Delay of polarization event increases the number of Cdx2-positive blastomeres in mouse embryo

AbstractDuring preimplantation mouse embryo development expression of Cdx2 is induced in outer cells, which are the trophectoderm (TE) precursors. The mechanism of Cdx2 upregulation in these cells remains unclear. However, it has been suggested that the cell position and polarization may play a crucial role in this process. In order to elucidate the role of these two parameters in the formation of TE we analyzed the expression pattern of Cdx2 in the embryos in which either the position of cells and the time of polarization or only the position of cells was experimentally disrupted. Such embryos developed from the blastomeres that were isolated from 8-cell embryos either before or after the compaction, i.e. before or after the cell polarization took place. We found that in the embryos developed from polar blastomeres originated from the 8-cell compacted embryo, the experimentally imposed outer position was not sufficient to induce the Cdx2 in these blastomeres which in the intact embryo would form the inner cells. However, when the polarization at the 8-cell stage was disrupted, the embryos developed from such an unpolarized blastomeres showed the increased number of cells expressing Cdx2. We found that in such experimentally obtained embryos the polarization was delayed until the 16-cell stage. These results suggest that the main factor responsible for upregulation of Cdx2 expression in outer blastomeres, i.e. TE precursors, is their polarity

A comparative analysis of influenza virus infections in the 2013/2014 and 2014/2015 epidemic seasons in the reporting system, for different age groups in Poland

Background . Influenza remains the cause of many seasonal infections, leading even to death, in all age groups, for all patient health states, under all health policies, and in all latitudes. Influenza infection needs to be thought of not only in terms of the loss of health and the exacerbation of existing diseases, but also in terms of the quantifiable financial consequences borne by the state. Objectives . The aim of the study was to compare two influenza seasons: 2013/14 and 2014/15 through an analysis of the number of samples in different age groups, collected on a weekly basis for 52 weeks, and to interpret the results in terms of type and subtype. Material and methods. Virological and epidemiological data were obtained from the SENTIN EL and NON -SENTIN EL programs. Virological tests were performed using RT-PCR and multiplex RT-PCR biological molecular methods. Results . The maximum number of confirmed cases of influenza coincides in time with the maximum number declared cases and suspected cases of influenza and influenza-like viruses. The peak occurrence of influenza-like virus detection was earlier than the peak detection of influenza virus. In the 2014/15 influenza season, significant differences in the percentage of positive samples were observed between the 5–9 and 10–14 age groups. During the 2013/14 influenza season, there was no statistically significant difference in the percentage of positive samples between the 15–25, 26–44, and 45–64 year old age groups. Conclusions . A new division of age groups allows more accurate assessment of the incidence of influenza and influenza-like illnesses and can assist health workers in preventing multiorgan influenza-related complications and deaths

Relationship between Humoral Response in COVID-19 and Seasonal Influenza Vaccination

There is evidence that vaccination against seasonal influenza can improve innate immune responses to COVID-19 and decrease disease severity. However, less is known about whether it could also impact the humoral immunity in SARS-CoV-2 infected patients. The present study aimed to compare the SARS-CoV-2 specific humoral responses (IgG antibodies against nucleocapsid; anti-N, receptor binding domain; anti-RBD, subunit S2; anti-S2, and envelope protein; anti-E) between non-hospitalized, COVID-19 unvaccinated, and mild COVID-19 convalescent patients who were and were not vaccinated against influenza during the 2019/2020 epidemic season (n = 489 and n = 292, respectively). The influenza-vaccinated group had significantly higher frequency and titers of anti-N antibodies (75 vs. 66%; mean 559 vs. 520 U/mL) and anti-RBD antibodies (85 vs. 76%; mean 580 vs. 540 U/mL). The prevalence and concentrations of anti-S2 and anti-E antibodies did not differ between groups (40–43%; mean 370–375 U/mL and 1.4–1.7%; mean 261–294 U/mL) and were significantly lower compared to those of anti-RBD and anti-N. In both groups, age, comorbidities, and gender did not affect the prevalence and concentrations of studied antibodies. The results indicate that influenza vaccination can improve serum antibody levels produced in response to SARS-CoV-2 infection

Epileptogenesis following Kainic Acid-Induced Status Epilepticus in Cyclin D2 Knock-Out Mice with Diminished Adult Neurogenesis.

The goal of this study was to determine whether a substantial decrease in adult neurogenesis influences epileptogenesis evoked by the intra-amygdala injection of kainic acid (KA). Cyclin D2 knockout (cD2 KO) mice, which lack adult neurogenesis almost entirely, were used as a model. First, we examined whether status epilepticus (SE) evoked by an intra-amygdala injection of KA induces cell proliferation in cD2 KO mice. On the day after SE, we injected BrdU into mice for 5 days and evaluated the number of DCX- and DCX/BrdU-immunopositive cells 3 days later. In cD2 KO control animals, only a small number of DCX+ cells was observed. The number of DCX+ and DCX/BrdU+ cells/mm of subgranular layer in cD2 KO mice increased significantly following SE (p<0.05). However, the number of newly born cells was very low and was significantly lower than in KA-treated wild type (wt) mice. To evaluate the impact of diminished neurogenesis on epileptogenesis and early epilepsy, we performed video-EEG monitoring of wt and cD2 KO mice for 16 days following SE. The number of animals with seizures did not differ between wt (11 out of 15) and cD2 KO (9 out of 12) mice. The median latency to the first spontaneous seizure was 4 days (range 2-10 days) in wt mice and 8 days (range 2-16 days) in cD2 KO mice and did not differ significantly between groups. Similarly, no differences were observed in median seizure frequency (wt: 1.23, range 0.1-3.4; cD2 KO: 0.57, range 0.1-2.0 seizures/day) or median seizure duration (wt: 51 s, range 23-103; cD2 KO: 51 s, range 23-103). Our results indicate that SE-induced epileptogenesis is not disrupted in mice with markedly reduced adult neurogenesis. However, we cannot exclude the contribution of reduced neurogenesis to the chronic epileptic state

Epileptogenesis in wt and cD2 KO mice following intra-amygdala kainic acid injection.

<p><b>(A)</b> Neurodegeneration in CA3 of the hippocampus at 8 d after KA-induced status epilepticus. <b>(B)</b> Duration of status epilepticus, <b>(C)</b> percent of animals developing epilepsy, <b>(D)</b> latency to the first spontaneous seizure, <b>(E)</b> seizure frequency in epileptic mice and <b>(F)</b> average spontaneous seizure duration in wt and cD2 KO mice following intra-amygdala kainic acid injection. <b>(G)</b> An example of an electrographic seizure detected in a cD2 KO animal. Arrows in A indicate the area of neuronal loss. Each circle in B and D-F represents one animal, and horizontal bars indicate mean (B) or median (D-F) values; cx—cortex, KO—knock-out, SE—status epilepticus, wt—wild type.</p