Search PubMed⌕ Search

Biomedical subjects

G Beck

Publications and source records attributed to G Beck.

265 records · Page 15Linked to original sources
PubMedDate not supplied

Invertebrate cytokines: the phylogenetic emergence of interleukin-1.

Cytokines are polypeptides released by activated vertebrate blood cells which have profound effects on other blood cells and which have hormone-like properties affecting other organ systems as well. In recent years a wide variety of these mediators has been isolated and characterized. Many of these molecules have subsequently been cloned and expressed in E. coli. The tremendous importance of these proteins to host immune and non-specific defense systems along with the striking similarities of their properties among different species suggested to us that cytokines may have been proteins that have been conserved through evolution. Investigations of the evolution of cytokines will help us decipher the complex cellular, humoral and molecular interactions that regulate host defenses. Studies of the invertebrates will shed light on the phylogenetic emergence of these molecules as well.

Animals↗
PubMedDate not supplied

Evaluation of the 99mtechnetium labelling effect on Pseudomonas aeruginosa surface properties.

Gamma emitter isotopes present some advantages over beta emitters as radioisotopic microbial labels. The labelling of bacteria with 99mtechnetium (99mTc) has recently been described. However, it was not ascertained whether the labelling process modifies microbial physicochemical surface properties important in the interaction between bacteria and eukaryotic cells. In the present study, we evaluated the effect of the labelling process on Pseudomonas aeruginosa surface charge, hydrophobicity, adherence to human buccal epithelial cells and phagocytosis by human leukocytes. No significant differences in electrophoretic mobility or cationized ferritin distribution was observed on the cell surface of labelled and unlabelled bacteria. 99mTc labelling did not modify the hydrophobicity adhesiveness or phagocytosis of P. aeruginosa. It is concluded that bacterial labelling with 99mTc may be a useful method for the numeration of bacteria and the analysis of their functional properties.

Bacterial Adhesion↗
PubMedDate not supplied

Effect of growth on surface charge and hydrophobicity of Staphylococcus aureus.

Modifications in the surface charge and hydrophobicity of Staphylococcus aureus Oxford during growth were studied by analysing electrophoretic mobility and adherence to hydrocarbons (hexadecane), respectively. Bacterial concentration had no effect upon the measurements. Both surface charge and hydrophobicity varied during the exponential phase of growth (1 to 4 h): surface charge decreased significantly (p less than 0.001), while hydrophobicity increased (p less than 0.001). In the stationary phase (4 to 9 h), the surface charge increased significantly (p less than 0.001), whereas hydrophobicity showed no change. Cationized ferritin decreased the surface charge and had no effect on hydrophobicity. These results suggest that in S. aureus, different structures could be responsible for their surface charge and hydrophobic properties.

Alkanes↗
PubMedDate not supplied

[Family planning and pregnancy with thalassemia major].

We present the case of a young Italian woman with thalassemia major and describe a series of complications such as infertility, fetal growth restriction, difficult intubation, and cardiac decompensation that occurred in the course of family planning, pregnancy, and the puerperal period. By review of the literature and based on own experiences, we show how the preconceptional consultation and the care during a pregnancy, especially the individualized planning of delivery, can be optimized. The intensive and interdisciplinary care by obstetricians and internists is very important.

Adult↗
PubMedDate not supplied

[Quantitative bacteriology of sputum collected by a simple technic limiting salivary contamination].

A simple non-invasive method to improve the reliability of bacteriological analyses of sputum was evaluated in 25 patients with chronic bronchitis. This method consists of placing dental cotton swabs between the cheek and the gum and under the tongue at the level of the excretory salivary glands. Once these plugs are in place, the sputum is collected by coughing under the control of a physiotherapist. The quantitative bacteriological data from sputum collected by the "protected" and "unprotected" methods were compared with those from bronchial secretions collected by transtracheal aspiration, used as reference method. Oropharyngeal cells and commensal bacteria were isolated at a significantly lower frequency in sputum collected by the protected method. Considering the predominant pathogenic bacteria, an excellent correlation was obtained between transtracheal aspiration and sputum in 80% of cases when sputum was collected by protected method and in 68% of cases by unprotected method. In four patients, the transtracheal aspiration was sterile, while a potentially pathogenic organism associated with a high leukocyte numeration was identified in sputum. All the potential pathogens isolated in the positive transtracheal aspiration were recovered in the protected sputum (100%), but they could be associated with a non-predominant commensal flora (11 cases) or a potentially misleading pathogenic bacteria (2 cases).

Adult↗