Transcatheter aortic valve implantation using direct aortic access: first procedures in Poland

Transcatheter aortic valve implantation (TAVI) is an alternative option for the treatment of severe aortic stenosis in patients carrying an elevated operative risk of conventional surgical aortic valve replacement (AVR). Recently, data from randomised clinical trials confirmed superiority of TAVI when compared with the conservative treatment in inoperable patients, and its non-inferiority when compared with AVR in a high-risk population. Transfemoral vascular access remains the preferred route for delivering the bioprosthesis. However, in a significant proportion of patients, the presence of severe iliac-femoral arteriopathy or small vessel diameter render the transfemoral approach unusable. In this article, we report the first Polish experience of two successful TAVI procedures with bioprostheses (both balloon- and self-expandable) delivered using direct aortic access.     

Plasma thyroid hormones and corticosterone levels in blood of chicken embryos and post hatch chickens exposed during incubation to 1800 MHz electromagnetic field

Introduction

This study attempted to determine the effect of a 1800 MHz electromagnetic field (EMF) (only carrier frequency) on thyroxine (T₄), triiodothyronine (T₃) and corticosterone (CORT) concentrations in the blood plasma of chick embryos, and to investigate the effect of electromagnetic field (EMF) exposure during embryogenesis on the level of these hormones in birds that are ready for slaughter.

Material and Methods

Throughout the incubation period, embryos from the experimental group were exposed to a 1800 MHz EMF with power density of 0.1 W/m², 10 times during 24 h for 4 min. Blood samples were collected to determine T₄, T₃ and CORT concentrations on the 12th (E12) and 18th (E18) day of incubation, from newly hatched chicks (D1) and from birds ready for slaughter (D42).

Results

The experiment showed that T₄ and T₃ concentrations decreased markedly and CORT levels increased in the embryos and in the newly hatched chicks exposed to EMF during embryogenesis. However, no changes were found in the level of the analyzed hormones in the birds ready for slaughter. Differences in T₄ and T₃ plasma concentrations between the EMF-exposed group and the embryos incubated without additional EMF were the highest in the newly hatched chicks, which may be indicative of the cumulative effect of electromagnetic field on the hypothalamo-pituitary-thyroid axis (HPT).

Discussion

The obtained results suggest that additional 1800 MHz radio frequency electromagnetic field inhibits function of HPT axis, however, it stimulates hypothalamo-pituitary-adrenal axis by inducing adrenal steroidogenic cells to synthesize corticosterone. Further investigations are needed to elucidate the mechanisms by which radio EMFs affect HPT and HPA axis function in the chicken embryos.     

Terence Tao (1944–2020)

Journal of Muscle Research and Cell Motility -     

Role of cryptosporidiosis in diarrhea among hospitalized adults in Bamako

Etiologies of infectious diarrhoeas in hospitalised adults have been studied during one year; research of cryptosporidium and isospora oocysts is being made with Henriksen-Pohlenz and Kato methods. Diarrhoea is associated with a positive HIV serology in 40% cases. Cryptosporidium spp is found in 38% of cases. In 91% cases of cryptosporidiosis HIV serology is positive. Cryptosporidiosis is the main cause of AIDS diarrhoeas in Mali. 3 cases of isosporiasis are associated with cryptosporidiosis in AIDS patients. Emaciation and dehydration are the main signs of severity. Diarrhoea's profusion, its chronicity and inefficiency of the treatments explain the heavy death rate of cryptosporidiosis among seropositive patients, which reaches 40% during the first two weeks of hospitalisation.     

Migration of porcine endothelial and smooth muscle cells in response to platelet-associated factors

A NeuroProbe multiwell microchemotaxis assembly has been used to study the migration of porcine aortic endothelial and smooth muscle cells in vitro in response to serum factors. Whole pig serum was found to be chemokinetic for endothelial cells but not smooth muscle cells. Chemokinetic activity was higher in platelet-enriched, plasma-derived serum (PDS) than in platelet-free PDS. The supernatant from washed, lysed pig platelets also showed chemokinetic activity both for endothelial and smooth muscle cells. Chromatography on Sephadex G-200 showed that the lysate contained a number of activities that act independently on the two cell types. The chemokinetic activity that we have detected appears to be distinct from the chemotactic effect of platelet-derived growth factor and platelet factor 4 on the basis of insensitivity to protamine sulfate and molecular size. The role of these platelet factors in pathological changes in vascular structure is currently under study.     

Production and Characterization of Monoclonal Antibodies against Human Malignant Melanoma

The specific immunoreactivities of 31 monoclonal antibodies against human malignant melanoma were analyzed on a variety of malignant and nonmalignant human cells. Seven distinct groups were defined based on reactivity in radioimmunoassay and in mixed hemadsorption assay. The Group A antibody bound to 33 % of short- and long-term cultured melanomas; Group B antibodies reacted with the majority of melanomas, astrocytomas, neuroblastomas, and fetal polygonal cells; and Group C antibodies bound to melanomas, teratocarcinomas, and to melanocytes grown in the presence of tumor-promoting phorbol esters. Antibodies of Groups D-G showed a less restricted binding pattern. In all groups, antibodies of IgG2b and IgM isotypes mediated complement-dependent Iysis (CDC) and antibodies of IgG1, IgG2a, and IgG2b isotypes mediated antibody-dependent cell-mediated cytotoxicity (ADCC). Biochemical analysis indicated that 16 different proteins with molecular weights ranging between 28,000 and 500,000 were detected by the monoclonal antimelanoma antibodies.