Lamellated bodies in the neurons of the submucosal ganglia in the sphincter of Oddi of the dog.

Peculiar neurons and nerve processes, which contained remarkable amounts of lamellated, electron-dense bodies, "myeloid bodies", are described. They were found among normal looking neurons in the submucosal ganglia of the sphincteric musculature of Oddi. The innervation and ultrastructure of the ganglia were studied in apparently healthy, young dogs bred for experimental purposes. The possible function of these neurons and processes is discussed.     

Satellite observations of main oceanographic processes to identify ecological associations in the Northern Arabian Sea for fishery resources exploration

Ecological associations are the inter-relationship between the species and their environment. Oceanographic processes like upwelling events and formation of eddies, rings, and fronts have been monitored using National Oceanic and Atmospheric Administration Advanced Very High Resolution (NOAA AVHRR) and Indian Remote Sensing Satellite-P4-Ocean Colour Monitor (IRS-OCM) data. Sea Surface Temperature (SST) and chlorophyll concentration (CC) images were derived from AVHRR and OCM, respectively. Upwelling event was monitored using AVHRR-SST by detecting the differences in surface water temperature. The formation of eddies, rings, cyclonic eddies, and anti-cyclonic eddies and their biological responses were studied using CC. Eddies and rings were found with high phytoplankton production in the form of bloom, which provide grazing ground for fishes. The anti-cyclonic eddies were found with very low CC, indicating the biological deserts in the ocean. The impacts of these processes on fish catch were studied using fishing operations data procured from Fishery Survey of India. In this paper, the occurrence of different oceanographic processes, their persistence, and relevance with catch statistics of fishery resources in the study area are discussed. The study explains the potentials of satellite remote sensing to establish the habitat linkage between oceanographic processes and fishery resources. Guest editor: V. D. Valavanis Essential Fish Habitat Mapping in the Mediterranean     

Status of the spinal inhibitory reactions in humans subjected to hyperbaric oxygenation]

The state of human spinal inhibition responses under normo- and hyperbaric pressure (6.5 ata) was comparatively studied. The paired stimulation method has been used to estimate resetting of tested monosynaptic reflex in the 20-900 ms interval of paired stimulation at rest or against the background of supraspinal modulation of spinal reflective processes (Jendrassik manoeuvre, voluntary plantar flexion) were studied. The depression of inhibition reactions under hyperbaric pressure identical to that during the supraspinal modulation under normobaric conditions is shown. It is supposed that these influences on spinal reflection processes are caused by the same neuronal mechanism.     

Combined biological hydrogen-producing systems: A review

Possible ways for combining various biological processes of biohydrogen production are described. Some of these processes are being intensively studied now, whereas others are theoretically feasible, but have not been studied. A special focus is on the factors that influence the efficiency of coupled systems.     

Radial astrocytes and ependymocytes in the spinal cord of the adult toad (Bufo bufo L.)

Summary Immunohistochemical and ultrastructural techniques have been used to demonstrate glial fibrillary acidic protein (GFAP) immuno-positive cells in the adult toad spinal cord. Two types of GFAP-immunoreactive cells were observed: ependymocytes and radial astrocytes. GFAP-positive ependymocytes were scarce and contained the immunoreactive product in their processes. They showed intermediate filaments in the basal pole and in their processes when studied with the electron microscope. These immuno-positive ependymocytes represent the tanycytic form of ependymal cells because their processes ended at the subpial zone. The radial astrocytes showed a more intensive immunoreactive product in somata and processes when they were located far away from the ependymal layer. Cell bodies and processes were also associated with blood vessels, but most of the processes ended at the subpial zone forming a continuous subpial glia limitans. The GFAP-positive processes, which form this subpial glia limitans in the toad spinal cord, belong to both tanycytic ependymocytes and radial astrocytes, whose somata are located in the grey matter. These findings lead us to suggest that both types of GFAP-immunopositive cells might be the functional equivalents of mammalian astrocytes.     

Transient Synchrony of Distant Brain Areas and Perceptual Switching in Ambiguous Figures

We studied the relationship between perceptual switching in the Necker cube and long-distance transient phase synchronization in EEG. Transient periods of response related synchrony between parietal and frontal areas were observed. They start 800–600, ms prior to the switch response and occur in pairs. Four types of pairs could be distinguished, two of which are accompanied by transient alpha band activity in the occipital area. The results indicate that perceptual switching processes involve parietal and frontal areas; these are the ones that are normally associated with various cognitive processes. Sensory information in the visual areas is involved in some, but not in all, of switching processes. The intrinsic variability, as well as the participating areas, points to the role of strategic cognitive processes in perceptual switching.     

Change of some quantitative indices of the proximal and the distal growth cartilage of the human tibia during the period of the prenatal osteogenesis

The zones of the tibial growth cartilage of human fetuses (6th lunar month), premature newborns (7th-8th lunar month) and mature newborns were micrometrically studied. The zone thickness, the chondrocyte number in a certain area and in the cell columns as well, and the volume density of the chondrocytes were determined. The obtained quantitative data show that the three indices undergo certain changes during the three age periods of the prenatal osteogenesis studied. They differ in the proximal and in the distal cartilages as well. The fetal tibia is found to be growing more intensively at its distal end. The quantitative processes within the growth cartilages of the tibia are more active during the earlier stages of the intrauterine period while the qualitative processes are found to be more active at the end of the intrauterine period.     

Spatial heterogeneity and function of voltage- and ligand-gated ion channels in retinal amacrine neurons.

The spatial distribution of ion channels within amacrine cells of the tiger salamander retina was studied using patch recording in the retinal slice preparation. By focally puffing kainate, GABA and glycine at amacrine cell processes in the inner plexiform layer, it was determined that the cell's glutamate receptors were located in a confined region of the processes near the soma, while glycine and GABA receptors were located throughout the processes. Likewise, similar techniques in conjunction with voltage steps demonstrated that voltage-gated sodium channels were located throughout the cell and were shown to generate sodium-dependent spikes, while only the processes contained voltage-gated calcium channels. These results suggest that this form of transient amacrine cell collects its excitatory synaptic inputs in a region confined to a central annular region near the soma, that the signal is actively propagated throughout its processes by voltage-gated sodium channels and that calcium-dependent neurotransmitter release of glycine from this neuron can occur throughout its processes. Thus, excitatory signals are collected in the processes near the soma, inhibitory signals throughout the processes and excitation is probably propagated throughout the processes of the amacrine cell.     

Long cytoplasmic processes in pancreatic polypeptide cells

Pancreatic polypeptide (PP) cells were studied in human endocrine pancreatic tumours and in normal human pancreata by immunohistochemical techniques and electron miscroscopy. The existence of long cytoplasmic processes was demonstrated both in tumours and normal tissue. These processes are in close contact with other endocrine cells or with acinar cells. This particular morphological aspect suggests that PP cells may control the function of other cells via paracrine secretion.     

Changes in liver of Apodemus sylvaticus mice from East-Ural radioactive territories

Male Microtus arvalis mice from radionuclide polluted territories in the South Urals (90Sr activity of ground--0.2, 2, 500, 800 Ci/km2) were used. The 90Sr content in a mouse bony skeleton was determined. Carbohydrate, energy and protein metabolism, lipid peroxidation processes in liver were studied. The intensification of protein and carbohydrate enzymes. On the increase of antioxidant activity we found the reduction of lipid peroxidation processes. The decrease of microsome oxidoreductases was found. Possible mechanisms of the observed effects are discussed.     

Microbiological monitoring in prophylaxis and treatment of pyoinflammatory complications during early postoperative period in patients with cicatricial tracheostenosis]

The species composition and antibiotic susceptibility of microflora isolated from patients with cicatricial tracheostenosis (CTS) and infectious processes were investigated. Schemes for the treatment of CTS with an account of the pathogen species and multidrug resistant staphylococcal infection are described. Comparative efficacy of the combined schemes (antibiotic + bacteriophage) for the therapy of pyoinflammatory processes in the patients with CTS and the efficacy of the treatment of the patients with CTS according to the traditional antibacterial schemes were studied.     

Kinetic Characterization of Ca2+ Transport in Synaptic Membranes

Lysed synaptosomal membranes were prepared from brain cortices of HA/ICR Swiss mice, and the ATP-stimulated Ca2+ uptake, Ca2+-stimulated Mg2+-dependent ATPase activity, and the Ca2+-stimulated acyl phosphorylation of these membranes were studied. The Km values for free calcium concentrations ([Ca2+]f) for these processes were 0.50 microM, 0.40 microM, and 0.31 microM, respectively. Two kinetically distinct binding sites for ATP were observed for the ATP-stimulated Ca2+ uptake and the Ca2+-stimulated Mg2+-ATPase activity. The high-affinity Km values for ATP for these two processes were 16.3 microM and 28 microM, respectively. These results indicate that the processes studied operate in similar physiological concentration ranges for the substrates [Ca2+]f and ATP under identical assay conditions and, further, that these processes may be functionally coupled in the membrane.     

Immunocytochemical Distribution of 5-HT (Serotonin) in the Nervous System of the Gastrotrich Turbanella cornuta

The 5-HT (serotonin) distribution in the nervous system of the macrodasyoid gastrotrich Turbanella cornuta was studied using immunocytochemical methods. Positive immunoreaction was found in two pairs of neurons. The neurons of one pair had processes which extended peripherally to the surface of the body. Central processes of both pairs entered the brain commissure and proceeded into the longitudinal cords. Unlike other acoelomate worms studied so far, the Platyhelminthes and the Nematoda, in this gastrotrich no 5-HT positive perikarya or processes were present in the pharynx innervation, and no positive neurons sent processes directly to the nerve cords     

Analysis of hepatocyte cell membrane antigens in regenerating rat liver]

Antigens of plasma membranes in hepatocytes from regenerating rat liver were studied. Immunochemical investigation with polyvalent rabbits antiserum against plasma membrane proteins in hepatocytes from regenerating and normal rat liver have shown that liver regeneration processes are accompanied by the increase of proteins number with molecular weight of--80 kDa, 62 kDa, 40 kDa and 27 kDa. It is not excluded that protein with molecular weight of 27 kDa is the tissue-specific peripheral protein. The influence of antibodies against proteins of hepatocytes plasmatic membranes on histostructure of pathologically changed liver tissue has been studied. The data obtained testify to a possibility of participation of the above mentioned proteins in the regulation of rat liver regeneration processes.     

Spectrophotometric assay of the interaction between malaria erythrocyte lysates with methylene blue and neutral red dyes

Changes of oxidative processes induced in mouse erythrocytes by Plasmodium berghei were studied in the presence of methylene blue, neutral red or of both cationic redox dyes. The results are discussed in terms of redox and metachromatic modifications of the dyes which are produced by malarial and normal erythrocyte lysates.     

中国大鲵视网膜的光镜和扫描电镜研究

用光镜和扫描电镜观察了大鲵视网膜各类细胞的形态及分布, 对视细胞和节细胞进行计数。视网腊中三个核层及两个网状层分布均匀,无中央凹。每张视网膜的视细胞总数约130000,节细胞约8000,视杆与视锥之比为8.5：1。扫描电镜下,视杆外节表面的小叶间沟清晰;视杆视锥外节均有从内节伸出的20-30条萼状突起;核周体表面亦有20-30条细胞质突起。文中还报道了幼体视细胞的形态及密度。讨论了上述结构的机能。     

Changes in the fine structure of tanycytes during the annual reproductive cycle of the male little brown bat Myotis lucifugus lucifugus.

The hypothalamic arcuate nucleus in the male little brown bat Myotis lucifugus lucifugus was studied with the electron microscope. Animals were killed by intracardial perfusion at each season throughout the year so that the arcuate nucleus could be examined for seasonal variations in morphology. Striking seasonal changes in the fine structure of ependymal tanycytes lining the arcuate nucleus were observed. Tanycytes in animals collected in the fall and early winter exhibited pale processes characterized by a scant internal framework of microtubules and fine filaments. These processes, which were found throughout the arcuate nucleus, exhibited simple irregular shapes. In animals collected between January and June, tanycyte processes contained dense accumulations of fine filaments intermingled with microtubules, and projected long attenuated extensions that often formed multilamellar sheets around axodendritic terminals or other neuronal elements. Tanycyte processes of animals collected in July and August were densely packed with microtubules and fine filaments. The processes radiated elaborate multilamellar extensions that encapsulated axons, dendrites and even entire neuronal perikarya. Multilamellar sheets consisted of as many as 10 or 12 closely spaced gyres. The seasonal variations in tanycyte structure are suggestive of astrocyte-like behaviour. These changes are discussed with respect to seasonal changes in hypothalamic neuroendocrine activity.     

Synaptic organization of the indoleamine-accumulating neurons in the cyprinid retina

The distribution and synaptic connections of the indoleamine-accumulating neurons in the retinae of the goldfish and carp were studied by means of fluorescence and electron microscopy. The indoleamine-accumulating neurons were visualized after intravitreal injection and uptake of the indoleamine 5,6-dihydroxytryptamine. This labeling procedure produced a characteristic yellow fluorescence of the indoleamine-accumulating neurons and also characteristic ultrastructural changes in these cells. To avoid interference from the dopaminergic neurons of the retina, their processes were either removed by prior treatment with 5-hydroxydopamine or prevented from taking up 5,6-dihydroxytryptamine by the simultaneous injection of the catecholamine alpha-methyl-noradrenaline. Fluorescence-microscopic studies confirmed earlier reports that the indoleamine-accumulating perikarya and processes are distributed similar to those of amacrine cells. The indoleamine-accumulating processes ramify in three bands in the inner plexiform layer, the outermost one being the densest. Electron-microscopic investigations showed the indoleamine-accumulating neurons to have synapses of the conventional type, similar to amacrine cells. Their main synaptic contacts are with other amacrine cells, but synapses with bipolar cell terminals are also present. Both the distribution of the indoleamine-accumulating processes and their synaptic arrangement in the cyprinid retina differ from those found in mammalian retinae investigated previously.     

MADS-complexes regulate transcriptome dynamics during pollen maturation

Background  

Differentiation processes are responsible for the diversity and functional specialization of the cell types that compose an organism. The outcome of these processes can be studied at molecular, physiologic, and biochemical levels by comparing different cell types, but the complexity and dynamics of the regulatory processes that specify the differentiation are largely unexplored.