Previous clinical and epidemiological studies have shown that over time antibody titers decrease, and they do not provide long-term mucosa protection against SARS-CoV-2 infection. Additionally, the ...increase in breakthrough infections that occur more frequently in the vaccinated than in the study participants with previous SARS-CoV-2 infection has recently become a priority public health concern. We measured the amount of interferon-gamma (Quan-T-Cell ELISA) and the level of antibodies (Anti-SARS-CoV-2 QuantiVac ELISA IgG) in the blood of the same patients simultaneously to compare cellular and humoral immunity. A total of 200 study participants (before Omicron variant appearance) were divided into four groups whose levels of cellular and humoral immunity we compared: study participants previously infected with SARS-CoV-2 (group 1); study participants vaccinated with EMA-approved vaccines (group 2); study participants previously infected with SARS-CoV-2, and vaccination history (group 3); and study participants without a history of SARS-CoV-2 infection or vaccination (group 4). Our results showed that study participants who received one of the EMA-approved vaccines and who recovered from COVID-19 (group 3) had significantly higher levels of cellular immunity and antibody titers in comparison with groups 1 and 2. Additionally, we have noticed that the study participants previously infected with SARS-CoV-2 and the study participants vaccinated with EMA-approved vaccines had a long-lasting cellular immunity. Furthermore, antibody levels showed a negative correlation with time since the last contact with a viral antigen, while cellular immunity within 20 months showed as long-term protection. Moreover, out of 200 study participants, only 1 study participant who recovered from COVID-19 (0.5%) was re-infected, while a total of 6 study participants (3%) were infected with SARS-CoV-2 after receiving the vaccine. This study suggests that cellular immunity-unlike humoral immunity, thanks to memory T cells-represents long-term protection in individuals recovered from SARS-CoV-2 and after vaccination.
Recent studies have highlighted the underestimated importance of the cellular immune response after the emergence of variants of concern (VOCs) of SARS-CoV-2, and the significantly reduced ...neutralizing power of antibody titers in individuals with previous SARS-CoV-2 infection or vaccination. Our study included 303 participants who were tested at St. Catherine Specialty Hospital using the Quan-T-Cell SARS-CoV-2 in combination with the Quan-T-Cell ELISA (Euroimmun Medizinische Labordiagnostika, Lübeck, Germany) for the analysis of IFN-γ concentration, and with Anti-SARS-CoV-2 QuantiVac ELISA IgG (Euroimmun Medizinische Labordiagnostika, Lübeck, Germany) for the detection of human antibodies of the immunoglobulin class IgG against the S1 domain of the SARS-CoV-2 spike protein. The statistical analysis showed a significant difference in the concentration of IFN-γ between reinfected participants and those without infection (
= 0.012). Participants who were not infected or reinfected with SARS-CoV-2 after vaccination and/or previous SARS-CoV-2 infection had a significantly higher level of cellular immunity. Furthermore, in individuals without additional vaccination, those who experienced infection/reinfection had significantly lower levels of IFN-γ compared to uninfected participants (
= 0.016). Our findings suggest a long-lasting effect of cellular immunity, measured by IFN-γ concentrations, which plays a key role in preventing infections and reinfections after the emergence of SARS-CoV-2 variants of concern.
Despite the identification of a wide range of inherited and acquired risk factors for arterial ischemic stroke (AIS) in children, genetic risk factors are incompletely characterized and may vary ...among different populations. We investigated the role of individual and combined inherited prothrombotic and intermediate-risk factors in 73 children with perinatal (n = 35) and childhood AIS (n = 38) and 100 age- and sex-matched controls. Ten polymorphisms in 8 candidate genes encoding coagulation and fibrinolytic proteins (factor V FV Leiden, FV HR2, factor II FII G20210A, β-fibrinogen β-FBG-455G>A, factor XIII FXIII-A p.Val34Leu, plasminogen activator inhibitor 1 4G/5G), homocysteine metabolism (methylenetetrahydrofolate reductase MTHFR C677T, MTHFR A1298C), and intermediate-risk factors (angiotensin-converting enzyme I/D, apoE ∊2-4) were detected using a multilocus genotyping assay. Allele-specific polymerase chain reaction was used for the determination of human platelet alloantigens (HPA-1, HPA-2, HPA-3, and HPA-5). Factor V Leiden was associated with an increased risk of AIS (odds ratio OR: 4.72, 95% confidence interval CI: 1.22-18.27) and perinatal AIS (OR: 8.29, 95% CI: 1.95-35.24). Human platelet antigen-3b allele carriers had a 2-fold lower risk of AIS (OR: 0.51, 95% CI: 0.26-0.98) and perinatal AIS (OR: 0.40, 95% CI: 0.18-0.92). A 2.21-fold increased risk of childhood AIS (95% CI: 1.03-4.73) was identified in FXIII-A Leu34 allele carriers. Combined FV Leiden/FV HR2, FV Leiden/MTHFR A1298C, FV Leiden/MTHFR C677T/MTHFR A1298C, and FV Leiden/FV HR2/MTHFR A1298C heterozygosity was identified in children with AIS but not in controls, which revealed a statistically significant difference. This case–control study shows that besides already documented association between FV Leiden and AIS, other previously unreported polymorphisms (FXIII-A p.Val34Leu, HPA-3) and several genotype combinations that always include heterozygous FV Leiden can be related to AIS in Croatian population.
This study was undertaken to evaluate the impact of progestins as part of low-estrogen (ethinyl estradiol EE2 ≤35 μg) combined oral contraceptives (COCs) on hemostatic variables. One hundred ...ninety-five healthy women took oral contraceptives with following formulations: 35 EE2/norgestimate (NGM), 35 EE2/cyproterone acetate, 35 EE2/norethisterone, 30 EE2/levonorgestrel, 30 EE2/drospirenone (DRSP), 20 EE2/gestodene, and 20 EE2/DRSP, for 6 months. Hemostatic assays (prothrombin time, activated partial thromboplastin time, fibrinogen, resistance to activated protein C ratio, protein C, protein S, factor VIII FVIII, antithrombin, plasminogen, α2-antiplasmin, inhibitor of plasminogen activator type 1 PAI-1 and d-dimers) were performed in 3 time points: at baseline, after 3, and 6 cycles. For each formulation, results were compared according to baseline values, intergroup analysis, and the amount of estrogen or progestin component. Most of the variables were changed except FVIII. Significant difference between oral contraceptives was found in antithrombin, protein C, protein S activities, and PAI-1 values, but changes were mostly within reference range.
Flavonoids are natural polyphenolic compounds present in a wide spectrum of plants that have a beneficial effect on human health. In the context of cardiovascular diseases related to plaque and ...thrombus formation, flavonoids exhibit an anti-aggregatory effect. Previously, it has been reported that all tested flavonoids exhibit an antiaggregatory effect on platelet aggregation when measured by impedance aggregometry on whole blood, in the test of aggregation induced by adenosine diphosphate (ADP). As not all flavonoids have the same targets within signaling pathways, an assumption of a common non-specific mechanism related to lipophilicity is to be considered. To test this hypothesis, reverse-phase thin layer chromatography was used to assess the lipophilicity of flavonoids; impedance aggregometry was used for testing of platelet aggregation and flow cytometry to monitor the influence of flavonoids on platelet activation. Lipophilicity analysis showed a highly negative correlation of log
and
for groups of flavones and flavanones. As determined by flow cytometry, the exposition of receptors necessary for the promotion of platelet activation and primary clot formation was diminished,
., lowered expression of the activated form of integrin αIIbβ3 was observed in the presence of flavanone. Platelet membrane stabilization by flavonoids as a mechanism of antiaggregatory effect has been supported by impedance aggregometry experiments when specific inhibitors of platelet aggregation signaling pathways (U73122, indomethacin, verapamil) were used in the presence of a weak (ADP) and a strong (TRAP-6) agonist of aggregation. While individual flavonoids can have specific targets within aggregation signaling pathways, all flavonoids share a common non-specific mechanism of platelet aggregation inhibition related to their lipophilicity and membrane stabilization that, to some extent, contributes to their antiaggregatory effect.
In a relatively short period of time new coronavirus disease (COVID-19) has become a global threat, both to human health and to the functioning of human society in general. This pandemic is certainly ...neither the first nor is it likely to be the last disease episode in human history. At the moment, it is still too early to make a reliable assessment of its total effect on human civilization, but it can already be stated that this disease, and its causative agent SARS-CoV-2 virus, have caused a strong scientific response all around the World. For the first time in this magnitude, it has united the resources of large scientific institutions and companies with the aim of finding solutions for fast and accurate virus detection procedures, effective and safe vaccine, reliable medical treatments, etc. It is astonishing that only a month has passed from the first officially detected case to the complete sequencing of the SARS-CoV-2 virus genome and the creation of the first detection systems based on RT-PCR method. After that, numerous scientific teams and companies worked together, or independently, to improve the detection methods. Their work included further optimization of PCR and other genetic approaches, as well as the development of detection methods based on the analysis of specific antibodies and viral antigens. The aim of this paper is to review the results that were achieved in this area so far, analyze the strategies currently used in the world and the region, and to predict future steps in the process of optimizing and improving methods for SARS CoV-2 detection in individual patients and the global human population.
Aim:
To explore the clinical presentation and epidemiological history of the subjects who underwent SARS-CoV-2 antigen testing.
Methods:
We included 1,000 consecutive subjects who presented ...themselves at the diagnostic clinic in Croatia and analyzed their symptoms and epidemiological history. All subjects were classified into three groups, according to their reason of arrival; symptomatic, contacts of confirmed patients, and those who were tested due to administrative reasons.
Results:
On average, there were 24% of positive antigen results; the positivity rate was 51% among symptomatic, 16% in contacts, and 5% of administrative patients. The commonest symptoms of the disease included febrility and anosmia. We developed a clinical score to predict SARS-CoV-2 positivity, which had an area under the curve of 79.3 95% confidence intervals (CI) 75.8–82.8. Contact with the isolated person odds ratio 0.54 (95% CI 0.31–0.94) and international travel had a protective effect 0.20 (0.09–0.43), suggesting that risk perception and mandatory pretravel measures had a key role in the determination of the infection risk.
Conclusions:
A combination of clinical symptoms can have reasonable predictive power for an antigen-positive test result. Risk perception seems to have a role in the epidemic spread, probably
via
stricter adherence to personal preventative measures.
To analyze the frequency of atypical fluorescence
hybridization signal patterns and estimate the complete cytogenetic response (CCyR) and major molecular response (MMR) during 12 months of tyrosine ...kinase inhibitor therapy in patients with newly diagnosed chronic myeloid leukemia.
The study included bone marrow and peripheral blood samples from 122 patients with newly diagnosed chronic myeloid leukemia. Detection of the
-
fusion gene (
) was performed using fluorescence
hybridization with a dual-color dual-fusion translocation probe, and MMR analysis was performed using the real-time quantitative polymerase chain reaction method.
Variant translocation was determined in 10 samples and a deletion on the derivative chromosome 9 (del/der(9)) was found in 20 samples. The rates of CCyR and MMR were similar between patients with reciprocal translocation, variant translocation, deletion of derivative
, or
fusion gene. The Kaplan-Meier test did not show any significant differences in the rates of CCyR and MMR among those groups of patients.
The frequencies of variant translocation and del/der(9) in the present study agree with the results of other studies performed worldwide. No differences were observed in the rates of CCyR and MMR between patients with atypical patterns and reciprocal translocation.
The present study aimed to assess the association of 16 polymorphisms in genes encoding prothrombotic and cardiovascular risk factors with COVID‐19 disease severity: FV G1691A, FV H1299R, FII ...G20210A, MTHFR C677T, MTHFR A1298, factor XIII V34L, PAI‐1 4G/5G, EPCR haplotypes (A1/A2/A3), eNOS −786 T > C, eNOS G894T, LTA C804A, ACE I/D, ITGB3 PIA1/A2, ITGA2B Baka/b, β‐Fbg −455 G > A and ApoB R3500Q. The study included 30 patients with severe COVID‐19 and 49 non‐severe COVID‐19 patients. All studied polymorphisms except ITGA2B Baka/b were determined using multilocus genotyping assays CVD StripAssays (ViennaLab Diagnostics), while ITGA2B was genotyped using a real‐time PCR method based on TaqMan technology. A higher frequency of carriers of at least one ITGB3 PIA2 allele was found in severe COVID‐19 patients (p = 0.009). The distribution of genotypes was significantly different for ß‐Fbg −455 G > A (p = 0.042), with only three homozygous AA genotypes found among severe COVID‐19 patients. The association with an increased risk for severe COVID‐19 was found for ITGB3, with carriers of at least one ITGB3 PIA2 allele having a 3.5‐fold greater risk of severe COVID‐19 (p = 0.011). Genotype distribution differences were obtained for the combinations of FV H1299R and FXIII V34L (p = 0.026), ITGB3 PIA1/A2 and ITGA2B Baka/b (p = 0.024), and ACE I/D and PAI‐1 4G/5G (p = 0.046). ITGB3 polymorphism emerged as an independent risk factor for severe COVID‐19 and homozygosity for ß‐Fbg −455 G > A mutation could contribute to disease severity. The combined effect of polymorphisms in genes encoding prothrombotic and cardiovascular risk factors could further contribute to disease severity.
Mechanical loading is an essential environmental factor in skeletal homeostasis, but the response of osteoblast-associated genes to mechanical osteogenic signal is largely unknown. This study uses ...our recently characterized in vivo osteoinductive model to analyze the sequence of stimulation and the time course of expression of osteoblast-associated genes in mechanically loaded mouse periodontium. Temporal pattern of regulation of osteocalcin (OC), alkaline phosphatase (ALP), and type I collagen (collagen I) was determined during mechanically-induced osteoblast differentiation in vivo, using a mouse tooth movement model earlier shown to induce bone formation and cell-specific regulation of genes in osteoblasts. The expression of target genes was determined after 1, 2, 3, 4, and 6 days of orthodontic movement of the mouse first molar. mRNA levels were measured in the layer of osteoblasts adjacent to the alveolar bone surface, using in situ hybridization and a relative quantitative video image analysis of cell-specific hybridization intensity, with non-osseous mesenchymal periodontal cells as an internal standard. After 24 hours of loading, the level of OC in osteoblasts slightly decreased, followed by a remarkable 4.6-fold cell-specific stimulation between 1 and 2 days of treatment. The high level expression of OC was maintained throughout the treatment with a peak 7-fold stimulation at day 4. The expression of collagen I gene was not significantly affected after 1 day, but it was stimulated 3-fold at day 2, and maintained at a similar level through day 6. The ALP gene, which we previously found to be mechanically stimulated during the first 24 hours, remained enhanced from 1.8- to 2.2-fold throughout the 6 days of treatment. Thus, in an intact alveolar bone compartment, mechanical loading resulted in a defined temporal sequence of induction of osteoblast-associated genes. Stimulation of OC 48 h after the onset of loading (and 24 h prior to deposition of osteoid) temporally coincided with that of collagen I, and was preceded for 24 h by an enhancement of ALP. Identification of OC as a mechanically responsive gene induced in functionally active osteoblasts in this study is consistent with its potential role in limiting the rate of mechanically-induced bone modeling. Furthermore, these results show that temporal progression of mechanically-induced osteoblast phenotype in this in vivo model occurs very rapidly. This suggests that physiologically relevant mechanical osteoinductive signal in vivo is targeting a population of committed osteoblast precursor cells that are capable of rapidly responding by entering a differentiation pathway and initiating an anabolic skeletal adaptation process.
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