Hydrolysis of linalyl acetate and α-terpinyl acetate by yeasts

Of 104 yeasts tested for the hydrolysis of rac-linalyl acetate and rac--terpinyl acetate twelve hydrolysed rac-linalyl acetate. Five of these belonged to five different species of Geotrichum. The most promising strain, Geotrichum capitatum CBS 0572.82, yielded (S)-linalool in 56% enantiomeric excess after 6h (E value 5, c = 32%). Only one unclassified yeast isolate hydrolyzed rac--terpinyl acetate with a slight preference for the S-enantiomer (E value 2). © Rapid Science Ltd. 1998     

Protein kinase C (α, β, γ) in Pacinian corpuscle

Immunocytochemical demonstration of protein kinase C (PKC) subspecies (, , ) was carried out in Pacinian corpuscles of rat hind feet using monoclonal or polyclonal antibodies against each of these subspecies. The inner core cells and lamellae and the Schwann cell cytoplasm of the nerve fiber innervating the corpuscle were strongly positive for PKC -immunoreactivity (IR). In contrast, the axon terminal and the outer core did not display any positive -IR. Very weak PKC -IR was detected in the ultraterminal region of the axon terminal, while the trunk region showed no immunoreactivity. Very faint PKC -IR was found also in the lamellar cells located at the periphery of the inner core and the endoneurial fibroblasts in the intermediate layer. PKC -IR was not detected in any part of the corpuscle. The strong PKC -IR in the inner core and the presence of absence of PKC -, -, and -IR in the axon terminal are discussed from the point of view of the functional aspects of each part.     

L cells expressing DQ molecules of the DR3 and DR4 haplotypes: reactivity patterns with mAbs

cDNAs coding for the HLA class II DR and DQ and chains of the diabetogenic haplotypes DR3 and DR4 were introduced into a mammalian expression vector and transfected into L-cell mouse fibroblasts to produce cells expressing individual human class II molecules. Stable L transfectants were generated expressing each of the DR or DQ isotypes of the cis-encoded and chains of the DR3 or DR4 haplotypes, as well as the trans-encoded and chains of the DQ molecules of the two haplotypes. However, isotype mismatched combinations (DR/DQ or DQ/DR) did not result in any stable transfectants. The stable DQ L-cell transfectants obtained, along with homozygous B-cell lines expressing the DQ2 and DQ8 specificities, were tested against a large panel of twentyone anti-HLA class II monoclonal antibodies (mAbs). Their unusual reactivity patterns are described including the failure of most pan-DQ mAbs to react with all DQ expressing L-cell transfectants. Interestingly, some mAbs react with certain heterodimers expressed on B-LCL but fail to recognize the same heterodimers expressed on the transfectants. This is suggestive of minor structural modifications that class II molecules undergo depending on the cells they are expressed on.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession number U07848. The name DQB1 ^* 0202 was officially assigned by the WHO Nomenclature Committee in April 1994. This follows the agreed policy that, subject to the conditions stated in the most recent Nomenclature Report (Bodmer et al. 1992), names will be assigned to new sequences as they are identified. Lists of such new names will be published in the following WHO Nomenclature Report     

Histoenzymatic characterization of sub-types of Type I fibres in fast muscles of rats

Summary The histochemical activities of succinic dehydrogenase (SDH), myofibrillar Adenosine triphosphatase (ATPase) and alpha glycerophosphate dehydrogenase were studied in serial sections of rat vastus lateralis (red) (RVL), gastrocnemius and diaphragm muscles. Three main fibre-types were distinguished. The Type I fibres of RVL and gastrocnemius muscles fell into two distinct groups: one category-Type IA showed very low ATPase activity. The second category of Type IB fibres displayed moderate ATPase reaction. The Type IA fibres were divisible into two sub-groups when tested for SDH reaction. Type IA₁ fibres possessed a homogenous distribution of diformazan·granules throughout the fibre: Type IA₂ fibres displayed characteristic moth-eaten pattern of diformazan localization. The diaphragm muscle did not show either Type IB or Type IA₂ varieties. The great majority of Type I fibres were sub-type IA₁ in the three fast muscles studied. It is also demonstrated here that an inherent heterogeneity exists between Type I fibres of diaphragm and leg muscles in regard to -GPD localization. This histochemical data emphasizes the fact that subdivision of Type I striated muscle fibres of mammalian animals into two sub-types is only approximate and that a further subcategorization is possible.     

Average phase difference theory and 1∶1 phase entrainment in interlimb coordination

The dynamics of coupled biological oscillators can be modeled by averaging the effects of coupling over each oscillatory cycle so that the coupling depends on the phase difference between the two oscillators and not on their specific states. Average phase difference theory claims that mode locking phenomena can be predicted by the average effects of the coupling influences. As a starting point for both empirical and theoretical investigations, Rand et al. (1988) have proposed d/dt= — K sin ), with phase-locked solutions =arcsin( /K), where is the difference between the uncoupled frequencies and K is the coupling strength. Phase-locking was evaluated in three experiments using an interlimb coordination paradigm in which a person oscillates hand-held pendulums. was controlled through length differences in the left and right pendulums. The coupled frequency _c was varied by a metronome, and scaled to the eigenfrequency _v of the coupled system K was assumed to vary inversely with _c. The results indicate that: (1) and K contribute multiplicatively to (2) =0 or = regardless of K when =0; (3) 0 or regardless of when K is large (relative to ); (4) results (1) to (3) hold identically for both in phase and antiphase coordination. The results also indicate that the relevant frequency is _c/_v rather than _c. Discussion high-lighted the significance of confirming =arcsin(/K) for more general treatments of phase-locking, such as circle map dynamics, and for the 11 phase-entrainment which characterizes biological movement systems.     

The taxonomic significance of the trunk limbs of the chydoridae (Cladocera)

Summary The differences in the structure of the trunk limbs allow to outline three sections of Chydoridae (see table I and fig. 1), coinciding with the sections distinguished according to the structure of the head pores.

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Chydoridae (Cladocera)

Chydoridae (. ), , .

     

Is haemoglobin Gα Philadelphia linked to α-thalassaemia?

Summary The question, Is Hb G Philadelphia linked to -thalassaemia? was first posed because the abnormal haemoglobin is found in heterozygotes at a concentration greater than 25%, the proportion predicted from a 4 -chain gene model. Globin chain biosynthesis was studied in a West Indian family in which one parent had ⁺ thalassaemia and the other was heterozygous for the G Philadelphia chain gene. The former had a globin chain production ratio / well above 1, while the latter had a ratio significantly less than 1. One child of the marriage had inherited the ⁺ thallassaemia from one parent and the G Philadelphia chain gene from the other and showed the typical picture of /-thalassaemia (/ ratio slightly above normal). It is explained in the discussion that the evidence favours a close linkage of 2 -chain genes.     

The cytology of phytophthora infestans

Summary Phytophthora infestans has three kinds of somatic nuclei: an oval shaped nucleus (approx. 3.1×2.7 ) which stains diffusely except for a crescent shaped Feulgen positive cap which stains intensely; a granular nucleus whose contents are organized into a fairly constant number of stained bodies, and, a deeply staining condensed nucleus. The capped nucleus is thought to be metabolic or resting and the granular nucleus is thought to be dividing as it is most commonly found in hyphal tips. Attenuated forms of all three kinds of nuclei are found.Nuclear division is mitotic and intranuclear. Eight—ten chromosomes are seen at metaphase.Sporangia have a mean of 6.3 nuclei which is constant for age and strain of culture. Sporangia become multinucleate as a result of nuclear migration and not by division in the developing sporangium. Zoospores are usually uninucleate.The nuclear cap is persistent throughout nuclear division when it also divides. It is associated with flagella production and nuclear migration and has some of the properties of a blepharoplast.     

Correlation between the atmospheric conditions and the asthmatic symptom

A point process model is suitable for analysis of a sequence of binary variables, each of which may be dependent on the preceeding one. This model was used for analysis of the correlation between the state of the atmosphere and the presence or absence of asthmatic symptom known from diaries in which a day was divided into four parts. The diaries were kept during summer and autumn of a year by 19 adult and 12 child patients in Sapporo (43°03 N, 141°20 E), 39 adult and 20 child patients in Tokyo (35°41 N, 139°46 E), and 26 adult and 18 child patients in Naha (26°14 N, 127°41 E).Low temperature and decrease in temperature significantly related to the asthmatic symptom during the seasons. No reversions on correlations as to temperature were observed among places, between the adult and the child, and before and after taking in effects of the preceding symptom and/or the circadian rhythm. Some correlations relating to humidity or to barometric pressure, on the other hand, reversed from place to place, from the adult to the child, and from before to after taking in the effects.Availability of this model for further study on the correlation between the air with contents and the asthmatic symptom is shortly discussed.     

Concentration/response effect of 2,2′, 4,4′, 5,5′-hexabromobiphenyl on cell-cell communication in vitro: assessment by fluorescence redistribution after photobleaching (“FRAP”)

Inhibition of gap junction-mediated cell-cell communication might be a mechanism for several types of cellular dysfunctions, including tumor promotion. Although many different assays have been designed to measure gap junction-mediated intercellular communication, we applied a new technique, termed Fluorescence Redistribution After Photobleaching (FRAP), to assess the ability of a known tumor promoter, 2,2, 4,4, 5,5-hexabromobiphenyl (245-HBB), to inhibit cell-cell communication in a concentration-dependent manner. WB-F344 (rat epithelial) cells were plated at low density, exposed to noncytotoxic concentrations of 1, 5, or 20 µg 245-HBB/ml medium, and stained with 6-carboxyfluorescein diacetate. Single cells in pairs or clusters of touching cells in each exposure group were examined with FRAP. The results revealed an inverse correlation between the degree offluorescence redistribution in photobleached cells and the concentration of 245-HBB. Therefore, FRAP appears to be a sensitive and rapid technique for determining complete or partial inhibition of chemically induced intercellular communication in vitro. These results also provide further evidence for the ability of 245-HBB to inhibit gap junction-mediated cell-cell communication in a concentration-dependent manner.Abbreviations 6-CFDA 6-carboxyfluorescein diacetate - FRAP fluorescence redistribution after photobleaching - 245-HBB 2,2, 4,4, 5,5-hexabromobiphenyl Michigan Agricultural Experiment Station journal article No. 12531.     

Myosatellite cells associated with different muscle fibre types in the Atlantic hagfish (Myxine glutinosa,L.)

Summary The incidence of myosatellite cells associated with white and red muscle fibres of the parietal muscle and red fibres of the craniovelar muscle was estimated by quantitative electron microscopy in the Atlantic hagfish (Myxine glutinosa, L.). Myosatellite cell nuclei constitute 3, 11 and 23 % of the total number of nuclei inside the basal lamina of the three types of muscle fibres, respectively. However, the total number of nuclei is highest in white fibres, most of the nuclei belonging to striated muscle cells. Myosatellite cell profiles in transverse sections constitute 23, 41 and 61 % of the number of muscle fibre profiles of the three types, respectively. The intervals between adjacent myosatellite cells are 135 m in white fibres, 55 m in red parietal fibres, and only 25 m in craniovelar fibres. Since craniovelar fibres are also comparatively thin, myosatellite cells constitute a significant fraction of the volume inside the basal lamina in these fibres. The myosatellite cells are 30–50 m long and up to 5 m thick. Some myosatellite cells possess few organelles, whereas others appear to contain many free ribosomes, granular endoplasmic reticulum, prominent Golgi apparatus and lysosome-like bodies.This investigation was supported by the Norwegian Research Council for Science and the Humanities (NAVF grant No. C20.30–37). The authors are indebted to Jorunn Line Vaaland and Berit Branil for technical assistance, and to Dr. Finn Walvig, Biological Station, University of Oslo, Drøbak, for supplying the hagfish     

Structures of the N-linked sugar chains in the PAS-6 glycoprotein from the bovine milk fat globule membrane

The structures of the N-linked sugar chains in the PAS-6 glycoprotein (PAS-6) from the bovine milk fat globule membrane were determined. The sugar chains were liberated from PAS-6 by hydrazinolysis, and the pyridylaminated sugar chains were separated into a neutral (6N) and two acidic chains (6M and 6D), the acidic sugar chains then being converted to neutral sugar chains (6MN and 6DN). 6N was separated into two neutral fractions (6N13 and 6N5.5), while 6MN and 6DN each gave a single fraction (6MN13 and 6DN13). The structure of 6N5.5, which was the major sugar chain in PAS-6, is proposed to be Man16 (Man13) Man14GlcNAc14GlcNAc-PA; 6N13, 6MN13 and 6DN13 are proposed to be Gal13Gal14GlcNAc12Man16 (Gal13Gal14GlcNAc12Man13) Man14GlcNAc14 (Fuc16)GlcNAc-PA;6M and 6D had 1 or 2 additional NeuAc residues at the non-reducing ends of 6MN13 and 6DN13, respectively. © 1998 Rapid Science Ltd     

Regional and subcellular distribution of taurine-synthesizing enzymes in the rat central nervous system

The distribution of cysteine oxidase (CO) and cysteine sulfinate decarboxylase (CSD) was examined in 12 regions of the rat central nervous system (CNS). The distribution of CO activity, expressed as mol of cysteine sulfinate formed per h per g, was the following: hypothalamus, superior and inferior colliculi, 94–99 mol/h/g; olfactory bulbs, cerebral cortex, striatum, and hippocampus, 44–51 mol/h/g; cerebellum, 71 mol/h/g; pons-medula and spinal cord, 94 and 60 mol/h/g, respectively. The distribution of CSD activity expressed as mol of cysteine sulfinate decarboxylated per h per g was the following: hypothalamus and colliculi, 14–21 mol/h/g; olfactory bulbs, cerebral cortex, striatum, hippocampus, and cerebellum, 8–13 mol/h/g; pons-medulla, 7.3; and spinal cord, 3.6 mol/h/g. No CSD activity was detected in sciatic nerve. The subcellular distribution of CO and CSD activities was studied in hypothalamus, colliculi, and cerebral cortex. CO activity was localized in synaptosomes, mitochondria, and microsomes. CSD was primarily confined to the crude mitochondrial fraction and after subfraction, recovered mainly in the synaptosomal fraction.     

Intra- and extraganglionic peripheral cholinergic neurons in the urogenital organs of the cat

Summary The distribution of cholinergic neurons in the urinary tract and male genital organs of the cat was studied by a histochemical method for acetylcholinesterase. In addition to cell clusters in autonomic ganglia (intraganglionic cells), isolated extraganglionic cholinergic cells were found within the innervated tissues, usually in association with nerve trunks and blood vessels. Smaller neural cells with multiple axonal processes, identical to Cajal's interstitial cells, were found in the meshes of the terminal nerve plexus in smooth muscle, lamina propria and vascular wall.It is concluded that peripheral cholinergic neurons, like their adrenergic analogues, are arranged as a short intraganglionic, a shorter extraganglionic, and a terminal system of neurons.Supported in part by grants 10465 and 11285 from the USPHS and the Henry C. Buswell Urology Research Fund.     

Satellited chromosomes,systematics and phylogeny inTaraxacum (Asteraceae)

A survey is made of the occurrence, nature and frequency of satellited chromosomes in the agamospermous genusTaraxacum. Species belonging to the 10 sections thought to be most primitive in the genus lack satellited chromosomes. In most other sections, a characteristic satellited chromosome is seen with a large euchromatic region distal to the presumed nucleolar oraniser region (NOR). In sections of a precursor type, there is always one chromosome of this Taraxacum type per haploid genome. In sections thought to be of an advanced type the number of such satellited chromosomes is very unstable, sometimes even within the same tissue. In sectionHamata, two such satellited chromosomes are invariably found in triploids. This finding strongly supports the integrity of this section, suggests that the species of the section are monophyletic, and have evolved from a single ancestor subsequent to the occurrence of obligate agamospermy. In three sections of the genus, satellited chromosomes of the conventional type with a very small distal euchromatic region distal to the NOR are reported for the first time in the genus.     

Die Myelinscheide um Zentralnervensystem und periphere Nerven der Geophilomorpha (Chilopoda)

Zusammenfassung Eine bisher als äußere Neurallamelle bekannte Hüllschicht des Zentralnervensystems und der Nerven von Chilopoden besteht in Wirklichkeit aus größtenteils myelinisierten Zellen, die der Neurallamelle aufgelagert sind. Ihre Feinstruktur wurde bei einigen Geophilomorpha untersucht.Ganglien, Konnektiven und Nerven werden als Ganzes von dieser Myelinscheide umschlossen. Sie wird immer von mehreren Zellen, gebildet, deren myelinisierte Abschnitte spiralig angeordnet sind. Die Anzahl der Wicklungen und damit auch die der Zellen, die sich an ihrem Aufbau beteiligen, hängt von der Region und von deren Durchmesser ab: Ganglien zeichnen sich durch wenige, Konnektive und Nerven durch viele Wicklungen aus; bei Konnektiven und Nerven steht ihre Zahl im Verhältnis zu deren Dicke. Entsprechend dem Aufbau der Myelinscheide aus mehreren Zellen befinden sich deren Perikaryen vor allem innerhalb der Wicklungen. Die Kerne sind linsenförmig; das Zytoplasma enthält viele kugelige Mitochondrien, Zytosomen, überwiegend granuläres endoplasmatisches Retikulum und in Kernnähe Golgi-Komplexe und freie Ribosomen. In den myelinisierten Abschnitten findet man kein Zytoplasma, transparente Erweiterungen werden als Artefakte gedeutet. Den Zellmembranen ist außen eine Glykokalix aufgelagert. Zwischen benachbarten Glykokalizes befindet sich ein unterschiedlich weiter Hämozölspalt, in dem nicht selten Hämozyten eingezwängt liegen. Aneinander anschließende Zellen der Scheide überlappen sich mit ihren myelinisierten Abschnitten über eine größere Fläche. Dort ist die Glykokalix geschwunden und ein Zellkontakt ausgebildet, der im Schnitt häufig septierte Desmosomen erkennen läßt. Die Bedeutung dieser Myelinscheide wird diskutiert.

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The myeline sheath around central nervous system and peripheral nerves of the geophilomorpha (Chilopoda)

Summary An enveloping sheath of the central nervous system and nerves of chilopods, hitherto called outer neural lamella actually consists of mostly myelinized cells supporting the neural lamella. Its fine structure was examinated in some geophilomorphs.Ganglia, connectives and thick trunk-nerves are enclosed by this myeline sheath totally. The myeline sheath is always formed by several cells; the myelinized parts of them are arranged spirally. The number of their windings and therefore also the number of the cells taking part in their construction depend on the region and its diameter: ganglia are distinguished by few windings — even missing sporadically —, connectives and nerves are distinguished by numerous ones. In connectives and nerves the number of windings is correlated with the thickness of the former. Corresponding to the construction of the myeline sheath by several cells, the pericarya of these cells are located above all within the windings. The nuclei are lens-shaped; the cytoplasm contains many spherical mitochondria, cytosomes of various form and density, prevailingly rough endoplasmic reticulum and Golgi fields and free ribosomes near the nucleus. Within the myelinized parts there is no cytoplasm, transparent dilatations between the membranes may be artificial. Cell membranes are outwardly supported by a glycocalyx. Between neighbouring glycocalices there is a haemocoele-cleft of variable width in which haemocytes are not seldom found squeezed in. Adjoining cells of the sheath overlap with their myelinized parts over a large area. Their glycocalyx disappeared and cell contacts have formed, recognizable in sections as septated desmosomes. The meaning of this myeline sheath is discussed.

     

Activation of multiple MAPK pathways (ERKs,JNKs, p38‐MAPK) by diverse stimuli in the amphibian heart

We investigated the expression and activation of three MAPK subfamilies in the isolated perfused amphibian heart. ERK was detected as a 43 kDa band; p38MAPK was detected as a band corresponding to 38 kDa and JNKs were detected as two bands corresponding to 46 and 52 kDa, respectively. PMA induced the activation of the ERK pathway as assessed by determining the phosphorylation state of ERK and the upstream component MEK1/2. PD98059 abolished this activation. p38MAPK was phosphorylated by sorbitol (almost 12fold, maximal within 10–15 min) and JNKs were phosphorylated and activated by sorbitol or anoxia/reoxygenation (approximately 4 and 2.5fold, respectively). SB203580 completely blocked the activation of p38MAPK by sorbitol. These results indicate that the MAPK pathways activated by phorbol esters, hyperosmotic stress or anoxia/reoxygenation in the amphibian heart may have an important role in this experimental system.     

Circadian changes in synaptic ribbons and spherules in pinealocytes of the Syrian hamster (Mesocricetus auratus)

Summary In the present study, synaptic ribbons were studied morphologically and quantitatively in hamster pineal gland. The number of ribbons and spherules of hamster pinealocytes was counted over a 24-h period. The 24-h variations in the quantity of synaptic ribbons were found to parallel fluctuations in pineal melatonin concentrations. No significant circadian changes were observed for synaptic spherules, indicating different roles for these two structures.