Ultrastructural demonstration of amine granules in the adrenal medullary cells of the rat using acid permanganate fixation

Summary Potassium permanganate fixative is usually employed at pH 7.0. At this pH the amines in the granules of the adrenal medullary cells do not react with permanganate. When the pH was adjusted to 5.0, electron dense precipitates were seen in the amine granules of part of the medullary cells, probably noradrenalin containing cells.Supported by the grant from the Finnish Cultural Foundation     

Comparing RADseq and microsatellites for estimating genetic diversity and relatedness — Implications for brown trout conservation

The conservation and management of endangered species requires information on their genetic diversity, relatedness and population structure. The main genetic markers applied for these questions are microsatellites and single nucleotide polymorphisms (SNPs), the latter of which remain the more resource demanding approach in most cases. Here, we compare the performance of two approaches, SNPs obtained by restriction‐site‐associated DNA sequencing (RADseq) and 16 DNA microsatellite loci, for estimating genetic diversity, relatedness and genetic differentiation of three, small, geographically close wild brown trout (Salmo trutta) populations and a regionally used hatchery strain. The genetic differentiation, quantified as F_ST, was similar when measured using 16 microsatellites and 4,876 SNPs. Based on both marker types, each brown trout population represented a distinct gene pool with a low level of interbreeding. Analysis of SNPs identified half‐ and full‐siblings with a higher probability than the analysis based on microsatellites, and SNPs outperformed microsatellites in estimating individual‐level multilocus heterozygosity. Overall, the results indicated that moderately polymorphic microsatellites and SNPs from RADseq agreed on estimates of population genetic structure in moderately diverged, small populations, but RADseq outperformed microsatellites for applications that required individual‐level genotype information, such as quantifying relatedness and individual‐level heterozygosity. The results can be applied to other small populations with low or moderate levels of genetic diversity.     

Exploring the homogeneity of terrestrial subterranean communities at a local spatial scale

1. Although caves are generally perceived as isolated habitats, at the local scale, they are often interconnected via a network of fissures in the bedrock. Accordingly, caves in close proximity are expected to host the same, or very similar, animal communities. 2. We explored the extent to which subterranean arthropod communities are homogenous at a local spatial scale of less than 1 km², along with which cave-specific environmental features result in a departure from the expected homogeneous pattern. We approached this question by studying richness and turnover in terrestrial invertebrate communities of 27 caves in a small karst massif in the Western Italian Alps. 3. Specialised subterranean species were homogeneously distributed among caves and were not influenced by seasonality. The only factor driving their distribution was the distance from the cave entrance, with deeper caves yielding a greater diversity of species. 4. Significant spatio-temporal turnover in species not specialised to subterranean life was observed. In summer, there was a significant homogenisation of the community and a more even distribution of species among sites; in winter, these species were missing or found exclusively at greater depths, where environmental conditions were more stable. Furthermore, caves at lower elevations yielded, on average, a greater diversity and abundance of these species. 5. This study demonstrated that the theoretical expectation of no turnover in community composition in caves in close proximity is not always met. Turnover can be mostly attributed to seasonal patterns and sampling depth; thus, our findings have implications for planning sampling and monitoring activities in caves.     

Cytochemical demonstration of adenylate cyclase activity with cerium

Summary Cerium was applied for the ultrastructural, cytochemical localization of adenylate cyclase (EC 4.6.1.1.). The enzyme activity was stimulated with norepinephrine, prenalterol and choleratoxin in the brown fat cells of newborn rats. The final reaction product was observed in the plasmalemmas of the stimulated adipocytes. The precipitate was finely crystalline, easily visible in the electron microscope and in the X-ray microprobe analysis it yielded cerium and phosphate peaks, respectively. The use of cerium offers a new tool valid for the cytochemical localization of adenylate cyclase enzyme related to the membrane receptors.This study was supported by the grant from Reino Lahtikari Foundation     

Ultrastructural changes in the neurohypophysis of the aged male rat

Summary The neurohypophyses (neural lobes of the pituitary) of young adult (3–6 months) and aged (12–30 months) male rats were studied by means of electron microscopy. Stereomorphometric analyses were performed to determine the size, number and relative volume of the hormone-containing vesicles. The principal observations included: 1) the conspicuous depletion in aged rats of the granular hormone-containing vesicles from the axon terminals and the Herring bodies, with a decrease in the relative volume fraction of the vesicles from 4.8 Vv % in the control animals to 1.1 Vv % in the aged rats; 2) a change in the size-distribution of the hormone vesicles; 3) an increase in the extracellular space around the nerve terminals, axons and capillaries; and 4) lipid accumulations and signs of activation in the pituicytes. The possible physiological significance of the findings is discussed in the light of several regulatory functions known to be altered during the process of ageing.     

Chemical investigation of wheat

Summary The extent and the mechanism of phytic acid decomposition in germinating wheat grain of a low-yielding and a high-yielding wheat variety have been investigated.While in the high-yielding variety this decomposition was most important on the first, fifth, and seventh day of germination, in the low-yielding variety extensive decomposition began only on the second day and reached its maximum value on the fifth day of germination. If one accepts the criterion of Mellanby for the rate of phytic acid decomposition, it appears that phytic acid is completely decomposed within seven days in the high-yielding variety and within six days in the low-yielding variety. The increase of free orthophosphate was not equivalent to the decrease of phytic acid, the difference representing the amount of orthophosphate phosphorus uptake in oxidative and photosynthetic phosphorylation.It was found that enzymatic hydrolysis of phytic acid in germinating wheat grain occurred stepwise, by the successive liberation of phosphoric acid and through the intermediate formation of penta-, tetra-, tri-, di-, and monophosphates of inositol, the final products being inositol and phosphoric acid. In ripe wheat grain before germination, only inositol hexaphosphate (phytic acid) was present.Paper 7: Glasnik hem. drustva (Beograd (Bull. soc. chim. Beograd)),28, 303–325 (1963)     

Paraganglia in the urogenital tract of man

Summary According to the earlier concept, the paraganglia of man are believed to degenerate during the first postnatal years after their dominance during the fetal period. Clinical case reports on persisting paraganglia led us to extensive exploration of surgical material obtained from urological and gynecological surgery. The formaldehyde induced fluorescence (FIF) was used for tracing the catecholamine containing tissues. The fluorescence intensities were recorded with a Lietz MPV 2 microspectrophotometer.Solitary, small paraganglia were found in all patients studied. They were expecially frequent in the walls of the urinary bladder and in the connective tissue surrounding the urogenital organs. The intensity of the fluorescence was comparable to pharmacological standard of 10^–2 M noradrenaline and at the same level as the FIF of human fetal paraganglia. All cells of the paraganglionic clusters exhibited FIF and no signs of degeneration could be observed.It is suggested that the paraganglia of man do not degenerate postnatally but persist as a remarcable catecholamine reservoir, which might be of physiological importance.     

Unidentified Antioxidant Defences of Human Plasma in Immobilized Patients: A Possible Relation to Basic Metabolic Rate

Plasma total peroxyl radical scavenging capacity was studied in terminal patients who were chronically immobilized because of an acute (stroke) or chronic neurodegenerative disease (Alzheimer's disease). A luminometric assay was used to measure total antioxi-dant capacity (TRAP). The immobilized patients showed significant decrease in TRAP primarily because of a decrease in the concentration of unknown antioxidants. Our results suggest that human plasma may contain unknown antioxidants, the regulation of which could be related to the basic metabolic rate.