Effect of androgens on histochemical fibre type

Summary The temporal muscles of the guinea pig show a sexual differentiation reflected in their histochemical enzyme pattern. Using histochemical methods for mitochondrial (SDH, -GPDH), and glycolytic enzymes (phosphorylase, LDH) it could be shown, that in adult animals the male muscle is a white muscle with marked activity of glycolytic enzymes, the female muscle a red muscle displaying high activity of mitochondrial enzymes. This differential enzyme pattern can be converted by the application of testosterone to the female type during the postnatal development. The male sex hormone thus affects the histochemical enzyme pattern of the muscle, converting the red, female into a white, male muscle in the female guinea pig.     

Functional inactivation by interleukin-1β of glyceraldehyde-3-phosphate dehydrogenase in insulin-secreting cells

Aims/hypothesis: It is well established that long-term exposure of isolated cells to cytokines [e.g., IL-1] results in increased expression of inducible nitric oxide synthase and subsequent release of nitric oxide, which in turn, has been shown to mediate a wide array of effects, including alterations in cellular high-energy metabolism. In this context, several extant studies have demonstrated significant reduction in adenine and guanine nucleotide triphosphate levels in cells exposed to IL-1. Herein, we examined the functional status of glyceraldehyde-3-phosphate dehydrogenase [GAPDH] in insulin-secreting cells exposed to IL-1, since it represents the first enzyme in the glycolytic pathway that is involved in the generation of ATP. Methods: GAPDH was assayed spectrophotometrically in the cytosolic fraction derived from control and IL-1 -treated [300 pM for 24 hrs] insulin-secreting cell lines [HIT-T15 and RINm5F]. Results: IL-treatment resulted in marked attenuation of GAPDH activity in HIT and RIN cells; such a reduction in this activity was not due to inhibition of its expression by IL-1. Instead, we observed that incubation of HIT and RIN lysates with peroxynitrite, a reactive intermediate of nitric oxide with superoxide anion, resulted in significant reduction in the GAPDH activity. Conclusion/interpretation: These results identify a GAPDH as one of the biochemical loci for the effects of IL-derived peroxynitrite in the islet cell. The previously reported reduction in high-energy phosphate levels in an IL-treated cell may, in part, be due to inhibition of GAPDH activity, and subsequent reduction in the glycolytic efficiency of the cell.     

Comparative residual toxicities of pesticides to the predator Agistemus industani (Acari: Stigmaeidae) on citrus in Florida

Residual toxicities of registered and selected experimental pesticides used on citrus against Agistemus industani Gonzalez (Acari: Stigmaeidae) were compared. Pesticides considered highly toxic to A. industani were: abamectin 0.15 EC at 731ml/ha+FC 435-66 petroleum oil at 46.8l/ha, pyridaben 75WP at 469g/ha, ethion 4EC at 7.01l/ha+FC 435-66 petroleum oil at 46.8l/ha, propargite 6.55 EC at 3.51l/ha, chlorfenapyr 2SC at 1.46l/ha applied alone or in combination with FC 435-66 petroleum oil at 46.8l/ha, sulphur 80DF at 16.81kg/ha, dicofol 4EC at 7.01l/ha, fenbutatin oxide 50WP at 2.24kg/ha, benomyl 50WP at 2.24kg/ha, benomyl 50WP at 1.68kg/ha+ferbam 76 GF at 5.60kg/ha, ferbam 76GF at 11.21kg/ha, neem oil 90EC at 46.8l/ha, and copper hydroxide DF (40% metallic copper) at 4.48kg metallic copper/ha+FC 435-66 petroleum oil at 46.8l/ha. Pesticides that were moderately to slightly toxic included: copper sulphate 98% at 4.48kg metallic copper/ha+FC 435-66 petroleum oil at 46.8l/ha, fenbuconazole 2F at 280ml/ha+FC 435-66 petroleum oil at 46.8l/ha, FC 435-66 petroleum oil applied alone at 46.8l/ha or 23.4l/ha, and diflubenzuron 25WP at 1.40kg/ha. Pesticides that were non-toxic included: fenbuconazole 2F at 585ml/ha, malathion 57EC at 5.85l/ha, FC 435-66 petroleum oil at 46.8l/ha, carbaryl 80S at 3.36kg/ha, chlorpyrifos 4EC at 4.68l/ha, and formetanate 92SP at 1.12kg/ha. Understanding the toxic effects of field weathered pesticides against key predacious mite species is important for effective IPM. The results of this study provide a comparison of direct and indirect toxic effects of various pesticides to A. industani under field conditions.     

Binding of the galactose-specificPseudomonas aeruginosa lectin,PA-I,to glycosphingolipids and other glycoconjugates

The carbohydrate-binding specificity ofPseudomonas aeruginosa lectin I (PA-I) in iodinated or biotinylated form was studied. A large number of glycosphingolipids, as well as some glycoproteins and neoglycoproteins were used as ligands. Also, inhibition by free saccharides of PA-I binding to glycosphingolipids was tested. It was found that the lectin binds most strongly to terminal and nonsubstituted Gal3Gal- or Gal4Gal-structures.Abbreviations PA-I Pseudomonas aeruginosa lectin I - Cer ceramide - lactosylceramide Gal4GlcCer - iso globotriaosylcerami Gal3Gal4GlcCer - globotriaosylceramide Gal4Gal4GlcCer - globoside or globotetraosylceramide GalNAc3Gal4Gal4GlcCer - Forssman glycolipid GalNAc3GalNAc3Gal4Gal4GlcCer - P1 glycolipid Gal4Gal4GlcNAc3Gal4GlcCer - lactoneotetraosylceramide Gal4GlcNAc3Gal4GlcCer - B5 glycolipid Gal3Gal4GlcNAc3Gal4GlcCer - gangliotetraosylceramide Gal3GalNAc4Gal4GlcCer - GM1 Gal3GalNAc4(NeuAc3)Gal4GlcCer - RBC red blood cells - BSA bovine serum albumin - PBS phosphate-buffered saline - SDS sodium dodecyl sulfate - TLC thin-layer chromatography - HPLC high pressure liquid chromatography - MS mass spectrometry - FAB fast-atom bombardment - EI electron impact     

The mitochondrially encoded "phantom ATPase" of S. cerevisiae. II. A heterogeneous mitochondrial ATPase population in situ.

Summary The mitochondrial ATPase from a PHO 1 mutant (OLI 2, PHO 1, OLI 4 region on mit DNA of S. cerevisiae) was further examined. A new purification method using Lysolecithin instead of Triton allowed us to solubilize and separate a heterogeneous ATPase population from PHO 1-mitochondria: the major abnormal fraction had extremely low oligomycin-sensitivity (but normal specific immunological reactivity), while a minor normal fraction (representing about 20% of the initial mitochondrial ATPase activity) had high sensitivity and affinity for oligomycin.Moderate urea treatment of PHO 1-mitochondria leads to partial loss of ATPase activity and a concomitant increase of oligomycin-sensitivity, suggesting that a heterogeneous ATPase population exists in situ in the mitochondrial membrane: part of the major abnormal ATPase fraction is selectively inactivated by urea, producing a concomitant enrichment in the initially minor normal ATPase fraction.If the minor normal ATPase fraction is the only one capable of in vivo ATP synthesis, the deficient but oligomycin-sensitive cell growth and oxidative phosphorylation in vitro are readily explained.Further structural studies are under way to ascertain whether the minor normal ATPase fraction is strictly identical to the wild type, in which case PHO 1 is a regulatory gene, or not, in which case PHO 1 is a structural gene.     

Fragmenta mycologica

Summary Castellani's water culture method for microscopic fungi was re-examined and confirmed in its every detail. It is an ideal method for, at least, the smaller culture collection, in order to avoid continuous, short term subculturing. Benedek's suggestion for establishment of a mycotheca preserved in chlorallactophenol on the analogy of the herbarium of phanerogamists, may fill a long felt gap in mycological laboratories.

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Zusammenfassung Castellani's Wasserkultur-methode für mikroskopische Pilze wurde einer Kontrolluntersuchung unterzogen. Sie konnte in all ihren Einzelheiten bestätigt werden. Sie ist eine ideale Methode, wenigstens für kleine Kultursammlungen, um eine fortgesetzte, kurz-fristige Überimpfung zu vermeiden. Benedek's Vorschlag für die Einrichtung einer Mykotheka in Chlorallactophenol in Analogie mit dem Herbarium für Blütenpflanzen, mag eine lang gefühlte Lücke im mykologischen Laboratorium beseitigen.

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Résumé La méthode deCastellani, la culture en d'eau des champignons microscopiques, a été ré-examinée. Elle pouvait être confirmée en tous les détails. C'est une méthode idéale, au moins, pour la collection de cultures de petite dimension, pour éviter les transferts continus et d'intervalle courte.La suggestion deBenedek pour établir une mycothèque en chlorallactophénol, par analogie avec l' herbier pour les phanérogames peut remplir une lacune, existante pour long temps, aux laboratoires mycologiques.

     

Autotrophic carbon sources for heterotrophic bacterioplankton in a floodplain lake of central Amazon

The relative contribution of autotrophic carbon sources (aquatic macrophytes, flooded forest, phytoplankton) for heterotrophic bacterioplankton was evaluated in a floodplain lake of the Central Amazon. Stable carbon isotopes (¹³C) were used as tracers. Values of ¹³C of different autotrophic sources were compared to those of dissolved organic carbon (DOC) and those of bacterially produced CO₂.The percentage of carbon derived from C₄ macrophytes for bacterially produced CO₂ was the highest, on average 89%. The average ¹³C value of CO₂ from bacterial respiration was –18.5 ± 3.3. Considering a fractionation of CO₂ of 3 by bacterial respiration, ¹³C value was –15.5, near C₄ macrophyte ¹³C value (–13.1).The average value of total DOC ¹³C was –26.8 ± 2.4. The percentage of C₄ macrophytes carbon for total DOC was on average 17%. Considering that bacteria consume mainly carbon from macrophytes, the dominance of C₃ plants for total DOC probably reflects a faster consumption of the former source, rather than a major contribution of the latter source.Heterotrophic bacterioplankton in the floodplain may be an important link in the aquatic food web, transferring the carbon from C₄ macrophytes to the consumers.     

Pullulan production from brewery wastes by Aureobasidium pullulans

The production of pullulan from brewery wastes by Aureobasidium pullulans in shake flask culture was investigated. The maximum pullulan concentration (6.0g/l) was obtained after 72h of fermentation. The external addition of nutrients into the spent grain liquor improved significantly the production of pullulan. In this case, the highest values of pullulan concentration (11.0±0.5g/l), pullulan yield (48.2±1.5%), and sugar utilization (99.0±0.5%) were obtained in the medium (pH 6.5–7.5) supplemented with K₂HPO₄ 0.5%, l-glutamic acid 1%, olive oil 2.5%, and Tween 800.5%.     

Kinetics of growth and lactic acid production in continuous and batch culture

Summary In a lactic acid fermentation by Streptococcus faecalis, the specific consumption rate of glucose (v) and the specific production rate of lactic acid () were represented by the following simple equations as functions of the specific growth rate (): 1/=(1/) + 1/ = (1/) + By use of data from a batch culture, these two equations were derived from enzyme kinetics of the product inhibition. These equations were successfully applied to the results of batch culture and chemostat culture. In addition, calculation of ATP yield by these equations agreed with the experimental results better than the conventional Leudeking-Piret type equation, which includes two terms associated with growth and not with growth. Correspondence to: H. Ohara     

Action of rat liver Galβ1-4GlcNAc α(2-6)-sialyltransferase on Manβ1-4GlcNAcβ-OMe,GalNAcβ1-4GlcNAcβ-OMe,Glcβ1-4GlcNAcβ-OMe and GlcNAcβ1-4GlcNAcβ-OMe as synthetic substrates

Incubation of synthetic Man\1-4GlcNAc-OMe, GalNAc1-4GlcNAc-OMe, Glc1-4GlcNAc-OMe, and GlcNAc1-4GlcNac-OMe with CMP-Neu5Ac and rat liver Gal1-4GlcNAc (2-6)-sialyltransferase resulted in the formation of Neu5Ac2-6Man1-4GlcNAc-OMe, Neu5Ac2-6GalNAc1-4GlcNAc-OMe, Neu5Ac2-6Glc1-4GlcNAc-OMe and Neu5Ac2-6GlcNAc1-4GlcNAc-OMe, respectively. Under conditions which led to quantitative conversion of Gal1-4GlcNAc-OEt into Neu5Ac2-6Gal1-4GlcNAc-OEt, the aforementioned products were obtained in yields of 4%, 48%, 16% and 8%, respectively. HPLC on Partisil 10 SAX was used to isolate the various sialyltrisaccharides, and identification was carried out using 1- and 2-dimensional 500-MHz¹H-NMR spectroscopy.Abbreviations 2D 2-dimensional - CMP cytidine 5-monophosphate - CMP-Neu5Ac cytidine 5-monophospho--N-acetylneuraminic acid - COSY correlation spectroscopy - DQF double quantum filtered - HOHAHA homonuclear Hartmann-Hahn - MLEV composite pulse devised by M. Levitt - Neu5Ac N-acetylneuraminic acid - Neu5Ac2en 2-deoxy-2,3-didehydro-N-acetylneuraminic acid     

Expression of a chimeric stilbene synthase gene in transgenic wheat lines

A chimeric stilbene synthase (sts)gene was transferred into wheat. Stilbene synthases play a role in the defence against fungal diseases in some plant species (e.g. groundnut or grapevine) by producing stilbenetype phytoalexins like resveratrol. Resveratrol is also claimed to have positive effects to human health. Embryogenic scutellar calli derived from immature embryos of the two commercial German spring wheat cultivars Combi and Hanno were used as target tissue for cotransformation by microprojectile delivery. The selectable marker/reporter gene constructs contained the bargene either driven by the ubiquitinpromoter from maize (pAHC 25, also containing the uidAgene driven by the ubiquitinpromoter), or by the actinpromoter (pDM 302) from rice. The cotransferred plasmid pStil 2 consisted of a grapevine stscoding region driven by the ubiquitin promoter. Eight transgenic Combi and one Hanno T_Oplant were obtained and, except one Combi T_Oplant, found to be cotransformants due to the integration of both the stsgene and the selectable marker or reporter genes. Expression of the stsgene was proven by RTPCR, and, for the first time, by detection of the stilbene synthase product resveratrol by HPLC and mass spectrometry. The stsgene was expressed in four of the seven transgenic Combi T_{_o}plants. Two of the respective T₁progenies segregated in a Mendelian manner were still expressing the gene. Investigations into methylation of the stsgene showed that in three nonexpressing progenies inactivation was paralleled by methylation.     

Effect of oxygen on growth and respiration of potato tuber callus

Growth and oxygen uptake of potato callus is faster in an oxygen-enriched atmosphere (70% oxygen, v/v; oxygen-callus) than in air (20% oxygen, v/v; air-callus). Especially the non-mitochondrial, so-called residual respiration is increased in oxygen-callus. The capacities of the mitochondrial respiratory pathways (cytochrome pathway, V_cyt and alternative pathway, V_alt) are also higher in this callus. In both callus types only a small part of the alternative pathway capacity is used in uninhibited respiration. The lower oxygen uptake of air-callus at normal air oxygen pressures is partially due to diffusional impedance. Measurement of the respiratory parameters of air-callus in oxygen-saturated medium leads to higher values than measurement in air-saturated medium, although these values are still lower than those of oxygen-callus.ATP-production was calculated from the oxygen-uptake data and compared with the dry weight production of the callus to give values of 10.0 and 10.8 g dry weight produced.-mol ATP^-1, for air-callus and oxygen-callus respectively. As no harmful side-effects are observed, cultivation of callus under elevated oxygen pressures may be useful, when rapid callus-growth is necessary.Abbreviations AA antimycin A; A; - BHAM benzohydroxamate - DW dry weight - FW fresh weight - 8-OHQ 8-hydroxyquinolin - RC respiratory control - SHAM salicylhydroxamate     

Studies on aneuploids of Petunia

Summary The seven possible primary trisomics of Petunia (2 n= 14) located in the progenies of triploid, hypertriploid and hypotriploid plants were distinguished from one another and from diploid on the basis of cytological and morphological criteria. They were provisionally named as Oval, Semi, Slender, Pseudonormal, Arrow, Narrow and Giant. In three of the trisomics, the extra chromosome was identified for the first time at pachytene stage. Postpachytene studies revealed no precise relationship between the length of extra chromosome and the frequency of multiple association.     

Karyosystematics of thePhleum alpinum polyploid complex (Poaceae)

The karyotypes of three taxa from thePhleum alpinum group of sect.Phleum (P. alpinum subsp.rhaeticum, 2n = 14,P. commutatum, 2n = 28, and informally namedP. commutatum, 2n = 14) were investigated by Giemsa C-banding. The overall similarity of diploid genomes suggests thatP. alpinum subsp.rhaeticum andP. commutatum are closely related — their karyotypes vary only with respect to their average amounts of telomeric heterochromatin. TheP. commutatum genome contains less telomeric heterochromatin than the genome ofP. alpinum subsp.rhaeticum, but in theP. alpinum group as a whole almost fluent transition between low (1.5%) and high (25.5%) amounts of telomeric heterochromatin was observed among populations. In the karyotype of tetraploidP. commutatum, seven distinguishable chromosome types were observed. Each of them is represented at somatic metaphase by four chromosomes. C-band structure of karyotype and average amount of telomeric heterochromatin suggest that this taxon has originated from hybridization between two related diploid forms of theP. commutatum — P. alpinum complex.     

ATP Synthases in the Year 2000: Defining the Different Levels of Mechanism and Getting a Grip on Each

ATP synthases are unusually complex molecules, which fractionate most readily into two major units, one a water soluble unit called F₁ and the other a detergent soluble unit called F₀. In almost all known species the F₁ unit consists of 5 subunit types in the stoichiometric ratio ₃₃ while the F₀ unit contains 3 subunit types (a, b, and c) in E. coli, and at least 10 subunit types (a, b, c, and others) in higher animals. It is now believed by many investigators that during the synthesis of ATP, protons derived from an electrochemical gradient generated by an electron transport chain are directed through the F₀ unit in such a way as to drive the rotation of the single subunit, which extends from an oligomeric ring of at least 10 c subunits in F₀ through the center of F₁. It is further believed by many that the rotating subunit, by interacting sequentially with the 3 pairs of F₁ (360° cycle) in the presence of ADP, P_i, and Mg⁺⁺, brings about via power strokes conformational/binding changes in these subunits that promote the synthesis of ATP and its release on each pair. In support of these views, studies in several laboratories either suggest or demonstrate that F₀ consists in part of a proton gradient driven motor while F₁ consists of an ATP hydrolysis driven motor, and that the subunit does rotate during F₁ function. Therefore, current implications are that during ATP synthesis the former motor drives the latter in reverse via the subunit. This would suggest that the process of understanding the mechanism of ATP synthases can be subdivided into three major levels, which include elucidating those chemical and/or biophysical events involved in (1) inducing rotation of the subunit, (2) coupling rotation of this subunit to conformational/binding changes in each of the 3 pairs, and (3) forming ATP and water (from ADP, P_i, and Mg⁺⁺) and then releasing these products from each of the 3 catalytic sites. Significantly, it is at the final level of mechanism where the bond breaking/making events of ATP synthesis occur in the transition state, with the former two levels of mechanism setting the stage for this critical payoff event. Nevertheless, in order to get a better grip in this new century on how ATP synthases make ATP and then release it, we must take on the difficult challenge of elucidating each of the three levels of mechanism.     

In vivo effects of vanadium in diabetic rats are independent of changes in PI‐3 kinase activity in skeletal muscle

The PI3 kinase signalling pathway is an important pathway in mediating the glucoregulatory effects of insulin and skeletal muscle (SKM) is the major tissue involved in glucose utilization. In diabetes this pathway is impaired, either due to lack of insulin as in Type 1 diabetes, or due to insulin resistance as in Type 2 diabetes. Bis(maltolato)oxovanadium IV (BMOV), an insulin mimetic/enhancing agent, produces a marked glucose lowering effect in models of both types of diabetes. Some in vitro studies have shown that phosphatidylinositol 3 kinase (PI3 kinase) activity is enhanced by vanadium. In the present study we looked at changes in PI3 kinase expression and activity in SKM from STZdiabetic and fa/fa Zucker rats treated with BMOV for 3 weeks. Although BMOV treatment completely normalized glucose levels in STZdiabetic rats, no effect was observed on basal or insulin-stimulated PI3 kinase activity. In fatty Zucker rats, activation of PI3 kinase activity after insulin injection was impaired as compared to age matched lean controls, but BMOV again did not affect the activity. These results suggest that although PI3 kinase is an important signalling factor in glucose utilization, vanadium treatment does not reduce hyperglycemia through activation of SKM PI3 kinase in vivo.     

Optimumβ-D-glucosidase supplementation of cellulase for efficient conversion of cellulose to glucose

Summary To assess optimal saccharification performance, -cellulose and dilute acid pretreated aspen (DAA) wood meal were subjected to various loadings of commercial cellulase and -D-glucosidase preparations. Fifteen international filter paper units (IFPU)/g cellulose content and 30 IFPU/g cellulose content were required to digest 95% of the available cellulose in -cellulose and pretreated aspen, respectively. The optimal supplementation ratios, based on Genencor GC 123 cellulase and -D-glucosidase from Novo SP 188 for the -cellulose and DAA digestions range from 0.25 to 0.5 and 0.12 to 0.25, respectively.     

A new base substitution in the 5′ regulatory region of the humanAγ globin gene is linked with the βs gene

A new TA base substitution, identified inside the 5 regulatory region of the human^A globin gene (^A –499 T A), is reported. This nucleotide change was found to be linked incis with the mutation producing sickle cell anemia (CD6 GAGGTG: ^s gene).     

γδ T-cell receptor repertoire in human peripheral blood and thymus

T-cell clones expressing the T-cell receptor (Tcr) were generated from peripheral blood lymphocytes (PBLs) and from a thymus sample. In the panel of ten thymus-derived clones, four Tcr phenotypes [as defined by the reaction of monoclonal antibodies (mAbs) directed against known V and V regions] were identified. All the clones lacked expression of the V3 V region, while seven clones were V1+ . V1 was found in combination with V9 or with undefined VVregions. In addition, two other Tcr phenotypes were identified on these clones: V9⁺ V1^– V3^– and V9^– V1^– V3^– One of the clones expressed CD4 and another was CD8positive. The remaining clones were CD4^– CD8^–. In the panel of 76 PBL-derived, Tcr-bearing clones, five Tcr phenotypes could be identified. In contrast to the thymus-derived clones, 30% of the clones were V3⁺ whereas V1 was expressed by a minority of the clones only. One clone was CD4-positive and approximately 30% of the clones were CD8-positive. Four of the five mAb-defined Tcr phenotypes could be identified on both thymus and PBL-derived T-cell clones. However, biochemical analysis of the Tcrs demonstrates differences in the usage of Ct- and C2-encoded y chains by T cells derived from the thymus and PBLs. The results therefore indicate that, at the clonal level, similarities and differences exist between the Tcr repertoires expressed in the thymus and by PBLs. Furthermore, they indicate that combinatorial Tcr heterogeneity is larger than has so far been described. The receptor diversity, combined with the potential of Tcr+ cells to express CD4 or CD8, indicates that these cells are a heterogeneous population that might mediate a number of immune functions.     

Axillary shoot induction and plant regeneration in Plantago ovata Forssk

Axillary shoot induction and plant regeneration were obtained in Plantago ovata. The optimum medium for inducing axillary shoots was Murashige & Skoog (MS) medium [5] supplemented with 4.6 M kinetin and 0.05 M NAA. Rooting of shoots was best on half-strength MS medium containing 5.0 M IBA and 0.05 M kinetin. The regenerated plants were similar to the control plants in karyotypic and phenotypic details.