A single nucleotide deletion resulting in a frameshift in exon 4 of TAB2 is associated with a polyvalular syndrome.

OBJECTIVE: Polyvalvularmyxomatous degeneration is a rare clinical condition. A 51-year-old male patient presented at our centre with all four heart valves with myxomatous degeneration and severe mitral and aortic regurgitation due to leaflet prolapse. The patient referred five further family members with valvular heart disease at different stages of presentation. The aim of this study was to investigate the genetic basis of this familial polyvalvularmyxomatous degeneration which was associated with mild dysmorphic facial anomalies and short stature. DESIGN: A detailed family history was recorded. Nine members of the family, affected or not by valvular heart disease, were studied clinically, echocardiographically and by detailed genetic analyses. RESULTS: Six of the nine family members had echocardiographic features of different degrees of degenerative heart valve disease. In addition, the affected subjects shared similar mild dysmorphic facial anomalies and short stature. Exome sequencing identified a rare heterozygous single nucleotide deletion in the TAB2 gene in all affected family members, which was absent in the unaffected members. CONCLUSIONS: A variant in the TAB2 gene is proposed as the cause of syndromic congenital heart disease, displaying congenital myxomatous degenerative heart valve disease, mild dysmorphic fascial anomalies and short stature in this family.

Flow cytometry applications in the food industry.

Flow cytometry has become a valuable tool in food microbiology. By analysing large numbers of cells individually using light-scattering and fluorescence measurements, this technique reveals both cellular characteristics and the levels of cellular components. Flow cytometry has been developed to rapidly enumerate microorganisms; to distinguish between viable, metabolically active and dead cells, which is of great importance in food development and food spoilage; and to detect specific pathogenic microorganisms by conjugating antibodies with fluorochromes, which is of great use in the food industry. In addition, high-speed multiparametric data acquisition, analysis and cell sorting, which allow other characteristics of individual cells to be studied, have increased the interest of food microbiologists in this technique. This mini-review gives an overview of the principles of flow cytometry and examples of the application of this technique in the food industry.

Flow cytometry discrimination between bacteria and clay-humic acid particles during growth-linked biodegradation of phenanthrene by Pseudomonas aeruginosa 19SJ.

Abstract Methods that quickly assess microbial density and aggregation in soil and sediments are needed in environmental microbiology. We report a flow cytometry method that uses the green and orange emission of the fluorochrome SYTO-13 to discriminate between bacteria and clay-humic acid particles. This approach distinguishes single or clustered bacteria, and clusters of bacteria and abiotic particles during the growth of the biosurfactant-producing strain Pseudomonas aeruginosa 19SJ on solid phenanthrene in the presence of humic acid-clay complexes.

Flow cytometric detection and quantification of heterotrophic nanoflagellates in enriched seawater and cultures.

A flow cytometric protocol to detect and enumerate heterotrophic nanoflagellates (HNF) in enriched waters is reported. At present, the cytometric protocols that allow accurate quantification of bacterioplankton cannot be used to quantify protozoa for the following reasons: i) the background produced by the bacterial acquisitions does not allow the discrimination of protozoa at low abundance, ii) since the final protozoan fluorescence is much higher than the bacterioplankton fluorescence (more than 35 fold) the protozoa acquisitions lie outside the range. With an increase in the fluorescence threshold and a reduction of the fluorescence detector voltage, low fluorescence particles (bacteria) are beneath the detection limits and only higher fluorescence particles (most of them heterotrophic nanoflagellates) are detected. The main limitation for the application of the cytometric protocol developed is that a ratio of bacteria/HNF below 1000 is needed. At higher ratios, the background of larger cells of bacterioplankton makes it difficult to discriminate protozoa. The proposed protocol has been validated by epifluorescence microscopy analyzing both a mixed community and two single species of HFN: Rhynchomonas nasuta and Jakoba libera. Taking into account the required bacteria/HNF ratio cited above, the results provide evidence that the flow cytometric protocol reported here is valid for counting mixed communities of HNF in enriched seawater and in experimental micro or mesocosms. In the case of single species of HNF previous knowledge of the biological characteristics of the protist and how they can affect the effectiveness of the flow cytometric count is necessary.