Pair formation in the hypotrichous ciliate Euplotes octocarinatus is a poorly understood phenomenon. In order to obtain information about the molecules involved in this process, we compared ciliary ...and cell body-associated glycoconjugates of non-mating-competent, mating-competent, and conjugating cells. Detection of glycoconjugates was carried out on Western blots by immunostaining of oxidized, digoxigenin-labeled carbohydrate moieties. Using this method, in both of two complementary mating types a 130-kDa glycoprotein was identified, which appeared on cilia during acquisition of mating competence and was reduced during cell pairing. This suggests an active role of this glycoprotein in ciliary adhesion during pair formation, Additionally, in both of the two mating types a cell body-associated 135-kDa glycoprotein was detected, which is present in non-mating-competent cells as well as in mating-competent cells, but is strongly reduced in conjugating cells. In contrast to the ciliary 130-kDa glycoprotein, the cell body-associated 135-kDa glycoprotein is not surface-exposed 8. We therefore propose that the cell body-associated glycoprotein is either involved in the preparation for cell fusion or meiosis or that it serves as a cytoplasmic pool for the ciliary 130-kDa glycoprotein.
The ciliate Euplotes octocarinatus and some close relatives of it are triggered by predator-released substances to undergo morphogenetic changes that inhibit their engulfment. The changes occur ...within a few hours and do not require cell division. They are perpetuated during reproduction so long as the concentration of the morphogen is maintained. The ability of Euplotes to respond to predator-produced signals by a defensive change in cell architecture probably provides an effective mechanism for damping population oscillations of both prey and predators and fosters coexistence. The signal-induced cell transformation merits study for its own sake because of its developmental implications.
To suppress the reactivity of nanoscaled non-oxidic powders of titanium nitride (TiN) and silicon carbonitride (SiCN) against hydrolysis and oxidation, chemical surface modification with ...nitrogen-containing surfactants was investigated. Among these surfactants, long-chain primary amines, ethylenediamines, guanidines, nitriles, isocyanates, and succinimides were examined. Thermogravimetry, elemental analysis, and behavior against the water-vapor adsorption of the modified particles were used as methods to estimate the protective capacity of the organic coating material. The best results were obtained by using the long-chain amines and octadecylisocyanate, which were indicated by a significant shift of the powder oxidation toward the higher temperatures and an increase of the particle hydrophobicity. A long-chain succinimide was found to be the most effective in dispersing nanoscaled TiN in organic media. Preparation of a stable aqueous dispersion without significant changes in the elemental composition of the powder was achieved by the application of an ionic surfactant to the surface-modified particles.
Amplification of macronuclear DNA of the ciliate Euplotes octocarinatus revealed the presence of two genes encoding putative polypeptide release factors (RFs) of the codon specific class-I type. They ...are named eRF1a and eRF1b, respectively. cDNA amplification revealed that both eRF1 genes are expressed. Determination of their copy numbers showed that they are similarly amplified to a level of about 27,000. The deduced protein sequences of the two genes are 57 and 58% identical with human eRF1 and 79% identical to each other. The gene encoding eRF1b possesses three in-frame UGA codons. This codon is known to encode cysteine in Euplotes; only UAA and UAG are used as stop codons in this organism. The primary structure of the two release factors is analyzed and compared with the primary structure of other eukaryotic release factors including the one of Tetrahymena thermophila which uses only UGA as a stop codon. eRF1a and eRF1b of Euplotes as well as eRF1 of Tetrahymena differ from human eRF1 and other class-I release factors of eukaryotes in a domain recently proposed to be responsible for codon recognition. Based on the changes which we observe in this region and the differential use of the stop codons in these two ciliates we predict the amino acids participating in stop codon recognition in eRF1 release factors.
We have isolated and sequenced two
γ-tubulin (
γ-Tub)-encoding macronuclear genes of the ciliate
Euplotes crassus (
Ec), as well as their corresponding cDNAs. Our results reveal that the two genes (
...γ-tub 1 and
γ-tub 2) have introns in homologous positions, but differ in their sequences, codon usage, transcription initiation sites and poly(A) addition sites. They both consist of three exons, two introns and two short non-coding sequences on both ends, and they both code for polypeptides of 462 amino acids (aa). The two genes share 76% identity at the nucleotide (nt) level, 86% at the deduced aa level and show 61–92% aa homology to the
γ-Tubs of other organisms. The
γ-tub 2 gene contains two in-frame UGA codons which, like UGA codons in other
Euplotes genes, probably code for cysteines. No UGA triplet was found in the
γ-tub 1 gene. Further studies on the cDNA ends indicate that
γ-tub 1 uses at least three transcription initiation sites and two poly(A) addition sites. In contrast, only one transcription initiation site and one poly(A) addition site were identified in
γ-tub 2.
In this thesis, we investigate the dissipative transport phenomena of strongly interacting matter. The special interest is in the shear viscosity and its value divided by entropy density. The ...performed calculations are based on effective models for Quantum Chromodynamics, mostly focused on the 2-flavor Nambu-Jona-Lasinio model. This allows
us to study the hadronic sector as well as the quark sector within one single model. We expand the models up to next-to-leading order in inverse numbers of colors. We present different possibilities of calculating linear transport coefficients and give an overview over qualitative properties as well as over recent ideas concerning ideal
fluids. As present methods are not able to calculate the quark two-point function in Minkowski space-time in the self-consistent approximation scheme of the Nambu-Jona-Lasinio model, a new method for this purpose is developed. This self-energy parametrization method is
applied to the expansion scheme, yielding the quark spectral function with meson back-coupling effects. The usage of this spectral function in the transport calculation is only one result of this work. We also
test the application of different transport approaches in the NJL model, and find an interesting behavior of the shear viscosity at the critical end point of the phase diagram. We also use the NJL model to calculate the viscosity of a pion gas in the dilute regime. After an
analysis of other models for pions and their interaction, we find that the NJL-result leads to an important modification of transport properties in comparison with the calculations which purely rely on pion properties in the vacuum.
Two new stocks of the hypotrichous ciliate
Euplotes octocarinatus isolated in Pennsylvania and Florida/USA were identified as members of a new mating type XI (mt
5mt
5) secreting a so far unknown ...pheromone 5. As deduced from their pheromone encoding genes, the pheromones secreted by the two stocks differ from each other by 14 amino acids and a few silent mutations. Their 5′-non-coding sequences are almost identical with the 5′-non-coding sequences of the pheromone genes 1 to 4. This holds also true for the prepro-sequences which contain a 16 amino acids long ER-import signal. The 3′-non-coding sequences are also highly conserved. Like the other pheromone encoding genes the two mt
5 alleles contain in-frame TGA stop codons, probably encoding cysteines. Both genes are interrupted by three introns in positions which are homologous to those in the other pheromone genes. Intron 1 of the stock from Florida is 143 bp longer than intron 1 of the stock from Pennsylvania. Indirect evidence suggests that the two stocks do not belong to
E. octocarinatus syngen 1. In this respect the two stocks resemble two other stocks isolated in North America which we have previously investigated. Whether the two stocks belong to the same syngens as the other two North American stocks is unclear.
Reflex sympathetic dystrophy/complex regional pain syndrome type I (RSD/CRPS I) is a painful neuropathic disorder that may develop as a disproportionate consequence of a trauma affecting the limbs ...without overt nerve injury. Clinical features are spontaneous pain, hyperalgesia, impairment of motor function, swelling, changes in sweating, and vascular abnormalities.
To investigate pathophysiological mechanisms of vascular abnormalities in RSD/CRPS I.
Case study.
Autonomic test laboratory at a university hospital.
A patient with an early stage of RSD/ CRPS I of the upper limb and 2 healthy control subjects.
Cutaneous sympathetic vasoconstrictor innervation was assessed by measuring cutaneous blood flow (laser Doppler flowmetry) and skin temperature (infrared thermometry). To quantify sympathetic vasoconstrictor function, phasic (induced by deep inspiration) and tonic (induced by controlled thermoregulation) sympathetic reflexes were analyzed. Venous norepinephrine levels were determined bilaterally. The same tests were performed in the controls after induction of cutaneous antidromic vasodilation produced by histamine dihydrochloride application.
Sympathetic cutaneous vasoconstrictor function in RSD/CRPS 1.
Two weeks after the onset of RSD/CRPS I, skin temperature on the affected side was higher (close to core body temperature) than on the contralateral side at room temperature and during controlled thermoregulation, indicating maximal vasodilation. Phasic and tonic stimulation of cutaneous vasoconstrictor neurons did not induce a decrease of skin blood flow or temperature on the affected side but were normal on the contralateral side. Venous norepinephrine levels were lower on the affected side. Parallel to clinical improvement, loss of vasoconstrictor function completely recovered within weeks. Results of investigations in healthy subjects ruled out the possibility that antidromic vasodilation caused by activation of nociceptive afferents is responsible for the complete depression of sympathetic vasoconstrictor reflexes.
Demonstrated for the first time is a complete functional loss of cutaneous sympathetic vasoconstrictor activity in an early stage of RSD/CRPS I with recovery. The origin of this autonomic dysfunction is in the central nervous system.
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