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  • sediments  (42)
  • Immunocytochemistry  (29)
  • Springer  (71)
  • American Chemical Society
  • Cambridge University Press
  • 1980-1984  (71)
  • 1945-1949
  • 1925-1929
  • 1982  (71)
  • 1925
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  • Springer  (71)
  • American Chemical Society
  • Cambridge University Press
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  • 1980-1984  (71)
  • 1945-1949
  • 1925-1929
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Hydrobiologia 91-92 (1982), S. 207-216 
    ISSN: 1573-5117
    Keywords: sediments ; water column ; nitrification ; denitrification ; experiments ; modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This research examines the role of sediment nitrification and denitrification in the nitrogen cycle of Hamilton Harbour. The Harbour is subject to large ammonia and carbon loadings from a waste-water treatment plant and from steel industries. Spring ammonia concentrations rapidly decrease from 4.5 to 0.5 mg 1−1, while spring nitrate concentrations increase from 1 to 2 mg l−1, by mid-summer. A three-layer sediment model was developed. The first layer is aerobic; in it, oxidation of organics and nitrification occurs. The second layer is for denitrification, and the third layer is for anaerobic processes. Ammonia sources for nitrification include diffusion from the water column, sources associated with the oxidation of organics, sources from denitrification and from anaerobic processes. Diffusion of oxygen, ammonia and nitrate across the sediment-water interface occurs. Temperature effects are modelled using the Arrhenius concept. A combination of zero-order kinetics for nitrate or ammonia consumption with diffusion results in a half-order reaction, with respect to the water column loss rate to sediments. From experimental measurement, the rate of nitrification is 200 mg N 1−1 sediment per day, while that of denitrification is 85 mg N 1–1 sediment per day at 20 °C. The Arrhenius activation energy is estimated as 15 000 cal/ mole-K and 17 000 cal/ mole-K for nitrification and denitrification, respectively, between 10 °C and 20 °C. Calculations of the flux of ammonia with the sediments, using the biofilm model, compare favourably with experimental observations. The ammonia flux from the water column is estimated to account for 20% of the observed decrease in water column stocks of ammonia, while the nitrate flux from the water column is estimated to account for 25% of the total nitrogen produced by the sediments.
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  • 2
    Electronic Resource
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    Springer
    Hydrobiologia 91-92 (1982), S. 341-353 
    ISSN: 1573-5117
    Keywords: Impoundment ; sediments ; particle size ; major ions ; nutrients ; cation exchange
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract As part of an ecosystem study of a small mesotrophic turbid impoundment in the semi-arid part of South Africa, an investigation was made of the particle size distribution, organic content and inorganic chemical composition of the sediment. Nine transects 50 m apart were made during February 1980. Sediments were sampled with an Eckman grab. The following analyses were made: size fractionation by wet sieving, cation exchange capacity, exchangeable Na, K, Ca, Mg and PO4, total P, and loss on ignition. From the results it was clear that the finer particles, in or near the original river bed, had higher cation exchange capacity, total P, exchangeable phosphorus and organic content. Littoral areas with avian habitat and extensive macrophyte vegetation, contained coarser sediments. Organic detritus apparently migrated to the deeper part of the impoundment. Sediments of lacustrine and fluvial origin were identified by means of the Passega classification.
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  • 3
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    Hydrobiologia 91-92 (1982), S. 235-240 
    ISSN: 1573-5117
    Keywords: sediments ; nutrients ; loading estimates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Studies of nutrient loadings, to shallow culturally eutrophied Alberta lakes, suggest internal inputs are significant. In this regard, estimation of bottom sediment P loads to Lake Wabamun (80 km2, 5.5 m $$\bar x$$ depth) were examined. Initially we determined the spatial variability in Total Organic Content (% loss on ignition) and Total Phosphorus, as indicators. Phosphorus fractions and biologically available phosphorus (BAP) were measured at specific stations. These data showed a very uniform distribution in sediment type with a Total Organic Content of 40.6 ± 3.3 (95% C.L.) at the west end, gradually declining to 26.3 ± 0.9 at the east end. Transects performed at routine monitoring stations indicate the representativeness of each station, e.g., station 2, 40.8 ± 1.3 (10 sites). One explanation of this uniformity is provided from210Pb analysis of shallow cores which indicate mixing to a depth of 16 cm. This is also thought to explain the mechanics of P loading to the water phase. Finally, Total Organic Content relates well to BAP (r2 = 0.80). It is hoped that this simple technique may well permit more precise extrapolation to whole lake BAP estimates at least on this lake.
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  • 4
    ISSN: 1573-5117
    Keywords: sediments ; uranium ; radium ; radionuclides ; models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Uranium mining and milling operations can contribute to environmental degradation through the increased release of naturally-occurring radionuclides. However, studies of the interactions of these radionuclides with freshwater sediments have been limited. The present study examined the vertical distribution of uranium, thorium, radium-226, polonium-210 and lead-210 in undisturbed sediment cores collected in the vicinity of mining, milling and exploration activities. Uranium levels in surface sediments ranged from 1.9 to 5650 µg g−1, Ra-226 from 〈0.1 to 480 pCi g−1 and Pb-210 from 0.8 to 931 pCi g−1 in the samples reported here, with the highest values occurring downstream of waste rock disposal areas. Concentrations usually decreased with depth, and there was little evidence of any strong effect of bioturbation on radionuclide profiles at the scale examined here. Mathematical models of uranium and radium-226 adsorption on and movement into the sediment were constructed, based on expected adsorption coefficients and estimated loading. The model predictions of radionuclide distribution with depth were qualitatively similar to those actually measured, but the predicted concentrations were generally lower than those observed, both in unaffected areas and in areas adjacent to uranium extraction activities.
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  • 5
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    Hydrobiologia 91-92 (1982), S. 587-596 
    ISSN: 1573-5117
    Keywords: dating ; sediments ; geomagnetic variations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Field and laboratory methods, developed to recover the record of past secular variations of geomagnetic declination and inclination carried by the remanent magnetization of some lake sediments, are described. Type curves, delineating these parameters through post-Glacial time, have now been constructed for Europe and east-central N. America. These curves, once established for any region, are useful for dating lake sediments from that region. The principal inclination features exhibited by the European curves can also be identified along the N. American curves with a delay of some 600 years, on average.
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  • 6
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    Hydrobiologia 91-92 (1982), S. 611-622 
    ISSN: 1573-5117
    Keywords: zoobenthos ; Great Lakes ; sediments ; radionuclides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Recent sediments of the North American Great Lakes are inhabited by numerous species of macrobenthos which alter the physical and chemical properties of sediments and modify interface transport characteristics. Distributions of such radionuclides as cesium-137, lead-210, and isotopes of plutonium exhibit a zone of constant activity extending down from the sediment-water interface from 1 to 15 cm. Recent studies have confirmed that radiometrically determined mixed depths are consistent with the vertical distribution of oligochaete worms and the amphipod,Pontoporeia hoyi. Generally, 90% of the benthos are contained within the radiometrically defined mixed zone. Where comparisons are possible, rates of sediment reworking by ‘conveyor belt’ species are comparable to or exceed sedimentation rates. Systematic variations in the mixed depth occur within depositional basins with greatest depths tending to be associated with least consolidated, organically rich materials. A quantitative steady-state mixing model accounts satisfactorily for observed radioactivity and heavy metal profiles. Bioturbation appears to be an important process, limiting the resolution with which historical records of particle-associated contaminants may be reconstructed from sediment cores. As bioturbation serves to maintain contact of contaminated sediments with overlying water, this time may also characterize the long-term lake recovery for contaminants removed by burial. As the time varies with location, a mean for an entire lake is not well known, but is on the order of 20 years for Lake Huron.
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  • 7
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    Hydrobiologia 91-92 (1982), S. 463-471 
    ISSN: 1573-5117
    Keywords: iron ; manganese ; sediments ; water ; transport ; model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A model is presented which describes the transport of iron and manganese in the vicinity of a redox boundary. It is based on input of a particulate component, to form a point source, from which soluble species diffuse along a concentration gradient. The shapes of concentration-depth profiles in marine and freshwater sediments and water columns are reviewed and discussed in terms of the model. Transport, either entirely within a water column or within the sediment, may be simply treated because the rate of vertical transport can be regarded as constant. The discontinuity in the rate of vertical transport which occurs at the sediment-water interface can provide a complicated example of the model, especially when it coincides with the redox boundary. Authigenic mineral formation processes can modify the model, sometimes to such an extent that it becomes invalid. This is particularly true for soluble iron profiles in organically rich marine sediments. Sampling interval is critical to the resultant profile shape and must be relevant to the particular environment, e.g. metres in water columns and millimetres in sediments. The differences in the rates of reduction and oxidation of iron and manganese tend to modify both the position of the profile with respect to the redox-cline and its stage of development in a seasonally anoxic system. It is these factors which determine why most of the iron which reaches a sediment is permanently incorporated whereas manganese is re-released. This mechanism determines the average ratio of iron to manganese in sedimentary rocks. The development of peaked profile shapes in water columns implies that under certain conditions dissolved iron and manganese may be transported from the water column to the pore waters of the sediment.
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  • 8
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    Hydrobiologia 91-92 (1982), S. 597-602 
    ISSN: 1573-5117
    Keywords: eutrophication ; diagenesis ; sediments ; nitrogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sediment cores were taken from near maximum depth in 15 Florida lakes representing a wide range of trophic conditions. Chemical analyses of surface sediments showed Al, Fe, and Ca to be the most abundant elements in all samples, and the ratio of Al to Ca to be smaller for eutrophic lakes. Sediment organic matter increased with trophic state, as did the degree to which it was enriched in nitrogen. Corresponding sediment C/N ratios decreased with increasing lake trophic state and showed significant negative correlation with chlorophyll a, total N, and total P in the water column. Concentrations of sedimentary chlorophyll derivatives showed some relation to trophic state but differences in basin morphometry hinder its use as an inter-lake index of chlorophyll production.
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  • 9
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    Hydrobiologia 91-92 (1982), S. 207-216 
    ISSN: 1573-5117
    Keywords: sediments ; water column ; nitrification ; denitrification ; experiments ; modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This research examines the role of sediment nitrification and denitrification in the nitrogen cycle of Hamilton Harbour. The Harbour is subject to large ammonia and carbon loadings from a waste-water treatment plant and from steel industries. Spring ammonia concentrations rapidly decrease from 4.5 to 0.5 mg 1−1, while spring nitrate concentrations increase from 1 to 2 mg l−1, by mid-summer. A three-layer sediment model was developed. The first layer is aerobic; in it, oxidation of organics and nitrification occurs. The second layer is for denitrification, and the third layer is for anaerobic processes. Ammonia sources for nitrification include diffusion from the water column, sources associated with the oxidation of organics, sources from denitrification and from anaerobic processes. Diffusion of oxygen, ammonia and nitrate across the sediment-water interface occurs. Temperature effects are modelled using the Arrhenius concept. A combination of zero-order kinetics for nitrate or ammonia consumption with diffusion results in a half-order reaction, with respect to the water column loss rate to sediments. From experimental measurement, the rate of nitrification is 200 mg N 1−1 sediment per day, while that of denitrification is 85 mg N 1–1 sediment per day at 20 °C. The Arrhenius activation energy is estimated as 15 000 cal/ mole-K and 17 000 cal/ mole-K for nitrification and denitrification, respectively, between 10 °C and 20 °C. Calculations of the flux of ammonia with the sediments, using the biofilm model, compare favourably with experimental observations. The ammonia flux from the water column is estimated to account for 20% of the observed decrease in water column stocks of ammonia, while the nitrate flux from the water column is estimated to account for 25% of the total nitrogen produced by the sediments.
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  • 10
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    Hydrobiologia 91-92 (1982), S. 1-1 
    ISSN: 1573-5117
    Keywords: symposium ; sediments ; freshwater
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 11
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    Hydrobiologia 91-92 (1982), S. 463-471 
    ISSN: 1573-5117
    Keywords: iron ; manganese ; sediments ; water ; transport ; model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A model is presented which describes the transport of iron and manganese in the vicinity of a redox boundary. It is based on input of a particulate component, to form a point source, from which soluble species diffuse along a concentration gradient. The shapes of concentration-depth profiles in marine and freshwater sediments and water columns are reviewed and discussed in terms of the model. Transport, either entirely within a water column or within the sediment, may be simply treated because the rate of vertical transport can be regarded as constant. The discontinuity in the rate of vertical transport which occurs at the sediment-water interface can provide a complicated example of the model, especially when it coincides with the redox boundary. Authigenic mineral formation processes can modify the model, sometimes to such an extent that it becomes invalid. This is particularly true for soluble iron profiles in organically rich marine sediments. Sampling interval is critical to the resultant profile shape and must be relevant to the particular environment, e.g. metres in water columns and millimetres in sediments. The differences in the rates of reduction and oxidation of iron and manganese tend to modify both the position of the profile with respect to the redox-cline and its stage of development in a seasonally anoxic system. It is these factors which determine why most of the iron which reaches a sediment is permanently incorporated whereas manganese is re-released. This mechanism determines the average ratio of iron to manganese in sedimentary rocks. The development of peaked profile shapes in water columns implies that under certain conditions dissolved iron and manganese may be transported from the water column to the pore waters of the sediment.
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  • 12
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    Hydrobiologia 91-92 (1982), S. 597-602 
    ISSN: 1573-5117
    Keywords: eutrophication ; diagenesis ; sediments ; nitrogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sediment cores were taken from near maximum depth in 15 Florida lakes representing a wide range of trophic conditions. Chemical analyses of surface sediments showed Al, Fe, and Ca to be the most abundant elements in all samples, and the ratio of Al to Ca to be smaller for eutrophic lakes. Sediment organic matter increased with trophic state, as did the degree to which it was enriched in nitrogen. Corresponding sediment C/N ratios decreased with increasing lake trophic state and showed significant negative correlation with chlorophylla, total N, and total P in the water column. Concentrations of sedimentary chlorophyll derivatives showed some relation to trophic state but differences in basin morphometry hinder its use as an inter-lake index of chlorophyll production.
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  • 13
    ISSN: 1573-5117
    Keywords: microbial metabolism ; phosphorus ; sediments ; oligotrophic lake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Rapid microbial metabolism and a large phosphorus uptake potential were observed in surface sediments of Lake George, New York. This sediment (termed the flocculent layer) also exhibited a phosphorus limited condition and a large reservoir of inorganic phosphorus associated with humic substances. These observations suggest that the empirically observed phosphorus retention in oligotrophic lake sediments may be promoted by a rapid cycling of phosphorus between microflora and its associated organic matter.
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  • 14
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    Hydrobiologia 91-92 (1982), S. 689-695 
    ISSN: 1573-5117
    Keywords: standardization ; heavy metals ; sediments ; base-line levels ; chemical partition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In studies of heavy metals in sediments, there is a need for standardization of the procedures for sample collection and preservation, chemical analyses and presentation of results. The method and depth of sampling depend on the aim of the investigation and on local sediment conditions, such as consistency of the sediment, rate of sedimentation, diagnetic processes and bioturbation. Therefore no general recommendations can be given in this respect. During collection and preservation, contamination and loss of constituents ust be avoided. In sediments, the best means for estimating total contents of metals is digestion with HF, in combination with strong acids. Other methods include X-ray fluorescence and neutron activation analyses. The use of HF is considered objectionable by some laboratories. A reasonable alternative is aqua regia. Because variations in granular composition affect metal contents, it is advisable to use the fraction 〈 63 μm for the analysis. Chemical partition of sediments provides an insight into the source of metallic constituents, and their pathways to deposition areas. A three-step extraction procedure, in the sequence 0.1 M hydroxylamine-HCl, H2O2 30% and HF, is proposed. Finally, attention is paid to the anthropogenic enrichment of metals in sediments. The establishment of base-line levels is discussed.
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  • 15
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    Hydrobiologia 91-92 (1982), S. 155-160 
    ISSN: 1573-5117
    Keywords: heavy metals ; zinc ; lakes ; sediments ; pollution ; industrial load ; sedimentation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The distribution of zinc in Lake Vanajavesi and Lake Mallasvesi, South Finland, was determined on the basis of water and sediment studies. Lake Vanajavesi is one of the most polluted of large inland lakes, in Finland. The zinc load comes mainly from industrial sources. Lake Mallasvesi, situated near Vanajavesi, is in almost natural condition. The water samples were taken by a Ruttner sampler. In collecting sediment samples, a freezing technique was used. The results of zinc analyses indicate that, during several winters, zinc has spread with waste water to different parts of L. Vanaja against the main course of flow. A close correlation between sedimentation of zinc and waste discharge from a textile factory was found in the present study.
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  • 16
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    Hydrobiologia 91-92 (1982), S. 689-695 
    ISSN: 1573-5117
    Keywords: standardization ; heavy metals ; sediments ; base-line levels ; chemical partition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In studies of heavy metals in sediments, there is a need for standardization of the procedures for sample collection and preservation, chemical analyses and presentation of results. The method and depth of sampling depend on the aim of the investigation and on local sediment conditions, such as consistency of the sediment, rate of sedimentation, diagnetic processes and bioturbation. Therefore no general recommendations can be given in this respect. During collection and preservation, contamination and loss of constituents ust be avoided. In sediments, the best means for estimating total contents of metals is digestion with HF, in combination with strong acids. Other methods include X-ray fluorescence and neutron activation analyses. The use of HF is considered objectionable by some laboratories. A reasonable alternative is aqua regia. Because variations in granular composition affect metal contents, it is advisable to use the fraction 〈 63 μm for the analysis. Chemical partition of sediments provides an insight into the source of metallic constituents, and their pathways to deposition areas. A three-step extraction procedure, in the sequence 0.1 M hydroxylamine-HCl, H2O2 30% and HF, is proposed. Finally, attention is paid to the anthropogenic enrichment of metals in sediments. The establishment of base-line levels is discussed.
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  • 17
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    Hydrobiologia 91-92 (1982), S. 71-84 
    ISSN: 1573-5117
    Keywords: sediments ; lakes ; seas ; oceans ; energy relationships ; population statistics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sediments in the marine environment are generally subject to higher energy levels than those of lake systems, and lakes are virtually unaffected by tidal range which modifies beach structures formed in response to wave effects. However, despite different energy levels, the textural characteristics of both marine and lacustrine sediments are very similar. The main difference between marine and lacustrine facies is the depth range over which these characteristics remain consistent. In lakes, depth limitation may influence the development of surface waves and restrict textural distributions. Simple textural relationships can be used to describe comparable marine and lacustrine sedimentary conditions. Sediments which have been altered by post-depositional erosion, such as lag deposits, or by ice-drop or wind blown settlement, show comparable textural modifications. The settlement of silt and clay size particulates, in the marine environment and lakes, may differ slightly because of the chemical differences between salt and fresh water.
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  • 18
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    Hydrobiologia 91-92 (1982), S. 697-700 
    ISSN: 1573-5117
    Keywords: sediments ; Mössbauer spectroscopy ; iron ; phosphorus ; geochemistry ; analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Iron compounds of phosphorus form a large part of the phosphorus bound in sediments. Mössbauer spectroscopy is a technique that enables us to study, directly, chemical forms of iron in solid samples. Mössbauer spectroscopy allowed us to check, directly, the selectivity of the extraction scheme for soil phosphorus proposed by Chang & Jackson (1957), but only as far as the iron compounds are concerned. It appears that selectivity of the extraction method leaves much to be desired.
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  • 19
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    Hydrobiologia 91-92 (1982), S. 175-188 
    ISSN: 1573-5117
    Keywords: simulation ; sediments ; radioisotopes ; heavy metals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the Athabaska sandstone region of northern Saskatchewan, mining and milling of uranium-bearing ore is subjecting, and will continue to subject, surface waters to inputs of soluble heavy metals and uranium and thorium decay series radioisotopes. A mathematical simulation model was developed to assess the role of riverine sediments in regulating soluble concentrations of heavy metals and radioisotopes released to the environment through treated mining and milling process effluents. Specific elements studied included As, Ni, Pb, U, and Ra-226. The model considered that diffusion into sediment porewater and adsorption by sediment particulates from sediment porewater were the two dominant mechanisms regulating sediment loading. Experiments indicated that the equilibrium adsorption behaviour of the heavy metals and radioisotopes studied could be adequately explained using a linear adsorption isotherm, over the range of concentrations expected in the environment. Experimentally determined linear isotherm slopes ranged from 200 ml g−1 to 21 000 ml gl. Diffusion into the effective depth of the sediments (20 cm) was modelled using a quadratic (second order) driving force and a corresponding mass transfer coefficient. The model coefficients were calibrated using field and laboratory data. Results of the modelling suggested that the sediments have a small effect on instream concentrations during the active phases of mining and milling. The sediments were predicted to accumulate sufficient adsorbed mass, during the operational phase of mining and milling, to act as a distributed instream source after completion of milling activities. The significance of this post-operational source was a function of the initial effluent loading, elapsed time and site specific river characteristics.
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  • 20
    ISSN: 1573-5117
    Keywords: microbial metabolism ; phosphorus ; sediments ; oligotrophic lake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Rapid microbial metabolism and a large phosphorus uptake potential were observed in surface sediments of Lake George, New York. This sediment (termed the flocculent layer) also exhibited a phosphorus limited condition and a large reservoir of inorganic phosphorus associated with humic substances. These observations suggest that the empirically observed phosphorus retention in oligotrophic lake sediments may be promoted by a rapid cycling of phosphorus between microflora and its associated organic matter.
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  • 21
    ISSN: 1573-5117
    Keywords: sediments ; uranium ; radium ; radionuclides ; models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Uranium mining and milling operations can contribute to environmental degradation through the increased release of naturally-occurring radionuclides. However, studies of the interactions of these radionuclides with freshwater sediments have been limited. The present study examined the vertical distribution of uranium, thorium, radium-226, polonium-210 and lead-210 in undisturbed sediment cores collected in the vicinity of mining, milling and exploration activities. Uranium levels in surface sediments ranged from 1.9 to 5650 µg g−1, Ra-226 from 〈0.1 to 480 pCi g−1 and Pb-210 from 0.8 to 931 pCi g−1 in the samples reported here, with the highest values occurring downstream of waste rock disposal areas. Concentrations usually decreased with depth, and there was little evidence of any strong effect of bioturbation on radionuclide profiles at the scale examined here. Mathematical models of uranium and radium-226 adsorption on and movement into the sediment were constructed, based on expected adsorption coefficients and estimated loading. The model predictions of radionuclide distribution with depth were qualitatively similar to those actually measured, but the predicted concentrations were generally lower than those observed, both in unaffected areas and in areas adjacent to uranium extraction activities.
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  • 22
    ISSN: 1573-5117
    Keywords: sediments ; uranium ; radium ; radionuclides ; models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Uranium mining and milling operations can contribute to environmental degradation through the increased release of naturally-occurring radionuclides. However, studies of the interactions of these radionuclides with freshwater sediments have been limited. The present study examined the vertical distribution of uranium, thorium, radium-226, polonium-210 and lead-210 in undisturbed sediment cores collected in the vicinity of mining, milling and exploration activities. Uranium levels in surface sediments ranged from 1.9 to 5650 µg g−1, Ra-226 from 〈0.1 to 480 pCi g−1 and Pb-210 from 0.8 to 931 pCi g−1 in the samples reported here, with the highest values occurring downstream of waste rock disposal areas. Concentrations usually decreased with depth, and there was little evidence of any strong effect of bioturbation on radionuclide profiles at the scale examined here. Mathematical models of uranium and radium-226 adsorption on and movement into the sediment were constructed, based on expected adsorption coefficients and estimated loading. The model predictions of radionuclide distribution with depth were qualitatively similar to those actually measured, but the predicted concentrations were generally lower than those observed, both in unaffected areas and in areas adjacent to uranium extraction activities.
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  • 23
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    Hydrobiologia 91-92 (1982), S. 697-700 
    ISSN: 1573-5117
    Keywords: sediments ; Mössbauer spectroscopy ; iron ; phosphorus ; geochemistry ; analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Iron compounds of phosphorus form a large part of the phosphorus bound in sediments. Mössbauer spectroscopy is a technique that enables us to study, directly, chemical forms of iron in solid samples. Mössbauer spectroscopy allowed us to check, directly, the selectivity of the extraction scheme for soil phosphorus proposed by Chang & Jackson (1957), but only as far as the iron compounds are concerned. It appears that selectivity of the extraction method leaves much to be desired.
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  • 24
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    Hydrobiologia 91-92 (1982), S. 235-240 
    ISSN: 1573-5117
    Keywords: sediments ; nutrients ; loading estimates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Studies of nutrient loadings, to shallow culturally eutrophied Alberta lakes, suggest internal inputs are significant. In this regard, estimation of bottom sediment P loads to Lake Wabamun (80 km2, 5.5 m $$\bar x$$ depth) were examined. Initially we determined the spatial variability in Total Organic Content (% loss on ignition) and Total Phosphorus, as indicators. Phosphorus fractions and biologically available phosphorus (BAP) were measured at specific stations. These data showed a very uniform distribution in sediment type with a Total Organic Content of 40.6 ± 3.3 (95% C.L.) at the west end, gradually declining to 26.3 ± 0.9 at the east end. Transects performed at routine monitoring stations indicate the representativeness of each station, e.g., station 2, 40.8 ± 1.3 (10 sites). One explanation of this uniformity is provided from210Pb analysis of shallow cores which indicate mixing to a depth of 16 cm. This is also thought to explain the mechanics of P loading to the water phase. Finally, Total Organic Content relates well to BAP (r2 = 0.80). It is hoped that this simple technique may well permit more precise extrapolation to whole lake BAP estimates at least on this lake.
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  • 25
    ISSN: 1573-5117
    Keywords: Hong Kong ; man-made lake ; marginal zone ; sediments ; Melanoides tuberculata ; freshwater gastropods ; allochthonous ; water-level fluctuations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A series of laboratory experiments were carried out in order to investigate the effects of selected physical and biotic processes on the substratum of a recently flooded gently sloping marginal zone of Plover Cove Reservoir, Hong Kong. The physical effects of disturbance of the sediments promoted the redistribution of organic matter, as shown by differences in the percentage of organic matter in the supernatant and residue resulting when reservoir mud was stirred. It is suggested that such a process would promote the transfer of allochthonous organic carbon from the marginal zone (the area of input of such material) to the rest of the water body. Substrate characteristics were also influenced by the activities of two species of benthic gastropod,Sinotaia quadrata andMelanoides tuberculata. These animals increased the rate of production of particles from soaked blocks of parent mud when compared with experimental treatments in the absence of snails. Additionally both species enhanced the production of aggregates from fine sediments with a particle size of less than 125 µm. The magnitudes of both processes were statistically significant. Laboratory observations showed thatM. tuberculata had a significantly faster rate of aggregate and fine particulate production thanS. quadrata and it is possible that the former species may have the capacity to modify the substrate characteristics of the newly flooded marginal zone of Plover Cove.
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  • 26
    ISSN: 1573-5117
    Keywords: lake stratification ; artificial destratification ; lake mixing ; heavy metals ; sediments ; benthic macroinvertebrates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ham's Lake was destratified in the summers of 1977 and 1978 by pumping surface water to the bottom. However, an arm was prevented from mixing by a submerged dam of a former farm pond and remained stratified. The concentration of manganese in the water increased to over 5 000 µg 1−1 in the hypolimnion of the anoxic arm in summer. Soluble manganese averaged 28% of total concentration. Total iron concentrations were relatively high in the water and sorbed iron values were extremely low in the sediments. Soluble iron averaged 12% of total concentration. Zinc values were low in the water and sediments. Chaoborus punctipennis and Chironomus riparius concentrated iron and zinc and discriminated against manganese. Concentration factors were unaffected by mixing.
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  • 27
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    Hydrobiologia 91-92 (1982), S. 697-700 
    ISSN: 1573-5117
    Keywords: sediments ; Mössbauer spectroscopy ; iron ; phosphorus ; geochemistry ; analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Iron compounds of phosphorus form a large part of the phosphorus bound in sediments. Mössbauer spectroscopy is a technique that enables us to study, directly, chemical forms of iron in solid samples. Mössbauer spectroscopy allowed us to check, directly, the selectivity of the extraction scheme for soil phosphorus proposed by Chang & Jackson (1957), but only as far as the iron compounds are concerned. It appears that selectivity of the extraction method leaves much to be desired.
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  • 28
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    Hydrobiologia 91-92 (1982), S. 597-602 
    ISSN: 1573-5117
    Keywords: eutrophication ; diagenesis ; sediments ; nitrogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sediment cores were taken from near maximum depth in 15 Florida lakes representing a wide range of trophic conditions. Chemical analyses of surface sediments showed Al, Fe, and Ca to be the most abundant elements in all samples, and the ratio of Al to Ca to be smaller for eutrophic lakes. Sediment organic matter increased with trophic state, as did the degree to which it was enriched in nitrogen. Corresponding sediment C/N ratios decreased with increasing lake trophic state and showed significant negative correlation with chlorophylla, total N, and total P in the water column. Concentrations of sedimentary chlorophyll derivatives showed some relation to trophic state but differences in basin morphometry hinder its use as an inter-lake index of chlorophyll production.
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  • 29
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    Hydrobiologia 91-92 (1982), S. 1-8 
    ISSN: 1573-5117
    Keywords: symposium ; sediments ; freshwater
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  • 30
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    Hydrobiologia 91-92 (1982), S. 71-84 
    ISSN: 1573-5117
    Keywords: sediments ; lakes ; seas ; oceans ; energy relationships ; population statistics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sediments in the marine environment are generally subject to higher energy levels than those of lake systems, and lakes are virtually unaffected by tidal range which modifies beach structures formed in response to wave effects. However, despite different energy levels, the textural characteristics of both marine and lacustrine sediments are very similar. The main difference between marine and lacustrine facies is the depth range over which these characteristics remain consistent. In lakes, depth limitation may influence the development of surface waves and restrict textural distributions. Simple textural relationships can be used to describe comparable marine and lacustrine sedimentary conditions. Sediments which have been altered by post-depositional erosion, such as lag deposits, or by ice-drop or wind blown settlement, show comparable textural modifications. The settlement of silt and clay size particulates, in the marine environment and lakes, may differ slightly because of the chemical differences between salt and fresh water.
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  • 31
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    Hydrobiologia 91-92 (1982), S. 121-130 
    ISSN: 1573-5117
    Keywords: sediments ; lead
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The anthropogenic stable lead content of the sediments of eight softwater Precambrian lakes in southern Ontario was measured at 34–92 sites per lake. Whole-lake anthropogenic lead burdens varied between only 610 and 770 mg m−2. There was no relationship between lead burden and either water replenishment time of the lake (TW) or the ratio of watershed area to lake area (Ad/A0), which varied by factors of 4 and 12 respectively. These results can be explained if a) the lead deposition in this region is uniform, and b) the only significant input of lead to the lakes is via deposition from the atmosphere directly on the lakes' surfaces. Therefore spatial differences in anthropogenic lead within a lake represent the redistribution or focusing pattern of the sediments.
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  • 32
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    Hydrobiologia 91-92 (1982), S. 341-353 
    ISSN: 1573-5117
    Keywords: Impoundment ; sediments ; particle size ; major ions ; nutrients ; cation exchange
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract As part of an ecosystem study of a small mesotrophic turbid impoundment in the semi-arid part of South Africa, an investigation was made of the particle size distribution, organic content and inorganic chemical composition of the sediment. Nine transects 50 m apart were made during February 1980. Sediments were sampled with an Eckman grab. The following analyses were made: size fractionation by wet sieving, cation exchange capacity, exchangeable Na, K, Ca, Mg and PO4, total P, and loss on ignition. From the results it was clear that the finer particles, in or near the original river bed, had higher cation exchange capacity, total P, exchangeable phosphorus and organic content. Littoral areas with avian habitat and extensive macrophyte vegetation, contained coarser sediments. Organic detritus apparently migrated to the deeper part of the impoundment. Sediments of lacustrine and fluvial origin were identified by means of the Passega classification.
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  • 33
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    Hydrobiologia 91-92 (1982), S. 587-596 
    ISSN: 1573-5117
    Keywords: dating ; sediments ; geomagnetic variations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Field and laboratory methods, developed to recover the record of past secular variations of geomagnetic declination and inclination carried by the remanent magnetization of some lake sediments, are described. Type curves, delineating these parameters through post-Glacial time, have now been constructed for Europe and east-central N. America. These curves, once established for any region, are useful for dating lake sediments from that region. The principal inclination features exhibited by the European curves can also be identified along the N. American curves with a delay of some 600 years, on average.
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  • 34
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    Hydrobiologia 91-92 (1982), S. 611-622 
    ISSN: 1573-5117
    Keywords: zoobenthos ; Great Lakes ; sediments ; radionuclides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Recent sediments of the North American Great Lakes are inhabited by numerous species of macrobenthos which alter the physical and chemical properties of sediments and modify interface transport characteristics. Distributions of such radionuclides as cesium-137, lead-210, and isotopes of plutonium exhibit a zone of constant activity extending down from the sediment-water interface from 1 to 15 cm. Recent studies have confirmed that radiometrically determined mixed depths are consistent with the vertical distribution of oligochaete worms and the amphipod, Pontoporeia hoyi. Generally, 90% of the benthos are contained within the radiometrically defined mixed zone. Where comparisons are possible, rates of sediment reworking by ‘conveyor belt’ species are comparable to or exceed sedimentation rates. Systematic variations in the mixed depth occur within depositional basins with greatest depths tending to be associated with least consolidated, organically rich materials. A quantitative steady-state mixing model accounts satisfactorily for observed radioactivity and heavy metal profiles. Bioturbation appears to be an important process, limiting the resolution with which historical records of particle-associated contaminants may be reconstructed from sediment cores. As bioturbation serves to maintain contact of contaminated sediments with overlying water, this time may also characterize the long-term lake recovery for contaminants removed by burial. As the time varies with location, a mean for an entire lake is not well known, but is on the order of 20 years for Lake Huron.
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  • 35
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    Hydrobiologia 91-92 (1982), S. 689-695 
    ISSN: 1573-5117
    Keywords: standardization ; heavy metals ; sediments ; base-line levels ; chemical partition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In studies of heavy metals in sediments, there is a need for standardization of the procedures for sample collection and preservation, chemical analyses and presentation of results. The method and depth of sampling depend on the aim of the investigation and on local sediment conditions, such as consistency of the sediment, rate of sedimentation, diagnetic processes and bioturbation. Therefore no general recommendations can be given in this respect. During collection and preservation, contamination and loss of constituents ust be avoided. In sediments, the best means for estimating total contents of metals is digestion with HF, in combination with strong acids. Other methods include X-ray fluorescence and neutron activation analyses. The use of HF is considered objectionable by some laboratories. A reasonable alternative is aqua regia. Because variations in granular composition affect metal contents, it is advisable to use the fraction 〈 63 μm for the analysis. Chemical partition of sediments provides an insight into the source of metallic constituents, and their pathways to deposition areas. A three-step extraction procedure, in the sequence 0.1 M hydroxylamine-HCl, H2O2 30% and HF, is proposed. Finally, attention is paid to the anthropogenic enrichment of metals in sediments. The establishment of base-line levels is discussed.
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  • 36
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    Hydrobiologia 91-92 (1982), S. 121-130 
    ISSN: 1573-5117
    Keywords: sediments ; lead
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The anthropogenic stable lead content of the sediments of eight softwater Precambrian lakes in southern Ontario was measured at 34–92 sites per lake. Whole-lake anthropogenic lead burdens varied between only 610 and 770 mg m−2. There was no relationship between lead burden and either water replenishment time of the lake (TW) or the ratio of watershed area to lake area (Ad/A0), which varied by factors of 4 and 12 respectively. These results can be explained if a) the lead deposition in this region is uniform, and b) the only significant input of lead to the lakes is via deposition from the atmosphere directly on the lakes' surfaces. Therefore spatial differences in anthropogenic lead within a lake represent the redistribution or focusing pattern of the sediments.
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  • 37
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    Hydrobiologia 91-92 (1982), S. 155-160 
    ISSN: 1573-5117
    Keywords: heavy metals ; zinc ; lakes ; sediments ; pollution ; industrial load ; sedimentation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The distribution of zinc in Lake Vanajavesi and Lake Mallasvesi, South Finland, was determined on the basis of water and sediment studies. Lake Vanajavesi is one of the most polluted of large inland lakes, in Finland. The zinc load comes mainly from industrial sources. Lake Mallasvesi, situated near Vanajavesi, is in almost natural condition. The water samples were taken by a Ruttner sampler. In collecting sediment samples, a freezing technique was used. The results of zinc analyses indicate that, during several winters, zinc has spread with waste water to different parts of L. Vanaja against the main course of flow. A close correlation between sedimentation of zinc and waste discharge from a textile factory was found in the present study.
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  • 38
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    Hydrobiologia 91-92 (1982), S. 175-188 
    ISSN: 1573-5117
    Keywords: simulation ; sediments ; radioisotopes ; heavy metals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the Athabaska sandstone region of northern Saskatchewan, mining and milling of uranium-bearing ore is subjecting, and will continue to subject, surface waters to inputs of soluble heavy metals and uranium and thorium decay series radioisotopes. A mathematical simulation model was developed to assess the role of riverine sediments in regulating soluble concentrations of heavy metals and radioisotopes released to the environment through treated mining and milling process effluents. Specific elements studied included As, Ni, Pb, U, and Ra-226. The model considered that diffusion into sediment porewater and adsorption by sediment particulates from sediment porewater were the two dominant mechanisms regulating sediment loading. Experiments indicated that the equilibrium adsorption behaviour of the heavy metals and radioisotopes studied could be adequately explained using a linear adsorption isotherm, over the range of concentrations expected in the environment. Experimentally determined linear isotherm slopes ranged from 200 ml g−1 to 21 000 ml gl. Diffusion into the effective depth of the sediments (20 cm) was modelled using a quadratic (second order) driving force and a corresponding mass transfer coefficient. The model coefficients were calibrated using field and laboratory data. Results of the modelling suggested that the sediments have a small effect on instream concentrations during the active phases of mining and milling. The sediments were predicted to accumulate sufficient adsorbed mass, during the operational phase of mining and milling, to act as a distributed instream source after completion of milling activities. The significance of this post-operational source was a function of the initial effluent loading, elapsed time and site specific river characteristics.
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  • 39
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    Hydrobiologia 91-92 (1982), S. 463-471 
    ISSN: 1573-5117
    Keywords: iron ; manganese ; sediments ; water ; transport ; model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A model is presented which describes the transport of iron and manganese in the vicinity of a redox boundary. It is based on input of a particulate component, to form a point source, from which soluble species diffuse along a concentration gradient. The shapes of concentration-depth profiles in marine and freshwater sediments and water columns are reviewed and discussed in terms of the model. Transport, either entirely within a water column or within the sediment, may be simply treated because the rate of vertical transport can be regarded as constant. The discontinuity in the rate of vertical transport which occurs at the sediment-water interface can provide a complicated example of the model, especially when it coincides with the redox boundary. Authigenic mineral formation processes can modify the model, sometimes to such an extent that it becomes invalid. This is particularly true for soluble iron profiles in organically rich marine sediments. Sampling interval is critical to the resultant profile shape and must be relevant to the particular environment, e.g. metres in water columns and millimetres in sediments. The differences in the rates of reduction and oxidation of iron and manganese tend to modify both the position of the profile with respect to the redox-cline and its stage of development in a seasonally anoxic system. It is these factors which determine why most of the iron which reaches a sediment is permanently incorporated whereas manganese is re-released. This mechanism determines the average ratio of iron to manganese in sedimentary rocks. The development of peaked profile shapes in water columns implies that under certain conditions dissolved iron and manganese may be transported from the water column to the pore waters of the sediment.
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  • 40
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    Hydrobiologia 91-92 (1982), S. 587-596 
    ISSN: 1573-5117
    Keywords: dating ; sediments ; geomagnetic variations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Field and laboratory methods, developed to recover the record of past secular variations of geomagnetic declination and inclination carried by the remanent magnetization of some lake sediments, are described. Type curves, delineating these parameters through post-Glacial time, have now been constructed for Europe and east-central N. America. These curves, once established for any region, are useful for dating lake sediments from that region. The principal inclination features exhibited by the European curves can also be identified along the N. American curves with a delay of some 600 years, on average.
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  • 41
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    Hydrobiologia 91-92 (1982), S. 611-622 
    ISSN: 1573-5117
    Keywords: zoobenthos ; Great Lakes ; sediments ; radionuclides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Recent sediments of the North American Great Lakes are inhabited by numerous species of macrobenthos which alter the physical and chemical properties of sediments and modify interface transport characteristics. Distributions of such radionuclides as cesium-137, lead-210, and isotopes of plutonium exhibit a zone of constant activity extending down from the sediment-water interface from 1 to 15 cm. Recent studies have confirmed that radiometrically determined mixed depths are consistent with the vertical distribution of oligochaete worms and the amphipod,Pontoporeia hoyi. Generally, 90% of the benthos are contained within the radiometrically defined mixed zone. Where comparisons are possible, rates of sediment reworking by ‘conveyor belt’ species are comparable to or exceed sedimentation rates. Systematic variations in the mixed depth occur within depositional basins with greatest depths tending to be associated with least consolidated, organically rich materials. A quantitative steady-state mixing model accounts satisfactorily for observed radioactivity and heavy metal profiles. Bioturbation appears to be an important process, limiting the resolution with which historical records of particle-associated contaminants may be reconstructed from sediment cores. As bioturbation serves to maintain contact of contaminated sediments with overlying water, this time may also characterize the long-term lake recovery for contaminants removed by burial. As the time varies with location, a mean for an entire lake is not well known, but is on the order of 20 years for Lake Huron.
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  • 42
    ISSN: 1573-5117
    Keywords: amino acids ; protein ; sediments ; ninhydrin reaction ; gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A sensitive modification of the ninhydrin-CO2 method involving the gas chromatographic determination of the total protein and amino acid content of sediment is described. The method gives a linear response over the amino acid concentration range 10−5 M to 4 × 10−2 M. It can be used for whole sediment, hydrolysates and interstitial water. The performance of the method is compared with the fluorescamine method for primary amines.
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  • 43
    ISSN: 1432-0878
    Keywords: Vertebrate-type neuropeptides ; Neuroendocrine system of insects ; Neurosecretion ; Peptidergic neurons ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The presence and differential distribution of substances antigenically related to known vertebrate neuropeptides demonstrated within the corpus cardiacum of the insect Leucophaea are as follows: Of ten mammalian antisera tested, six yielded substantial immunoreactive deposits resembling oxytocin, somatostatin, Substance P, met-enkephalin, bombesin, and neurotensin, respectively. In the remaining four, the reaction was moderate (vasopressin, β-endorphin) or marginal (LH-RF, calcitonin). With regard to their regional distribution, these biochemically distinct reaction products seem to fall into two groups: (1) Materials resembling oxytocin, vasopressin, met-enkephalin, β-endorphin (and presumably also neurotensin and LH-RF) predominate in the central release area of the organ and are considered to be of extrinsic (cerebral) origin. (2) Substances localized primarily in areas rich in intrinsic glandular cells of the corpus cardiacum, and revealed by antisera raised against somatostatin, Substance P, and bombesin, are judged to be synthesized and stored within this organ. In peptidergic fibers entering the adjacent corpora allata, thus far Substance P-, β-endorphin-, and LH-RF-like immunoreactivities have been demonstrated. Some of these “new” neuropeptides may be contained in classical neurosecretory neurons, formerly identified by less specific methods, others must be assigned to additional peptidergic neurons heretofore unknown.
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  • 44
    ISSN: 1432-0878
    Keywords: Immunocytochemistry ; Cardioactive peptide ; Lymnaea stagnalis ; Neurohormone ; Neurotransmitter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary With an antiserum to the molluscan cardioactive tetrapeptide FMRF-amide immunoreactive perikarya and nerve fibers were identified in the central and peripheral nervous system of the pond snail Lymnaea stagnalis. Their localization is described. The same antiserum yielded reactive product in particular cells of the epithelium of the alimentary tract. The use of two different fixatives, glutaraldehyde, and a mixture of glutaraldehyde, picric acid, and acetic acid (GPA) showed that certain nerve cells can be identified only in material fixed with either the one or the other of these two fixatives, a result which indicates that in Lymnaea more than one FMRF-amide-like substance may occur. “Positive” axon endings were found in the periphery of various nerves, i.e., in places where neurohormones are released into the blood. Other fibers were found to end, probably synaptically, on other neurons, on epithelial cells in the stomach, and between muscle cells in various parts of the body, e.g., in the heart. In these cases the FMRF-amide-like substance may function as a neurotransmitter or a neuromodulator.
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  • 45
    ISSN: 1432-0878
    Keywords: Rat brain ; Hypothalamus ; Prolactin ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The presence of prolactin (PRL)-like material is demonstrated in the brain of rats with the aid of anti-ovine PRL (oPRL) IgG as primary antibody in the unlabeled antibody-enzyme method. Immunoreactive deposits are visualized as an intraneuronal constituent with a widespread distribution in the hypothalamus and neural lobe of the pituitary. Dense networks of reactive nerve terminals derived from two prominent fibre tracts, a ventral (VHT) and a dorsal hypothalamo-neurohypophysial tract (DHT) are seen. The VHT is confined to the median eminence and pars oralis tuberis, the DHT to the pars caudalis tuberis. Both fibre tracts pass through the infundibular stalk into the neural lobe. The origin of the immunoreactive nerve terminals can be elucidated only to some extent. The VHT gives off beaded fibres entering the ependymal and glandular layer of the median eminence. Immunoreactive perikarya are observed in the supraoptic nucleus, the paraventricular nucleus, the anterior hypothalamic nucleus, the anterior commissural nucleus, the preoptic nucleus and the interstitial nucleus of the stria terminalis. A few of the immunoreactive perikarya are observed in close connection with brain vessels and the ependymal cells of the third ventricle. The results indicate that the anti-oPRL has a unique region specificity implying that only a segment of the mammalian PRL molecule is present in these nuclei of the brain. Fragments of PRL may function as neuromodulators or neurotransmitters in the rat brain.
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  • 46
    ISSN: 1432-0878
    Keywords: Cryo-ultramicrotomy ; Immunocytochemistry ; Pituitary gland ; Gonadotropic cells ; Salmo gairdneri
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The most frequently occurring cell types in the pars distalis of the pituitary gland of the rainbow trout, (i) the lactotropic, (ii) the gonadotropic, and (iii) the somatotropic cells, were identified in cryosections. Their morphological characteristics were compared with those of Epon-embedded material. Cell location, cell form, position of the nucleus, arrangement of rough endoplasmic reticulum and sizes of secretory granules proved to be useful parameters for identification. The size distribution of secretory granules of corresponding cells in cryosections and Epon sections proved to be similar. Additionally, both the immunoferritin and the unlabeled antibody enzyme method were applied for the immunocytochemical labeling of gonadotropic hormone-producing cells in cryosections. Anti-salmon-GTH as well as anti-carp-GTH serum showed the presence of GTH in both the smaller and the larger granules of the classical GTH cells, but also produced a reaction in TSH cells. Labelling of TSH cells was absent when using anti-β-carp-GTH. Specificity of the reaction depended upon the degree of dilution of the anti-GTH serum. Results with dilutions of 1∶4,000 and 1∶8,000 in the unlabeled antibody enzyme method, and of 1∶8,000 up to 1∶32,000 in the immunoferritin technique were optimal. Acid phosphatase activity in the smaller granules was demonstrated by enzyme cytochemistry in Epon sections. The relationship of the presence of hormone in these granules is discussed. The high sensitivity of the immunocytochemical labeling procedure is discussed with respect to cryo-ultramicrotomy.
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  • 47
    ISSN: 1432-0878
    Keywords: Substance P ; Immunocytochemistry ; Neurohypophysis ; Hypothalamus ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Substance-P immunoreactivity has been located in semithin sections of mouse hypothalami and pituitaries and compared with the distribution of other hypothalamic peptides. In the mouse, nerve fibres and terminals reacting with antibodies against substance P (SP) were detected both in the external zone of the median eminence (ME) and in the neural lobe of the pituitary. Immunoreactive SP (ISP) axons of the ME did not react with antibodies against other peptides, i.e. arginine-vasopressin (AVP), oxytocin (OT), somatostatin and enkephalin, and were also negative with an antibody to serotonin. In the neural lobe, SP immunostaining occurred in AVP but not in OT axons. In the hypothalamus, ISP axons were widespread but conspicuously lacking in areas containing AVP neurones, i. e. in the suprachiasmatic nucleus and the clusters of AVP cells in the SO and PV nuclei. In contrast, multiple ISP endings were seen in contact with OT neurones. Immunoreactive cell bodies, only detected after colchicine treatment, belonged to two distinct classes of neurones: 1) single AVP neurones of the SO and PV nuclei; 2) specific (staining only for SP) neurones, scattered or grouped in different areas of the hypothalamus, not showing relationship with any circumscribed nucleus. These results reinforce the opinion that SP can be released as a neurohormone into the vascular portal system and can directly affect the pars distalis. The presence of immunoreactive SP in the neural lobe, which has not been reported in species other than the mouse, may have a different physiological significance.
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  • 48
    ISSN: 1432-0878
    Keywords: Substantia nigra (rat) ; Substance P ; Striatonigral pathway ; Immunocytochemistry ; Synaptic vesicles ; Synapses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A monoclonal antibody that recognises the C-terminal part of substance P was used to study immunoreactive structures in the substantia nigra by the unlabeled antibody, peroxidase-antiperoxidase procedure. Immunoreactivity was present in nerve fibres in all parts of the substantia nigra, particularly in the pars reticulata and pars lateralis. Electron microscopically two types of bouton immunoreactive for substance P were found: Type 1 contained large electron-lucent vesicles, occasional large granulated vesicles and formed symmetrical synapses with dendrites. Type 2 boutons contained smaller, round electron-lucent vesicles, many large granular vesicles and formed asymmetrical synapses (having prominent postjunctional dense bodies) with dendrites and perikarya. Immunoreactive fibres with varicosities that had been identified light microscopically were studied in serial sections in the electron microscope. Each identified varicosity contained synaptic vesicles and formed a single synapse. An individual fibre formed boutons of only one kind (type 1 or type 2) and could form multiple synapses with the same neuron. Thus, an identified fibre in the pars compacta had eight varicosities, each of which was in synaptic contacts (type 2) with the dendrites or soma of the same neuron. The results are consistent with the concept that substance P is a synaptic transmitter in the substantia nigra and indicate that neurons in this region may receive a significant input from substance P-containing afferents, and that there are at least two types of such afferent fibres.
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  • 49
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    Cell & tissue research 223 (1982), S. 627-639 
    ISSN: 1432-0878
    Keywords: Immunocytochemistry ; Progesterone-binding protein (PBP) ; Placenta ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cellular localization of progesterone-binding protein (PBP) in the guinea-pig placenta was studied by use of immunocytochemical procedures. Within the chorioallantoic placenta, a strong positive reaction was observed in the interlobar and marginal trophoblast from the third week of gestation to term. PBP was localized in the cytoplasm of the syncytiotrophoblast, and the nuclei were never stained. At the ultrastructural level, the immunoreaction was associated with the rough endoplasmic reticulum, the Golgi apparatus and the perinuclear space. No deposits were seen in any other cell organelles. This localization strongly suggests that the interlobar syncytium is related to PBP synthesis. In the labyrinth, a weak immunoreaction was observed by light microscopy around some blood lacunae. At the ultrastructural level the dense deposits were localized in vesicles located near the maternal lacunae. The distribution of PBP was also studied by light microscopy in other tissues from pregnant guinea-pig. No PBP, or PBP-like material, was detected inside cells from liver, muscle, heart, lung, kidney, ovary, and uterus. A weak immunoreaction for PBP was detected in vascularized zones of these organs. These observations strongly suggest that PBP, a protein related to gestation in the guinea-pig, is elaborated by the placental tissue of this hystricomorph rodent. PBP is the first steroid-binding plasma protein shown to be of extrahepatic origin.
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  • 50
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    Cell & tissue research 223 (1982), S. 695-698 
    ISSN: 1432-0878
    Keywords: Pineal gland ; Luteinizing hormone-releasing hormone (LHRH) ; Immunocytochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Immunoreactive luteinizing hormone-releasing hormone (LHRH)-like material has been demonstrated in the pineal gland of the adult rat. The objective of the present study was to examine the ontogenetic development of this LHRH-like substance in the rat pineal with the peroxidase-antiperoxidase (PAP) method of Sternberger. LHRH-like immunoreactive material was not observed in pineal glands of newborn rats. The amount of material increased progressively from the 6th–12th day of postnatal development. On day 12, the amount of LHRH-like immunoreactivity was consistent and comparable in all pineal glands of male and female animals examined.
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  • 51
    ISSN: 1432-0878
    Keywords: Gonadotrophs ; Male rats ; Immunocytochemistry ; Cytophotometry ; Image analysis
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    Topics: Biology , Medicine
    Notes: Summary Quantitative studies on the population of the gonadotropic cells in the pituitary of adult male rats were performed after trypsic dissociation of the pituitary glands and immunoenzymatic staining with anti-β-LH or anti-β-FSH antisera. Number, area and extinction of labelled cells were measured by use of an image analyser and a cytophotometer. The gonadotrophs represent approximately 14% of the pituitary cells. The mean area of gonadotrophs is significantly larger after staining with anti-β-LH serum than after staining with anti-β-FSH serum. Planimetric measurement of the gonadotrophs reveals their variability in size ranging between 30 and 160 μm2. Moreover, the size distribution depends on the staining serum used: more numerous small-sized cells (〈75 μm2) are stained with anti-β-FSH serum than with anti-β-LH serum, which conversely stains more numerous large-sized cells. Cytophotometric measurements indicate that immunostaining varies greatly among cells of the same size class and that the staining intensity appears to increase according to the cell size. These results emphasize the morphofunctional heterogeneity of the gonadotropic cell population.
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  • 52
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    Keywords: Somatostatin ; Immunocytochemistry ; CSF-contacting neurons ; Hypothalamus ; Xenopus laevis, tadpoles ; Amphibia, Anura
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In untreated tadpoles of Xenopus laevis, stage 60 (Nieuwkoop and Faber 1956), somatostatin-immunoreactive perikarya and fiber networks are already discernible in the pallium and the septum, as well as in the anterior and posterior hypothalamus. In addition, somatostatin-immunoreactive cerebrospinal fluid (CSF)-contacting neurons were found in the periventricular gray of the most caudal division of the ventral tuber cinereum. The results are discussed with respect to the inhibitory influence of the system of CSF-contacting and other somatostatin-immunoreactive neurons on the anterior pituitary and other target sites, especially during the climax of metamorphosis.
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  • 53
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    Cell & tissue research 225 (1982), S. 79-93 
    ISSN: 1432-0878
    Keywords: Immunoreactive prolactin ; Immunocytochemistry ; Circumventricular organs ; Choroid plexus
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    Topics: Biology , Medicine
    Notes: Summary Immunoreactive prolactin (IMP) has been localized in the male rat brain using the soluble peroxidase-anti-peroxidase (PAP) technique. In normal untreated animals, reaction product was seen in choroid plexus (CP) and in ependymal cells of the ventricular lining with heaviest concentrations of positively staining cells in the 3rd ventricle near the subcommisural organ (SCO), in the lateral ventricles near the subfornical organ (SFO), and in the 4th ventricle near the area postrema (AP). IMP was also present in numerous ependymal cells resembling tanycytes in the cerebral aqueduct, central canal of the spinal cord at the level of the AP, the organum vasculosum of the lamina terminalis (OVLT) and the floor of the infundibular recess. Immunoreactive cells resembling neurons were localized within the substance of the AP, SCO, and OVLT. IMP was also present in fibers of the zona externa of the median eminence and infundibular stalk; a few cells of the pars tuberalis contained reaction product. Hypophysectomized rats and bromocriptine-treated rats exhibited a similar staining pattern except that bromocriptine treatment eliminated IMP from most CP cells. Hypophysectomy, bromocriptine or estrogen treatment enhanced staining for IMP in cells of the pars tuberalis; estrogen treatment or hypophysectomy produced an increase in the number and distribution of immunoreactive cells as well as increased density of reaction product in cells of the medial habenular nucleus. The functional relevance of prolactin in these locations in the brain, the possible routes of transport of prolactin from the pituitary gland to the central nervous system, and the strong suggestion of extra-pituitary sites of synthesis of a prolactin-like hormone are discussed.
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  • 54
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    Keywords: Domestic fowl ; Hypothalamus ; LHRH-neurosecretion ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The location of LHRH-containing neuronal elements was investigated in the domestic fowl by means of immunohistochemical techniques. LHRH antisera were raised against synthetic LHRH in the rabbit. The antiserum used in the present study cross-reacted with LHRH of mammalian and avian tissues. LHRH-immunoreactive perikarya are located in the preoptic and in the septal areas, and in the bulbus olfactorius; however, no LHRH-immuno-reactive perikarya were found in the tuberal part of the hypothalamus. LHRH-immunoreactive fibers course from these areas toward the median eminence mainly along the wall of the third ventricle in the form of a periventricular network. Originating from the same cell groups other fibers run caudally immediately above the optic chiasma, forming the median bundle of the tractus preoptico-infundibularis. The third bundle running toward the OVLT is named the tractus preoptico-terminalis. In addition to these structures, LHRH-containing fibers and terminals were also present in different regions of the limbic system, in the dorsal part of the hippocampus, in the tuberculum and bulbus olfactorius, as well as in the optic lobe, nuclei commissurales tectales, organon subcommissurale, periaqueductal area, and pars ventralis mesencephali. The general distribution of the LHRH system in the chicken corresponds principally to that described previously in rodents (Sétáló et al. 1976, 1978). However, some subtle differences were demonstrated between the location of the LHRH system in birds and mammals.
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  • 55
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    Cell & tissue research 227 (1982), S. 93-112 
    ISSN: 1432-0878
    Keywords: Neurophysins ; Immunocytochemistry ; Age-dependent changes ; Hypophysectomy ; Rat
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    Topics: Biology , Medicine
    Notes: Summary The hypothalamo-extrahypophyseal neurophysin pathways (HEH) and the three hypothalamic nuclei secreting neurophysins, the supraoptic (SON), paraventricular (PVN) and suprachiasmatic (SCN) nuclei, of normal and hypophysectomized rats were studied by application of the immunoperoxidase procedure. Eight well-defined HEH pathways were recognized. Their main sites of projection were: lateral septum and subfornical organ (1 and 2); tractus diagonalis (3); medial nucleus of the amygdala and lateral ventricle (4); nucleus periventricularis thalami, nucleus habenulae lateralis and periaqueductal gray (5); periaqueductal gray, pineal organ, collicular recess and subependymal region of the fourth ventricle (6); dorsomedial nucleus and premammillary area (7); perimammillary region, corpus trapezoideum, ventral surface of medulla oblongata, nucleus tractus solitarii, nucleus commissuralis, substantia gelatinosa and formatio reticularis lateralis of the medulla oblongata and spinal cord (8). Neurophysin fibers of unknown origin were found in the frontal cerebral cortex. It was noted that in pathway 5 the amount of immunostainable material undergoes changes with age. The three neurophysin-secreting nuclei reacted differently following hypophysectomy. Among the HEH pathways the only one that seemed to be affected by hypophysectomy was that innervating the lateral septum. It is suggested that the neurons that survive hypophysectomy either do not project to the neural lobe or, alternatively, display axon collaterals projecting outside the neural lobe. Such a neuronal population could be the origin of the HEH pathways.
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  • 56
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    Cell & tissue research 227 (1982), S. 423-427 
    ISSN: 1432-0878
    Keywords: Liver (Rat) ; Albumin ; Metabolism ; Hepatocytes ; Immunocytochemistry ; Nutrition
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    Topics: Biology , Medicine
    Notes: Summary The indirect immunoperoxidase method was used to identify albumin in hepatocytes of rats before and after periods of starvation. All hepatocytes in fed rats contained a relatively large amount of nascent albumin. Overnight fasting reduced the number of hepatocytes with a large amount of albumin to primarily those surrounding terminal hepatic venules. These were estimated to be about 30% of the population. The other cells had only a slight amount of albumin. After 48 h of fasting all hepatocytes contained a low level of albumin.
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  • 57
    ISSN: 1432-0878
    Keywords: Luteinizing hormone ; releasing hormone ; Immunocytochemistry ; Distribution ; Forebrain ; Rat
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    Notes: Summary The distribution of luteinizing hormone-releasing hormone (LHRH)-immunoreactive perikarya and processes was examined, in the untreated rat, with the unlabeled antibody enzyme method of immunocytochemistry on thick 50 μm vibratome sections. LHRH neurons were primarily observed in the preoptico-anterior hypothalamic and septal areas. Projections from these cell bodies to the median eminence form three distinct pathways, one laterally along the course of the optic tracts, one medially through the periventricular stratum of the third ventricle, and one through the tractus infundibularis. In addition, some of these cell bodies project to the organum vasculosum of the lamina terminalis (OVLT) and the subfornical organ (SFO). LHRH immunoreactive neurons were also noted in the anterior olfactory regions; they project along the medial olfactory tract to the olfactory bulb.
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  • 58
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    Cell & tissue research 222 (1982), S. 81-100 
    ISSN: 1432-0878
    Keywords: Turtle ; Immunocytochemistry ; Pars tuberalis ; Pituitary ; Hormones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Examination of pituitaries from young and adult turtles representing four families, reveals that in addition to the abundant juxtaneural pars tuberalis (JuxPT) found in this class of reptiles, there is generally a substantial amount of pars tuberalis (PT) tissue closely associated with the pars distalis (PD). The PT forms a cortical layer especially conspicuous around the anterior tip of the PD in some species (Trionyx, Kinosternon, Sternotherus), or it forms a thick dorsal layer of tissue irregularly extending onto the sides of the PD in others (Pseudemys, Chrysemys, Lepidochelys, Chelonia). Immunocytochemical studies using unlabelled second antibody and peroxidase-antiperoxidase reveal that in turtles of all ages, the PT tissue allied with the PD (the PTinterna) is composed primarily of cells containing glycoprotein hormones (FSH, LH and TSH), especially the gonadotropins. The juxPT, however, consists mainly of secretory cells unstained by the antisera tested and includes only a small number of gonadotropes and thyrotropes. Although usually widely distributed in the testudinate adenohypophysis, the great majority of gonadotropes and thyrotropes present in the hatchling are in the PTinterna. It is probable that a concentration of these cells in the PTinterna is widespread among vertebrates. In all turtles examined, lactotropes occur principally in the anterior and ventral part of the PD proper; somatotropes are posterior and dorsal. Corticotropes are concentrated as the lactotropes in the anterior PD, but some are also scattered throughout the posterior half of the gland. Lactotropes, corticotropes, and with a few exceptions, somatotropes, do not occur in PT tissue in the turtle.
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  • 59
    ISSN: 1432-0878
    Keywords: Neuropeptides ; Substance P ; Uvea ; Immunocytochemistry ; Iris ; Smooth muscle contraction ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Substance P-immunoreactive nerve terminals were found in several locations in the anterior segment of the rabbit eye. In the iris they occurred in the sphincter muscle and were randomly distributed in the iris stroma with some fibres running close to the dilator muscle. In the ciliary body these immunoreactive elements were few and occurred within bundles of nerve fibres, while in the ciliary processes they were more numerous with a predominantly subepithelial location. Blood vessels in the anterior uvea were often surrounded by substance P-immunoreactive fibres. No substance P-fibres were found in the cornea, while the sclera contained very few such elements. Using conventional in vitro techniques it was found that the sphincter pupillae muscle of the iris responded to electrical stimulation with a contraction that was resistant to cholinergic and adrenergic blockade, but was inhibited by the neuronal blocker tetrodotoxin. This indicates the existence of a non-cholinergic, non-adrenergic neuronal mediator of the contractile response. Exogenously applied substance P produced a long-lasting contraction of the spincter muscle, an observation compatible with the view that substance P is the noncholinergic, non-adrenergic neurotransmitter involved.
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  • 60
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    Cell & tissue research 223 (1982), S. 287-303 
    ISSN: 1432-0878
    Keywords: Neuropeptides ; Avian brain ; Endocrine glands ; Avian embryos ; Immunocytochemistry
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    Topics: Biology , Medicine
    Notes: Summary In embryos of the domestic mallard, domestic fowl, and Japanese quail vasotocin-, mesotocin-, luliberin (LHRH)-, met-enkephalin-, cortico- tropin-, and somatostatin-immunoreactive perikarya and fiber formations were visualized at different incubation stages by means of the PAP technique (Sternberger 1979). The most striking results were: (1) Vasotocin-, mesotocin-, and luliberin-immunoreactive systems display, up to the late embryonic period, morphological features most probably related to a neurohormonal function. (2) Met-enkephalin immunoreactivity appears very late during embryonic life; it is restricted to fiber networks and not found in perikarya. (3) Corticotropin immunoreactivity is observed in the tuberal region temporarily at the end of the second and the beginning of the last third of the incubation period. (4) Somatostatin-immunoreactive material is present (i) at the end of the first third of incubation, in association with the olfactory system; (ii) during the same period, adjacent to thin-layered portions of the roof of the brain; (iii) shortly thereafter, in cells of both pancreatic primordia and thyroid gland; and (iv) onward from the middle of the incubation period, in a mesencephalic cell group. The striking difference, in the early embryo, between the mature somatostatin system and the immature character of the surrounding tissues may indicate that somatostatin plays a role in the development of the brain, as well as the pancreas, and the thyroid gland.
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  • 61
    ISSN: 1432-0878
    Keywords: Newborn rat epidermis ; Soluble epidermal protein ; Thiolproteinase inhibitor ; Immunocytochemistry
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    Topics: Biology , Medicine
    Notes: Summary Subcellular distribution of a thiol-proteinase inhibitor protein was determined in the epidermis of the newborn rat by light and electron microscopy. This protein was highly soluble in basal cells and concentrated on ribosomes in the perinuclear region. Solubility in Tris buffer decreased in granular and cornified cells in which the protein appeared on polysomes which were attached on other cellular structures such as dense homogenous deposits and tonofilaments. The protein also appeared to be deposited on the plasma membrane and became insoluble in Tris buffer at 37° C, but solubilized in 1 M phosphate buffer. Location of the protein around keratohyalin granules or by the plasma membrane suggested that the inhibitor protein bound to cysteinerich protein of the epidermis with or without forming a thiol-proteinase inhibitor complex. The thiol-proteinase inhibitor protein seems to contribute to epidermal cell differentiation at multiple points through changes in its solubility and subcellular localization from basal cells to cornified cells.
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  • 62
    ISSN: 1432-0878
    Keywords: Cholecystokinin ; Spinal cord ; Immunocytochemistry ; Rat ; Neuropeptides
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    Topics: Biology , Medicine
    Notes: Summary Cholecystokinin-like immunoreactivity has been demonstrated by radioimmunoassay and immunocytochemistry in the spinal cord of various mammals, in particular in nerve fibers of the superficial layers of the posterior column, but had not been detected in neuronal cell bodies. We report immunohistochemical evidence for the presence of a group of cholecystokinincontaining neuronal cell bodies in the lumbar spinal cord of the rat. This group of cells is only visualized after direct injection of colchicine into the spinal cord and is located near the central canal in the intermedio-medial nucleus of area X of Rexed.
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  • 63
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    Cell & tissue research 224 (1982), S. 25-31 
    ISSN: 1432-0878
    Keywords: Spleen ; Ig-containing cells ; Immunocytochemistry ; Germinal center ; Rat
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    Topics: Biology , Medicine
    Notes: Summary The morphology and localisation of IgM- and IgG-containing cells in the spleen of rats immunized with sheep red-blood cells (SRBC) were studied by combining immunohistochemical reactions with routine histological and histochemical methods. It was shown that IgM cells occur only in the outer periarteriolar lymphocyte sheath (PALS), whereas IgG cells are present throughout the whole PALS. It has been concluded that these cell types have different routes of migration. Both IgM- and IgG-containing cells were found in the germinal center in close relation with the extracellular immune complexes. The significance of this localisation is discussed.
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  • 64
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    Cell & tissue research 224 (1982), S. 361-368 
    ISSN: 1432-0878
    Keywords: Steroids ; Pituitary ; Gonadotrops ; Immunocytochemistry ; Teleosts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Immunocytochemical reactions with anti-h(uman) TSHβ and anti-c(arp) GTHβ indicate that in juvenile rainbow trout, the dorsal basophils of the proximal pars distalis (ppd) are TSH cells, and that the ventral ones are GTH cells. Small GTH cells first appear in some fish at D(ay) 50 following fertilization (= D17 from hatching), when gonads are still undifferentiated. GTH cells increase greatly in number and size after D100. Contrary to treatment with 11β(OH)androstenedione, addition of methyl testosterone, progesterone and 17α(OH)progesterone stimulate the development of granular GTH cells in rainbow trout, shortly after hatching. It is suggested that steroid receptors in the brain or pituitary discriminate between 11-steroids and other steroids rather than between aromatizable androgens and other steroids.
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  • 65
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    Cell & tissue research 225 (1982), S. 581-594 
    ISSN: 1432-0878
    Keywords: Immunocytochemistry ; Oligodendrocytes ; Cell culture ; Maturation
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    Topics: Biology , Medicine
    Notes: Summary Antiserum produced in rabbits against purified myelin contains antibodies that bind to the surface of cells having multiple branched processes in live cultures of cerebral hemispheres of newborn rats. The identity of these cells was determined by double immunolabelling experiments with other specific antigenic markers (W1 Wolfgram protein, myelin basic proteins, glial fibrillary acidic protein). It was demonstrated that the cells are a subclass of oligodendrocytes which have reached a certain degree of maturation; nearly all of them contain basic proteins. Indeed, a number of oligodendrocytes, that contain the W 1 protein, and may or may not have processes, are not surface-labelled in similar conditions. The usefulness of such an anti-myelin serum in the isolation of pure oligodendrocytes is discussed.
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  • 66
    ISSN: 1432-0878
    Keywords: Immunocytochemistry ; Vasoactive intestinal polypeptide ; Brain-gut peptide ; Pyloric antrum ; Cat
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    Topics: Biology , Medicine
    Notes: Summary Immunoreactivity to VIP by endocrine-like cells in the feline pyloric mucosa was examined by using three kinds of region-specific anti-porcine VIP sera. VIP-immunoreactive endocrine-like cells were detected clearly with all of the VIP antisera used. They were located mainly around the neck of the pyloric glands. Some of these endocrine-like cells showed dilution-dependent immunoreactivity against VIP antisera. The immunostaining intensity of VIP-immunoreactive endocrine-like cells showing dilution-independence could not be distinguished from those of nerve elements. The present results suggest that the immunoreactivity with properties very similar to those of authentic VIP may be present in the endocrine-like cells of the feline pyloric glands.
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  • 67
    ISSN: 1432-0878
    Keywords: Enteroendocrine cells ; Pancreatic endocrine cells ; Gastroenteropancreatic hormones ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Four immunoreactive endocrine cell types can be distinguished in the pancreatic islets of B. conchonius: insulin-producing B cells, somatostatin-producing A1 (= D) cells, glucagon-producing A2 cells and pancreatic poly-peptide-producing PP cells. The principal islet of this species contains only a few PP cells, while many PP cells are present in the smaller islets. Except for the B cell all pancreatic endocrine cell types are also present in the pancreatic duct. At least six enteroendocrine cell types are present in the gut of B. conchonius: 1. a cell type (I) with small secretory granules, present throughout the intestine, and possibly involved in the regulation of gut motility; 2. a C-terminal gastrin immunoreactive cell, probably producing a caerulein-like peptide; these cells are located at the upper parts of the folds, especially in the proximal part of the intestinal bulb; 3. a met-enkephalin-immunoreactive cell, present throughout the first segment; 4. a glucagon-immunoreactive cell, which is rare in the first segment; 5. a PP-immunoreactive cell, mainly present in the first half of the first segment; 6. an immunoreactive cell, which cannot at present be specified, located in the intestinal bulb. The latter four cell types are mostly located in the basal parts of the folds, although some PP-immunoreactive cells can also be found in the upper parts. Most if not all enteroendocrine cells are of the open type. The possible functions of all enteroendocrine cell types are discussed.
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  • 68
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    Cell & tissue research 226 (1982), S. 231-235 
    ISSN: 1432-0878
    Keywords: Secretin-like cells ; Immunocytochemistry ; Digestive tract ; Styela plicata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Secretin-like cells have been detected in the digestive tract of the ascidian Styela plicata by means of immunofluorescent and immunocytochemical methods. Especially, in the esophageal epithelium there are immunoreactive cells (S2) in which a biogenic amine (5-HT) and a regulatory peptide (secretin) occur together. In the gastric epithelium only secretin-like cells (S1) are present. Tests of cross-reactivity performed with glucagon, GIF and VIP, have confirmed the presence of a secretin-like molecule only in the S1 and S2 cells.
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  • 69
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    Cell & tissue research 227 (1982), S. 67-77 
    ISSN: 1432-0878
    Keywords: Pancreatic polypeptide ; Neurosecretory cells ; Neuropeptides ; Calliphora vomitoria ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of a neuropeptide, previously shown to have the same or a very similar amino acid composition as vertebrate pancreatic polypeptide (PP), has been studied in the nervous system and gut of the blowfly, Calliphora vomitoria. Neurones immunoreactive to a bovine PP antiserum occur in the thoracic and abdominal ganglionic components of the central nervous system, in addition to the brain and suboesophageal ganglion. Pancreatic polypeptide appears to be relayed from its cells of origin to a neurohaemal organ in the dorsal sheath of the thoracic ganglion. PP immunoreactivity is also found in cells of the hypocerebral ganglion of the stomatogastric nervous system and in associated nerve fibres. The mid-gut contains PP-positive material in flask-shaped cells of its epithelial lining.
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  • 70
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    Keywords: Pancreatic polypeptide (PP)-like material ; Immunocytochemistry ; Nervous system ; Periplaneta americana
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    Topics: Biology , Medicine
    Notes: Summary The central and visceral nervous systems of the cockroach Periplaneta americana were studied by means of the peroxidase-antiperoxidase immunocytochemical method, with the use of antibody to bovine pancreatic polypeptide (PP). PP-like immunoreactive neuron somata are most numerous in the brain; at least 6 pairs of cell groups occur in clearly defined regions. Three pairs of cells each are also present in the suboesophageal ganglion and the thoracic ganglia, one pair of a single cell each in the first abdominal and the frontal ganglia, and 4 to 6 pairs of single cells in the terminal ganglion. No reactive cells were found in the retrocerebral complex and the second to the fifth abdominal ganglia. The axons containing PP-like immunoreactivity issue many branches that are distributed in the entire brain-retrocerebral complex, ventral cord, and visceral nervous system. PP-like immunoreactive material produced in the brain seems to be transported by three routes: protocerebrum to corpora cardiaca (-allata) through the nervi corporis cardiaci, tritocerebrum to visceral nervous system through frontal commissures, and to ventral cord through circumoesophageal connectives. A possible homology between the mammalian brain-GEP (gastro-enteropancreatic) system and the brain-midgut system of this insect is discussed.
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  • 71
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    Keywords: Enolase (neuron-specific) ; S-100 protein ; Carotid body ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Light- and electron-immunocytochemical investigation with the peroxidase-antiperoxidase (PAP) procedure revealed neuron-specific enolase and S-100 protein-like immunoreactivities specifically localized in the chief cells and the sustentacular cells of the rat carotid body, respectively. This finding suggests a neuron-like nature of the chief cells and a glia-like nature of the sustentacular cells on both embryological and functional bases.
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