Assisted oocyte activation significantly improves zygote formation, cleavage, and implantation rates in patients with a history of fertilization failures.

Background: Fertilization check performed at the 18th hour following classic in vitro fertilization procedure (IVF) or intracytoplasmic sperm injection (ICSI) is a critical stage in assisted reproduction. The success of the treatment is significantly reliant on the quantity of zygotes exhibiting two pronuclei. Consequently, low fertilization rates or complete fertilization failure are highly undesirable outcomes for both patients and reproductive specialists. Applying additional calcium ionophore for oocyte activation subsequent to ICSI may offer benefits and potentially enhance treatment outcomes, particularly for patients who have experienced low or absent fertilization rates (FR) in previous treatment cycles. The aim of the study is to evaluate the efficacy of Ca2+ ionophore application for oocyte activation. Methods: A retrospective analysis of 924 oocytes obtained from 120 patients who underwent ICSI cycles with a history of low or no fertilization as a result of previous unsuccessful treatment rounds. The next ART cycle followed with additional oocyte Ca2+ ionophore activation applied in 57 of the cases in order to optimize the treatment process (Group 1), and 63 patients were included and their outcomes followed as a control group (Group 2).We conducted a comparative analysis of results in both groups. The study's primary outcomes encompassed fertilization, cleavage embryo quality, blastocyst rate, and established clinical pregnancies. Results: At day 1 fertilization check we had 274/386 zygotes (71%FR) in group 1 and 132/410 in group 2 (32.2%FR), (P < 0.0001). Twenty-two (34.9%) cycles in group 2 resulted in total fertilization failure (TFF). At the cleavage stage top-quality embryos from group 1 were significantly higher (P = 0.0021) in comparison to group 2. Forty-eight embryo transfers (ET) were performed in group 1 resulting in 41.67% clinical pregnancies versus 33 ET and only 4 pregnancies (12.12%) for group 2 (P = 0.0044). Conclusions: The results confirm the appropriateness of assisted oocyte activation as an additional method in cases of previous fertilization failure cycles.

The incidence of small for gestational age neonates in singleton IVF pregnancies.

INTRODUCTION: Various factors related to an "in vitro" fertilization (IVF) procedure may influence the rate of small for gestational age (SGA) newborns in such pregnancies. AIM: The aim of the study was to determine neonatal SGA incidence in singleton IVF pregnancies compared to spontaneous ones. MATERIALS AND METHODS: We conducted both a prospective and a retrospective study within the period of January 2013-December 2017, which included 336 patients with a singleton IVF pregnancy at the time of delivery - the study group (SG), and 493 women with a spontaneous conception - the control group (CG). RESULTS: Neonatal SGA rate was significantly higher in the SG as compared to the CG, p < .05, as well as in case of multiple embryotransfer (ET), vanishing twin syndrome (VTS), fresh ET against frozen embryotransfer (FET), female infertility factor. CONCLUSION: Singleton pregnancies after an IVF technique show a higher neonatal SGA rate compared to spontaneous ones.

Alternative RNA Splicing-The Trojan Horse of Cancer Cells in Chemotherapy.

Almost all transcribed human genes undergo alternative RNA splicing, which increases the diversity of the coding and non-coding cellular landscape. The resultant gene products might have distinctly different and, in some cases, even opposite functions. Therefore, the abnormal regulation of alternative splicing plays a crucial role in malignant transformation, development, and progression, a fact supported by the distinct splicing profiles identified in both healthy and tumor cells. Drug resistance, resulting in treatment failure, still remains a major challenge for current cancer therapy. Furthermore, tumor cells often take advantage of aberrant RNA splicing to overcome the toxicity of the administered chemotherapeutic agents. Thus, deciphering the alternative RNA splicing variants in tumor cells would provide opportunities for designing novel therapeutics combating cancer more efficiently. In the present review, we provide a comprehensive outline of the recent findings in alternative splicing in the most common neoplasms, including lung, breast, prostate, head and neck, glioma, colon, and blood malignancies. Molecular mechanisms developed by cancer cells to promote oncogenesis as well as to evade anticancer drug treatment and the subsequent chemotherapy failure are also discussed. Taken together, these findings offer novel opportunities for future studies and the development of targeted therapy for cancer-specific splicing variants.

Contribution of Cyanotoxins to the Ecotoxicological Role of Lichens.

The fascinating world of lichens draws the attention of the researchers because of the numerous properties of lichens used traditionally and, in modern times, as a raw material for medicines and in the perfumery industry, for food and spices, for fodder, as dyes, and for other various purposes all over the world. However, lichens being widespread symbiotic entities between fungi and photosynthetic partners may acquire toxic features due to either the fungi, algae, or cyano-procaryotes producing toxins. By this way, several common lichens acquire toxic features. In this survey, recent data about the ecology, phytogenetics, and biology of some lichens with respect to the associated toxin-producing cyanoprokaryotes in different habitats around the world are discussed. Special attention is paid to the common toxins, called microcystin and nodularin, produced mainly by the Nostoc species. The effective application of a series of modern research methods to approach the issue of lichen toxicity as contributed by the cyanophotobiont partner is emphasized.