In this paper we report that a combination of noncontact and contact atomic force microscopy is a convenient and reliable method for imaging and dissecting single plasmid deoxyribonucleic acid (DNA) strands on mica at ambient conditions without leaving feedback and without damage to the scanning tips. The width and thickness measured at different points of the DNA strands agree with literature data and are the same before and after dissection.

DNA↗

PubMedDate not supplied

Improvement of DNA-visualization in dynamic mode atomic force microscopy in air.

Near-contact mode atomic force microscopy (AFM) imaging leads to sharper representations of DNA double strands on mica imaged at ambient conditions compared with noncontact mode AFM. Phase shift was used for feedback control yielding height information using a simple model calculation. No contact between tip and sample occurs. Measured DNA widths were up to four times smaller than measured with the same AFM tip in noncontact mode at ambient condition.

Animals↗

PubMedDate not supplied

Glycogen phosphorylase isoenzyme BB in diagnosis of myocardial ischaemic injury and infarction.

This review deals with glycogen phosphorylase (GP) and its isoenzyme BB in the diagnosis of ischaemic myocardial injury. Early identification and confirmation of acute myocardial infarction is essential for correct patient care and disposition decision in the emergency department. In this respect, glycogen phosphorylase isoenzyme BB (GPBB) based on its metabolic function is an enzyme for early laboratory detection of ischaemia. In the aerobic heart muscle GPBB together with glycogen is tightly associated with the vesicles of the sarcoplasmic reticulum. Release of GPBB, the main isoform in the human myocardium, essentially depends on the degradation of glycogen, which is catalyzed by GP. Ischaemia is known to favour the conversion of bound GP in the b form into GP a, thereby accelerating glycogen breakdown, which is the ultimate prerequisite for getting GP into a soluble form being able to move freely in the cytosol. The efflux of GPBB into the extracellular fluid follows if ischaemia-induced structural alterations in the cell membrane become manifest. The clinical application of GPBB as a marker of ischaemic myocardial injury is a very promising tool for extending our knowledge of the severity of myocardial ischaemic events in the various coronary syndromes. The rational roots of this development were originated from Albert Wollenberger's research work on the biochemistry of cardiac ischaemia and the transient acceleration of glycogenolysis mainly brought about by GP activation.

Anaerobiosis↗