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K J Halbhuber

Publications and source records attributed to K J Halbhuber.

150 records · Page 9Linked to original sources
PubMedDate not supplied

Ultrastructure and reproduction behaviour of single CHO-K1 cells exposed to near infrared femtosecond laser pulses.

In the present work, the authors investigated ultrastructural changes as well as the reproduction behaviour of preselected single CHO-K1 cells exposed to 170 femtosecond laser pulses at different power output levels in comparison with cells outside the illumination volume. The ultrashort laser pulses were provided by an 80 MHz Ti:sapphire laser at 780 nm. The cells were scanned ten times with a scan rate of 1/16 s(-1). Single CHO-K1 cells exposed to low mean power of 2 mW revealed no significant changes in ultrastructure after laser exposure. In some cases, changes of mitochondria with slight disordering of cristae were found. Cytoplasm was filled with vesicles that seemed to be released from Golgi stacks. Cells irradiated with higher powers demonstrated more dramatic changes in ultrastructure. A considerable number of swollen mitochondria in conjunction with loss of cristae was observed. The main event of mitochondrial changes was the formation of electron dense bodies in the mitochondrial matrix. In addition, lumen of endoplasmatic reticulum was enlarged. Highest applied mean laser power of 12.5 mW lead to complete destruction of mitochondria and their transformation to electron dense structures containing membrane material. Compared with cell targets irradiated with 2 mW mean power, the release of vesicles from Golgi stacks seemed to be rather moderate. Cells localised outside the laser beam revealed no ultrastructural changes. Low mean laser power at 2 mW was unable to impair the reproduction behaviour of CHO-K1 cells. At higher laser power output levels, CHO-K1 cells started to delay cell division. At 12.5 mW, no cell division occurred. The obtained results may be helpful in recommending parameters for safe femtosecond laser microscopy of living specimens.

Animals↗
PubMedDate not supplied

Procainized murine macrophages fail in the agglutination of opsonized isologous erythrocytes.

Murine peritoneal macrophages exhibit numerous slender microvilli and several invaginations of the cell membrane. By treatment with isotonic 2.10(-2) M procain-PBS the surface of macrophages is smoothed significantly. Isolated macrophages agglutinate opsonized isologous erythrocytes. Procainizing of macrophages inhibits this agglutination. The finding provides evidence for typing of macrophage receptors whether or not sensitive to procain treatment.

Agglutination↗
PubMedDate not supplied

Electron microscopical demonstration of alkaline phosphatase activity with the cerium-based method in citrate-containing medium at pH 9.3 and the influence of glutaraldehyde fixation.

A cerium-based incubation medium, developed for the light microscopical demonstration of alkaline phosphatase activity, was tried out for the electron microscopical demonstration of this enzyme in kidney and heart muscle of the rat. The medium is very stable and the pH is in the optimum range of the enzyme. The medium consists of 14 mM CeCl3, 11 mM Na-citrate, 4 mM MgCl2, 10 mM p-nitrophenyl phosphate, 0.18 M glycine/NaOH buffer, pH 9.3. Other concentrations of cerium and citrate were tried out as well but 14 mM CeCl3, and 11 mM Na-citrate gave the best results with a small amount of non-specific reaction product in the nucleus that can be largely avoided by postincubation rinsing in cerium-containing buffer. In the kidney reaction product was only present along the microvilli of the proximal tubular epithelial cells. In the glomerulus no reaction product could be found whereas light microscopical cryotome sections contained activity in the glomerulus. Replacement of glutaraldehyde by formaldehyde fixatives resulted in reaction product in glomerular and tubular basement membranes, on podocyte plasma membranes and in tubular basal infoldings. In glutaraldehyde-fixed heart muscle, reaction product was present in the basement membranes and on lateral plasma membranes of endothelial cells of blood capillaries.

Alkaline Phosphatase↗