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.

Ultra structural differentiation and the renewal of the receptor cells in the sensory epithelia of the lips and the anterior tentacles of the snail Helix pomatia.

Renewal and ultrastructure of the receptor cell bodies in the sensory epithelia of the lips and anterior tentacles of helix pomatia were studied by light microscopic autoradiography and electron microscopy. The autoradiography revealed continuous mitosis in the receptor cell mass of both organs. After a short survival time (30 min) following the 3H-thymidine injection only heavily labelled cell pairs could be located predominantly at the periphery of the sensory lobules.

Ultrastructure of the developing muscle and enteric nervous system in the small intestine of human fetus.

The ultrastructural organization and some histochemical characteristics of the enteric nervous system (ENS) were investigated in 10- and 18-week-old human fetuses. In the 10-week-old human fetus immature myoblasts, and mostly neuroblasts were found in the ganglia. Simple, undifferentiated neuropil was observed among neuronal cells.

Immunohistochemical and ultrastructural study of the enteric nervous system of earthworm, Lumbricus terrestris L.

Light and electronmicroscopic data reveal the presence of a well developed nerve plexus in the gut of the earthworm. The plexus contains subepithelial solitary nerve cells and fibers and an extensive neuropil among the muscle cells. There are two types of nerve cells in the enteric plexus.

Detection of phenol-induced subcellular alteration by electron microscopy in the liver and panceres of carp.

A sublethal dose (5 mg L(-1)) of phenol was applied in the experiment. Liver and pancreas samples were taken at 24, 48, 72, and 96 hr for electron microscopy. The following alterations were manifested during the experiment: amitosis, irregular nuclear forms, decrease of chromatin, nucleolar segregation and numerous phagosomes and autophagic vacuoles in the cytoplasm.

Effect of sublethal concentrations of phenol on some enzyme activities and blood sugar level of carp (Cyprinus carpio L.).

To measure the phenol induced tissue necrosis and its adverse effects on nervous system, GOT, GPT, LDH, AChE enzyme activities and blood sugar level detections were used under aquarium conditions and in field experiments.Under aquarium conditions all experimental animals survived 5 ppm phenol concentration even at 96 hr exposure time. However the increase of plasma GOT, GPT, and LDH activities reflected serious tissue damage.

The effects of pesticides on some biochemical parameters of carp (Cyprinus carpio L.).

Treatments with copper sulphate (CuSO4), paraquat (PQ) and methidathion (MD) caused tissue damage and stress effects in carp, indicated by the increased lactate dehydrogenase (LDH), glutamic oxaloacetic transaminase (GOT), and glutamate dehydrogenase (GIDH) enzyme activities and elevated blood-sugar levels. Copper sulphate, administered together with PQ and MD, were synergistic in terms of tissue damage and stress effects. The isoenzyme patterns showed organ-specific tissue damage.

Distribution of GABA-like immunoreactivity in myenteric plexus of carp, frog and chicken.

The distribution of GABA-like immunoreactivity was studied by means of indirect immunocytochemical methods in some lower vertebrate species (carp, frog, chicken). An immunoreactive network was revealed in the myenteric plexus of the alimentary canal of carp. GABA-positive nerve cells were attached closely to the fibres in the stomach.

Electron microscopic structure of the cephalic gland of the bee Andrena variabilis Smith (Hymenoptera: Apoidea).

The structure of the glandular tissue located beneath the eye sulcus in Andrena variabilis Smith was studied by means of light and electron microscopy. The glandular tissue was found to be constituted of single-layered, high cylindrical epithelial cells. Electron microscopy revealed strong foldings of the cell membrane on the basal pole of the gland cells.

Histochemical characterization of myenteric plexus in domestic fowl small intestine.

The myenteric plexus of the domestic fowl (Gallus domesticus) small intestine was studied by means of silver staining, glyoxylic acid-induced fluorescence, the modified Koelle-Friedenwald method for the detection of acetylcholinesterase, NADH-diaphorase techniques and the unlabelled antibody method involving the use of an antiserum raised against GABA conjugated by glutaraldehyde to bovine serum albumin. The majority of the perikarya were in the ganglia, with an average density of 3370 +/- 942 nerve cells/cm2. Cholinesterase-positive and a few GABA-immunoreactive nerve cell bodies were seen in the myenteric ganglia, while fluorescent ganglion cells were not observed.

Myenteric plexus of frog large intestine: light and electron microscopy of fiber system and neurons.

The myenteric plexus of the frog large intestine was studied by means of silver impregnation, NADH-diaphorase histochemistry and electron microscopy. The main fiber bundles of the myenteric plexus are situated between the longitudinal and circular smooth muscle layers. Most of the branches of this main plexus could be followed into the circular muscle layer.

Acetylcholinesterase in the alimentary canal of fish: light and electron microscopic detection, quantitative distribution in different segments of the gut.

The acetylcholinesterase activity was measured and histochemically localized in the alimentary tract of 2 fish species, carp (Cyprinus carpio) and tench (Tinca tinca). A comparison was made of the activities in the different gut segments. Light and electron microscopic histochemistry revealed acetylcholinesterase-positive cell bodies along the entire length of the alimentary canal in both species, between the muscular layers.

Visualization of non-synaptic release sites in the myenteric plexus of the snail Helix pomatia.

Following conventional glutaraldehyde-osmium tetroxide fixation, a rich myenteric plexus was detected in the gastrointestinal tract of the snail Helix pomatia. Although hundreds of nerve processes were observed in the extensive myoneural neuropil, true synaptic specializations were not recognized in them. In the absence of synaptic specializations, tannic acid-Ringer incubation was applied to visualize the non-synaptic release sites in the enteric nerve plexus.

Enteric neuromuscular junctions: comparison of ultrastructural features in different phylogenetic groups.

The enteric neuromuscular junctions of snail (Helix pomatia), locust (Locusta migratoria migratorioides), cockroach (Periplaneta americana), carp (Cyprinus carpio) and tench (Tinca tinca) were studied by means of different light and electron microscopic methods. The nitroblue tetrazolium staining revealed that the myenteric plexuses of the above species are composed of nerve cells, a network of varicose nerves and nerve bundles. Instead of highly organized ganglia, single neurons or small groups of 2-4 cells are characteristic of the invertebrates and fish studied.

Comparison of effects of paraquat and methidation on enzyme activity and tissue necrosis of carp, following exposure to the pesticides singly or in combination.

Under aquarium conditions, treatment with the herbicide paraquat (PQ) and with the insecticide methidation (MD) caused cell damage and stress in carp (Cyprinus carpio L.), as shown by increases in glutamate-dehydrogenase (GIDH, EC 1.4.

Fine structure of the neuromuscular junctions in the alimentary tract of phylogenetically different animal species.

Authors studied the fine structural characteristics of the neuromuscular junctions in the alimentary tract of phylogenetically different animal species. Nearly in each studied species the so-called close contacts were observable, where the sarcolemma and axolemma establish a junction; the gap of this contact is 10-100 nm wide, and the neurotransmitters can affect the muscles through non-synaptic release (exocytosis). The junctional gap is widest in the gut wall of earthworm: 100-200 nm.

Localization and quantitative distribution of biogenic monoamines in the intestinal tract of locust, snail and carp.

The localization and quantitative distribution of the biogenic monoamines of the intestinal tract has been studied in Locusta migratoria, Helix pomatia and Cyprinus carpio with morphological and biochemical methods. Electron microscopically dense-core vesicles of aminergic character were found in the varicose nerve fibres located in the intestinal muscles of all three animal species. Intensive green fluorescence characteristic of catecholamines was detectable in both the varicose nerve fibres and perikarya.

Fine structure of the neuromuscular junction in the small intestine of a teleostean fish: tench (Tinca tinca L.).

Innervation of the midgut musculature has been studied in the tench (Tinca tinca) by light and electron microscopic methods. Smooth and striated muscle layers of the tunica muscularis of the gut are innervated by the same nerve bundles. Thick nerve bundles are found in the connective tissue between the two muscle layers projecting branches into both the smooth and striated muscle layers.

Cytochemical demonstration of cyclic 3',5'--AMP phosphodiesterase in the superior cervical ganglion of the rat.

The localization of cyclic 3',5'-phosphodiesterase in the superior cervical ganglion of the rat was studied by an ultrastructural cytochemical method. Large amounts of evenly distributed electron dense granular reaction products were detectable on the cytoplasmic processes of Schwann cells while a discontinuous and rough reaction product was observed in the postganglionic neurones. Usually, a significant number of lead phosphate deposits was found in the capillaries but endothelial cells sometimes were free from the reaction product.

Neuromuscular transmission in the visceral muscle of locust oviduct.

Innervation of the locust oviduct has been investigated with morphological and electrophysiological methods. Using Co2+ and Ni2+ labelling technique, it was found that G7 N2B1 and B2a nerves innervate the oviduct musculature. Ultrastructurally two different terminals could be distinguished: (a) nerve endings containing mainly clear vesicles forming neuromuscular junctions with the muscle fibers; and (b) nerve terminals containing electron-dense granules which showed only "synaptoid" structures, but failed to form junctions with the muscle cells.

Ultrastructural organization of the round window membrane in the infant human middle ear.

Ultrastructural studies of the round window membrane in infants revealed that the membrane is made up of three layers. The relatively wide outer epithelial layer consists of 3-4 cell layers and is formed by cuboidal and round cells. The outer two or three cell layers contain mainly rough endoplasmic reticulum and secretory granules, indicative of a secretory function of the epithelial cell layer of middle ear mucosa.