Giant Mitochondria as Possible Bioindicators of Environmental Injuries in Fish Liver.

The effect of hypoxia (80 pHg) and simultaneously applied paraquat (1,1'-dimethyl-4,4-bipyridynum dichloride) was investigated on carp liver using electron microscopic methods. The appearance of giant mitochondria was the most conspicuous alteration in the liver cells. Most of the giant mitochondria were elongated and rod-shaped, often arranged side by side forming clusters beside the nucleus.

Sequential pattern of nerve-muscle contacts in the small intestine of developing human fetus. An ultrastructural and immunohistochemical study.

The developing enteric nervous system of the human fetus has been studied by means of electron microscopy and neuron-specific enolase immunocytochemistry between the 10th and 26th week of gestation, with special reference to the development of nerve-muscle contacts. In the 10th week of gestation the circular muscle layer is formed, followed by the appearance of a primitive myenteric plexus, and the longitudinal smooth muscle layer in the 12th week of gestation. Adherens-type junctions between the smooth muscle cells and the elements of the myenteric plexus, interdigitation of nerve and muscle processes, and also contacts without any morphological specialization are frequent until the 18th week, when the mechanical points of attachment are relocated from the circular to the longitudinal muscle layer.

Tyrphostin induces non-apoptotic programmed cell death in colon tumor cells.

The programmed cell death inducing effect of the EGF receptor tyrosine kinase inhibitor alpha-cyano-3,4-dihydroxycinnamthioamide (AG213) was investigated in vitro on HT-29 human colon tumor. AG213 at concentrations between 45 to 450 microM blocks the proliferation of HT-29 cells. Morphological findings suggest that the selective tyrosine kinase inhibitor AG213 induces Clarke III type (non-lysosomal vesiculate cytoplasmic) programmed cell death; unlike ATP analog non-selective tyrosine kinase inhibitors like Genistein which were found to induce apoptosis.

Histochemical and ultrastructural features of the developing enteric nervous system of the human foetal small intestine.

The developing enteric nervous system of the human foetus has been analyzed at the 10th and 18th week of gestation with a special reference to the development of nerve-muscle contacts. The myenteric plexus formation was analyzed by means of electron microscopy and on whole-mounts after NADH diaphorase histochemistry. The development of noradrenergic innervation as an extrinsic inhibitory supply was followed by means of a glyoxylic acid-induced fluorescence method.

The cisternal organelle as a Ca(2+)-storing compartment associated with GABAergic synapses in the axon initial segment of hippocampal pyramidal neurones.

The axon initial segment of cortical principal neurones contains an organelle consisting of two to four stacks of flat, membrane-delineated cisternae alternating with electron-dense, fibrillar material. These cisternal organelles are situated predominantly close to the synaptic junctions of GABAergic axo-axonic cell terminals. To examine the possibility that the cisternal organelle is involved in Ca2+ sequestration, we tested for the presence of Ca(2+)-ATPase in the cisternal organelles of pyramidal cell axons in the CA1 and CA3 regions of the hippocampus.