Indian J Otolaryngol Head Neck Surg
April 2024
Unlabelled: Deep neck space infections are an ENT (Ear, Nose, Throat) emergency. Navigation system (NS) can be utilized to assist in locating the exact site of pathology and avoiding iatrogenic injury especially in paediatric patients. This manuscript explores the importance of NS in managing retro pharyngeal abscess (RPA) in an 11 month old baby.
View Article and Find Full Text PDFMalic enzymes (ME1, ME2, and ME3) are involved in cellular energy regulation, redox homeostasis, and biosynthetic processes, through the production of pyruvate and reducing agent NAD(P)H. Recent studies have implicated the third and least well-characterized isoform, mitochondrial NADP-dependent malic enzyme 3 (ME3), as a therapeutic target for pancreatic cancers. Here, we utilized an integrated structure approach to determine the structures of ME3 in various ligand-binding states at near-atomic resolutions.
View Article and Find Full Text PDFIndian J Otolaryngol Head Neck Surg
March 2023
Aim: N95 masks are recommended for the healthcare providers (HCPs) taking care of patients with coronavirus disease 2019. However, the use of these masks hampers communication. We aimed to evaluate the effect of N95 masks on speech comprehension among listeners and vocal efforts (VEs) of the HCPs.
View Article and Find Full Text PDFIndian J Otolaryngol Head Neck Surg
October 2022
Globally adenoidectomy is increasingly being performed in isolation for children who have middle ear effusion or chronic otitis media, chronic rhinosinusitis and nasopharyngeal obstruction causing sleep apnoea and mouth breathing. Several techniques have been described lately including endoscopic powered adenoidectomy with debrider. The present study was undertaken to compare the effectiveness of endoscopic powered adenoidectomy (EA) with respect to conventional adenoidectomy (CA).
View Article and Find Full Text PDFRare monogenic disorders often share molecular etiologies involved in the pathogenesis of common diseases. Congenital disorders of glycosylation (CDG) and deglycosylation (CDDG) are rare pediatric disorders with symptoms that range from mild to life threatening. A biological mechanism shared among CDG and CDDG as well as more common neurodegenerative diseases such as Alzheimer's disease and amyotrophic lateral sclerosis, is endoplasmic reticulum (ER) stress.
View Article and Find Full Text PDFAggregation of the hyperphosphorylated protein tau into neurofibrillary tangles and neuropil threads is a hallmark of Alzheimer disease (AD). Identification and characterization of the epitopes recognized by anti-tau antibodies might shed light on the molecular mechanisms of AD pathogenesis. Here we report on the biochemical and structural characterization of a tau-specific monoclonal antibody CBTAU-24.
View Article and Find Full Text PDFMisfolding and aggregation of tau protein are closely associated with the onset and progression of Alzheimer's Disease (AD). By interrogating IgG memory B cells from asymptomatic donors with tau peptides, we have identified two somatically mutated V5-51/V4-1 antibodies. One of these, CBTAU-27.
View Article and Find Full Text PDFRespiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract infections in infants and the elderly, and yet there remains no effective treatment or vaccine. The surface of the virion is decorated with the fusion glycoprotein (RSV F) and the attachment glycoprotein (RSV G), which binds to CX3CR1 on human airway epithelial cells to mediate viral attachment and subsequent infection. RSV G is a major target of the humoral immune response, and antibodies that target the central conserved region of G have been shown to neutralize both subtypes of RSV and to protect against severe RSV disease in animal models.
View Article and Find Full Text PDFSeveral reports have described the presence of antibodies against Alzheimer's disease-associated hyperphosphorylated forms of tau in serum of healthy individuals. To characterize the specificities that can be found, we interrogated peripheral IgG memory B cells from asymptomatic blood donors for reactivity to a panel of phosphorylated tau peptides using a single-cell screening assay. Antibody sequences were recovered, cloned, and expressed as full-length IgGs.
View Article and Find Full Text PDFBackground: Human metapneumovirus (HMPV) is a leading cause of acute respiratory tract infection, with significant morbidity and mortality. No licensed vaccines or therapeutic agents exist. Monoclonal antibodies (mAbs) are effective at preventing other infectious diseases and could be used against HMPV in high-risk hosts.
View Article and Find Full Text PDFCold Spring Harb Protoc
January 2013
The ability to modulate cellular function by the transfer and expression of novel genes or by affecting the levels of endogenous proteins by genetic means has been of tremendous benefit in studying cellular functions and offers great promise in the treatment of a variety of diseases. Consequently, the development of novel and efficient nonviral DNA delivery systems is an important goal. Small cationic peptides, termed peptide/protein transduction domains (PTDs), effectively deliver a wide variety of cargoes, including DNA, into all cells.
View Article and Find Full Text PDFTransmissible spongiform encephalopathies, including variant-Creutzfeldt-Jakob disease (vCJD) in humans and bovine spongiform encephalopathies in cattle, are fatal neurodegenerative disorders characterized by protein misfolding of the host cellular prion protein (PrP(C)) to the infectious scrapie form (PrP(Sc)). However, the mechanism that exogenous PrP(Sc) infects cells and where pathologic conversion of PrP(C) to the PrP(Sc) form occurs remains uncertain. Here we report that similar to the mechanism of HIV-1 TAT-mediated peptide transduction, processed mature, full length PrP contains a conserved N-terminal cationic domain that stimulates cellular uptake by lipid raft-dependent, macropinocytosis.
View Article and Find Full Text PDFStudies on amyloid beta (Abeta|), the peptide thought to play a crucial role in the pathogenesis of Alzheimer's disease, have implicated mitochondria in Abeta-mediated neurotoxicity. We used differentiated PC12 cells stably transfected with an inducible green fluorescent protein (GFP) fusion protein containing an N'-terminal mitochondrial targeting sequence (mtGFP), to examine the effects of sub-lethal Abeta on the import of nuclear-encoded proteins to mitochondria. Exposure to sub-lethal Abeta(25-35) (10 mumol/L) for 48 h inhibited mtGFP import to mitochondria; average rates decreased by 20 +/- 4%.
View Article and Find Full Text PDFThe direct intracellular delivery of proteins, or active peptide domains, has, until recently, been difficult to achieve due primarily to the bioavailability barrier of the plasma membrane, which effectively prevents the uptake of macromolecules by limiting their passive entry. Traditional approaches to modulate protein function have largely relied on the serendipitous discovery of specific drugs and small molecules which could be delivered easily into the cell. However, the usefulness of these pharmacological agents is limited by their tissue distribution and unlike 'information-rich' macromolecules, they often suffer from poor target specificity, unwanted side-effects, and toxicity.
View Article and Find Full Text PDFJ Control Release
January 2005
Naturally occurring and synthetic short arginine containing protein transduction domains (PTDs), including HIV1 TAT, poly-Arg and Antp, have been used to deliver a wide variety of macromolecular, biologically active therapeutic cargo into cells, including peptides, proteins, antisense oligonucleotides and liposomes, in vitro and to treat pre-clinical models of cancer and stroke. PTDs enter cells in a rapid, receptor-independent fashion. Recently, large TAT-fusion proteins (in excess of 30,000 Da) were shown to transduce into cells by fluid-phase macropinocytosis, a specialized form of endocytosis that is independent of caveolae, clathrin and dynamin.
View Article and Find Full Text PDFThe TAT protein transduction domain (PTD) has been used to deliver a wide variety of biologically active cargo for the treatment of multiple preclinical disease models, including cancer and stroke. However, the mechanism of transduction remains unknown. Because of the TAT PTD's strong cell-surface binding, early assumptions regarding cellular uptake suggested a direct penetration mechanism across the lipid bilayer by a temperature- and energy-independent process.
View Article and Find Full Text PDFBackground: Mitochondrial protein import is typically measured by adding radiolabeled precursor proteins to isolated mitochondria. We have developed a novel, high-throughput method for measuring protein import in live differentiated PC12 cells using a tetracycline (Tet) regulated, nuclear encoded, mitochondrially-targeted GFP fusion protein and flow cytometry.
Methods: We generated a PC12 cell line stably transfected with an inducible GFP fusion protein (GFPmt) targeted to mitochondria.
Curr Protein Pept Sci
April 2003
Due to the barrier imposed by the cell membrane, delivery of macromolecules in excess of 500 Daltons directly into cells remains problematic. However, proteins, which have been evolutionarily selected to perform specific functions, are therefore an attractive therapeutic agent to treat a variety of human diseases. In practice, the direct intracellular delivery of these proteins has, until recently, been difficult to achieve due primarily to the bioavailability barrier of the plasma membrane, which effectively prevents the uptake of the majority of peptides and proteins by limiting their passive entry.
View Article and Find Full Text PDFIntracellular delivery of macromolecules remains problematic because of the bioavailability restriction imposed by the cell membrane. Recent studies on protein transduction domains have circumvented this barrier, however, and have resulted in the delivery of peptides, full-length proteins, iron beads, liposomes, and radioactive isotopes into cells in culture and animal models in vivo.
View Article and Find Full Text PDFHow seizures arise and recur in epilepsy is unknown. Recent genetic, pharmacological and electrophysiological data indicate a significant but undisclosed role for voltage-dependent calcium channels. Since the contribution such channels make to nerve function reflects the targeting of discrete subtypes to distinct cellular regions, we hypothesized that epilepsy reflects alterations in their spatiotemporal patterns of expression at the cell surface.
View Article and Find Full Text PDFThe mechanisms underlying epilepsy are largely unknown. Recent genetic, pharmacological and electrophysiological data indicate a significant, but poorly understood, role for voltage-dependent calcium channels (VDCCs). Since the contribution of ion channels to nerve function depends on their cell surface distribution, we hypothesized that epilepsy might alter VDCC surface densities.
View Article and Find Full Text PDFSeizures may cause brain damage due to mechanisms initiated by excessive excitatory synaptic transmission. One such mechanism is the activation of death-promoting intracellular cascades by the influx and the perturbed homeostasis of Ca2+. The neuroprotective effects of preventing the entry of Ca2+ from voltage-dependent Ca2+ channels, NMDA receptors, and non-NMDA receptors, is well known.
View Article and Find Full Text PDFStudies in non-neural cells have suggested that a fall in mitochondrial membrane potential (DeltaPsiM) is one of the earliest events in apoptosis. It is not known whether neural apoptosis caused by nerve growth factor (NGF) and serum withdrawal involves a decrease in DeltaPsiM. We used epifluorescence and laser confocal microscopy with the mitochondrial potentiometric dyes chloromethyl-tetramethylrosamine methyl ester and 5,5',6, 6'-tetrachloro-1,1',3,3'-tetraethybenzimidazol carbocyanine iodide to estimate DeltaPsiM.
View Article and Find Full Text PDFJ Neural Transm Suppl
October 1997
Apoptotic, rather than necrotic, nerve cell death now appears as likely to underlie a number of common neurological conditions including stroke, Alzheimer's disease, Parkinson's disease, hereditary retinal dystrophies and Amyotrophic Lateral Sclerosis. Apoptotic neuronal death is a delayed, multistep process and therefore offers a therapeutic opportunity if one or more of these steps can be interrupted or reversed. Research is beginning to show how specific macromolecules play a role in determining the apoptotic death process.
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