Serological recognition of HLA-DR allodeterminant corresponding to DNA sequence involved in gene conversion

HLA class 11 molecules were isolated from mouse L cells transfected with a DR gene and an allele, 52a, of locus DR III from an HLA-homozygous cell line, AVL, of the DR3 haplotype. The isolated molecules were found to possess a new allospecificity, named TR81. This specificity behaved allelic to the previously described DR III locus. The TR81 specificity was also present on the DR I gene product of the DR3 haplotype. The nucleotide sequence of the gene encoding TR81 differs from TR81-negative DR genes of the DRw52 family in only two codons, both located in the regions known to be involved in a gene conversion event. Consequently, the following conclusions can be formulated. (a) TR81 is a bi-locus specificity and allelic to TR22 only in its DR III locus localization. (b) The TR81 specificity is the phenotypic counterpart of the gene conversion event which led to the generation of the DR I gene of the DR3 haplotype. (c) One or both individual amino acid substitutions in the first domain of the DR chain are responsible for the TR81 allospecificity. (d) Since TR81 is expressed on the DR I chain of the DR3 haplotype, it is possible that TR81 and DR3 represent the same serological specificity.     

Micropropagation of Phytolacca dodecandra through shoot-tip and nodal cultures

A procedure for micropropagation of endod (Phytolacca dodecandra) is described. BA at 0.44 M produced 3.1 new shoots per expiant in six weeks using shoot tips. Nodal expiants, however, produced up to 4.7 shoots per explant on medium with 0.44 M BA and 0.27 M GA,. IBA at 0.49 M induced 90% rooting with minimal callus. Plantlets were successfully transferred to the greenhouse and some staminate clones produced flowers after six months.Abbreviations BA 6 benzylaminopurine - kinetin 6-furfurylaminopurine - 2iP N⁶-(2-isopentyl)adenine - IAA indole-3-acetic acid - NAA 1-naphthaleneacetic acid - GA₃ Gibberellic acid - IBA indole-3-butyric acid     

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.     

Physicochemical characterization of alpha-crystallins from bovine lenses: hydrodynamic and conformational properties

A detailed investigation of hydrodynamic and conformational behavior has been made of the HM-crystallin and -crystallins of bovine lens. Results from this study indicated that HM (high-molecular-weight -crystallin) and (low-molecular-weight -crystallin) possess considerable size and charge heterogeneities in their native structures and subunit polypeptides, respectively. Sedimentation velocity showed a heterogeneous polydisperse system of HM with an average sedimentation coefficient of about 50 S and a more homogeneous system of -crystallin of 20 S. Viscosity and circular dichroism studies pointed to a compact and globular shape of dominant -sheet conformation for -crystallin, yet a highly asymmetrical and aggregated form for HM. The conformational stability of -crystallin was investigated in the presence of various denaturants. The evidence presented shows that hydrogen bonding is the main force in maintaining the quaternary structure of compact native -crystallin. Conformational flexibility of -crystallin demonstrated in the equilibrium unfolding study indicated a multistep transition that made the extraction of thermodynamic data from the heat denaturation study difficult. Temperature perturbation on -crystallin suggested the possible involvement of hydrophobic interaction in the aggregation process, leading to the formation of HM from -crystallin. The comparison of conformational properties between HM and -crystallin strongly indicated that HM is a denatured form of -crystallin.     

Immobilized Lotus tetragonolobus agglutinin binds oligosaccharides containing the Lex determinant

A defined set of oligosaccharides and glycopeptides containing -linked fucose were used to examine the specificity of the immobilized fucose-binding lectin Lotus tetragonolobus agglutinin (LTA1), also known as lotus lectin. Glycans containing the Lewis x determinant (Lex) Gal1-4[Fuc1-3]GlcNAc1-3-R were significantly retarded in elution from high density LTA-Emphaze columns. The lectin also bound the fucosylated lacdiNAc trisaccharide GalNAc1-4[Fuc1-3]GlcNAc. The lectin did not bind glycans containing either sialylLex or VIM-2 determinants, nor did it bind the isomeric Lea, Gal1-3[Fuc1-4]GlcNAc-R. Although 2-fucosyllactose Fuc1-2Gal1-4Glc) was retarded in elution from the columns, larger glycans containing the H-antigen Fuc1-2Gal1-3(4)GlcNAc-R interacted poorly with immobilized LTA. Our results demonstrate that immobilized LTA is effective in isolating glycans containing the Lex antigen and is useful in analyzing specific fucosylation of glycoconjugates. Abbreviations: LTA, Lotus tetragonolobus agglutinin; UEA-1, Ulex europaeus agglutinin-I; LNT, AAL, Aleuria aurantia agglutinin; Gal1-3GlcNAc1-3Gal1-3Glc; LNnT, Gal1-4GlcNAc1-3Gal1-3Glc; Lex, Lewis x antigen; Lea, Lewis a antigen; GDPFuc, guanosine 5-diphosphate--L-fucose     

Gibberellin-antagonizing protein in dwarf peas

Summary Seedlings of dwarf pea grown under red light for 9 d were homogenized in 0.1 M phosphate buffer (pH 6.8) and a water-soluble extract was obtained by centrifugation, dialysis and lyophilization. The extract contained a proteinaceous substance (or substances) which interfered with the GA₃ response of dwarf peas, probably due to complex formation with the hormone.     

Initial Stages of Trisporic Acid Synthesis in Blakeslea trispora

Biotransformation of -carotene with enzyme preparations isolated from the mycelium of Blakeslea trispora resulted in the formation of its hydroxylated metabolite and apocarotenals, products of oxidative degradation of this compound. Based on its spectral, chromatographic, and chemical properties, the -carotene derivative was identified as 4-hydroxy--carotene (isocryptoxanthine). One of the products of oxidative degradation of -carotene, -apo-13-carotenone, was modified in the presence of enzyme preparations from Blakeslea trispora to form trisporic acid precursors. -Apo-13-carotenone transformation proceeded more rapidly than -carotene oxidation at the carbon atom at position 4. The data suggest that, under oxidative stress, oxidative degradation of -carotene into -apo-13-carotenone leads to the formation of considerable amounts of trisporic acids.     

Topography of the subunits of Micrococcus lysodeikticus F1-ATPase

Summary The combined use of proteolytic digestion and lactoperoxidase catalyzed labelling with [¹²⁵I] applied to membrane-bound or soluble pure F₁-ATPase from Micrococcus lysodeikticus has allowed us to establish the topography of its , , and subunits within the protein molecule and with respect to the plane of the membrane.The subunit is most externally located to the membrane bilayer looking towards the cytoplasmic face, a position consistent with its proposed catalytic role. The and subunits lie in an intermediate layer between the subunits and the membrane, in which the subunit occupies a central position within the F₁-ATPase molecule in contact with the subunit. The subunit appears to be tightly bound to the F₀ component of the ATPase complex, probably buried in the membrane bilayer. A molecular arrangement of M. lysodeikticus ATPase is proposed that, taking into account the subunit stoichiometry _{3 3 2 2} (MW 420 000), accommodates the role assigned to each subunit and most, if not all, the known properties of this bacterial energy-transducing protein.     

Immunocytological localization of LH,FSH, TSH and their subunits in the pituitary of normal and anencephalic human fetuses

Summary Immunostaining with antisera to oLH, hCG, hLH, pLH, hFSH, hFSH, hTSH and bTSH was used to delineate the gonadotropic and thyrotropic cells of the human fetal anterior pituitary. Hypophyses from 29 normal fetuses, 3 newborn infants, and 5 totally ancencephalic fetuses were used. Several controls to check for the specificity of the immunocytological reaction were made.In normal fetuses, observations showed that: 1) the subunit was detected from the eighth week and throughout gestation without sex differences; 2) intact LH was detected during the third month, however, age and sex differences were observed during the fourth and fifth months; 3) intact FSH was detected in female fetuses from the beginning of the fourth month, a sex difference was observed; 4) LH and FSH were detected in the same cells; 5) the thyrotropic cells were detectable from 15 weeks of gestation and their number increased during gestation without sex difference; 6) at birth the gonadotropic cells were scarce and were located in the ventromedian zone of the anterior pituitary, while the thyrotropic cells remained numerous and were located in the dorsomedian zone.In anencephalic fetuses: 1) the subunit existed at each stage studied; 2) the reaction induced by anti-pLH and anti-hFSH sera was always very weak regardless of sex or age; 3) the thyrotropic cells were more numerous in comparison to the gonadotropic cells. These data are discussed in terms of the relationship of the hypophysiotropic hypothalamic factors to the appearance and evolution of the glycoprotein hormones and their subunits.     

The effect of monoterpenes on astaxanthin production by a mutant ofPhaffia rhodozyma

Summary The total pigment and astaxanthin content ofPhaffia rhodozyma increased with increasing concentrations -pinene up to 500 l -pinene/l. Above this concentration the total pigment and astaxanthin content as well as the biomass production decreased. The addition of 500 l -pinene/l increased the total pigment content from 1652 g/g to 2201 g/g and the astaxanthin content from 1554 g/g to 1883 g/g. A sharp decrease in maximum specific growth rate occurred above 150 l -pinene/l.     

Induction of cellulose- and xylan-degrading enzyme complex in the yeast Trichosporon cutaneum

The specificity of induction of cellulose- and xylan-degrading enzymes was investigated on the yeast strain Trichosporon cutaneum CCY 30-5-4 using series of compounds structurally related to cellulose and xylan, including monosaccharides, glycosides, glucooligosaccharides and xylooligosaccharides. Determination of activities of secreted cellulase and -xylanase, intracellular, cell wall bound and extracellular -glucosidase and -xylosidase revealed that: (1) The synthesis of xylan-degrading enzymes is induced in the cell only by xylosaccharides, 1,3--xylobiose, 1,2--xylobiose, 1,4--xylosyl-L-arabinose, 1,4--xylobiose and thioxylobiose being the best inducers. The xylan-degrading enzymes show different pattern of development in time and discrete cellular localization, i.e. intracellular -xylosidase precedes extracellular -xylanase. (2) A true cellulase is not inducible by glucosaccharides and cellulose. Negligible constitutive cellulase activity was detected which was about two orders lower than an induced cellulase in the typical cellulolytic fungus Trichoderma reesei QM 9414. (3) The best inducer of intracellular -glucosidase splitting cellobiose was thiocellobiose in a wide range of concentration (0.1–10 mM), whereas xylosaccharides at high concentrations induced -xylosidase of xylobiose type and a non-specific aryl -D-glucosidase.The results were confirmed by growing cells on cellulose and xylan. T. cutaneum was found to be a xylan-voracious yeast, unable to grow on cellulose.     

The mechanism of object fixation and its relation to spontaneous pattern preferences in Drosophila melanogaster

The orientation behavior of walking flies, Drosophila melanogaster, towards a single 6° wide black vertical stripe (elementary stripe) can be explained by use of the turning tendency function H(). This function is characterized by maximal values at an angular distance of =25° from the stable zero position (=orienting direction), a sharp decline from this maximum to =60°, and a very slow approach to the unstable zero position (Horn and Wehner, 1975). The shape of this function is influenced by both translatory and rotatory components of movement. If the translatory component is minimized by measuring the turning function W() (see 2.3) at a distance of 10 mm (C1) from the center of the arena, a change in the strength of this decline is caused. But with increasing translatory component, i.e. at a greater distance from the center of the arena, W() approximates the heuristical function H() (Fig. 12). The turning functions W() are pattern-specific; the angular positions of the maximum responses shift to greater angles with increasing width of the patterns (Fig. 2). In the twopattern configuration with double or single stripes, there is always a coincidence between the stable zero positions of W (), the mean of the frequency distributions P() of the flies' positions and n _g() of the straight courses, and the stable zero positions of H () obtained from an additive superposition of two or more angular shifted turning tendency functions H() (Fig. 5, 7). Therefore, the mean positions of the flies in a multi-stripe experiment composed of elementary stripes can be predicted from the addition of many angular shifted turning tendency functions H(). Between H() and the frequency distribution P() of the flies' positions , the following formula holds: P() =C·H()d (Fig. 13). With this equation, the spontaneous preference of the broader of two double stripes can be explained presuming lateral interactions between the components of the patterns (Fig. 8, 10). The strength x _i ^* of this lateral interaction depends on the width of the double stripes. The greater , the smaller is x _i ^* . x _i ^* is a pattern-specific value (Table 1, 2).Supported by the Deutsche Forschungsgemeinschaft, Ho 664/2     

Ellagic acid toxicity and interaction with benzo[a]pyrene and benzo[a]pyrene 7,8-dihydrodiol in human bronchial epithelial cells

Ellagic acid, a plant phenol present in various foods consumed by humans, has been reported to have both anti-mutagenic and anti-carcinogenic potential. To evaluate the potential anti-carcinogenic property of ellagic acid, we tested its effects on the toxicity of ben-zo[a]pyrene and benzo[a]pyrene, 7,8-dihydrodiol and binding of benzo[a]yrene to DNA in cultured human bronchial epithelial cells. The toxicity of ellagic acid itself for human bronchial epithelial cells was also determined. Using a colony-forming efficiency assay, it was found that a nontoxic concentration of ellagic acid (5 g/ml) enhanced the toxicity of benzo[a]pyrene.7,8-dihydrodiol in human bronchial epithelial cells. In contrast, ellagic acid at concentrations of l.5 and 3.0 g/ml inhibited binding of benzo[a]pyrenemetabolites to DNA in these cells. An explanation for the potentiating effect of ellagic acid on the toxicity of benzo[a]pyrene, 7,8-dihydrodiol will require further investigation into the possible mechanisms of interaction between these two compounds.Abbreviations B[a]P benzo[a]pyrene - B[a]P 7,8-DHD (±)trans-7,8-dihydro-7,8-dihydroxybenzo[a]pyrene - B[a]PDE-1 (±)-7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene - B[a]PDE-2 (±) 7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene - B[a]PDE-1:dG N²-]10{7,8,9-dihydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene]yl}:deoxyguanosine - B[a]PDE-2:dG NZ-{10-[7,8,9-trihydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene]yl}:deoxyguanosine - CFE colony forming efficiency - EA ellagic acid - HBE human bronchial epithelial     

Pancreatic glucagon cells contain endorphin-like immunoreactivity

Summary On the basis of the histochemical activity of succinic dehydrogenase, only two fibre-types are distinguished in pigeon pectoralis major muscle. These are narrow Red and broad White. The histochemical activity of myofibrillar ATPase was studied in these two distinct fibre-types. Both fibre-types showed high activity for the ATPase. Red fibres of pigeon pectoralis were not alkali-labile, at incubation pH 9.4, as were the Type I fibres of both avian and mammalian muscles. Again unlike Type I fibres, the Red fibres of pigeon pectoralis lacked the characteristic activation of acid-preincubated ATPase reaction. Pigeon pectoralis Red fibres are known to posses some characteristics of fast-twitch fibres (e.g. high fat, considerable phosphorylase, fibrillenstruktur myofibrillar arrangement, focal en plaque pattern of nerve endings). It is emphasized, therefore, that the pigeon pectoralis Red fibres are not equivalent to Type I or slow-twitch, muscle fibres, but they are possibly fast-twitch fatigue resistent or Type II Red muscle fibres.     

In vitro plant regeneration via somatic embryogenesis from root culture of some rhizomatous irises

A method for plant regeneration of Iris via somatic embryogenesis is described. Root and leaf pieces from in vitro-grown plants of several genotypes of rhizomatous Iris sp. were cultured in vitro. Callus induction occurred only on root cultures incubated under low light intensity (35 mol m^-2 s^-1) on two induction media containing 2,4-D (4.5 or 22.5 M), NAA (5.4 M) and kinetin (0.5 M). Somatic embryos developed after transfer of callus onto four regeneration media containing 9 or 22 M BA, or 5 M kinetin and 2 M TIBA or 9 M BA and 4 M TIBA. Plantlets could be obtained from these somatic embryos. Genotypic differences were found both in callus induction and somatic embryo formation, with I. pseudacorus responding better than I. versicolor or I. setosa. Cytological analysis performed on root tips of 80 regenerated plants revealed that two of the I. pseudacorus regenerants were tetraploid.Abbreviations 2,4-D dichlorophenoxy acetic acid - NAA naphthaleneacetic acid - BA 6-benzyladenine - TIBA 2,3,5-triiodobenzoic acid - IBA indolebutyric acid     

Regional specialization of the sperm membrane in the tick Amblyomma hebraeum koch (Acari: Ixodidae)

Summary The spermatozoon of Amblyomma hebraeum is about 200 m long and comprises: (1) a thick, club-shaped anterior part, about 20 m long bearing at its apex a tactile hemisphere, and (2) an elongated tail-like part, about 180 m long. The surface of the tactile hemisphere is covered by numerous bulbous expansions, attached to it by short stalks. The base of the hemisphere is surrounded by a fringe of thin motile processes; the remaining surface of the spermatozoon is covered with long cellular processes which run more or less parallel to one another.The membrane-associated particles found on the membrane beneath the cellular processes are regularly arranged as groups of parallel strands. The external surface of the so-called peripheral granules, as revealed by freeze-etching, is smooth with a very small number of particles. Internally the particles exhibit a regular hexagonal pattern which has not been observed, so far, on any other membrane of these sperm cells.The regional specialization of the spermatozoon surface membrane in relation to sperm motility is discussed. The results obtained indicate that processes of three types: (1) bulbous expansions, (2) motile processes, and (3) cellular processes are regional specializations, all engaged in aspects of sperm motility.The technical assistance of Mr. R. Haemmerle of Balzers Research Laboratories, Mrs. F. Seif and Miss C. Pugin, is gratefully acknowledged     

Electrophoretic variation between class II molecules expressed on HLA-DRw8 homozygous typing cells reveals multiple distinct haplotypes

Two-dimensional (2D) gel electrophoresis of immunoprecipitated HLA-DR antigens from eight homozygous typing cells (HTC) expressing the HLA-DRw8 specificity revealed a clustering of polymorphic chain patterns into distinct electrophoretic variants. The variant patterns correlate with three discrete HLA-D clusters that are defined in the mixed leukocyte culture reaction (MLR) using DRw8-positive HTC. These HLA-D clusters have been provisionally designated Dw8.1, detected primarily in Caucasoids, Dw8.2, detected primarily in American Indians, and Dw8.3, detected predominantly in Orientals. All three HLA-Dw8.1 cell lines express a single DR-locus product as defined by immunoprecipitation with a DR-specific monoclonal antibody, P4.1. This DR chain is identical among the Dw8.1 cell lines and different from the DR chains of the Dw8.2 and Dw8.3 cell lines. Two separate Dw8.2 HTC express a shared DR chain that is slightly more basic than the 8.1 DR molecule; interestingly, one of these lines also expresses an additional DR-like chain not found in the other cells. Thus, the two lines defining the Dw8.2 cluster share one distinct class 11 molecule, but differ in another and therefore are not biochemically HLA-identical. Cells from the Dw8.3 cluster are likewise distinct from all other Dw8 clusters. One additional DRw8-positive HTC has been analyzed and found to be distinct from the Dw8.1, 8.2 and 8.3 clusters by both MLR and 2D gels. lmmunoprecipitates using monoclonal antibody 1B5 [anti-DR and anti-DQ(DS)] identify additional polymorphic class II variants among the cell lines tested. These data indicate that HLA-DRw8 is a public serologic specificity present on class II molecules expressed on multiple distinct haplotypes. These haplotypes differ from each other in expression of polymorphic class II molecules encoded by at least two HLA loci. They also differ in HLA-D, even though they all type as HLA-DRw8 homozygous. In Dw8.2, variation in expressed chains is not reflected in variation in HLA-D, indicating that MLR, as well as serologic typing, does not detect the full degree of allelic polymorphism within HLA.     

Mass spectrometric analysis of genetic and post-translational heterogeneity in the lectins Jacalin andMaclura pomifera agglutinin

Jacalin andM. pomifera agglutinin are T-antigen specific lectins with ₄₄ structures that show far greater microheterogeneity than plant lectins from other families, due to multiple genetic isoforms and post-translational processing. Electrospray mass spectrometry and combined liquid chromatography-electrospray mass spectrometry were used to characterize the various forms. For both lectins, the mass data were consistent with previous protein sequencing of the major -chain species of 133 residues and three -chain species of 20 or 21 residues. In addition, for jacalin the mass of one minor -chain species was consistent with a second of the four reported gene sequences. However, the glycopeptide -chain form and one -chain form did not match any of the genes, suggesting a fifth gene remains to be found. ForM. pomifera agglutinin, three more -chain forms were found, but all six could arise from only two genes, with additional post-translational proteolysis and post-translational substitution with an unidentified component of 106 Da creating the set of six forms. Only two -chain forms were found also, with no glycosylation.