Nucleotide Sequences of Double-Stranded RNA Segments from a Hypovirulent Strain of the White Root Rot Fungus Rosellinia necatrix: Possibility of the First Member of the Reoviridae from Fungus

Twelve double-stranded (ds) RNA segments were detected from a hypovirulent strain W370 of the white root rot fungus Rosellinia necatrix. The estimated molecular weights ranged from 0.41×10⁶ to 2.95×10⁶. Full length cDNA clones for eight segments were obtained. Northern blot analysis suggested that each segment was genetically unique. The nucleotide sequences of eight full length dsRNA segments were determined. One long open reading frame was found in each segment. Conserved sequences at the 5-end (5-ACAAUUU-3) and at the 3-end (5-UGCAGAC-3) were identified in all eight segments. Segment-specific panhandle structures, formed by inverted terminal repeats, were also found in all segments. Comparative analyses of the predicted translational products of eight dsRNA segments showed that the deduced amino acid sequence partially matched those of the Reoviridae family members: Colorado tick fever virus, Nilaparvata lugens reovirus, and rice black streaked dwarf virus. The results suggested that W370 dsRNA is derived from a new member of the family Reoviridae detected in fungus.     

The oligodendroglial reaction to brain stab wounds: An immunohistochemical study

Summary Myelin/oligodendrocyte specific protein was compared to glial fibrillary acidic protein and 23-cyclic nucleotide 3-phosphodiesterase expression in normal rat brains and following stab wounds to the cerebral cortex, corpus callosum and hippocampus. Animals with stab wounds were allowed to recover for 5,15,28, 45 and 70 days post-operation before fixation by perfusion. Sections were reacted with antibodies against myelin/oligodendrocyte specific protein, glial fibrillary acidic protein and 23-cyclic nucleotide 3-phosphodiesterase, and observed by light and electron microscopy. Normal cerebral cortex had very few myelin/oligodendrocyte specific protein-positive and 23-cyclic nucleotide 3-phosphodiesterasepositive cells, but some glial fibrillary acidic protein-positive cells. The myelinated fibres of the corpus callosum were heavily stained for myelin/oligodendrocyte specific protein but unstained by glial fibrillary acidic protein or 23-cyclic nucleotide 3-phosphodiesterase antibodies. Some immunopositive cells were present in the corpus callosum and hippocampus with all three antibodies. After stab wound myelin/oligodendrocyte specific protein-positive reactive cells had more and longer processes and stained more intensely than equivalent cells in normal brain. These cells were distributed along the wound track, including within the cerebral cortex. The numbers of these cells increased until 28 days post-operation and then decreased so that very few were found at 70 days post-operation except in the corpus callosum. Where demyelination occurred myelin/oligodendrocyte specific protein-staining was lost. Staining for 23-cyclic nucleotide 3-phosphodiesterase revealed a similar pattern. Glial fibrillary acidic protein-positive reactive cells, which were also more robust than the normal cells, were more widely distributed. They increased in number throughout the time periods studied and gliosis was evident on the contralateral side. The glial fibrillary acidic protein-positive astrocytes were also different from the myelin/oligodendrocyte specific protein-positive and 23-cyclic nucleotide 3-phosphodiesterase-positive oligodendrocytes in terms of cell shape. With electron microscopy myelin/oligodendrocyte specific protein-positive cells showed features typical of immature oligodendrocytes. We conclude that the injury caused a numerical increase in oligodendrocytes and that myelin/ oligodendrocyte specific protein is a good marker for the oligodendroglial response and demyelination in pathological conditions.     

Molecular organisation of an A mating type factor of the basidiomycete fungus Coprinus cinereus

Summary The A3 and A3 genes, which together constitute the A42 mating type factor of Coprinus cinereus, were isolated from a cosmid genomic library by walking 50 kb, a map distance of 0.5 units, from the closely linked metabolic gene pab-1. Cosmid clones having A gene function were identified by transformation into compatible A6 (22) and A5 (11) host cells where either 3 or 3 was expected to elicit the A factor — regulated development of unfused clamp cells. DNAs were digested with various enzymes before transformation in order to identify the smallest fragments containing an active 3 or 3 gene. Two non-overlapping fragments were identified as containing the 3 and 3 genes respectively. Southern hybridisation analyses showed that these two cloned genes had no detectable sequence homology, and that there was little or no hybridisation to the and gene alleles that constitute the A5 and A6 factors. 3 and 3 were shown to be less than 2.0 kb apart and embedded in a DNA sequence extending over 9.0 kb which was unique to our A42 strain and may contain a third A factor gene.     

Einstellzeit der Pt-Elektrode bei Messungen nicht stationärer O2-Partialdrucke

Zusammenfassung Das Meßsignal bei sprunghaftenpO₂-Änderungen wird anhand des Diffusionsfeldes der Elektrode beschrieben. Es wird das zeitliche Verhalten des Meßsignals von blanken und membranbespannten Elektroden in gasförmigen und nicht gasförmigen Meßmedien betrachtet. Aus dem Verhalten des Meßsignals kann jeweils die Einstellzeit alssystematischer Meßfehler abgeleitet werden. In nicht gasförmigen Medien (z. B. biologisches Gewebe) übersteigt das Meßsignal nach einempO₂-Sprung zu höheren Werten das stationäre Endsignal. Daraus ergibt sich eine besondere Betrachtung der Einstellzeit in solchen Medien.Die Einstellzeit für Pt-Elektroden mit einfacher und doppelter Membran wird explizit angegeben. Schließlich wird für biologische Medien die Einstellzeit mit dem Diffusionsfehler [8] verglichen. Die Forderungen an eine Membran der Pt-Elektrode mit kleiner Einstellzeit und gleichzeitig kleinem Diffusionsfehler sind zusammengestellt.

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Erklärung der Symbole a Verhältnis der Diffusionskoeffizienten zweier Membranen - Bunsenscher Löslichkeitskoeffizient des Mediums - _m Bunsenscher Löslichkeitskoeffizient der Membran - b Verhältnis der Diffusionsleitfähigkeiten von Membran und Medium - C ₁,C ₂ Proportionalitätskonstanten zwischen Meßsignal und O₂-Partialdruck - D Diffusionskoeffizient des Mediums - D _m,D _m Diffusionskoeffizienten der Membranen - Diffusionskoeffizient der effektiven Membran - DF Diffusionsfehler - DGl Differentialgleichung - d _m,d _m Dicke der Membranen - Dicke der effektiven Membran - dimensionsloser Parameter des Diffusionsfehlers - erf Fehlerfunktion - exp Exponentialfunktion - F Faradaykonstante - grad Gradient - I stationäres Meßsignal vor dempO₂-Sprung - I stationäres Meßsignal nach dempO₂-Sprung - I(t), I(),I() instationäres Meßsignal als Funktion der Zeit bzw. zeitabhängiger dimensionsloser Parameter - K Diffusionsleitfähigkeit des Mediums - K _m Diffusionsleitfähigkeit der Membran - Diffusionsleitfähigkeit der effektiven Membran - dimensionsloser Parameter - n Summationsindex - pO₂ O₂-Partialdruck - pO₂ als Funktion von Ort und Zeit bzw. zeitabhängiger dimensionsloser Parameter; Diffusionsfeld der Elektrode - p _c konstanterpO₂ vor dempO₂-Sprung - p _c konstanterpO₂ nach dempO₂-Sprung - p(r ₀+d _m , ) pO₂ an der Grenze Membran/Medium in Abhängigkeit des Zeitparameters - p(r,o) Diffusionsfeld zum Zeitpunkt (t=0) despO₂-Sprunges - p(r₀+d_m, o) pO₂ an der Grenze Membran/Medium zum Zeitpunkt despO₂-Sprunges - R Radius der ebenen, kreisförmigen Elektrode - r ₀ Radius der Elektrode mit halbkugelförmiger Pt-Oberfläche - r Kugelkoordinate - ₁,₂ dimensionslose ortsabhängige Parameter - T ₉₀,T ₉₅ Zeit, bis 90% bzw. 95% des Signalunterschiedes nach dempO₂-Sprung ausgeglichen sind (Einstellzeit) - T ₉₀,T ₉₅ Einstellzeit der Elektrode mit Doppelmembran - T _90*,T _95* Zeit, bis sich das Signal nach Übersteigen des stationären Endwertes diesem auf 10% bzw. 5% angenähert hat - dimensionslose Parameter zu den vorangegangenen Einstellzeiten - t Zeitkoordinate - , dimensionslose zeitabhängige Parameter - t _max, _max Zeit maximaler Signalhöhe nachpO₂-Sprung und zugehöriger dimensionsloser Parameter - V(t) Diffusionsgesamtfluß zur Pt-Oberfläche - Stromdichtevektor der diffundierenden O₂-Moleküle - x, y, z Kartesische Koordinaten - Integrationsvariable - ² Laplace-Operator - partielle Ableitung nach der Zeit - Integral über eine Fläche - gerichtetes Flächenelement     

Die seltenen Rh-Phänotypen rhy rh und rh′ rh′ in einer deutschen Familie

Zusammenfassung Nach einer Literaturübersicht wird das Vorkommen der seltenen Rh-Genotypen rr und rr in 2 Generationen einer deutschen Familie beschrieben.     

Suppression of human polymorphonuclear leukocyte phagocytosis by adenosine analogs

The effects of adenosine analogs on human polymorphonuclear leukocyte (PMN) phagocytosis to latex beads or sheep red blood cells were investigated in an in vitro experiment. The purine compounds such asN ⁶-phenylisopropyladenosine (PIA), 5-N-ethylcarboxamido-adenosine (NECA), an A₂ adenosine receptor agonist, and adenosine as high as 2 mM had no effect on PMN phagocytosis. In contrast, 2,5-dideoxyadenosine (DDA), a P-site adenosine receptor agonist, and 5-methylthioadenosine (MTA), a naturally occuring purine nucleoside, caused profound inhibition of phagocytic function of PMNs in a dose-dependent manner. Dipyridamole, which blocks purine nucleoside uptake, reversed the suppression due to MTA. Theophylline, an R-site receptor antagonist did not prevent the effect of MTA. These results suggested that phagocytosis of PMNs is suppressed by stimulation of the P-site adenosine receptors.     

Mechanisms underlying facilitation by dopamine of ATP-activated currents in rat pheochromocytoma cells

Mechanisms underlying facilitation by dopamine of extracellular adenosine 5-triphosphate (ATP)-activated current were investigated in rat pheochromocytoma PC12 cells using the whole-cell voltage-clamp techniques. Dopamine (10 and 100 M) augmented the peak amplitude of an inward current elicited by ATP (3–100 M). The activation time course of the ATP-evoked current was accelerated by dopamine; the presence of 10 M dopamine shifted the dependence of activation rate constants on the concentration of ATP toward a lower concentration range two fold. Dopamine also accelerated the inactivation and the deactivation, which was determined from the current decay upon washout of ATP. Intracellular mediators responsible for the dopamine-induced facilitation was estimated by loading various compounds in patch pipettes. Facilitation was not observed when K-252a (1 M), a protein kinase inhibitor, was included in the intracellular solution. In addition, facilitation was also attenuated by intracellular adenosine 5-O-(thiotriphosphate)tetralithium salt (ATPS (1 mM) or --methylene ATP (1 mM). Inclusion of adenosine 3, 5-cyclic monophosphate sodium salt (cAMP, 100 M), guanosine 3,5-cyclic monophosphate sodium salt (cGMP, 100 M), 12-O-tetradecanoylphorbol-13-acetate (TPA, 1 M) or phorbol-12,13-dibutylate (1 M) in the intracellular solution did not affect the facilitation. Guanonsine 5-O-(thiotriphosphate)tetralithium salt (GTPS, 500 M) or guanosine 5-O(2-thiodiphosphate)-trilithium salt (GDPS, 500 M) did not modify the facilitation either. The results suggest that dopamine augments the ATP-activated inward current by facilitating association of ATP to its binding site, and that the augmentation may be mediated through some protein kinase which is different from cyclic-nucleotide-dependent protein kinases or protein kinase C.     

Cyclic nucleotide changes induced in human leukocytes by a product of axenically grownEntamoeba histolytica that inhibits human monocyte locomotion

Pulse exposure of human mononuclear phagocytes to the monocyte locomotion-inhibitory factor produced byEntamoeba histolytica (i.e., the 369- to 765-Da chromatographic fraction obtained from the supernatant fluid of axenically grownE. histolytica) led to a swift increase in the intracellular concentration of adenosine 3:5 cyclic monophosphate (cAMP). A weaker response was observed in human polymorphonuclear leukocytes, the locomotion of which, however, is not inhibited by this amebic factor. The same chromatographic fraction obtained from the axenic medium control lacked this effect, at least upon mononuclear phagocytes. On the other hand, both the monocyte locomotion-inhibitory factor and the axenic medium control, possibly through shared culture medium components, induced comparable increases in guanosine 3:5 cyclic monophosphate (cGMP) in human mononuclear phagocytes and in polymorphonuclear leukocytes, thus suggesting that the latter nucleotide is not critical for the leukotactic inhibitory phenomenon. Our results suggest that like other leukotactic inhibitors, the monocyte locomotion-inhibitory factor produced byE. histolytica operates through modulations of intracellular cAMP.Abbreviations MP Mononuclear phagocytes (monocytes) - MLIF monocyte locomotion-inhibitory factor - PMN polymorphonuclear leukocytes - cAMP adenosine 3:5 cyclic monophosphate - cGMP guanosine 3:5 cyclic monophosphate - PBS phosphate-buffered (pH 7.4) normal saline - AMC axenic medium control Gey's-A; Gey's medium with 2% albumin - ZAS zymosan-activated serum - hpf high-power field (400x)     

Dissociation of acetylcholine- and cyclic GMP-induced currents inXenopu oocytes

InXenopus follicular oocytes, activation of muscarinic receptors evokes a slow potassium current (H-response); a similar current is evoked by intracellular injection of cyclic guanosine 3,5-monophosphate, cGMP (Dascal et al. 1984). We have tested the hypothesis that cGMP may be the second messenger that mediates the opening of K channel by acetylcholine (ACh). ACh elevated the intracellular level of cGMP with a time course similar to that of the development of the muscarinic H-response; maximal increase in cGMP concentration above the control was about 0.2 pmole/oocyte. The amount of injected cGMP that produced a detectable K current (threshold dose) varied between 0.5 and 3 pmole/oocyte. At low doses of cGMP, the slope of log dose-log response curve was about 2.5, suggesting involvement of a biochemical process with a positive cooperativity of at least 3. Higher doses of cGMP evoked, in addition to the outward current, an irregular, rapidly developing, long-lasting inward current, that never reached amplitudes comparable to those of ACh-evoked Cl currents. The K current elicited by cGMP was insensitive to elevation or depletion of external Ca. It was potentiated by isobutylmethylxanthine (IBMX). ACh strongly inhibited the cGMP-evoked K current when applied at the plateau of the latter. 4-Phorbol 12,13-dibutyrate (PDBu) (1 M) rapidly and completely inhibited the cGMP response. It is concluded, that most of the results presented in this report contradict the hyothesis that cGMP is the intracellular mediator of ACh-induced changes in membrane conductance in the oocytes.Abbreviations ACh acetylcholine - cAMP cyclic adenosine 3,5-monophosphate - cGMP cyclic guanosine 3,5-monophosphate - EGTA ethylenediaminetetraacetic acid - Hepes N-2-hydroxyethyl-piperazinc-N-2-hydroxypropanesulphonic acid - IBMX 3-isobutyl-l-methylxanthine - IP₃ inositol 1,4,5-trisphosphate - PDBu 4-phorbol 12,13-dibutyrate     

A homologous and self-replicating system for efficient transformation ofFusarium oxysporum

A highly efficient transformation system has been developed forFusarium oxysporum f. sp.lycopersici based on the complementation of a nitrate-reductase mutant with the homologousnitI gene and on the presence ofARS and telomeric sequences in the vector. Preliminary transformation experiments with theniaD gene fromAspergillus niger generated self-replicating plasmids within the transformed entity that contained extra-fungal DNA. A fragment of the extra DNA was inserted into pUC19 together with theF. oxysporum nitl gene, resulting in plasmid pFNit-Lam. This allowed the isolation of a new linear plasmid within self-replicativeF. oxysporum transformants (pFNit-Lam-TLam, linear). The circular form of this vector yielded 5600 fungal transformants per g of DNA. All of the transformants contained autonomous linear plasmids harboring direct repeats of fungal DNA at both ends. The sequence of the 1.2-kb fragment fromF. oxysporum responsible for autonomous replication, and maintenance as linear plasmid molecules, has been determined. Comparison analysis with theARS from different organisms has shown that this fragment contained the commonly identifiedARS consensus sequence, 5A/TTTTATA/GTTTA/T3 and, in addition to this core, ten copies of theARS-box, TNTA/GAA3. Adjacent to this presumedARS, the telomeric hexanucleotide sequence (TTAGGG)_n was present in six tandem copies followed by 18 copies of its complementary sequence.     

In wheat ctDNA,segments of ribosomal protein genes are dispersed repeats,probably conserved by nonreciprocal recombination

Summary Some dispersed repeated sequences and their flanking regions from wheat and maize ctDNAs have been characterized. Two sets of wheat ctDNA repeats were found to be the chloroplast ribosomal protein genesrpl2 andrpl23, plus nonfunctional segments of them, designatedrpl2 andrpl23. Pairwise comparisons were made between the wheatrp123 andrpl23, and the maizerp123 sequences. The precise patterns of homology suggest that the divergence of the wheat and maize nonfunctional (rpl23) sequences is being retarded by nonreciprocal recombination, biased by selection for individuals with functional (rpl23) sequences. The implied involvement of these sequences in mechanisms of homologous recombination, and therefore in the creation and spread of new ctDNA variants, is discussed.     

Structure of the cloned Locusta migratoria mitochondrial genome: restriction mapping and sequence of its ND-1 (URF-1) gene

Summary We have cloned the entire mitochondrial genome of Locusta migratoria in four fragments and characterised by restriction mapping. In addition, we have sequenced a 1,095 kb region containing the ND-1 (URF-1) gene. The inferred primary structure of the protein is highly homologous to its Drosophila counterpart (68%). The gene is flanked at the 5 end by the tRNA _CUN ^leu gene, interrupted by the sequence TTG. The 3 end is flanked by the tRNA _ser ^UCN gene, followed by a sequence homologous to the 3 end of D. yakuba cytochrome b. The relative position of the genes is conserved between Locusta and Drosophila, thus indicating conservation of mitochondrial gene order in insects.     

Effects of 5-hydroxytryptamine,dopamine, and acetylcholine on accumulation of cyclic AMP and cyclic GMP in the anterior byssus retractor muscle ofMytilus edulis L. (Mollusca)

We investigated in vitro accumulation of adenosine 3,5-monophosphate (induced by 5-hydroxytryptamine and dopamine) and of guanosine 3,5-monophosphate (induced by acetylcholine) in the anterior byssus retractor muscle ofMytilus.The response to 5-hydroxytryptamine exceeded that induced by equimolar concentrations of dopamine.1-methyl lysergic acid, a 5-hydroxytryptamine-blocking agent, diminished the 5-hydroxytryptamine-induced increase of cyclic AMP level. This parallels the effect of this amine on the contracted muscle.Acetylcholine, which causes a tonic contraction of the muscle, increased intracellular levels of cyclic GMP in a dose-dependent (max. 45-fold at 10^–4 M ACh) manner. The time course of the rise in cyclic GMP level was rapid and transient (peak concentration of cyclic GMP at 2 min).Mytolon was the most effective of all cholinergic blockers tested. It was concluded that cyclic nucleotides may play a role in the modulatory process of the transmitters. A direct relation to the relaxation-contraction process could not be established.Abbreviations ABRM anterior byssus retractor muscle - cyclic AMP adenosine 3,5-monophosphate - cyclic GMP guanosine 3,5-monophosphate - ACh acetylcholine - 5-HT 5-hydroxytryptamine, serotonin - DA dopamine - TCA trichloroacetic acid - UML 1-methyl lysergic acid hydrogen maleinate     

Two polymorphicAvaI andHhaI sites in a differentially methylated region of the human H19 gene

Summary The H19 gene is paternally imprinted both in the human and mouse (Bartolomeiet al., 1991; Zhang and Tycko, 1992), although its expression pattern seems somewhat different between the two species (Jinno,et al., 1995). DNA-methylation is a promising candidate for a parent-of-origin mark of the gene, and a paternal allele-specific methylation imprint was recently identified at the mouse H19 locus (Tremblayet al., 1995). We found a 50% methylated region in the human H19 gene (Jinno, unpublished data). A search for polymorphisms in this region revealed two novelAvaI andHhaI RFLPs, which contribute to the detection of allele-specific methylation at the human H19 locus.PCR primers for the AvaI-site PANL2 5-GAGCCTGCCAAGCAGAGCG-3 - PANR2 5-CACATAAGTAGGCGTGACTTGA-3 PCR primers for the HhaI-site ASMA 5-CAATGAGGTGTCCCAGTTCCA-3 - PANR2 5-CACATAAGTAGGCGTGACTTGA-3     

Selection and characterization of pyrG mutants of Penicillium chrysogenum lacking orotidine-5′-phosphate decarboxylase and complementation by the pyr4 gene of Neurospora crassaa

Summary Pyrimidine auxotrophs of Penicillium chrysogenum have been isolated at a high frequency among mutants resistant to 5-fluoroorotic acid (5.2 mM). Some of the pyrimidine auxotrophs (e.g. strain pyrG1) showed no reversion. A radiometric assay based on the conversion of (6-¹⁴C)orotidine 5-monophosphate (OMP) into (6-¹⁴C)uridine 5-monophosphate (UMP) was developed to determine OMP-decarboxylase activity. One of the pyrimidine auxotrophs (P. chrysogenum pyrGl) was studied in detail. It was deficient in OMP-decarboxylase activity, whereas the parental strain (P. chrysogenum Wis. 54-1255) showed a normal enzyme activity. A five-fold higher OMP-decarboxylase activity was found in a P. chrysogenum pyrGI clone transformed with plasmids containing the Neurospora crassa pyr4 gene (which codes for the same enzyme).Abbreviations OMP orotidine 5-monophosphate - UMP uridine 5-monophosphate     

Cyclische Nucleotide als intracelluläre Überträgerstoffe bei Hormonwirkungen

Zusammenfassung Hormone dienen als extracelluläre Informationsüberträger zwischen ihrem Bildungsort, einer endokrinen Drüse, und den Zellen, deren Funktion sie regulieren. Durch die Reaktion des Hormons mit den an der Zellmembran gelegenen Receptoren wird die Aktivität der mit diesen eng verknüpften Adenyl-Cyclase beeinflußt. Die meisten Hormone erhöhen in ihrem Zielorgan die Aktivität dieses Enzyms und führen hierdurch zu einem raschen Anstieg der intracellulären Konzentration von Adenosin-3:5-monophosphat (Ado-3:5-P). Dieses cyclische Nucleotid wird durch eine spezifische Phosphodiesterase zu Adenosin-5-monophosphat abgebaut. Auch die Aktivität dieses Enzyms bestimmt die intracelluläre Ado-3:5-P-Konzentration, die im Vergleich zu der anderer Nucleotide sehr gering ist.Ado-3:5-P beeinflußt als zweiter, intracellulärer Überträgerstoff die Aktivität zahlreicher Schlüsselenzyme. Die Ado-3:5-P-Konzentration bestimmt hierdurch das Gleichgewicht verschiedener Stoffwechselwege zueinander und damit die Reaktion einer Zelle auf eine hormonale Stimulierung. An einer Reihe von Enzymen wird die durch Ado-3:5-P bedingte Aktivitäts-Änderung durch einen gleichartigen Mechanismus bewirkt. Das cyclische Nucleotid stimuliert Proteinkinasen, die eine Phosphatgruppe des ATP auf verschiedene Proteine übertragen und hierdurch deren Eigenschaften verändern können. So steigt bei Phosphorylierung durch eine Ado-3:5-P-stimulierbare Proteinkinase die Aktivität der Triglyceridlipase und der Glykogen-Phosphorylase-b-kinase an, dagegen nimmt die Aktivität der Glykogen-Synthetase ab; durch Phosphorylierung von Histonen kann deren Repressorcigenschaft vermindert und die Synthese von Enzymen gesteigert werden.In manchen tierischen Geweben wurde auch eine spezifisch durch Guanosin-3:5-monophosphat (Guo-3:5-P) stimulierbare Proteinkinase nachgewiesen. Dieses cyclische Nucleotid kommt wie Ado-3:5-P in allen Säugerorganen vor. Die Bildung von Guo-3:5-P aus GTP wird durch die Guanyl-Cyclase katalysiert, ein Ferment, das im Gegensatz zur Adenyl-Cyclase zum großen Teil nicht an die Zellmembranen gebunden ist. Die Konzentration von Guo-3:5-P in verschiedenen Geweben, im Blutplasma und im Urin wird durch Hormone beeinflußt. Es ist noch nicht bekannt, welche hormonalen Regulationen durch Guo-3:5-P vermittelt werden; dagegen ist bei vielen, rasch einsetzenden Hormonwirkungen die Beteiligung von Ado-3:5-P nachgewiesen worden.

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Abkürzungen Ado-3:5-P Adenosin-3:5-monophosphat - dAdo-3:5-P Desoxy-adenosin-3:5-monophosphat - Guo-3:5-P Guanosin-3 : 5-monophosphate - Nuc-3:5-P Nucleosid-3:5-monophosphat - NTP Nucleosidtriphosphat - NMP Nuclcosid-5-monophosphat - dATP Desoxyadenosintriphosphat - P_i anorganisches Phosphat - PP_i anorganisches Pyrophosphat - DNS Desoxyribonucleinsäure - RNS Ribonucleinsäure - r-RNS ribosomale RNS - m-RNS Boten-RNS - Glykogen-Synthetase UDP-Glucose--1,4-glucan--4-glucosyltransferase - ICSH interstitial-cell-stimulating hormone     

Differences in antigenic properties of Fc-binding activity during infection with herpes simplex virus type 1

Summary The antigenic properties of the Fc receptor induced by herpes simplex virus type 1 (HSV-1) were studied with anti-HSV F(ab)₂ and pFc from infected rabbits.It appeared that the HSV-induced Fc-binding receptor had different antigenic characteristics at different times after infection. The Fc receptor present early in the infection (0.5 hours), during the adsorption period, most probably is the result of a fusion event between the virus envelope and the infected cell. We found that this Fc receptor reacted with anti-HSV F(ab)₂ and thus showed HSV-antigenic properties in such a way that binding of anti-HSV F(ab)₂ prevented the binding of pFc fragments.Later on in the infection (5 hours), the Fc-binding activity present on the surface of the infected cell is the result of newly synthesized and in the plasma membrane integrated polypeptides. The Fc-binding activity present on the cell surface of 5 hours infected cells could not be inhibited by anti-HSV F(ab)₂ and did not interfere with the binding of pFc to the Fc receptor.With 1 Figure     

Studien über den Mechanismus der Immunhämolyse: Der Bindungsmodus der vierten Komplementkomponente

Zusammenfassung Die Bindung der vierten Komplementkomponente (C₄) an sensibilisierte Hammelblutzellen (EA) ist von der vorhergehenden Bindung der ersten Komplementkomponente abhängig. Das Präparat EAC₁ kann, wenn ihm C₄ in geeigneter Form angeboten wird, in den Komplex EAC_1,4 überführt werden. Hierbei verschwindet der titrierbare Gehalt der flüssigen Phase an C₄; gleichzeitig acquirieren die Zellen die Fähigkeit, mit R₄ zu lysieren. Der zeitliche Ablauf dieser Veränderung wird untersucht. Die Eeaktion zwischen EAC₁ und C₄ verläuft äußerst schnell, und ihre Geschwindigkeit wird durch die Reaktionstemperatur nicht beeinflußt. Während die Bindung von C₁ an EA nur in Gegenwart von Ca⁺⁺ erfolgt, läuft die Bindung von C₄ an EAC₄ auch in Abwesenheit von zweiwertigen Metallionen ab. Die vonLevine u.Mayer als ein Ganzes betrachtete Ca⁺⁺-abhängige Überführung von EA in EAC_1,4 besteht mithin aus zwei aufeinanderfolgenden Teilreaktionen, von denen die erste (C₁-Bindung) calciumabhängig und die zweite (C₄-Bindung) von zweiwertigen Ionen unabhängig ist.Mit Unterstützung der Deutschen Forschungsgemeinschaft sowie der Gesellschaft der Freunde und Förderer der Medizinischen Akademie Düsseldorf.     

Inverse Correlation Between IgG-Antihinge Region and Antierythrocyte Autoantibody in Chronic Benign and Malignant Cold Agglutination

Previous reports provided evidence of an immunosuppressive role of natural anti-F(ab)₂ antibodies. If suppressive anti-F(ab)₂ antibodies also regulated the autoantibody production in cold agglutination, one would expect high titers of anti-F(ab)₂ to be associated with low titers of cold agglutinins. Indeed, our previous studies revealed an inverse correlation between IgG-anti-F(ab)₂ and cold agglutinins. Many previous experiments focused on anti-F(ab)₂ of an antiidiotypic nature. Recent epitope mapping showed that anti-F(ab)₂ of healthy persons is not an antiidiotype but recognizes a hinge region sequence. We attempted to answer the question whether this IgG-antihinge antibody is responsible for the previously described association between anti-F(ab)₂ and cold agglutinins. IgG-antihinge and IgG-anti-F(ab)₂ antibody was determined and statistically analyzed in the serum of 334 patients with cold agglutination. Our experiments revealed a strong correlation between the concentrations of antihinge and the previously described anti-F(ab)₂ antibody. The anti-F(ab)₂ activity was competitively inhibited by a synthetic hinge peptide. Moreover, patients with high antihinge titers had low cold agglutinin titers, and vice versa. A stratification according to cold agglutinin specificity and disease etiology showed that the inverse correlation is present only in anti-I and anti-i patients suffering from monoclonal B-lymphocyte proliferation. In conclusion, our results confirm the correlation previously described for anti-F(ab)₂ antibody and antierythrocyte autoantibody and define for the first time an association between an idiotype-independent anti-IgG autoantibody and cold agglutinin.     

An α-mating-type-specific mutation causing specific defect in sexual agglutinability in the yeast Saccharomyces cerevisiae

We have identified a recessive -mating-type-specific gene agl causing agglutinability defect without significant effects on other sexual activities. a cells carrying agl showed sexual agglutination with cells but cells carrying agl showed sexual agglutination with neither cells nor a cells. cells carrying agl produced pheromone and responded to a pheromone just like wild cells. cells carrying agl showed a little decreased but significant mating ability when tested on solid media or membrane filter. The agl mutant is different from any -specific ste mutants found so far in many sexual activities. The agl gene is recessive, and unlinked to the mating type locus. Biological significance of the mating type agglutinability is discussed based on the results obtained with the mutant.