulating gene expression of depression-associated genes. Of the 18 genes, seven and two genes tended to up- and down-regulate, respectively, and, for the remaining genes, different genotypes, an outcome of SNPs were responsible alone or in combination with differential expression for different conditions associated with depression. Codon context analysis revealed the abundance of identical GTG-GTG and CTG-CTG pairs, and the rarity of methionine-initiated codon pairs. Information based on codon usage, preferred codons, rare, and codon context might be used in constructing a deliverable synthetic construct to correct the gene expression level of the human body, which is altered in the depressive state. Other molecular signatures also revealed the role of evolutionary forces in shaping codon usage.