Electroporation is a method that shows great promise as a non-viral approach for delivering genes by using high-voltage electric pulses to introduce DNA into cells to induce transient gene expression. This research aimed to evaluate the interplay between electric pulse intensity and 100 µs-duration pulse numbers as an outcome of gene electrotransfer efficacy and cell viability. Our results indicated a close relationship between pulse number and electric field strength regarding gene electrotransfer efficacy; higher electric pulse intensity resulted in fewer pulses needed to achieve the same gene electrotransfer efficacy. Subsequently, an increase in pulse number had a more negative impact on overall gene electrotransfer by significantly reducing cell viability. Based on our data, the best pulse parameters to transfect CHO cells with the pMax-GFP plasmid were using 5 HV square wave pulses of 1000 V/cm and 2 HV of 1600 V/cm, correspondingly resulting in 55 and 71% of transfected cells and maintaining 79 and 54% proliferating cells. This shows ESOPE-like 100 µs-duration pulse protocols can be used simultaneously to deliver cytotoxic drugs as well as immune response regulating genetically encoded cytokines.

The aim of the present study is to present the composition of the leech fauna from Lithuania. Based on morphology, 12 species of leeches belonging to 10 genera and 5 families (Haemopidae, Hirudinidae, Glossiphoniidae, Erpodellidae and Piscicolidae) were identified in the country. Comparison of the data generated in current study with historical records, we extend the list of species to 21. Additional localities of Hirudo medicinalis and Erpobdella monostriata, two uncommon leeches, were established in Lithuania.

Nine species of freshwater bryozoans were recorded in Lithuania in a survey of 18 various types of freshwater bodies. Eight species were assigned to the Class Phylactolaemata and families Plumatellidae and Cristatellidae (Plumatella repens, Plumatella fungosa, Plumatella fruticosa, Plumatella casmiana, Plumatella emarginata, Plumatella geimermassardi, Hyalinella punctata and Cristatella mucedo). The ninth species, Paludicella articulata, represented the Class Gymnolaemata. Plumatella geimermassardi and P. casmiana were recorded for the first time in Lithuania. For the plumatellids, species identification was achieved partly by analysing statoblasts(,) morphological ultrastructures by scanning electron microscopy.

Leeches play a critical role in the transmission of digenean trematodes, yet their parasitic infections remain understudied in the Baltic region. This study investigates the diversity, prevalence, and molecular identification of trematode infections in freshwater leeches from central Lithuania. A total of five leech species (Alboglossiphonia heteroclita, Glossiphonia complanata, Glossiphonia verrucata, Helobdella stagnalis, and Erpobdella octoculata) were examined using compression and dissection techniques to detect trematode cysts, which were predominantly found in the soft tissues rather than the intestinal tract. Molecular sequencing of 18S rRNA, COI, and ITS markers, combined with phylogenetic analyses, confirmed the presence of three trematode genera: Cotylurus, Australapatemon, and Posthodiplostomum. The overall infection rate among leeches was 40.8%, with the highest prevalence observed in G. complanata (53.3%). Cotylurus spp. were the most frequently detected parasites, with genetic analyses revealing close affinities to Cotylurus syrius and Cotylurus spp. from Poland. Australapatemon species were also identified, though species-level classification remained inconclusive. Notably, this study provides the first molecular evidence of Posthodiplostomum cuticola utilizing leeches as intermediate hosts, extending the known range of hosts for this trematode. Phylogenetic analyses demonstrated the broad geographic distribution of these parasites, with close genetic matches to isolates from Poland, Russia, Canada, and Japan. The findings highlight the ecological significance of leeches in parasite transmission networks and contribute to the understanding of trematode diversity and host interactions in the Baltic region. Further molecular and ecological studies are needed to clarify species diversity and the role of leeches in the life cycles of aquatic parasites.

The Baltic states—Estonia, Latvia, and Lithuania—are situated on the eastern coast of the Baltic Sea between Russia and the Scandinavian countries. This region is characterized by diverse landscapes and numerous bodies of water, including lakes, peat bogs, and marshes, which serve as natural habitats for aquatic invertebrates, including leeches. Despite the rare and uncertain taxonomic status of leech species in the area, research in the Baltic region has been inadequate. Therefore, this study aims to examine the composition of leech species in the Baltic countries, drawing on both past and current research. The study also seeks to assess the status of Hirudo medicinalis in the Baltic region and discuss the rare, questionable, and potentially present leech species in the Baltic states. A scoping review method was employed, surveying published references, books, and databases. In total, the study found records of 21 leech species in Estonia, 15 in Latvia, and 26 in Lithuania, belonging to the families Glossiphoniidae, Erpobdellidae, Hirudinidae, Haemopidae, and Piscicolidae. Hirudo medicinalis L. is distributed throughout all Baltic countries, but the most recent records on their location are only available for Estonia. The data on a few Piscicolidae species is questionable and requires verification, but further research on Piscicolid leeches can potentially lead to the discovery of rare species.