Barrett’s Esophagus: Environmental Influences in the Progression of Dysplasia

Barretts esophagus (BE) is composed of multiple lineages including Paneth cells and endocrine cells in addition to gastric and intestinal cells. Although the origin of the BE stem cell is a matter of conjecture, the stem cells are clearly multipotent, and therefore the phenotype is restricted by genomic imprinting (termed restricted potency). Recent evidence suggests that the microenvironment may select various lineages. In this regard the proportion of gastric and specialized intestinal metaplastic cells has been attributed to the composition of the refluxate, acid or bile, respectively. Experimental evidence also implicates specific xenobiotics in this process, including bile acids. In particular we discuss the potential biologic roles of bile acids in epithelial adaptation from in vivo and in vitro models.     

Genetic variability of Bordetella pertussis strains. Part II. Perspectives

In some highly immunized countries with long history of pertussis vaccination (The Netherlands, Finland, Poland, USA, France, Great Britain) differences in the DNA patterns and ptxS1 and prn alleles present in B. pertussis strains used for production of pertussis component in the DTP vaccine, in comparison to strains presently isolated from clinical materials have been found. Studies on efficacy of whole-cell and acellular pertussis vaccines in elimination of B. pertussis strains harbouring different gene variants in a particular country might indicate a need for a change of B. pertussis strains used for production of the vaccine against pertussis.     

Newborn outcome after assisted reproductive technology: experiences and reflections from Poland

In spite of much ethical uncertainty and wide variations in obstetric and neonatal outcomes reported in the literature, we have studied the outcome of Polish newborns after assisted reproductive technology (ART). In all of our patients, both obstetrics and neonatal care were performed in the Level Three Center in Poznan, Poland. A total of 45 and 82 newborns were analyzed from the ART and the control group, respectively. We analyzed gestational age, birth weight, Apgar score, duration of hospitalization, newborn mortality, and congenital malformations. We found a far higher rate of mothers over 35 years and with university education in ART compared to controls. The incidence of cesarean section and birth weight <1,500 g was much higher in ART. Newborn mortality was much higher among ART newborns compared to controls and was related to premature delivery of triplet pregnancy. The most important factor resulting in high neonatal mortality in our study group was multiple pregnancy. We consider the lack of regulation in Poland concerning the number of replaced embryos as a main factor influencing newborns' outcome after ART.     

Oncogenes as regulators of tissue factor expression in cancer: implications for tumor angiogenesis and anti-cancer therapy

Up-regulation of tissue factor (TF) is often observed in cancer. TF is a cell-associated receptor for coagulation factor VII/VIIa, an interaction known to activate the coagulation cascade. At the same time, TF is also known as a mediator of intracellular signaling events that can alter gene expression patterns and cell behavior. Both aspects of TF activity are of possible relevance to tumor growth, metastasis, and angiogenesis, including up-regulation of vascular endothelial growth factor (VEGF). TF up-regulation is often observed on the surfaces of tumor-associated endothelial cells, inflammatory cells, and particularly on cancer cells themselves. In the last case, high TF levels may be associated with poor prognosis and parallel clinical (and genetic) tumor progression. We have proposed elsewhere that TF may be a target of oncogenic events in cancer. Here we discuss our observations suggesting that oncogene-targeting agents may down-regulate TF expression. Such is the effect of treatment with the neutralizing monoclonal antibody (C225) raised against the epidermal growth factor receptor (EGFR) in EGFR-dependent squamous cell carcinoma cells (A431). This two- to threefold TF down-regulation by C225 treatment is paralleled by a decrease in expression of VEGF. It is conceivable that TF participates in signals that regulate VEGF and angiogenesis triggered by activated oncogenic pathways. Therefore, direct targeting of TF in cancer should be considered in combination with other treatment modalities such as oncogene-directed therapies, antiangiogenic agents (e.g., VEGF antagonists), and anti-cancer chemotherapy.     

Guillain-Barré syndrome with central nervous system symptoms. Report of two cases

Guillain-Barré syndrome - acute inflammatory demyelinating polyradiculoneuropathy - is characterized by symmetrical flaccid paresis of limbs and areflexia or hyporeflexia which progress over a few days, up to 4 weeks. The central nervous system lesion is rarely reported in the course or treatment of the disease. In the paper two cases of patients with diagnosed Guillain-Barré syndrome with the central nervous system manifestations were discussed. A case of a 55-year-old woman was presented, who during hospitalization, on the last day of intravenous immunoglobulin therapy developed a hallucinatory syndrome. Furthermore, a case of a 18-year-old female patient with classic features of Guillain-Barré syndrome was described, because of its atypical initial presentation (headache, drowsiness and meningismus).