Alzheimer's disease (AD) is the most common neurodegenerative dementia worldwide. AD is a multifactorial disease that causes a progressive decline in memory and function precipitated by toxic beta-amyloid (Aβ) proteins, a key player in AD pathology. In 2022, 6.
View Article and Find Full Text PDFAlzheimer's disease (AD) is a brain disorder that eventually causes memory loss and the ability to perform simple cognitive functions; research efforts within pharmaceuticals and other medical treatments have minimal impact on the disease. Our preliminary biological studies showed that Repeated Electromagnetic Field Stimulation (REFMS) applying an EM frequency of 64 MHz and a specific absorption rate (SAR) of 0.4 - 0.
View Article and Find Full Text PDFWe provide a multidimensional sequence of events that describe the electromagnetic field (EMF) stimulation and biological system interaction. We describe this process from the quantum to the molecular, cellular, and organismal levels. We hypothesized that the sequence of events of these interactions starts with the oscillatory effect of the repeated electromagnetic stimulation (REMFS).
View Article and Find Full Text PDFIn this paper, we follow up with our preliminary biological studies that showed that Repeated electromagnetic field stimulation (REMFS) decreased the toxic amyloid-beta (A) levels, which is considered to be the cause of Alzheimer's disease (AD). The REMFS parameters of these exposures were a frequency of 64 MHz and a Specific absorption rate (SAR) of 0.4 to 0.
View Article and Find Full Text PDFThe antibody-drug conjugate (ADC) is a well-validated modality for the cell-specific delivery of small molecules with impact expanding rapidly beyond their originally-intended purpose of treating cancer. However, antibody-mediated delivery (AMD) remains inefficient, limiting its applicability to targeting highly potent payloads to cells with high antigen expression. Maximizing the number of payloads delivered per antibody is one key way in which delivery efficiency can be improved, although this has been challenging to carry out; with few exceptions, increasing the drug-to-antibody ratio (DAR) above ∼4 typically destroys the biophysical properties and efficacy for ADCs.
View Article and Find Full Text PDFLate Onset Alzheimer's Disease is the most common cause of dementia, characterized by extracellular deposition of plaques primarily of amyloid-β (Aβ) peptide and tangles primarily of hyperphosphorylated tau protein. We present data to suggest a noninvasive strategy to decrease potentially toxic Aβ levels, using repeated electromagnetic field stimulation (REMFS) in primary human brain (PHB) cultures. We examined effects of REMFS on Aβ levels (Aβ40 and Aβ42, that are 40 or 42 amino acid residues in length, respectively) in PHB cultures at different frequencies, powers, and specific absorption rates (SAR).
View Article and Find Full Text PDFBackground: The rapid development of a variety of devices that emit Radiofrequency Electromagnetic fields (RF-EMF) has sparked growing interest in their interaction with biological systems and the beneficial effects on human health. As a result, investigations have been driven by the potential for therapeutic applications, as well as concern for any possible negative health implications of these EM energies [1-4]. Recent results have indicated specific tuning of experimental and clinical RF exposure may lead to their clinical application toward beneficial health outcomes [5].
View Article and Find Full Text PDFThe impact of the electromagnetic waves (EM) on human neurons (HN) has been under investigation for decades, in efforts to understand the impact of cell phones (radiation) on human health, or radiation absorption by HN for medical diagnosis and treatment. Research issues including the wave frequency, power intensity, reflections and scattering, and penetration depths are of important considerations to be incorporated into the research study. In this study, computer simulation for the EM exposure to HN was studied for the purpose of determining the upper limits of the electric and magnetic field intensities, power consumption, reflections and transmissions, and the change in temperature resulting from the power absorption by human neurons.
View Article and Find Full Text PDFUnlabelled: The type I signal peptidase of Staphylococcus aureus, SpsB, is an attractive antibacterial target because it is essential for viability and extracellularly accessible. We synthesized compound 103, a novel arylomycin-derived inhibitor of SpsB with significant potency against various clinical S. aureus strains (MIC of ~1 µg/ml).
View Article and Find Full Text PDFStaphylococcus aureus is considered to be an extracellular pathogen. However, survival of S. aureus within host cells may provide a reservoir relatively protected from antibiotics, thus enabling long-term colonization of the host and explaining clinical failures and relapses after antibiotic therapy.
View Article and Find Full Text PDFLittle is known about the expression of methicillin-resistant Staphylococcus aureus (MRSA) genes during infection conditions. Here, we described the transcriptome of the clinical MRSA strain USA300 derived from human cutaneous abscesses, and compared it with USA300 bacteria derived from infected kidneys in a mouse model. Remarkable similarity between the transcriptomes allowed us to identify genes encoding multiple proteases and toxins, and iron- and peptide-transporter molecules, which are upregulated in both infections and are likely important for establishment of infection.
View Article and Find Full Text PDFInfection of host tissues by Staphylococcus aureus and S. epidermidis requires an unusual family of staphylococcal adhesive proteins that contain long stretches of serine-aspartate dipeptide-repeats (SDR). The prototype member of this family is clumping factor A (ClfA), a key virulence factor that mediates adhesion to host tissues by binding to extracellular matrix proteins such as fibrinogen.
View Article and Find Full Text PDFMycobacterium marinum is a waterborne mycobacterial pathogen. Due to their common niche, protozoa likely represent natural hosts for M. marinum.
View Article and Find Full Text PDFModern medicine is directed towards the prevention, detection and cure of individual diseases. Yet, current medical models inadequately describe aging-associated diseases. We now know that failure in longevity pathways including oxidative stress, multisystem dysregulation, inflammation, sarcopenia, protein deposition and atherosclerosis are associated with age-related diseases.
View Article and Find Full Text PDFA new consensus of gerontologists proposes that delay of biological senescence is the most potent public health measure for preventing chronic disease in late life. At the most fundamental level, cellular aging is characterized by a decline in repair and homeostatic systems. Thus, interventions that protect or rejuvenate these cellular systems hold significant promise for preventing or delaying the onset of age-related diseases.
View Article and Find Full Text PDFExocytosis of lysosomes from macrophages has been described as a response to microbial cytotoxins and haemolysins, as well as for releasing pro-inflammatory cytokines interleukin (IL)-1beta and IL-18 during inflammasome activation. The mycobacterial ESX-1 secretion system, encoded in part by the Region of Difference-1, is a virulence factor necessary for phagosome escape and host cell lysis by a contact-dependent haemolysin in Mycobacterium marinum. Here we show that ESX-1 from M.
View Article and Find Full Text PDFHormesis may result when mild repetitive stress increases cellular defense against diverse injuries. This process may also extend in vitro cellular proliferative life span as well as delay and reverse some of the age-dependent changes in both replicative and non-replicative cells. This study evaluated the potential hormetic effect of non-thermal repetitive electromagnetic field shock (REMFS) and its impact on cellular aging and mortality in primary human T lymphocytes and fibroblast cell lines.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2008
The pathogenic mycobacteria that cause tuberculosis (TB) and TB-like diseases in humans and animals elude sterilizing immunity by residing within an intracellular niche in host macrophages, where they are protected from microbicidal attack. Recent studies have emphasized microbial mechanisms for evasion of host defense; less is known about mycobactericidal mechanisms that remain intact during initial infection. To better understand macrophage mechanisms for restricting mycobacteria growth, we examined Mycobacterium marinum infection of Drosophila S2 cells.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
October 2005
Mycobacterium marinum, a natural pathogen of fish and frogs and an occasional pathogen of humans, is capable of inducing actin tail formation within the cytoplasm of macrophages, leading to actin-based motility and intercellular spread. Actin tail formation by M. marinum is markedly reduced in macrophages deficient in the Wiskott-Aldrich syndrome protein (WASP), which still contain the closely related and ubiquitously expressed protein N-WASP (neuronal WASP).
View Article and Find Full Text PDFMycobacteria are responsible for a number of human and animal diseases and are classical intracellular pathogens, living inside macrophages rather than as free-living organisms during infection. Numerous intracellular pathogens, including Listeria monocytogenes, Shigella flexneri, and Rickettsia rickettsii, exploit the host cytoskeleton by using actin-based motility for cell to cell spread during infection. Here we show that Mycobacterium marinum, a natural pathogen of fish and frogs and an occasional pathogen of humans, is capable of actively inducing actin polymerization within macrophages.
View Article and Find Full Text PDFMycobacterium tuberculosis infects one-third of the world's population and causes two million deaths annually. The unusually low permeability of its cell wall contributes to the ability of M. tuberculosis to grow within host macrophages, a property required for pathogenesis of infection.
View Article and Find Full Text PDFIntegrin ligation activates both cell adhesion and signal transduction, in part through reorganization of the actin cytoskeleton. Plastins (also known as fimbrins) are actin-crosslinking proteins of the cortical cytoskeleton present in all cells and conserved from yeast to mammals. Here we show that plastin-deficient polymorphonuclear neutrophils (PMN) are deficient in killing the bacterial pathogen Staphylococcus aureus in vivo and in vitro, despite normal phagocytosis.
View Article and Find Full Text PDFNon-O1 strains of Vibrio cholerae implicated in gastroenteritis and diarrhea generally lack virulence determinants such as cholera toxin that are characteristic of epidemic strains; the factors that contribute to their virulence are not understood. Here we report that at least one-third of diarrhea-associated nonepidemic V. cholerae strains from Mexico cause vacuolation of cultured Vero cells.
View Article and Find Full Text PDFCHO and BHK cells which overexpress either wild-type rab5 or rab5:Q79L, a constitutively active rab5 mutant, develop enlarged cytoplasmic vesicles that exhibit many characteristics of early endosomes including immunoreactivity for rab5 and transferrin receptor. Time-lapse video microscopy shows the enlarged endosomes arise primarily by fusion of smaller vesicles. These fusion events occur mostly by a 'bridge' fusion mechanism in which the initial opening between vesicles does not expand; instead, membrane flows slowly and continuously from the smaller to the larger endosome in the fusing pair, through a narrow, barely perceptible membranous 'bridge' between them.
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