Histologische Studien zur vegetativen und cerebralen Innervation des Innenohrs und seiner Gefässe beim Menschen und beim Hund

Zusammenfassung Das Nervengewebe in der Wand der Arteria labyrinthi, in dem vestibulären Abschnitt des membranösen Labyrinths und im Ductus cochlearis wurde mit der Silbermethode nach Bielschowsky-Gros überwiegend in Totalpräparaten untersucht.Innervation der Arteria labyrinthi Die Adventitia der Arteria labyrinthi birgt nebenden sympathischen Geflechten einen weitmaschigen Plexus bandförmiger Nervenfasern vermutlich cerebraler Herkunft. Die Kollateralen dieser Fasern entwickeln auf der Muscularis neurofibrilläre Endbäumchen. Eine derartige Nervenendigung ist in ein kernhaltiges Plasmodmm eingebettet.Kapillarnerven vermutlich cerebralen Ursprungs werden in dem membranösen Labyrinth beschrieben.Innervation der Pars superior labyrinthi Im Planum semilunatum breitet sich ein intra- und subepithelialer Neurofibrillenplexus aus. Er verdankt seine Entstehung den marklosen Nervenfasern des Ramus ampullaris.An der Basis der Sinneszellen in der Crista ampullaris, in der Macula sacculi und utriculi entwickeln die ursprünglich markhaltigen Neuriten des Ganglion vestibuli zarte, untereinander verbundene Neurofibrillenkelche. Engmaschige, perinucleäre Gitterwerke der Neurofibrillen in den Sinneszellen werden abgebildet.Innervation des Ductus cochlearis In dem sekundären Neurofibrillengeflecht des Plexus marginalis kommen bipolare, neurofibrillenarme Zellen vor. Sie ähneln den embryonalen Nervenzellen im Ganglion spirale cochleae. Der Plexus marginalis beim Menschen enthält nur gliaartige, multipolare Zellen. Die Fortsätze solcher Zellen gehen im Gegensatz zu den Fortsätzen der bipolaren Zellen nicht in das Nervengeflecht des Plexus marginalis über. In der Cupula setzen sich die schmal gewordenen Neurofibrillenbündelchen in die äußeren Spiralzüge fort. Einzelne Neurofibrillen des Plexus marginalis begleiten die Capillaren des Limbus spiralis. Die Verbindungen des Plexus marginalis mit den nervösen Formationen des Cortischen Organs werden geschildert.     

Mapping of β-glucan content and β-glucanase activity loci in barley grain and malt

Genetic study of -glucan content and -glucanase activity has been facilitated by recent developments in quantitative trait loci (QTL) analysis. QTL for barley and malt -glucan content and for green and finished malt -glucanase activity were mapped using a 123-point molecular marker linkage map from the cross of Steptoe/Morex. Three QTL for barley -glucan, 6 QTL for malt -glucan, 3 QTL for -glucanase in green malt and 5 QTL for -glucanase in finished malt were detected by interval mapping procedures. The QTL with the largest effects on barley -glucan, malt glucan, green malt -glucanase and finished malt glucanase were identified on chromosomes 2,1,4 and 7, respectively. A genome map-based approach allows for dissection of relationships among barley and malt glucan content, green and finished malt -glucanase activity, and other malting quality parameters.     

A simple method for the isolation and characterization of thymidylate uptaking mutants in Saccharomyces cerevisiae

Summary The mutant tmp1–10 ^ts which confers thermosensitive auxotrophy for thymidylate is employed for the selection of 5-dTMP uptaking mutants. At the nonpermissive temperature yeast cells phenotypically wild type for thymidylate uptake can grow for only 3 to 4 generations in the presence of 10^–2 M 5-dTMP. Thymidylate utilizing mutants (tum mutants) were isolated which can grow in the presence of 12 to 24 g 5-dTMP/ml. Genetical analysis revealed one of these mutant strains to be a double mutant, tuml tum2. For normal growth haploid thymidylate auxotrophic strains require approximately 360 g 5-dTMP/ml when tum1 and 24 g 5-dTMP when tum2 is present, respectively. Cells prototrophic for thymidylate (TMP) harbouring tum1 tum2 will also take up 5-dTMP and incorporate it specifically into their DNA. Thymidylate utilization in such strains is independent of functional mitochondria, as similar incorporation of labelled 5-dTMP is found in isogenic strains with rho ⁺, rho ^– and rho ⁰ status. Optimal stimulation of the 5-dTMP uptaking principle in haploid TMP strains is found at 4 g 5-dTMP/ml when tum1 and tum2 are present.     

Hydrodynamic characteristics of two-phase inverse fluidized bed

Hydrodynamic characteristics of a new mode of liquid-solid fluidization, termed as inverse fluidization in which low density floating particles are fluidized with downward flow of liquid, are experimentally investigated. The experiments are carried out with low density particles (<534 kg/m³) which allow high liquid throughputs in the system. During the operation, three regimes, namely, packed, semi-fluidization and fully fluidization are encountered. Empirical correlations are proposed to predict the pressure drop in each regime. A computational procedure is developed to simulate the variation of pressure drop with liquid velocity.List of Symbols Ar modified Archimedes number, d _p ³ (– _s)g/² - d _p particle diameter, mm - f friction factor (eq. 2) - g acceleration due to gravity, m/s² - H total bed height, m - H _c height of the column, m - H_f height of fluidized bed, m - H₀ height of initial bed, m - H_p height of the packed bed, m - (p) pressure drop across the bed, N/m² - (p) _f pressure drop across fluidized bed section, N/m² - (p) _p pressure drop across the packed bed section, N/m² - (p) _sf total pressure drop in semifluidization regime, N/m² - Re Reynolds number, d _pU ₁/ - Re_m modified Reynolds number, d _pU ₁/(1– _p) - U ₁ superficial liquid velocity, m/s - U_mf minimum fluidization velocity, m/s - U_osf onset fluidization velocity, m/s Greek Letters _f voidage of fluidized bed - _p voidage of packed bed - liquid viscosity, kg/ms - liquid density, kg/m³ - _s particle density, kg/m³     

Frequencies of synonymous substitutions in mammals are gene-specific and correlated with frequencies of nonsynonymous substitutions

The frequencies of synonymous substitutions of mammalian genes cover a much wider range than previously thought. We report here that the different frequencies found in homologous genes from a given mammalian pair are correlated with those in the same homologous genes from a different mammalian pair. This indicates that the frequencies of synonymous substitutions are gene-specific (as are the frequencies of nonsynonymous substitutions), or, in other words, that fast and slow genes in one mammal are fast and slow, respectively, in any other one. Moreover, the frequencies of synonymous substitutions are correlated with the frequencies of nonsynonymous substitution in the same genes.Correspondence to: D. Mouchiroud     

β-Glucuronidase activity in human T and B lymphocytes and the Tμ and Tγ subpopulations

Summary The -glucuronidase staining characteristics of isolated T cell populations and the T and T enriched fractions derived of them were studied. T lymphocytes were obtained from purified T lymphocytes by ox-IgG rosette sedimentation. The rosette-forming cells in the pellet were referred to as T lymphocytes, whereas the lymphocytes in the interface were referred to as T depleted or T lymphocytes. B cells were studied on rosetted mononuclear cells with either mouse erythrocytes or with Staphylococcus Aureus (Cowan I) bacteria, after a preceeding polyvalent anti-human Ig treatment of the cells. While B cells showed mostly no reactivity, T and T cells were respectively characterised by a dot-like and granular pattern of reactivity. These findings are in agreement with those observed by others after -naphthyl-acetate esterase or acid phosphatase staining. Within the T lymphocyte fraction, the T non-, non lymphocytes seemed to have a granular pattern of reactivity. The same staining pattern was found in non-B, non-T lymphocytes.     

Genetics of Ia-like alloantigens in chickens and linkage withB major histocompatibility complex

Two sets of backcross matings were performed to test for linkage between genes coding for the Ia-like antigens (Ia) and the B erythrocyte antigens (Ea-B) of the chicken. Evidence is presented which indicates that the la antigens are determined by a single codominant locus and that theEa-B and Ia loci are on the same chromosome. Failure to detect a single recombinant between theEa-B and Ia loci out of 208 progeny suggests close linkage of the two genes with a map distance of up to about 2 centimorgans. The Ia genes are thus included in theB major histocompatibility complex of the chicken.     

Highly efficient transformation and regeneration of aspen plants through shoot-bud formation in root culture

The natural capacity of aspen (Populus tremula L.) roots for direct shoot-bud regeneration was harnessed to establish a highly efficient transformation and regeneration procedure that does not require a pre-selection stage on antibiotics. Aspen stem segments were transformed using wildtype Agrobacterium rhizogenes (LBA9402) with the binary p35SGUSINT plasmid carrying the genes coding for -glucuronidase (GUS) and neomycin phosphotransferase II. High levels of transient GUS expression were found in the basal cut surface of 87% of the segments, and 98% of these formed well-developed adventitious roots. Proliferating root cultures were established in liquid culture, and GUS expression was found in 75% of the roots. Shoot-bud regeneration in root cultures was very high: 99% of the roots yielded shoot-buds (4.3 buds per root), of which 91% expressed GUS. Southern blot analysis and polymerase chain reaction confirmed the transgenic nature of the plants expressing GUS. Kanamycin resistance of transformants was tested with respect to callus growth and bud regeneration. Callus from transgenic plants exhibited a high growth rate in the presence of up to 100 g/l kanamycin, and bud regeneration from transformed roots occurred in the presence of up to 30 g/l kanamycin. Callus and buds from control (non-transformed) plants failed to proliferate or regenerate, respectively, in the presence of kanamycin at concentrations above 10 g/l. Ninety-four independent clones from different transformation events were established, of which 52 were phenotypically true-to-type.Abbreviations NAA -naphthaleneacetic acid - BA 6-benzylaminopurine - GUS -glucuronidase - NPTII neomycin phosphotransferase II - PCR polymerase chain reaction - EtOH ethanol - CTAB cetyltrimethylammonium bromide - SDS sodium dodecyl sulfate - NOS nopaline synthase - CaMV cauliflower mosaic virus     

Hexahydroindanone derivatives of steroids formed by Rhodococcus equi

Summary A mutant strain of Rhodococcus equi accumulates three metabolites from the androst-4-ene-3,17-dione or from its degradation intermediate, 3a-H-4(3'-propionic acid)-7a-methylhexahydro-1,5-indanedione (MEPHIP). These three metabolites are: 3a-H-4a(3'-propionic acid)-5-hydroxy-7a-methylhexahydro-1-indanone--lactone (HIL); 3a-H-4(3'-trans acrylic acid)-5-hydroxy-7a-methylhexahydro-1-indanone (^2'-5-hydroxy-MEPHIP); and 3a-H-4(3'-hydroxy-3'-propionic acid)-5-hydroxy-7a-methylhexahydro-1-indanone (3'-hydroxy-HIL). The behaviour of this mutant allows us to propose a pathway for degradation of the intermediates, methylperhydroindanone propionates. However, during this degradation, the side-chain propionate was eliminated by a-oxidation mechanism. Offprint requests to: A. Miclo     

Presence of hybridizing DNA sequences homologous to bovine acidic and basicβ-crystallins in all classes of vertebrates

Summary The eye lens-crystallins in cow and chicken are encoded by a family of at least six genes. In order to assess the distribution of the corresponding genes among other vertebrates we hybridized -crystallin sequences (A2, A3/A1, A4, B1, B2, B3), isolated from a bovine lens cDNA library, to Southern blots on whichEcoR1-digested chromosomal DNA was blotted from different vertebrate species. These included human, chimpanzee, calf, rat, pigeon, duck, monitor lizard, toad, trout, and lamprey. Positive hybridization signals were found in the representatives of virtually all classes of vertebrates. The basic B-crystallins gave hybridization signals in more species than the acidic A ones. In monitor lizard and toad the weakest hybridization signals for basic crystallin probes were found. For acidic crystallin probes the distribution pattern was more simple; among cold-blooded vertebrates a signal for A2 was found in trout and lamprey, for A4 in trout, and for A3/A1 only in toad. The results demonstrate that the duplications leading to the -crystallin gene family occurred before or during the earliest stages of vertebrate evolution.     

Curdlan and other bacterial (1→3)-β-d-glucans

Three structural classes of (13)--d-glucans are encountered in some important soil-dwelling, plant-associated or human pathogenic bacteria. Linear (13)--glucans and side-chain-branched (13,12)--glucans are major constituents of capsular materials, with roles in bacterial aggregation, virulence and carbohydrate storage. Cyclic (13,16)--glucans are predominantly periplasmic, serving in osmotic adaptation. Curdlan, the linear (13)--glucan from Agrobacterium, has unique rheological and thermal gelling properties, with applications in the food industry and other sectors. This review includes information on the structure, properties and molecular genetics of the bacterial (13)--glucans, together with an overview of the physiology and biotechnology of curdlan production and applications of this biopolymer and its derivatives.     

Distribution and specific central projections of mechanoreceptors in the thorax and proximal leg joints of locusts

Summary Tactile hairs on the locust thorax can be divided into two classes by their external morphology and their central projection pattern: Short hairs, 10–100 m in length, which are assembled in distinct plates and rows, and long hairs, 100–800 m in length, which are distributed all over the body and are organized in large fields or aligned along the ridges of the appendages.The sensory fibers of the first class arborize in the lateral dorsal neuropile of thoracic ganglia and then extend further into the ipsilateral half of the corresponding ganglion in three main bundles from which fine rami of fibers end in the intermediate neuropile. In all three thoracic ganglia the projection pattern of homologous hair plates is similar.The sensory fibers of the second class exclusively terminate in special median ventral neuropiles, the ventral association center (VAC) and ventralmost ventral association center (VVAC). In addition fibers from meso- and metathoracic hairs, located close to the longitudinal midline of the animal, may terminate in the contralateral VAC and with one branch project to the next anterior ganglion through the ipsilateral connective. In contrast, fibers from prothoracic hairs were not found to leave their ganglion.With support by the DFG Neurale Mechanismen des VerhaltensSome of the studies were started at Universität Bielefeld, Fakultät für Biologie II (Abtlg. Prof. Dr. P. Görner)     

Excitatoren und paarungsverhalten mitteleuropäischer malachiiden (Coleopt., Malacodermata)

Ohne ZusammenfassungAlphabetisches Verzeichnis der im Text gebranchten Abkürzungen AK Anbieten der Kopfgrube () - AR-seitig außenrandseitig (auf Elytre bezogen) - EO Elytralorgan (EO-Arten = Arten mit Elytralorganen im männlichen Geschlecht) - f Flucht () - F Flucht () - FA, fa frontale Auseinandersetzung (, ) - FS, fs Fühlertrillern bzw. Frontalspiel (, ) - gk Grubenknabbern () - IR-seitig innenrandseitig (auf Elytre bezogen) - K Kopulation - KG Kopfgrube (KG-Arten = Arten mit Kopfgrube im männlichen Geschlecht) - KI Abdomenkitzeln () - KV Kopulationsversuch () - LP-Feld den weiblichen Labialpalpen korreliertes Drüsenporenfeld - MP-Feld den weiblichen Maxillarpalpen korreliertes Drüsenporenfeld - 180 Drehung des um 180° - ob Organbeißen () - ok Organknabbern () - OZ Organzuwendung () - P Prüfung der Kopulationsbereitschaft durch - RB rückwärtige Berührung durch - SLV Seitwärtslauf nach vorn () - SLH Seitwärtslauf nach hinten () - U Umrundung () - vl Vorwärtslauf () - 180 Drehung des um 180° Habilitationsschrift.     

Chromosomal location of esterase,peroxidase and phosphoglucomutase isozyme structural genes in cultivated rye (Secale cereale L.)

Summary Isoelectric focusing of esterase (EST), peroxidase (PRX), and phosphoglucomutase (PGM) isozymes in Chinese Spring wheat, Imperial rye and several Chinese Spring/Imperial and Holdfast/King II addition, translocation and substitution lines revealed the chromosomal location of nine Est loci previously described and of one Prx and Pgm locus. Loci Est1, Est2, Est3, Est5, Est6 and Est7 were found on chromosome arm 5RL, Est8 and Est9 on chromosome 6R in Imperial rye, and the Est10 locus on chromosome arm 4RL in Imperial rye and King II rye. A discrepancy was found between the chromosomal location of the Prx locus in Imperial where chromosome 2R was responsible for the expression of the peroxidase enzyme, and King II with chromosome 1R carrying the Prx gene. As a possible explanation, the occurrence of translocation events during the production of wheat/rye aneuploid lines is discussed. The rye Pgm locus could be associated with chromosome 4RS in Imperial and King II rye. Except for the location of Est loci on chromosome 5RL, the results reported in this paper lend further evidence for the assumed homoeology relationships between the chromosomes of Triticinae and for the conservation of gene synteny groups during the evolution of the Triticeae tribe.     

Some observations on cyclodextrin-mediated boosting of secreted amylolytic enzymes byLactobacillus amylovorus

The amounts of a 160-kDa amylase and a 140-kDa -amylase (A. Burgess-Cassler and S. H. Imam, Curr. Microbiol. 23:207–213, 1991) secreted into culture medium by the starchutilizingLactobacillus amylovorus were enhanced by the use of cyclodextrin (CD) as the carbon source. The levels of total extracellular -amylase obtained with glucose as the carbon source could be boosted severalfold by use of CD. The best enhancer was -CD, and the rank order of best to least effective was -CD>-CD=-CD>glucose.Another amylase, a 65-kDa -amylase, which degraded para-nitrophenyl-(1,4)-d-glucopyranoside, was also detected in this study. The most effective enhancer in this case was -CD, and the rank order was -CD>-CD>-CD glucose. Despite its ability to degradep-nitrophenylated glucose, this enzyme did not convert maltose to glucose. It showed a cleared zone on starch zymograms and did degrade short maltodextrins to maltose. Neither this new -amylase nor the 140-kDa -amylase exhibited any detectable ring-decyclizing (cyclodextrinase) activity against -or -CD.Other extracellular amylases (not characterized here) appeared to be similarly enhanced by CDs. Although the precise mechanism by which this effect is accomplished remains undefined, CDs can be useful inducing agents, boosting the expression and/or secretion of otherwise low-level enzymes, either as additives to growth media or as sole carbon source.     

Schwermetallaffine Strukturen des peripheren Nerven

Zusammenfassung Konvertiertes Kupfer wurde an axonalen und Schwannschen Zellmembranen, vor allem im nodalen und paranodalen Bereich beobachtet. Kupfer wird offenbar in inner und outer leaflet der unit membrane ein- und an diese angelagert. Denn bei wenig Präzipitat oder geringer Elektronendichte des Niederschlags stellten sich die Membranen als dreischichtiger Komplex dar, der in den Dimensionen der unit membrane entsprach. Bei großen Präzipitatmengen oder bei hoher Elektronendichte des Niederschlags blieb nur die helle Mittelschicht von ca. 30 Å frei. Diese Metallaffinität wird im Zusammenhang mit den cytochemischen AChE-Nachweisverfahren diskutiert, weil bei diesen Methoden Schwermetallionen im Inkubationsmedium verwendet werden, und die Kupferbindungsstellen zum Teil mit den Lokalisationen der AChE identisch sind. Möglicherweise gibt beim cytochemischen AChE-Nachweis schon die Darstellung von unit membranes in unkontrastierten Präparaten Aufschluß auf erfolgte unspezifische Schwermetallbindung. Als weitere Kontrolle wird Inkubation in der verwendeten Schwermetallösung mit nachfolgender Konversion vorgeschlagen.

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Heavy metal affinity of peripheral nerve structuresI. Possibility of interference with cytochemical localisation of AChE

Summary The ultrastructural localisations of copper in ventral and dorsal roots of the rat were studied by varying fixation and converting medium. Precipitated copper was deposited in axonal membranes (axolemma, membranes of axonal organelles) and Schwann cell membranes (inner and outer plasmalemma, major and minor dense lines in the region of the splitting myelin sheath, terminal loops and Schwann cell interdigitations). Copper obviously was bound within and attached to inner and outer leaflet of these membranes. If there was little or less electron-dense precipitate membranes appeared three-layered, dimensions corresponding to those of the unit membrane. If there was electron-dense or plenty of precipitate only the middle electron-lucent layer of approximately 30 Å was revealed. The predominant deposition on nodal and paranodal membranes may be explained either by facilitated access to this region or by specific metal ion binding sites at those specialised membranes. Metal ion binding is discussed in relation to cytochemical demonstration of AChE activity, because these methods use incubation media containing heavy metal cations and copper binding sites partly correspond with the localisation of AChE activity. The appearance of unit membranes in unstained sections probably could be a hint at unspecific heavy metal ion binding ocouring in demonstration of specific AChE. Therefore control-incubation in the heavy-metal solution with subsequent conversion is suggested.

     

Involvement of β 1,4 galactosyltransferase 1 and Galβ 1→4GlcNAc groups in human hepatocarcinoma cell apoptosis

1,4 galactosyltransferase 1 ( 1,4GT1) synthesizes Gal 14GlcNAc groups in N-linked sugar chains of animal glycoproteins, which have been demonstrated to play an important role in many biological events, including sperm-egg interaction, cell migration and mammalian embryonic development. In this study, the mRNA level of 1,4GT1 was found to increase greatly during the 7721 hepatocarcinoma cells apoptosis induced by cycloheximide. Ricinus Communis Agglutinin-I staining indicated generous increase of Gal 14GlcNAc groups during apoptosis. Further study showed that the 7721 hepatocarcinoma cells transiently transfected with 1,4GT1 were more susceptible to the apoptosis induced by cycloheximide. The increased susceptibility was in accordance to the transfection concentration of 1,4GT1, which also led to the increased Gal 14GlcNAc groups on the transfected cell surface. All the observations suggested that 1,4GT1 and Gal 14GlcNAc groups might be associated with the apoptosis of human hepatocarcinoma cells.     

Simultaneous recognition of two chiral centers in α,β-diastereomeric amino acids by an N-carbamoyl-L-α-amino acid amidohydrolase from Alcaligenes xylosoxidans

Cells of Alcaligenes xylosoxidans containing N-carbamoyl-L--amino acid amidohydrolase strictly distinguished the configuration of not only the -carbon but also the -carbon of N-carbamoyl--methylphenylalanine, and produced threo-l--methylphenylalanine specifically from a mixture of the four stereoisomers.     

Synonymous nucleotide substitution rates of β-tubulin and histone genes conform to high overall genomic rates in rodents but not in sea urchins

Summary Sea urchin and rodent genomes have been posited to evolve rapidly as indicated by divergences in single copy nuclear DNA sequences. We have examined whether the synonymous substitution rates of three highly conserved genes, -tubulin, histone H4, and histone H3, adhere to these high genomic substitution rates by comparing sequences between two sea urchins,Strongylocentrotus purpuratus andLytechinus pictus, and between rodents and humans. Whereas the rate of change between the 3 untranslated regions of the -tubulin cDNA ofS. purpuratus (Sp-1), sequenced in this study, and ofL. pictus (Lp-3) was consistent with the overall rate of change estimated from previous DNA hybridization results between these species, the synonymous substitution rates for the carboxyl domains of these -tubulins, as well as for the late histones H4 and H3, were significantly depressed. In contrast, synonymous nucleotide substitution rates between rodents and between rodent and human for the carboxyl domain proper of identical -tubulin isotypes and for histone H4 and H3.1 did not differ from the overall rate of change for the rodent genomes. Moreover, an analysis of paralogous human and mouse -tubulin sequences supported the conclusion that the synonymous substitution rates in the mouse were higher than those in the human. Differences in constraint on evolutionary change were not evident strictly from the conserved amino acid sequences and base compositions of these genes. Other constraining influences seemed more relevant to the departure of the synonymous substitution rates of the sea urchin -tubulin and histone coding regions from the average genomic rate.