Characterization of mAb6-9-1 monoclonal antibody against hemagglutinin of avian influenza virus H5N1 and its engineered derivative, single-chain variable fragment antibody.

Hemagglutinin (HA), as a major surface antigen of influenza virus, is widely used as a target for production of neutralizing antibodies. Monoclonal antibody, mAb6-9-1, directed against HA of highly pathogenic avian influenza virus A/swan/Poland/305-135V08/2006(H5N1) was purified from mouse hybridoma cells culture and characterized. The antigenic specificity of mAb6-9-1 was verified by testing its cross-reactivity with several variants of HA. The mimotopes recognized by mAb6-9-1 were selected from two types of phage display peptide libraries. The comparative structural model of the HA variant used for antibody generation was developed to further facilitate epitope mapping. Based on the sequences of the affinity- selected polypeptides and the structural model of HA the epitope was located to the region near the receptor binding site (RBS). Such localization of the epitope recognized by mAb6-9-1 is in concordance with its moderate hemagglutination inhibiting activity and its antigenic specificity. Additionally, total RNA isolated from the hybridoma cell line secreting mAb6-9-1 was used for obtaining two variants of cDNA encoding recombinant single-chain variable fragment (scFv) antibody. To ensure high production level and solubility in bacterial expression system, the scFv fragments were produced as chimeric proteins in fusion with thioredoxin or displayed on a phage surface after cloning into the phagemid vector. Specificity and affinity of the recombinant soluble and phage-bound scFv were assayed by suitable variants of ELISA test. The observed differences in specificity were discussed.

Detailed analysis of research and practice in the life of a pediatric surgeon in East Central Europe in the 20th century - an example of prof. Zofia Umiastowska-Sawicka

Professor Zofia Umiastowska Sawicka laid the foundations for modern pediatric surgery in Poland, first in Bialystok, and subsequently in Kielce. She was a student of Prof. Jan Kossakowski from Warsaw Medical University to be counted among his most talented and skilled disciples. Professor Umiastowska became the head of the first Department of Pediatric Surgery in Bialystok, which was later incorporated into the Medical Academy of Bialystok. In 1977 she moved to Kielce to run the Department of Pediatric Surgery until her retirement in 1991. In these locations she was the one who trained generations of pediatric surgeons with special emphasis on surgical management of exstrophy of the bladder, vaginal labial adhesion (synechia), injuries of the male urethra, liver and hepatic ligament. During her professional lifetime she focused on congenital diaphragmatic hernia, Meckel's diverticulum, and some aspects of pediatric oncology as well. Every school she attended enriched her with the best of knowledge and skills that made her a perfect teacher for others. However, the Warsaw Medical University essentially played the main role at the core of her surgical training: here she was taught and she learnt how to be pediatric surgeon for good of public health of the society in concord with the motto of the Warsaw Medical University: Saluti publicae.

Oxazolinodoxorubicin - a promising new anthracycline.

Oxazolinodoxorubicin, a doxorubicin analog with a modified daunosamine moiety was synthesized. The properties of this compound and the parent doxorubicin were compared. The cytotoxicity in vitro studies against several human tumor cell lines (PC-3, MCF-7, SW707, HL-60, RPMI 8226, ACHN) showed higher antiproliferative potency for this new compound. Moreover, its ability to completely overcome the drug resistance of cancer cells in vitro was revealed (LoVo, LoVo/DX, MES-SA, MES-SA/DX5, HL-60, HL-60/Vinc, HL-60/MX2 cell lines). Cellular uptake analyzed on HL-60 and HL-60/MX2 cells, demonstrated higher penetration levels of oxazolinodoxorubicin compared to that of doxorubicin. In animal experiments, general toxicity of oxazolinodoxorubicin was lower than that observed for doxorubicin. Furthermore, similar antitumor effects was observed in NOD/SCID mice bearing resistant HL-60/Vinc leukemia tumor and in mice treated with the new or parent compounds. The presented results suggest that oxazolinodoxorubicin is a new anthracycline with an advantageous biological activity profile.