Search results for "Transmission"
showing 10 items of 2080 documents
Update of the statements on biology and clinical impact of occult hepatitis B virus infection
2019
In October 2018 a large number of international experts with complementary expertise came together in Taormina to participate in a workshop on occult hepatitis B virus infection (OBI). The objectives of the workshop were to review the existing knowledge on OBI, to identify issues that require further investigation, to highlight both existing controversies and newly emerging perspectives, and ultimately to update the statements previously agreed in 2008. This paper represents the output from the workshop.
Virulence of Streptococcus mutans: An intrafamilial cohort study on transmission of genotypes
2020
Background The main aims of this cohort study were to measure the intrafamilial risk of transmission, sharing and stability of the most virulent S. mutans genotypes. Material and Methods A total of 392 clinical isolates of S. mutans obtained from caries-active adults and genotyped to evaluate their transmissibility over time. After extraction of the chromosomal DNA, PCR were performed to detect the genes involved in the production of GbpA (gbpA) and mutacin types I, II, III and IV (mutAI, mutAII, mutAIII and mutAIV). Results The gbpA, mutAI, mutAII, mutAIII and mutAIV genes were detected in 77.3, 12.5, 51, 16.6 and 89.8% of S. mutans isolates, respectively. The virulence of S. mutans was as…
SARS-CoV2 vertical transmission with adverse effects on the newborn revealed through integrated immunohistochemical, electron microscopy and molecula…
2020
Background: The occurrence of trans-placental transmission of severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) infection remains highly debated. Placental positivity for SARS-CoV-2 has been reported in selected cases, but infection or virus-associated disease of fetal tissues or newborns remains to be demonstrated. Methods: We screened for SARS-CoV-2 spike (S) protein expression placentas from 101 women who delivered between February 7 and May 15 2020, including 15 tested positive for SARS-CoV-2 RNA, 34 tested negative, and 52 not evaluated as they did not meet testing criteria (32), or delivered before COVID-19 pandemic declaration (20). Immunostain for SARS-CoV-2 nucleocapsid…
A longitudinal DTI and histological study of the spinal cord reveals early pathological alterations in G93A-SOD1 mouse model of amyotrophic lateral s…
2017
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by selective motor neuron degeneration in the motor cortex, brainstem and spinal cord. It is generally accepted that ALS is caused by death of motor neurons, however the exact temporal cascade of degenerative processes is not yet completely known. To identify the early pathological changes in spinal cord of G93A-SOD1 AIS mice we performed a comprehensive longitudinal analysis employing diffusion-tensor magnetic resonance imaging alongside histology and electron microscopy, in parallel with peripheral nerve histology. We showed the gradient of degeneration appearance in spinal cord white and gray matter, startin…
Mesopolysaccharides: The extracellular surface layer of visceral organs
2020
The mesothelium is a dynamic and specialized tissue layer that covers the somatic cavities (pleural, peritoneal, and pericardial) as well as the surface of the visceral organs such as the lung, heart, liver, bowel and tunica vaginalis testis. The potential therapeutic manipulation of visceral organs has been complicated by the carbohydrate surface layer—here, called the mesopolysaccharide (MPS)—that coats the outer layer of the mesothelium. The traditional understanding of MPS structure has relied upon fixation techniques known to degrade carbohydrates. The recent development of carbohydrate-preserving fixation for high resolution imaging techniques has provided an opportunity to re-examine…
Modulation of information processing by AMPA receptor auxiliary subunits
2020
AMPA-type glutamate receptors (AMPARs) are key molecules of neuronal communication in our brain. The discovery of AMPAR auxiliary subunits, such as proteins of the TARP, CKAMP and CNIH families, fundamentally changed our understanding of how AMPAR function is regulated. Auxiliary subunits control almost all aspects of AMPAR function in the brain. They influence AMPAR assembly, composition, structure, trafficking, subcellular localization and gating. This influence has important implications for synapse function. In the present review, we first discuss how auxiliary subunits affect the strength of synapses by modulating number and localization of AMPARs in synapses as well as their glutamate…
Amorphous polyphosphate–hydroxyapatite: A morphogenetically active substrate for bone-related SaOS-2 cells in vitro
2015
There is increasing evidence that inorganic calcium-polyphosphates (polyP) are involved in human bone hydroxyapatite (HA) formation. Here we investigated the morphology of the particles, containing calcium phosphate (CaP) with different concentrations of various Na-polyP concentrations, as well as their effects in cell culture. We used both SaOS-2 cells and human mesenchymal stem cells. The polymeric phosphate readily binds calcium ions under formation of insoluble precipitates. We found that addition of low concentrations of polyP (10wt.%, referred to the CaP deposits) results in an increased size of the HA crystals. Surprisingly, at higher polyP concentrations (10wt.%) the formation of cr…
PTEN recruitment controls synaptic and cognitive function in Alzheimer's models
2016
Dyshomeostasis of amyloid-β peptide (Aβ) is responsible for synaptic malfunctions leading to cognitive deficits ranging from mild impairment to full-blown dementia in Alzheimer's disease. Aβ appears to skew synaptic plasticity events toward depression. We found that inhibition of PTEN, a lipid phosphatase that is essential to long-term depression, rescued normal synaptic function and cognition in cellular and animal models of Alzheimer's disease. Conversely, transgenic mice that overexpressed PTEN displayed synaptic depression that mimicked and occluded Aβ-induced depression. Mechanistically, Aβ triggers a PDZ-dependent recruitment of PTEN into the postsynaptic compartment. Using a PTEN kno…
Parasites Dampen Dendritic Cell Activation to Ensure Their Survival
2017
Dendritic cells (DCs) are critical for induction of protective immunity against Leishmania major. However, DC activation occurs only several weeks after parasite transmission. Parasites synthesize a macrophage-inducible C-type lectin (Mincle) ligand. Engagement of Mincle by the parasite ligand dampens DC activation, thus delaying induction of interferon-γ-producing T cells responsible for parasite eradication.
Endogenous β-neurexins on axons and within synapses show regulated dynamic behavior
2021
Summary: Neurexins are key organizer molecules that regulate synaptic function and are implicated in autism and schizophrenia. β-neurexins interact with numerous cell adhesion and receptor molecules, but their neuronal localization remains elusive. Using single-molecule tracking and high-resolution microscopy to detect neurexin1β and neurexin3β in primary hippocampal neurons from knockin mice, we demonstrate that endogenous β-neurexins are present in fewer than half of excitatory and inhibitory synapses. Moreover, we observe a large extrasynaptic pool of β-neurexins on axons and show that axonal β-neurexins diffuse with higher surface mobility than those transiently confined within synapses…