Biomedical subjects

S Bolte

Publications and source records attributed to S Bolte.

4 recordsLinked to original sources

PubMed2006

A guided tour into subcellular colocalization analysis in light microscopy.

It is generally accepted that the functional compartmentalization of eukaryotic cells is reflected by the differential occurrence of proteins in their compartments. The location and physiological function of a protein are closely related; local information of a protein is thus crucial to understanding its role in biological processes. The visualization of proteins residing on intracellular structures by fluorescence microscopy has become a routine approach in cell biology and is increasingly used to assess their colocalization with well-characterized markers. However, image-analysis methods for colocalization studies are a field of contention and enigma. We have therefore undertaken to review the most currently used colocalization analysis methods, introducing the basic optical concepts important for image acquisition and subsequent analysis. We provide a summary of practical tips for image acquisition and treatment that should precede proper colocalization analysis. Furthermore, we discuss the application and feasibility of colocalization tools for various biological colocalization situations and discuss their respective strengths and weaknesses. We have created a novel toolbox for subcellular colocalization analysis under ImageJ, named JACoP, that integrates current global statistic methods and a novel object-based approach.

Journal Article↗

PubMed2004

FM-dyes as experimental probes for dissecting vesicle trafficking in living plant cells.

FM-dyes are widely used to study endocytosis, vesicle trafficking and organelle organization in living eukaryotic cells. The increasing use of FM-dyes in plant cells has provoked much debate with regard to their suitability as endocytosis markers, which organelles they stain and the precise pathways they follow through the vesicle trafficking network. A primary aim of this article is to assess critically the current status of this debate in plant cells. For this purpose, background information on the important characteristics of the FM-dyes, and of optimal dye concentrations, conditions of dye storage, and staining and imaging protocols, are provided. Particular emphasis is placed on using the FM-dyes in double labelling experiments to identity specific organelles. In this way, staining of the Golgi with FM4-64 has been demonstrated for the first time.

Biological Transport, Active↗

PubMed2000

Characterization of a small GTP-binding protein of the rab 5 family in Mesembryanthemum crystallinum with increased level of expression during early salt stress.

A cDNA encoding a member of the Ypt/Rab family of small GTP-binding proteins was cloned from the facultative CAM plant Mesembryanthemum crystallinum. Mcrab5b includes an open reading frame of 201 amino acids. The deduced amino acid sequence shows 91% similarity to LjRAB5b isolated from Lotus japonicus. The amino acid sequence of McRAB5b provides interesting features suggesting that McRAB5b and its homologue from Lotus japonicus represent a new subclass of Ypt/Rab proteins. The fact that proteins like McRAB5b and LjRAB5b were only found in plants and not in yeast or vertebrates suggests that they have plant-specific functions. The expression of Mcrab5b as investigated by northern blot hybridization and RT-PCR was stimulated under salt stress. After heterologous expression in Escherichia coli an antibody was raised against recombinant McRABSb protein. Western blot analysis revealed that McRAB5b was bound to membranes. It is present in a monomeric and a dimeric form in vitro and in vivo. In vitro only the monomeric protein exhibits a binding capacity for radiolabelled GTP, while the dimer is unable to do so, indicating that the activity may be regulated by monomer/dimer transition.

Amino Acid Motifs↗

PubMed2000

[Injury profile in modern competitive karate--analysis of 1999 WKC-Karate World Championship Games in Bochum].

Competitions in Karate are either carried out as Shobu sanbon (with fist padding) or Shobu Ippon (without fist padding). Aim of this study was to gain current data on injuries in modern competitive Karate and to compare the two different competitive systems. During the WKC-Karate-World-Championships held from June 12-13 1999 at Bochum, 392 bouts were carried out. Every injury that was seen by the tournament doctor was registered. 142 competitors sustained 168 injuries: 141 mostly minor contusions of the head and throat, 12 facial lacerations, 3 knock-outs (mild brain injury), 3 thoracal contusions, 1 midfoot fracture and 9 other blunt injuries. We saw more injuries in Shobu Sanbon (146/302 bouts) than in Shobu Ippon (23/90). Most of the injuries (152) were caused by punches. In Shobu Sanbon, kicking techniques led to 17 injuries only. The injury pattern shown here is comparable to earlier studies. Severe injuries in competitive Karate are rare. The higher number of injuries in Shobu sanbon may be due to the longer fighting time and higher scoring. Fist pads used in Shobu Sanbon might also lead to a loss of control. Therefore, prophylactic fist padding to avoid injuries in competitive Karate has to be seen critically.

Adolescent↗