2,690 research outputs found
SARS-CoV-2 was already circulating in Italy, in early December 2019
– OBJECTIVE: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) identified in China, in December 2019 determines COronaVIrus Disease 19 (COVID-19). Whether or not the virus was present in Italy earlier the first autochthonous COVID-19 case was diagnosed is still uncertain. We aimed to identify anti-SARS-CoV-2 antibodies in sera collected from 4th November 2019 to 9th March 2020, in order to assess the possible spread of the virus in Italy earlier than the first official national diagnosis. PATIENTS AND METHODS: Anti-SARS-CoV-2 antibodies were evaluated in retrospective serum samples from 234 patients with liver diseases (Hep-patients) and from 56 blood donors (BDs). We used two rapid serologic tests which were confirmed by a validated chemoluminescence assay. RESULTS: Via rapid tests, we found 10/234 (4.3%) IgG-positive and 1/234 (0.4%) IgM-positive cases in the Hep-patient group. Two/56 (3.6%) IgG-positive and 2/56 (3.6%) IgM-positive cases were detected in BD group. Chemoluminescence confirmed IgG-positivity in 3 Hep-patients and 1 BD and IgM-positivity in 1 Hep-patient. RNAemia was not detected in any of the subjects, rendering the risk of transfusion transmission negligible. CONCLUSIONS: Our results suggest an early circulation of SARS-CoV-2 in Italy, before the first COVID-19 cases were described in China. Rapid tests have multiple benefits; however, a confirmation assay is required to avoid false positive results
Hydrogen molecule in a magnetic field: The lowest states of the Pi manifold and the global ground state of the parallel configuration
The electronic structure of the hydrogen molecule in a magnetic field is
investigated for parallel internuclear and magnetic field axes. The lowest
states of the manifold are studied for spin singlet and triplet as well as gerade and ungerade parity for a broad range of field
strengths For both states with gerade parity we
observe a monotonous decrease in the dissociation energy with increasing field
strength up to and metastable states with respect to the
dissociation into two H atoms occur for a certain range of field strengths. For
both states with ungerade parity we observe a strong increase in the
dissociation energy with increasing field strength above some critical field
strength . As a major result we determine the transition field strengths
for the crossings among the lowest , and
states. The global ground state for is the strongly
bound state. The crossings of the with the
and state occur at and , respectively. The transition between the and
state occurs at Therefore, the global ground state of the
hydrogen molecule for the parallel configuration is the unbound
state for The ground state for is the strongly bound state. This result is of great
relevance to the chemistry in the atmospheres of magnetic white dwarfs and
neutron stars.Comment: submitted to Physical Review
Minor and Unsystematic Cortical Topographic Changes of Attention Correlates between Modalities
In this study we analyzed the topography of induced cortical oscillations in 20 healthy individuals performing simple attention tasks. We were interested in qualitatively replicating our recent findings on the localization of attention-induced beta bands during a visual task [1], and verifying whether significant topographic changes would follow the change of attention to the auditory modality. We computed corrected latency averaging of each induced frequency bands, and modeled their generators by current density reconstruction with Lp-norm minimization. We quantified topographic similarity between conditions by an analysis of correlations, whereas the inter-modality significant differences in attention correlates were illustrated in each individual case. We replicated the qualitative result of highly idiosyncratic topography of attention-related activity to individuals, manifested both in the beta bands, and previously studied slow potential distributions [2]. Visual inspection of both scalp potentials and distribution of cortical currents showed minor changes in attention-related bands with respect to modality, as compared to the theta and delta bands, known to be major contributors to the sensory-related potentials. Quantitative results agreed with visual inspection, supporting to the conclusion that attention-related activity does not change much between modalities, and whatever individual changes do occur, they are not systematic in cortical localization across subjects. We discuss our results, combined with results from other studies that present individual data, with respect to the function of cortical association areas
IgG cryoglobulinemia
OBJECTIVE: Mixed Cryoglobulinemia is the most well-known Hepatitis C Virus (HCV)-associated extrahepatic manifestation. MC is both an autoimmune and B-lymphoproliferative disorder. Cryoglobulins (CGs) are classified into three groups according to immunoglobulin (Ig) composition: type I is composed of one isotype or Ig class. Type II and type III mixed CGs are immune complexes composed of polyclonal IgGs acting as autoantigens and mono, polyclonal or oligoclonal IgM with rheumatoid factor activity. IgG1 and IgG3 are the predominant subclasses involved. This study shows the simultaneous presence of IgG-RF and IgG3, supporting the hypothesis of an involvement of this subclass in the initiation of early stages of CGs.
PATIENTS AND METHODS: We describe a case series of six HCV-positive patients, all of whom had peripheral neuropathy and transient ischemic attacks, presenting cryoprecipitates formed by IgG3 and IgG1. Cryoprecipitate IgG subclass research was carried out by immunofixation electrophoresis by using antisera against IgG1, IgG2, IgG3, and IgG4.
RESULTS: Our six patients presented with an immunochemical pattern characterized by the mere presence of IgG1 and IgG3 subclasses with probable RF activity and one of these six patients exhibited monoclonal IgG3 in his cerebrospinal fluid.
CONCLUSIONS: We can hypothesize that the IgG passage through the blood-brain barrier could have contributed to the cause of TIAs, through a mechanism involving the precipitation of circulating immune complexes formed by the two subclasses in the intrathecal vessels
NLRP3 Inflammasome Involvement in Heart, Liver, and Lung Diseases—A Lesson from Cytokine Storm Syndrome
Inflammation and inflammasomes have been proposed as important regulators of the host-microorganism interaction, playing a key role in morbidity and mortality due to the coronavirus disease 2019 (COVID-19) in subjects with chronic conditions and compromised immune system. The inflammasome consists of a multiprotein complex that finely regulates the activation of caspase-1 and the production and secretion of potent pro-inflammatory cytokines such as IL-1 beta and IL-18. The pyrin containing NOD (nucleotide-binding oligomerization domain) like receptor (NLRP) is a family of intracellular receptors, sensing patterns associated to pathogens or danger signals and NLRP3 inflammasome is the most deeply analyzed for its involvement in the innate and adaptive immune system as well as its contribution to several autoinflammatory and autoimmune diseases. It is highly expressed in leukocytes and up-regulated in sentinel cells upon inflammatory stimuli. NLRP3 expression has also been reported in B and T lymphocytes, in epithelial cells of oral and genital mucosa, in specific parenchymal cells as cardiomyocytes, and keratinocytes, and chondrocytes. It is well known that a dysregulated activation of the inflammasome is involved in the pathogenesis of different disorders that share the common red line of inflammation in their pathogenetic fingerprint. Here, we review the potential roles of the NLRP3 inflammasome in cardiovascular events, liver damage, pulmonary diseases, and in that wide range of systemic inflammatory syndromes named as a cytokine storm
B-cell activating factor (BAFF), BAFF promoter and BAFF receptor allelic variants in hepatitis C virus related Cryoglobulinemic Vasculitis and Non-Hodgkin's Lymphoma
Cryoglobulinemic Vasculitis (CV) is an autoimmune/lymphoproliferative disorder associated with HCV infection that in 5%–10% of cases evolves into a B cell Non-Hodgkin's Lymphoma (NHL). B-cell activating factor (BAFF) is a key regulator in B-cell development and survival. Particular genetic variants are responsible for BAFF signaling impairment in autoimmune and neoplastic diseases. We evaluated BAFF and BAFF-receptor (BAFF-R) polymorphisms in order to determine if they predispose to HCV-related CV and NHL. The analysis was performed on 416 HCV-chronically infected patients: 136 HCV without signs/symptoms of lymphoproliferations/autoimmunity (HCV), 166 HCV with CV (HCV-CV) and 114 HCV with NHL (HCV-NHL). Rs9514828 SNP on BAFF promoter, rs61756766 on BAFF-R and rs12428930 on the BAFF gene were evaluated by Real-Time PCR. Concerning rs9514828, the frequency of C/T genotype was significantly higher in HCV-CV than in HCV. The difference in the distribution of the T/T mutant genotype in HCV-CV compared to HCV was significant as well as the distribution of C/T and T/T genotype in HCV-NHL versus HCV. T minor allele was more frequent in HCV-NHL and HCV-CV than in HCV. The distribution of C/T + T/T (for the dominant model of penetrance C/T + T/T vs. C/C) was significantly higher in HCV-CV and HCV-NHL than in HCV. Genotyping of rs61756766 on BAFF-R coding gene, revealed C/T heterozygosis at a frequency of 11% in HCV-NHL versus 3% in HCV. The T minor allele frequency was higher in HCV-NHL than in HCV. No differences emerged by genotyping rs12428930 SNP on BAFF coding gene. Our results reinforce the hypothesis that BAFF/BAFF-R genetic pattern has a role in the pathogenesis of HCV-related lymphoproliferations. BAFF/BAFF-R variants could identify a risk haplotype for HCV related CV and NHL and a BAFF/BAFF-R genetic profile assessment could potentially contribute to tailoring anti-BAFF therapy by identifying patients with BAFF alterations in which the treatment could be more beneficial
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