Histofluorescence of monoamines in newt forelimb regenerates

Summary Newt forelimb regenerates were studied at various stages of development using the histofluorescent method of Falck and Hillarp. A green formaldehyde-induced fluorescence was found in nerve fibres, large dendritic cells, skin gland cells and skin gland cell secretions. To ascertain the nature of the fluorescent material, animals were submitted to treatments with L-dopa, nialamide, benserazide and reserpine, used separately or in combination and administered before cutting off the regenerates. The modifications of the fluorescence after the various treatments confirmed the monoaminic nature of the fluorophores. Catecholaminic fibres were numerous in tissues of fast-growing stages while in dedifferentiated cell areas as well as in prochondral cell condensations and in cartilage they were completely absent. Fluorescent dendritic cells that have never been described before in regenerating limbs were observed and, from their localisation and cytological appearance, classed as promelanophores (or melanoblasts).     

Effects of Suanzaorentang on behavior changes and central monoamines

Previously, it was found that the ancient Chinese remedy of Suanzaorentang could be a promising anxiolytic drug (Chen and Hsieh, 1985a, Chen and Hsieh, 1985b). To understand the mechanism of the action of Suanzaorentang, the effects of Suanzaorentang on behavior changes and central monoamines and their metabolites were studied in rats. It was found that Suanzaorentang significantly (1) prolonged the period from the onset of clonic to tonic convulsions induced by pentylenetetrazol or picrotoxin, (2) prolonged the sleep duration induced by hexobarbital, (3) reduced locomotor activity, (4) enhanced the hypomotility induced by alpha-MT, (5) reduced the locomotor stimulation produced by levodopa plus benserazide, and (6) reduced central HVA, VMA, and 5-HIAA, but had no significant effects on central DA, NA, and 5-HT. These facts implied that Suanzaorentang decreased the turnover rate of central monoamines and central catecholaminergic activity.     

Mutagenicity studies of ambient airborne particles. II. Comparison of extraction methods

Organic materials were extracted with acetone from airborne particles by shaking, soxhletion and sonication for varying durations. 4-h, 1-h and 1/8-min extractions by shaking, soxhletion and sonication, respectively gave maximum his+ revertants with the Ames Salmonella/microsome assay. In a comparative study of extraction methods, sonication gave the highest and soxhletion the lowest mutagenic response. It appears that sonication with acetone is the best procedure for the extraction of mutagens from airborne particles as shown by Ames assay and Arar assay systems in Salmonella typhimurium.     

Fluorescence methods for the histochemical demonstration of monoamines

Summary The histochemical fluorescence method of Falck and Hillarp for the demonstration of catecholamines and certain tryptamines, e.g. 5-hydroxytryptamine is based on the principle that these amines can be condensed with formaldehyde to yield strongly fluorescent 6,7-dihydroxy-3,4-dihydroisoquinolines and 6-hydroxy-3,4-dihydro--carbolines respectively. The investigation here reported presents the fluorescence characteristics and relative fluorescence yields for formaldehyde treated biogenic monoamines and certain related compounds enclosed in a dried protein layer. The fluorescence properties of some synthetic 6,7-substituted-3,4-dihydroisoquinolines and 3,4-dihydro--carbolines are given, and the fluorescence characteristics in relation to the molecular structure are discussed.Abbreviations used A adrenaline - DA dopamine - DOPA 3,4-dihydroxyphenylalanine - DOPS 3,4-dihydroxyphenyl-serine - 5-HT 5-hydroxytryptamine - 5-HTP 5-hydroxytryptophan - 5-MT 5-methoxytryptamine - -m-DA -methyl-dopamine - -m-DOPA -methyl-3,4-dihydroxyphenylalanine - -m-NA -methyl-noradrenahne - MTA 3-methoxy-tyramine - NA noradrenaline - NM normetanephrine - T Tryptamine - Try Tryptophan     

Histofluorescence studies of monoamine neurons in the rat brain after cobaltous acetate intoxication

The aim was to study changes in brain monoamine neurons in an experimental animal model with an extrapyramidal motor syndrome of the parkinsonian type. The neurological signs were observed in rats after acute cobaltous acetate intoxication under mild ischemic conditions. Histofluorescence studies showed a decrease in catecholamine fluorescence (which signifies a decrease in the amine content) in the hypothalamus and mesencephalic reticular formation, but not in the substantia nigra or basal ganglia. Serotonin fluorescence was increased in nerve cell bodies of the dorsal and median raphe nuclei and in nerve terminals in some thalamic and preoptic regions. Histological staining of sections adjacent to the fluorescent ones showed no neuronal loss and some pathology of myelin. The disturbing effect of cobaltous ions on the neuronal transmission, and/or the imbalance between dopamine and serotonin in the extrapyramidal motor syndrome observed in poisoned rats have been discussed.     

Comparison of methods for calculating relative survival in population-based studies

Background: It is vital that unbiased estimates of relative survival are estimated and reported by cancer registries. A single figure of relative survival is often required to make reporting simpler. This can be obtained by pooling all ages or, more commonly, by using age-standardisation. The various methods for providing a single figure estimate of relative survival can give very different estimates. Methods: The problem is illustrated through an example using Finnish thyroid cancer data. The differences are further explored through a simulation study that investigates the effect of age on the estimates of relative survival. Results: The example highlights that in practice the all-age estimates from the various methods can be substantially different (up to 6 percentage units at 15 years of follow-up). The simulation study confirms the finding that differing estimates for the all-age estimates of relative survival are obtained. Performing age-standardisation makes the methods more comparable and results in better estimation of the true net survival. Conclusions: The all-age estimates of relative survival rarely give an appropriate estimate of net survival. We feel that modelling or stratifying by age when calculating relative survival is vitally important as the lack of homogeneity in the cohort of patients leads to potentially biased estimates. We feel that the methods using modelling provide a greater flexibility than life-table based approaches. The flexible parametric approach does not require an arbitrary splitting of the time-scale, which makes it more computationally efficient. It also has the advantage of easily being extended to incorporate time-dependent effects.     

Histochemical localization of cholinesterases and monoamines in the central heart of Sepia officinalis L. (Cephalopoda)

Summary The central heart of the coleoid cephalopod, Sepia officinalis, was studied using acetylcholinesterase and fluorescence histochemistry. Using histo- and cytochemical reactions, acetylcholinesterase was localized in the axolemma and axoplasm of specific cardiac nerve fibres, as well as in the sarcolemma and within the sarcotubular system of the muscle cells. Butyrylcholinesterase exhibited a different distribution, being found only in the luminal trabecular muscle layer. Glyoxylic-acid-induced fluorescence indicated the presence of catecholamines (emission maximum 470 nm) in cardiac nerve axons. These histochemical findings support the hypothesis that noradrenaline and/or dopamine and acetylcholine act antagonistically as natural transmitters. Fluorophores indicating the presence of serotonin were not observed. The present results are discussed in the light of previous pharmacological findings.     

Histochemical localization of cholinesterases and monoamines in the central heart of Sepia officinalis L. (Cephalopoda)

The central heart of the coleoid cephalopod, Sepia officinalis, was studied using acetylcholinesterase and fluorescence histochemistry. Using histo- and cytochemical reactions, acetylcholinesterase was localized in the axolemma and axoplasm of specific cardiac nerve fibres, as well as in the sarcolemma and within the sarcotubular system of the muscle cells. Butyrylcholinesterase exhibited a different distribution, being found only in the luminal trabecular muscle layer. Glyoxylic-acid-induced fluorescence indicated the presence of catecholamines (emission maximum, 470 nm) in cardiac nerve axons. These histochemical findings support the hypothesis that noradrenaline and/or dopamine and acetylcholine act antagonistically as natural transmitters. Fluorophores indicating the presence of serotonin were not observed. The present results are discussed in the light of previous pharmacological findings.     

Comparison of fungal glucose oxidases. Chemical, physicochemical and immunological studies.

Glucose oxidases (beta-D-glucose:oxygen 1-oxidoreductase, EC 1.1.3.4) from two fungal genera (Aspergillus and Penicillium) were studied chemically, physicochemically and immunologically to elucidate the similarities and dissimilarities between these enzymes. Investigation of circular dichroism spectra revealed that these enzymes proteins possess essentially identical conformations. However, differences found in thermal inactivation parameters, catalytic parameters and quantitative immunological reactivities indicate that these enzymes must have some minor but distinct variations in their structures. Interestingly, it was observed that the Penicillium enzyme cross-reacted with the antiserum against the Aspergillus enzyme with an association constant of two orders of magnitude lower than that of the Aspergillus enzyme, and that the precipitin one of the Penicillium enzyme fused together with that of the Aspergillus enzyme in the immunodouble diffusion test. These results lead to the conclusion that these enzymes are closely related but not completely identical, and suggest that they might have evolved from a common ancestral precursor.     

Effect of caponization on central nervous system monoamines in the Japanese quail

Depletion of brain regional norepinephrine (NE), dopamine (DA) after alpha methyl-paratyrosine (AMT), and serotonin (5HT) were measured in intact and caponized adult male Japanese quail (Coturnix coturnix japonica). Telencephalon, diencephalon, and cerebellum DA was depleted by AMT treatment, but brain stem was not affected. AMT-induced depletion of NE was greatest in telencephalon, diencephalon, and brain stem of capons. Neither caponization nor AMT affected brain regional 5HT. The results from this work indicate that caponization will affect catecholamine dynamics in brain regions other than the hypothalamus.     

Identification and quantitative measurements of biogenic monoamines in the central nervous tissue of some gastropods

Investigations were carried out to determine levels of biogenic monoamines in the central nervous tissue of seven species of terrestrial gastropods (taxonomic family: Helicidae) using high-performance liquid chromatography (HPLC) with electrochemical detection (ELCD). The central nervous tissue of all species examined contained assayable amounts of dopamine (DA) and serotonin (5-HT). Noradrenaline (NA) was occasionally present; adrenaline (A) could not be detected. The central ganglia of two Mediterranean species generally contain 3-4 times more 5-HT relative to DA than the ganglia of the other species which contain amounts of 5-HT only slightly higher than DA.