Sulphate and Chloride-Dependent Potassium Transport in Human Erythrocytes are Affected by Crude Venom from Nematocysts of the Jellyfish Pelagia noctiluca

Background: It has been reported that biologically active compounds extracted from Cnidaria venom may induce damage by oxidative stress. Erythrocytes are constantly exposed to oxidative stresses, which can contribute to sulphydril (SH-) group oxidation and cell membrane deformability accompanied with activation of K-Cl co-transport and inhibition of anion transport. In this regard, Band 3 protein is responsible for mediating the electroneutral exchange of chloride (Cl-) for bicarbonate (HCO3-), particularly in erythrocytes, where it is the most abundant membrane protein. The aim of this study was to elucidate the effect of crude venom extracted from Pelagia noctiluca nematocysts on Band 3 -mediated anion transport in human erythrocytes. Methods: Erythrocytes were tested for SO42- uptake, K+ efflux, glutathione (GSH) levels and concentration of SH- groups. Results: The rate constant of SO42- uptake decreased progressively to 58% of control with increasing venom doses, and showed a 28% decrease after 2 mM NEM treatment. These effects can be explained by oxidative stress, which was reflected by decreased GSH levels in venom-treated erythrocytes. Hence, the decreased efficiency of anion transport may be due to changes in Band 3 structure caused by SH-group oxidation and reduced GSH concentration. In addition, an increased Cl--dependent K+ efflux was observed in venom-treated erythrocytes. Conclusion: Our results suggest that crude venom from Pelagia noctiluca alters cell membrane transport in human erythrocytes

Effects of acute and chronic low frequency electromagnetic field exposure on PC12 cells during neuronal differentiation.

The purpose of this study was to provide information about the in vitro neuritogenesis during cell exposure to extremely low frequency electromagnetic fields (ELF-EMFs) of different intensities and durations using pheochromocytoma-derived cell line (PC12 cells) as neuronal model.Proliferative rates and neuritogenesis were tested by colorimetric assay and morphological analysis, respectively; reactive oxygen species (ROS) levels and intracellular Ca(2+) variations monitored using single cell videomicroscopy.The long-lasting ELF-EMF exposure (0.1-1.0 mT) did not appear to significantly affect the biological response (proliferation and neuritogenesis). However, during the acute ELF-EMF exposure (30 min), in undifferentiated PC12 cells, there were increased ROS levels and decreased catalase activity, that, conversely, resulted increased after chronic exposure (7 days) at 1.0 mT. Acute exposure (0.1-1.0 mT) affected the spontaneous intracellular Ca(2+) variations in undifferentiated cells, in which basal intracellular Ca(2+) resulted increased after chronic exposure. In addition acute exposure affected cell response to a depolarizing agent, while basal membrane potential was not changed.Even if further studies remain necessary to identify the ROS/intracellular Ca(2+)cross-talking pathway activated by ELF-EMF exposure, we support the hypothesis that ROS and Ca(2+) could be the cellular "primum movens" of the ELF-EMF induced effects on biological systems

Calcitonin-Induced Effects on Amniotic Fluid-Derived Mesenchymal Stem Cells

Background/Aims: Mesenchymal stem cells from human amniotic fluid (huAFMSCs) can differentiate into multiple lineages and are not tumorigenic after transplantation, making them good candidates for therapeutic purposes. The aim was to determine the effects of calcitonin on these huAFMSCs during osteogenic differentiation, in terms of the physiological role of calcitonin in bone homeostasis. Methods: For huAFMSCs cultured under different conditions, we assayed: expression of the calcitonin receptor, using immunolabelling techniques; proliferation and osteogenesis, using colorimetric and enzymatic assays; intracellular Ca2+ and cAMP levels, using videomicroscopy and spectrophotometry. Results: The calcitonin receptor was expressed in proliferating and osteo-differentiated huAFMSCs. Calcitonin triggered intracellular Ca2+ increases and cAMP production. Its presence in cell medium also induced dose-dependent inhibitory effects on proliferation and increased osteogenic differentiation of huAFMSCs, as also indicated by enhancement of specific markers and alkaline phosphatase activity. Conclusions: These data show that huAFMSCs represent a potential osteogenic model to study in-vitro cell responses to calcitonin (and other members of the calcitonin family). This leads the way to the opening of new lines of research that will add new insight both in cell therapies and in the pharmacological use of these molecules

Calcitonin-Induced Effects on Amniotic Fluid-Derived Mesenchymal Stem Cells

Background/Aims: Mesenchymal stem cells from human amniotic fluid (huAFMSCs) can differentiate into multiple lineages and are not tumorigenic after transplantation, making them good candidates for therapeutic purposes. The aim was to determine the effects of calcitonin on these huAFMSCs during osteogenic differentiation, in terms of the physiological role of calcitonin in bone homeostasis. Methods: For huAFMSCs cultured under different conditions, we assayed: expression of the calcitonin receptor, using immunolabelling techniques; proliferation and osteogenesis, using colorimetric and enzymatic assays; intracellular Ca2+ and cAMP levels, using videomicroscopy and spectrophotometry. Results: The calcitonin receptor was expressed in proliferating and osteo-differentiated huAFMSCs. Calcitonin triggered intracellular Ca2+ increases and cAMP production. Its presence in cell medium also induced dose-dependent inhibitory effects on proliferation and increased osteogenic differentiation of huAFMSCs, as also indicated by enhancement of specific markers and alkaline phosphatase activity. Conclusions: These data show that huAFMSCs represent a potential osteogenic model to study in-vitro cell responses to calcitonin (and other members of the calcitonin family). This leads the way to the opening of new lines of research that will add new insight both in cell therapies and in the pharmacological use of these molecules

Does Adiponectin Act as an Antiangiogenic Factor in B-Cell Chronic Lymphocytic Leukemia?

Angiogenesis is involved in the pathogenesis of B-cell chronic lymphocytic leukemia (CLL), and high microvascular density has been found in CLL to be associated with a poor prognosis. In this study, we assessed serum levels of adiponectin in 69 patients with Binet stage A B-CLL, and these values were retrospectively correlated with bone marrow (BM) microvessel area and serum levels of vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), angiogenin, PECAM-1 (CD31), matrix metalloproteinase-9 (MMP-9), interleukin-8 (IL-8), syndecan-1, and the percentage of CD38+ or ZAP-70+ CLL cells. The positive correlation between serum levels of adiponectin and VEGF (P = .03) does not translate into an increase of the extent of BM angiogenesis (P = .404), FGF-2 (P = .348), angiogenin (P = .402), and CD31 (P = .248) serum concentrations. Accordingly, IL-8 (P = .175), syndecan-1 (P = .06), and MMP-9 (P = .144) circulating levels were not likely to reflect adiponectin concentration. Furthermore, patients with higher levels of adiponectin had a more favorable biological profile as defined by a lower number of both CD38− (r = −0.294; P = .02) and ZAP-70+ (r = −0.285; P = .04). Finally, we evaluated the presence of adiponectin in B-CLL cells at gene expression level. RMA intensity values for adiponectin gene transcript denote a homogeneous low expression in B-CLL cells, whereas VEGF transcript was highly expressed with a degree of interpatient variability. Overall, these data seem to indicate that adiponectin could be involved as an antiangiogenic factor in B-CLL

Activity of ethanolic extracts of Asparagopsis taxiformis against the major molecular types of Cryptococcus neoformans/C. gattii complex

Infections due to Cryptococcus neoformans/C. gattii complex have been reported to afflict, not only humans but also other mammals including seabirds and cetaceans, proving that the actual animal exposure to these fungi in nature could be underestimated. In this study, antifungal activity of ethanolic extracts obtained from red alga Asparagopsis taxiformis was evaluated against eight major genotypes of the C. neoformans/C. gattii complex, using both disk diffusion and microdilution broth methods. The algal extracts were active against all fungal strains tested and were not cytotoxic to human red blood cells. This study suggests that Asparagopsis taxiformis extracts possess attractive antifungal properties which should encourage the search for new drugs derived from marine algae

Humoral and T-cell mediated response after administration of mRNA vaccine BNT162b2 in frail populations

Patients with frailty are considered to be at greater risk to get severe infection from SARS-CoV-2. One of the most effective strategies is vaccination. In our study we evaluated both the humoral immune response elicited by the vaccination at different time points, and the T-cell response in terms of interferon (IFN)-γ production in frail patients and healthy donors. Fifty-seven patients (31 patients undergoing hemodialysis and 26 HIV positive subjects) and 39 healthcare workers were enrolled. All participants received two doses of the mRNA vaccine BNT162b2. Healthcare workers showed a significantly higher antibody titer than patients twenty-one days after the first dose (p < 0.001). From the same time point we observed for both groups a decay of the antibody levels with a steeper slope of decline in the patients group. Regarding T-cell response the only significant difference between non-reactive and reactive subjects was found in median antibody levels, higher in the responders group than in non-responders. The healthcare workers seem to better respond to the vaccination in terms of antibodies production; the lack of T-cell response in about 50% of the participants seems to suggest that in our study population both humoral and cell-mediated response decline over time remarking the importance of the booster doses, particularly for frail patients

Extended flow cytometry characterization of normal bone marrow progenitor cells by simultaneous detection of aldehyde dehydrogenase and early hematopoietic antigens: implication for erythroid differentiation studies

<p>Abstract</p> <p>Background</p> <p>Aldehyde dehydrogenase (ALDH) is a cytosolic enzyme highly expressed in hematopoietic precursors from cord blood and granulocyte-colony stimulating factor mobilized peripheral blood, as well as in bone marrow from patients with acute myeloblastic leukemia. As regards human normal bone marrow, detailed characterization of ALDH⁺cells has been addressed by one single study (Gentry <it>et al</it>, 2007). The goal of our work was to provide new information about the dissection of normal bone marrow progenitor cells based upon the simultaneous detection by flow cytometry of ALDH and early hematopoietic antigens, with particular attention to the expression of ALDH on erythroid precursors. To this aim, we used three kinds of approach: i) multidimensional analytical flow cytometry, detecting ALDH and early hematopoietic antigens in normal bone marrow; ii) fluorescence activated cell sorting of distinct subpopulations of progenitor cells, followed by <it>in vitro </it>induction of erythroid differentiation; iii) detection of ALDH⁺cellular subsets in bone marrow from pure red cell aplasia patients.</p> <p>Results</p> <p>In normal bone marrow, we identified three populations of cells, namely ALDH⁺CD34⁺, ALDH^-CD34⁺and ALDH⁺CD34^-(median percentages were 0.52, 0.53 and 0.57, respectively). As compared to ALDH^-CD34⁺cells, ALDH⁺CD34⁺cells expressed the phenotypic profile of primitive hematopoietic progenitor cells, with brighter expression of CD117 and CD133, accompanied by lower display of CD38 and CD45RA. Of interest, ALDH⁺CD34^-population disclosed a straightforward erythroid commitment, on the basis of three orders of evidences. First of all, ALDH⁺CD34^-cells showed a CD71^bright, CD105⁺, CD45^-phenotype. Secondly, induction of differentiation experiments evidenced a clear-cut expression of glycophorin A (CD235a). Finally, ALDH⁺CD34^-precursors were not detectable in patients with pure red cell aplasia (PRCA).</p> <p>Conclusion</p> <p>Our study, comparing surface antigen expression of ALDH⁺/CD34⁺, ALDH^-/CD34⁺and ALDH⁺/CD34^-progenitor cell subsets in human bone marrow, clearly indicated that ALDH⁺CD34^-cells are mainly committed towards erythropoiesis. To the best of our knowledge this finding is new and could be useful for basic studies about normal erythropoietic differentiation as well as for enabling the employment of ALDH as a red cell marker in polychromatic flow cytometry characterization of bone marrow from patients with aplastic anemia and myelodysplasia.</p

Molecular and phenotypic typing of enteropathogenic Escherichia coli isolated in childhood acute diarrhea in Abuja, Nigeria

Introduction: Enteropathogenic Escherichia coli (EPEC) causes infectious diarrhea among children in developing countries. However, in Nigeria, due to limited laboratory resources, the genetic diversity of its virulence factors, which include intimin subtypes, remains undefined. Methodology: EPEC isolates from diarrheic children 60 months of age and younger in Abuja, Nigeria, were analyzed. Polymerase chain reaction (PCR) for EPEC virulence gene, Hep-2 cell adherence, and serotyping were performed. EPEC strains were further subtyped by PCR for the identification of intimin subtype genes α (alpha), β (beta), γ1 (gamma-1), and έ (epsilon). Antibiotic resistance and extended-spectrum beta-lactamase (ESBL) production was determined by Clinical and Laboratory Standards Institute guidelines. Results: Overall, 18 (4.5%) out of 400 children with acute diarrhea had EPEC infection. Typical EPEC (tEPEC) strains were detected in 14 (3.5%), whereas 4 (1.1%) were atypical EPEC (aEPEC). A total of 15 (83.3%) of the EPEC isolated belonged to β intimin subtype gene, while the remaining 3 EPEC isolates possessed the intimin έ subtype. No α and γ intimin subtypes were detected. Traditional EPEC serotypes O114:H14 were detected only in tEPEC strains. Marked resistance to β-lactam agents were observed but no ESBL-producing tEPEC or aEPEC was detected. Conclusions: This is the first report of intimin subtype genes in Abuja, Nigeria. EPEC isolates of diverse serotypes resistant to β-lactam antimicrobial agents were observed. These data will be useful in facilitating the characterization of intimin variants of EPEC and some Shiga toxin-producing E. coli (STEC) in humans and other animal species