β-(6-Bromopyridin-3-yl)alanine. A new plant growth regulator

Summary The heterocyclic amino acid, -(6-bromopyridin-3-yl)alanine [DL-a-amino--(6-bromopyridin-3-yl)propanoic acid], interferes with the morphological development of the cruciferArabidopsis thaliana when incorporated in the growth medium. It appears to overcome the normal apical dominance control mechanism within the seedling, producing multirather than single-stemmed plants.     

Incorporation of phospholipids in Ehrlich ascites tumor cells

Summary Ehrlich ascites tumor cells (EATC) were incubated with unilamellar vesicles (UV) or multilamellar vesicles (MV). UV and MV were incorporated differently into EATC. The increase in³²P-phospholipid in EATC in the presence of UV was 12% in 300 min. Absorption of phospholipid from MV could account for only 3%. About 50% of the UV incorporation of³²P was by endocytosis and/or fusion.This work was supported by a grant from the Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina. J. L. Corchs is an investigator from the Consejo Nacional de Investigaciones Científicas y Técnicas.     

Application of the linear partial information model to forecasting the Swiss timber market

Most often, statistical analyses only provide partial information about the appropriateness of different models, structures and parameters which may underlie the dynamic process that has generated a time series. Linear partial information (LPI), in particular, consists of linear restrictions such as LPI: p_a> p_b, p_a> p_c where p_a denotes the probability that structure a holds. Fuzzy information of this type can be put to use for decision-making by LPI analysis. In this paper, LPI analysis is applied to answer the question of whether subsidizing price, given an abnormal disturbance on the timber market, would contribute to continuous forest management, a stated goal of Swiss environmental policy.     

Incorporation of phospholipids in Ehrlich ascites tumor cells

Ehrlich ascites tumor cells (EATC) were incubated with unilamellar vesicles (UV) or multilamellar vesicles (MV). UV and MV were incorporated differently into EATC. The increase in 32P-phospholipid in EATC in the presence of UV was 12% in 300 min. Absorption of phospholipid from MV could account for only 3%. About 50% of the UV incorporation of 32P was by endocytosis and/or fusion.     

The prosthetic group of the green chromoprotein ofPatella ova

Résumé Les ovaires des PatellesPatella vulgata etPatella caerulea contiennent un chromoprotéide vert qui a été précédemment étudié. Dans le présent travail, le groupe prosthétique de ce pigment est identifié. Il s'agit d'un tètrapyrrole dont la structure est proche de celle de la chlorophyllea. L'identification repose sur l'isolement des esters méthyliques du phéophorbidea d'une part (à partir des gonades entières) et de la chlorinea ₆ d'autre part (à partir du chromoprotéide).     

Erythropoietic effects of PGE2 and 2 endoperoxide analogs

Summary The erythropoietic effects in exhypoxic polycythemic mice of two endoperoxide analogs were assessed and compared with PGE₂. The 9a, 11a epoxymethano analog (U-44069) was found to be a much more potent erythropoietic stimulus than the 11a,9a analog (U-46619) or PGE₂.This work was supported by a Senior Research Grant-in-Aid from the American Heart Association-Louisiana (DMG) and USPHS Grant No. AM 13211 (JWF).     

Role of phospholipid transfer protein in rabbit lung development

A 36-kDa phospholipid transfer protein (PLT-P_R), which preferentially transfers phosphatidyl choline (PC) compared to phosphatidyl inositol (PI), was purified 827-fold from rabbit lung homogenate. Incorporation of cholesterol in unilamellar vesicles reduced the PC transfer activity of PLTP_R. Dipalmitoyl phosphatidyl choline uptake by alveolar type II cells was increased in the presence of the protein, and further enhanced in the presence of surfactant liposomes. However, a decrease in uptake was noted with cholesterol in host membranes. Incorporation of PI into host membranes had a low stimulatory effect on the process. All these effects were more pronounced in adult type II cells compared to premature, term and 3-day-old pups. Received 12 September 2001; accepted 11 October 2001     

A role for the hinge/ear domain of the β chains in the incorporation of AP complexes into clathrin-coated pits and coated vesicles

The clathrin-associated adaptor protein (AP) complexes drive the polymerization of clathrin in coated pits to form coated vesicles. It has previously been shown that the carboxyl-terminal hinge/ear domain of the β2 chain contains a binding site for clathrin and that removal of this domain from APs or from isolated β2 chains abrogates their ability to form clathrin coats in vitro. We show here that the hinge/ear domain is necessary for efficient incorporation of AP complexes into coated pits and coated vesicles in cells, a result that is consistent with the view that the β chains indeed provide an important interaction between the AP complexes and clathrin. Received 7 April 1997; received after revision 22 May 1997; accepted 28 May 1997     

Effect of prostaglandins on skin tumorigenesis

Summary Concomitant administration of prostaglandins E₂ (PGE₂) and F₂ a(PGF₂ a) with a carcinogen, 3-methylcholanthrene (MCA) to mice for 2 months markedly enhanced the occurrence of squamous cell carcinomas. Only epidermal cell hyperplasia occurred in mice treated with MCA alone by that time. Radioactivity measurements and electron microscopic autoradiography revealed that prostaglandins stimulate DNA, RNA and protein synthesis in neoplastic cells. These findings indicate that PGE₂ and PGF₂ a can act as cocarcinogens on skin tumorigenesis.     

Relationship of ornithine decarboxylase activity to HCG induced androgen production by rabbit testis

Summary In the rabbit testicular ornithine decarboxylase activity and androgen content as well as serum androgens were increased 4 h after the injection of HCG. D,L-a-difluoromethylornithine (a-DFMO) alone or together with HCG inhibited enzyme activity although testicular and serum androgens were significantly increased aftera-DFMO and HCG. These data suggest that ODC activity is not required for testicular androgen production.This work was supported by the Medical Research Council of Canada, MT 4192.     

The metabolism of the soil fumigant 1,2-dibromo-3-chloropropane in the rat

Summary The soil fumigant 1,2-dibromo-3-chloropropane (I) undergoes hydrolysis in the rat to a series of epoxide metabolites. Alkylation of glutathione by these epoxides produces 2 urinary metabolites identified as the mercapturic acids VI (R=COCH₃) and VII (R=COCH₃). Hydrolysis of the epoxides produces the male antifertility agentsa-chlorohydrin (IX, X=Cl) anda-bromohydrin (IX, X=Br) which are oxidatively metabolized to oxalic acid (XII), thus causing renal damage. These metabolic pathways can explain the toxic nature of the fumigant as a carcinogen, a male chemosterilant and as an agent causing kidney damage.This work was supported in part by the National Health and Medical Research Council of Australia.     

Biotransformation of the flavonoid tiliroside to 7-methylether tiliroside: bioactivity of this metabolite and of its acetylated derivative

Incubation of kaempferol-3-O-β-D-(6"-E-p-coumaroyl)-glucopyranoside (tiliroside) (1) with Aspergillus nidulans gives the 7-methyl ether of tiliroside (2) which is a new compound. Its structure is determined by spectroscopic methods. Cytotoxic studies of 2 and of its acetylated derivative 2a were carried out in vitro against fourteen human leukemic cell lines. Results clearly show that compound 2 is ineffective against all leukemic cell lines tested. On the contrary, compound 2a exhibited cytotoxic activity against four of the cell lines (HL60, DAUDI, HUT78 and MOLT3) and additionally, a dose- and time-dependent effect on DNA synthesis. Received 18 February 1997; received after revision 8 April 1997; accepted 6 May 1997     

Distinction of influenza viruses of different host cell origin

Summary Influenza A viruses grown in different animal or human cells retain their antigenic make-up as tested by the usual immunological assays. With the aid of aSambucus nigra (L.) extract containing its lectins the viruses can be distinguished after one single passage in a different cell type by a change in their hemagglutinating properties. Binding of such lectins to influenza viruses may be a means for a more subtle classification, relating to the host cell origin of the virus.     

Furan fatty acid steryl esters from the marine spongeDictyonella incisa which show inflammatory activity

Summary Three new furan fatty acids, (9Z, 19Z)-3, 6-epoxyhexacosa-3,5,19-tetraenoic acid (1a), (8Z, 11Z, 14Z, 17Z)-3, 6-epoxyeicosa-3,5,8,11,14,17-hexaenoic acid (2a), and (8Z, 11Z, 14Z, 17E)-3, 6-epoxyeicosa-3,5,8,11,14,17-hexaenoic acid (3a), and a new polyunsaturated fatty acid (5Z, 8Z, 11Z, 14Z, 17E)-eicosa-5,8,11,14,17-pentaenoic acid (6a), present in the spongeDictyonella incisa as the respective steryl esters, have been isolated as methyl esters and their structures have been determined by spectral and chemical analysis. The furan fatty acid esters have shown a high inflammatory activity, which suggests their potential role as feeding deterrents.     

Two new kaempferol 3,7-diglycosides and kaempferitrin in the fernAsplenium trichomanes

Summary The fronds of the fernAsplenium trichomanes contain kaempferol 3,7-dirhamnoside (1) and the new compounds kaempferol 3-O-a-rhamnoside-7-O-a-arabinoside (2) and kaempferol 3-O-a-arabinoside-7-O-a-rhamnoside (3). The presence of the above flavonoids has been shown by spectroscopic methods and chemical degradations.Acknowledgments. The author thanks Prof. H. Wagner (Institut für pharmazeutische Arzneimittellehre der Universität München, München) for a sample of kaempferol 3,7-dirhamnoside, Dr K. R. Markham (Chemistry Division, D.S.I.R., Petone, New Zealand) for a gift of pectinase and Mr A. D'Urso (Botanic Institute, University of Catania) for help in acquiring the plant material.     

Lactate dehydrogenase polymorphism inMus musculus L. andMus spretus Lataste

Summary First variation at theLdh-A locus and a new allele at theLdh-B locus are reported in aM. musculus population dimorphic at theLdh-A locus and in aM. spretus population trimorphic at theLdh-B locus.Acknowledgments. This study was achieved with the technical assistance of J. Catalan. We thank N. Pasteur and F. Bonhomme for useful comments. This work was supported by the Université Montpellier 2 (service électrophorèse du Centre de Recherche sur l'Evolution et ses Mécanismes), the Ecole Pratique des Hautes Etudes and the Centre National de la Recherche Scientifique (ERA 261).     

Dissection of a novel molecular determinant mediating Golgi to trans-Golgi network transition

Two major functions of the Golgi apparatus (GA) are formation of complex glycans and sorting of proteins destined for various subcellular compartments or secretion. To fulfill these tasks proper localization of the accessory proteins within the different sub-compartments of the GA is crucial. Here we investigate structural determinants mediating transition of the two glycosyltransferases β-1,4- galactosyltransferase 1 (gal-T1) and the α-1,3-fucosyltransferase 6 (fuc-T6) from the trans-Golgi cisterna to the trans-Golgi network (TGN). Upon treatment with the ionophore monensin both glycosyltransferases are found in TGN-derived swollen vesicles, as determined by confocal fluorescence microscopy and density gradient fractionation. Both enzymes carry a signal consisting of the amino acids E₅P₆ in gal-T1 and D₂P₃ in fuc-T6 necessary for the transition of these glycosyltransferases from the trans-Golgi cisterna to the TGN, but not for their steady state localization in the trans-Golgi cisterna. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Received 30 July 2008; received after revision 17 September 2008; accepted 29 September 2008     

Tissue protection against oxidative stress

We used an enhanced luminescence technique to study the response of rat tissues, such as liver, heart, muscle and blood, to oxidative stress and to determine their antioxidant capacity. As previously found for liver homogenate, the intensity of light emission (E) of tissue homogenates and blood samples, stressed with sodium perborate, is dependent on concentration, and the dose-response curves can be described by the equation E=a·C/exp(b·C). Theb value depends on the antioxidant defence capability of the tissues. In fact, it increases when homogenates are supplemented with an antioxidant, and is correlated with tissue antioxidant capacity, evaluated by two previously set up methods both using the same luminescence technique. Our results indicate that the order of antioxidant capacity of the tissues is liver>blood>heart>muscle. Thea value depends on the systems catalysing the production of radical species. In fact, it is related to the tissue level of hemoproteins, which are known to act as catalysts in radical production from hydroperoxides. The equation proposed to describe the dose-response relation is simple to handle and permits an immediate connection with the two characteristics of the systems analysed which determine their response to the pro-oxidant treatment. However, the equation which best describes the above relation for all the tissues is the following: E=·C/exp(·C). The parameter assumes values smaller than 1, which seem to depend on relative amounts of tissue hemoproteins and antioxidants. The extension of the analysis to mitochondria shows that they respond to oxidative stress in a way analogous to the tissues, and that the adherence of the dose-response curve to the course predicted from the equation E=a·C/exp(b·C) is again dependent on hemoprotein content.     

The dissociation constant of the 1-aminoadamantane cation

Zusammenfassung Der pK _a -Wert des 1-Aminoadamantan zwischen 20° und 37° wurde durch potentiometrische Messungen bestimmt.