Effects of Influenza Vaccine on the Immune Responses to SARS-CoV-2 Vaccination.

A number of studies have suggested that influenza vaccination can provide protection against COVID-19, but the underlying mechanisms that could explain this association are still unclear. In this study, the effect of the 2021/2022 seasonal influenza vaccination on the immune response to the booster dose of anti-SARS-CoV-2 vaccination was evaluated in a cohort of healthy individuals. A total of 113 participants were enrolled, 74 of whom had no prior COVID-19 diagnosis or significant comorbidities were considered for the analysis. Participants received the anti-influenza tetravalent vaccine and the booster dose of the anti-SARS-CoV-2 vaccine or the anti-SARS-CoV-2 vaccine alone. Blood was collected before and 4 weeks after each vaccination and 12 weeks after SARS-CoV-2 vaccination and analyzed for anti-flu and anti-spike-specific antibody titers and for in vitro influenza and SARS-CoV-2 neutralization capacity. Results indicated an increased reactivity in subjects who received both influenza and SARS-CoV-2 vaccinations compared to those who received only the SARS-CoV-2 vaccine, with sustained anti-spike antibody titers up to 12 weeks post-vaccination. Immune response to the influenza vaccine was evaluated, and individuals were stratified as high or low responders. High responders showed increased antibody titers against the SARS-CoV-2 vaccine both after 4 and 12 weeks post-vaccination. Conversely, individuals classified as low responders were less responsive to the SARS-CoV-2 vaccine. These data indicate that both external stimuli, such as influenza vaccination, and the host's intrinsic ability to respond to stimuli play a role in the response to the vaccine.

Transglutaminase activity is involved in polyamine-induced programmed cell death.

Natural polyamines, i.e., putrescine, spermidine, and spermine, are ubiquitous molecules essential for cell proliferation and differentiation. In the present study, the effect of polyamines on primary cultures of bovine aortic endothelial cells (BAECs), rat aortic smooth muscle cells (RASMCs), and a human melanoma cell line was examined. While in the absence of fetal calf serum (FCS) polyamines had no effect on viability, in the presence of FCS spermidine and spermine, at concentrations close to physiologic levels, induced a dose-dependent cell death, whereas putrescine was ineffective. RASMCs were significantly more sensitive than other cells. FACS analysis, oligo-nucleosome ELISA, Hoechst nuclear staining, and Annexin V-FITC quantification showed that cell death was likely due to apoptosis. Cells exposed to spermidine showed a marked increase of intracellular transglutaminase (TGase) activity ( approximately 30-fold over control). Inhibitors of polyamine oxidation or inhibitors of TGase activity prevented polyamine-induced apoptosis. Moreover, tissue TGase overexpression significantly increased cell sensitivity to polyamine, suggesting that this effect is likely related to enhanced intracellular TGase activity. These data indicate that polyamines may modulate cell viability through a novel TGase-dependent process.

[Mycological study of 100 cases of ungual lesions of Rosario city (Republica Argentina)]. / Estudio micológico de 100 casos de lesiones ungueales de la ciudad de Rosario-República Argentina.

The aim of present work was to analyze several diagnostic methods of nail infections relating to various etiological agents with the different types of lesions and their probable predisposing causes. One hundred nail samples were studied including the following laboratory test: Direct microscopic exams with 40% KOH, direct exams in fluorescence microscope with calcoflúor white and mycological cultures. One or more of these methods gave positive results in 65% of the samples tested. The fungi isolated by culture were the following: Candida (predominantly non-albicans, which appeared in 70.8% of the cases), dermatophytes (25% of the cases) and opportunistic fungi (4.2%). Females showed a higher incidence of fungal infection. Candida were more frequent in finger nails, while dermatophytes occurred mainly in toe nails. The clinical characteristic of the lesions produced by Candida were: tricophytoid type (67%) and periungeal type (33%). On the other hand, dermatophytes and opportunistic fungi produced distal subungual type lesions. Since correlation between direct examination and cultures is not always found in mycological studies, based in our present results we suggest that, although they must always be carried out, both should be repeated with the addition of direct examination with calcoflúor in the cases in which the diagnosis is difficult.