ABSTRACT
Összefoglaló. Bevezetés: A SARS-CoV-2-fertozések és az anti-SARS-CoV-2-vakcinák által kiváltott immunvédelem tartóssága, nagysága és különbségeinek háttere nem teljesen tisztázott, az oltási protokollok optimális idozítése vitatott. Célkituzés: A humorális immunválaszok nagyságát, idobeli változását, a reinfekciók gyakoriságát, demográfiai és klinikai paraméterekkel való összefüggését vizsgáltuk magyarországi egészségügyi dolgozóknál. Módszerek: Megyei egyetemi oktató kórházunkban prospektív, longitudinális vizsgálatot végeztünk egészségügyi dolgozók két csoportjában. 1. kohorsz: SARS-CoV-2-fertozésen átesett, oltatlan 42 dolgozó (no: 100%) antinukleokapszid-IgG-szintjét mértük 8 hónapon keresztül (2020. június-2021. február). Az immunválasznak a változását és az életkorral, a krónikus betegségekkel, a vércsoporttal és a tünetek súlyosságával való összefüggését vizsgáltuk. 2. kohorsz: két dózis mRNS-vakcinával (Pfizer-BioNTech) végzett immunizálást követoen, fertozésnaiv 49 dolgozó (no: 73%) anti-spike-RBD-protein-IgG-szintjét monitoroztuk 8 hónapig (2020. december-2021. augusztus). Medián analízis, lineáris regresszió, ANCOVA, Kruskal-Wallis- és Skillings-Mack-teszt-elemzéseket végeztünk. Eredmények: 1. kohorsz: az IgG-szintek átlagosan a betegség 4-es súlyossági kategóriájában voltak a legmagasabbak, a negatív tartományba csökkenés medián ideje 6 hónap volt. 2. kohorsz: a második vakcina hatására az IgG-szint a 25-szörösére nott, majd 210 nap után a csúcsszint 6%-ra csökkent. Az ellenanyagtiter negatív összefüggést mutatott az idosebb életkorral és a férfinemmel. Tünetmentes (újra)fertozodést valószínusítettünk a fertozésen átesettek 17%-ánál és az immunizált kohorsz 14%-ánál. Az érintettek magas kockázatú osztályokon dolgoztak. Következtetés: 6 hónap után mind a fertozésen átesettek, mind az immunizáltak jelentosen csökkeno IgG-védelmet mutattak. A (re)infekciók átlagosan 15%-ban, tünetmentesen zajlottak. Az eredmények megerosítik az oltás hatékonyságát a betegség megelozésében, a harmadik emlékezteto vakcina fontosságát 6 hónap után és az anti-SARS-CoV-2-IgG-monitorozás potenciális értékét. Orv Hetil. 2022; 163(12): 455-462. INTRODUCTION: The length, level and variation of immune responses to infection with SARS-CoV-2 or following anti-SARS-CoV-2 vaccination remains unclear, optimal (re)vaccination protocols remain debated. OBJECTIVE: We investigated the magnitude of humoral immune responses, their over-time changes, the frequency of (re)infections and the association with demographic and clinical parameters in Hungarian healthcare workers. METHODS: We conducted a prospective, longitudinal study in two groups of healthcare workers of a public, county-level teaching hospital. Cohort 1: The anti-nucleocapsid IgG levels of 42 workers (female: 100%) were followed up over 8 months after SARS-CoV-2 infection (June 2020-February 2021). The change in humoral immune response and its associations with age, existing chronic conditions, blood type and severity of symptoms were investigated. Cohort 2: The anti-spike-RBD protein IgG levels of 49 workers (female: 73%) with no prior COVID-19 infection were monitored over 8 months (December 2020-August 2021) following immunisation with two doses of mRNA vaccine (Pfizer-BioNTech). Analyses included median analysis, linear regression, ANCOVA, Kruskal-Wallis and Skilling-Mack tests. RESULTS: Cohort 1: IgG levels were on average the highest among those in illness severity category 4, the median time of IgG level reduction below the positive test cut-off was 6 months. Cohort 2: The IgG levels increased 25-fold between the first and second immunisations, but decreased to 6% of the peak level after 210 days. They showed an overall negative association with older age and male sex. The suspected levels of (re)infections were 17% and 14% within the infected and the immunised cohorts, respectively, all symptomless. Those affected all worked on high-risk wards. CONCLUSION: Both the infected and the immunised cohorts showed significantly declining IgG protections beyond 6 months. The average observed rate of (re)infections was 15%, all asymptomatic. Our findings are confirmative of the effectiveness of vaccination to prevent illness, the importance of booster vaccination due to declining humoral immune protection beyond 6 months, and the potential value of anti-SARS-CoV-2 IgG monitoring. Orv Hetil. 2022; 163(12): 455-462.
Subject(s)
COVID-19 , Female , Health Personnel , Humans , Hungary , Immunity , Immunoglobulin G , Longitudinal Studies , Male , Prospective Studies , SARS-CoV-2 , Vaccination , Vaccines, Synthetic , mRNA VaccinesABSTRACT
A fibrous scaffold was prepared from poly(3-hudroxybutirate) (PHB) by wet spinning from chloroform solution. The fibers were precipitated into excess ethanol and they had a regular, cylindrical shape. The diameter of the fibers was regulated by the rate of spinning. A model drug, quercetin, was dissolved in the fiber in various amounts. The rate of drug release could be controlled by the adjustment of fiber diameter. A novel approach is proposed in the paper for the quantitative analysis of release kinetics. The model is based on Fick's laws, and does not use any simplification or introduce empirical constants. The prediction of the new model agreed well with experimental results and proved that the approach offers an exact description of experimental data. Although the method allows the estimation of the diffusion coefficient as well, the value obtained is biased because of the large surface to volume ratio of the scaffold. The comparison of the proposed model to empirical or semi-empirical approaches published earlier showed that the latter are less accurate and predict false results at various stages of the release study. The proposed method of fiber preparation and the model makes possible the prediction and control of the release rate of a drug from fibrous scaffolds.
Subject(s)
Hydroxybutyrates , Polyesters , 3-Hydroxybutyric Acid , KineticsABSTRACT
An improved method is described for culturing primary rat brain capillary endothelial cells (RBCEC) on glass, covered by Matrigel. The procedure using Matrigel yields spindle-shaped endothelial cells exhibiting close cell-cell appositions seen on electron microscopic sections. These cells permanently express tight junction proteins ZO-1, claudin-5 and the adherent junction protein beta-catenin, as revealed by immunofluorescence. Furthermore, glass coverslips covered with Matrigel provide a stable and low-background fluorescent base for microfluorimetric calcium measurements. By this method, hereby we show that the PAR-4 agonist peptide induces transient [Ca2+]i changes with different kinetics compared to that due to activation of the PAR-1 receptor. This indicates that RBCE cells grown on Matrigel express PAR-4 receptors.
Subject(s)
Cerebral Arteries/metabolism , Collagen/pharmacology , Endothelial Cells/metabolism , Laminin/pharmacology , Proteoglycans/pharmacology , Receptors, Thrombin/metabolism , Animals , Biocompatible Materials/pharmacology , Calcium/analysis , Calcium/metabolism , Calcium Signaling/drug effects , Calcium Signaling/physiology , Cell Culture Techniques , Cell Differentiation/drug effects , Cell Differentiation/physiology , Cell Separation , Cells, Cultured , Cerebral Arteries/ultrastructure , Claudin-5 , Drug Combinations , Endothelial Cells/ultrastructure , Immunohistochemistry , Intercellular Junctions/metabolism , Intercellular Junctions/ultrastructure , Membrane Proteins/metabolism , Microscopy, Electron, Transmission , Peptides/pharmacology , Phosphoproteins/metabolism , Protein Synthesis Inhibitors/pharmacology , Puromycin , Rats , Receptors, Thrombin/agonists , Time Factors , Zonula Occludens-1 Protein , beta Catenin/metabolismABSTRACT
Protease-activated receptors (PARs) mediate cell activation after proteolytic cleavage of their extracellular amino terminus. We have reported earlier that primary cultures of rat brain capillary endothelial (RBCE) cells express at least two receptors for thrombin: PAR-1 and PAR-3. In the present study we show that PAR-2 activation by trypsin or by the PAR-2 agonist peptide (SLIGRL) evokes [Ca(2+) ](i) signal in RBCE cells. Taking advantage of RBCE cells expressing PAR-1 and PAR-2, we show that trypsin activates both receptors. The relative agonist activity of trypsin and thrombin on PARs of RBCE cells compared with that of SLIGRL were 112% and 48%, respectively, whereas the potency of trypsin was 10(5) -fold higher than that of SLIGRL. Because under pathological conditions other proteases such as plasmin or leukocyte elastase may reach the cells of the blood-brain barrier, we investigated the effect of these proteases on RBCE cells. Elastase evoked a small increase in [Ca(2+) ](i) but preincubation of cells with elastase dose-dependently reduced the trypsin-induced [Ca(2+) ](i) signal. Plasmin had a 30% inhibitory effect on the trypsin-induced response, and reduced the SLIGRL signal by 20%. It is concluded that PAR-2 is functional in brain capillary endothelium, and that the main fibrinolytic proteases, plasmin and elastase, may regulate PAR-2 signalling under pathological conditions.
