The endocytosis of horseradish peroxidase (HRP) by the vascular cells of retinal and choroidal blood vessels was compared in immersion and perfusion fixed eyes from individual rats. The mechanisms of endocytosis of HRP appeared identical in both retinal and choroidal vessels. The bulk of internalised tracer occurred in macropinosomes 300-400 nm in diameter. Tracer was localised to a 20-30 nm la...

BACKGROUND Chronic stress affects the course of inflammatory bowel disease and experimental colitis, and may also initiate intestinal inflammation in rats. AIM To investigate the effects of stress on the M cell containing follicle associated epithelium, specialised in antigen uptake. SUBJECTS AND METHODS Wistar rats were submitted to acute water avoidance stress for one hour or chronic wate...

Biocytin is a biotin-lysine complex of low molecular weight containing about 65% biotin, which retains a high affinity for avidin. Since the latter molecule has been conjugated to several histochemical markers, the use of biocytin as an intracellular marker was investigated. Electrodes were filled with a solution of 4-6% biocytin dissolved in 0.5 M KCl and 0.05 M Tris buffer, pH 7-7.6. Neurons ...

A collagen mafrix (COL)gel was .used to fill a 3 mm gap resulting from transection of rat sdatic nerve. The nerve was initially stabilized with a split polyethylene tubing in order to remove elastic tension at the nerve repair site. The contralateral sdatic nerve was identically prepared but the gap was left empty. Animal survival time was '9 to 12 weeks. One day prior to killing. somatosensory...

New chromogens expand the colour palette for horseradish peroxidase chromogens used in immunohistochemistry. Tissue staining of cytokeratin with three new cyanine-based chromogens is described. Their use as fluorescent reporters is demonstrated.

Two engineered DNA nanostructures consisting of a nucleic acid functional hairpin and a DNA "tweezers" assembly act as pH-switchable devices for the "ON-OFF" activation/deactivation of the horseradish-peroxidase-mimicking DNAzyme.