Induction of in vitro flowering in Dendrobium Madame Thong-In (Orchidaceae) seedlings is associated with increase in endogenous N(6)-(Delta (2)-isopentenyl)-adenine (iP) and N (6)-(Delta (2)-isopentenyl)-adenosine (iPA) levels

We analysed the endogenous cytokinin levels of Dendrobium Madame Thong-In seedlings grown in vitro during vegetative and flowering-inductive periods. HPLC was used to fractionate the extracts and radioimmunoassay (RIA) was used for assay of zeatin (Z), dihydrozeatin (DZ), N(6)-(Delta(2)-isopentenyl)-adenine (iP) and their derivatives. Coconut water used in experiments was found to contain high level (>136 pmol ml(-1)) of zeatin riboside (ZR). Protocorms and seedlings cultured in medium with coconut water were found to contain 0.5-3.9 pmol g(-1) FW of the cytokinins analysed. Seedlings (1.0-1.5 cm) cultured in flowering-inductive liquid medium containing 6-benzyladenine (BA, 4.4 muM) and coconut water (CW, 15%) contained up to 200 and 133 pmol g(-1) FW of iP and iPA, respectively. These levels were significantly higher than all other cytokinins analysed in seedlings of the same stage and were about 80- to 150-folds higher than seedlings cultured in non-inductive medium. During the transitional (vegetative to reproductive) stage, the endogenous levels of iP (178 pmol g(-1) FW) and iPA (63 pmol g(-1) FW) were also significantly higher than cytokinins in the zeatine (Z) and dihydrozeatin (DZ) families in the same seedlings. Seedlings that grew on inductive medium but remained vegetative contained lower levels of iPA. The importance of the profiles of iP and its derivatives in induction of in vitro flowering of D. Madame Thong-In is discussed.     

Ruthenium(II) tris(bipyridine)-centered poly(ethylenimine) for gene delivery

Ruthenium(II) tris(bipyridine)-centered poly(ethylenimine) (Ru PEI) was synthesized via acid hydrolysis of Ru tris(bipyridine)-centered poly(2-ethyl-2-oxazoline) (Ru PEOX), and the luminescence, DNA entrapment, and transfection efficiencies were evaluated. Emission maxima for Ru PEI samples are red-shifted compared to Ru PEOX precursors, and the luminescence lifetimes are shorter in both methanol and aqueous solutions. Slower oxygen quenching of Ru PEOX and Ru PEI luminescence versus [Ru(bpy)3]Cl2 (bpy = bipyridine) is attributed to polymer shielding effects. Ru PEI luminescence is similar in the presence and absence of DNA. Ru PEI (7900 Da) and linear PEI (L-PEI; 22,000 Da) fully entrapped DNA (5.4 kb; pcDNA) at an N/P ratio of 2. LNCaP prostate cancer cells were transfected with a plasmid encoding for green fluorescent protein using Ru PEI and L-PEI vectors for comparison. For N/P = 48, the transfection efficiency for Ru PEI was approximately 50% relative to that of L-PEI.     

Fragile site (16) (q22)

Summary The rare autosomal fragile site, fra (16)(q22), is the most common of all rare autosomal fragile sites and has a heterozygote frequency of about 5%. Evidence for it was found following the segregation expected from a simple codominant trait with complete penetrance; this is in contrast to a variety of other rare autosomal fragile sites. Based on the analysis of 12 families in which fra (16)(q22) is segregating, we found that, whereas complete penetrance could be confirmed, the transmitting parent was significantly more likely to be of the female sex. On the other hand, there was no evidence for preferential transmission to offspring of either sex.     

Role of tfdC(I)D(I)E(I)F(I) and tfdD(II)C(II)E(II)F(II) gene modules in catabolism of 3-chlorobenzoate by Ralstonia eutropha JMP134(pJP4)

The enzymes chlorocatechol-1,2-dioxygenase, chloromuconate cycloisomerase, dienelactone hydrolase, and maleylacetate reductase allow Ralstonia eutropha JMP134(pJP4) to degrade chlorocatechols formed during growth in 2,4-dichlorophenoxyacetate or 3-chlorobenzoate (3-CB). There are two gene modules located in plasmid pJP4, tfdC(I)D(I)E(I)F(I) (module I) and tfdD(II)C(II)E(II)F(II) (module II), putatively encoding these enzymes. To assess the role of both tfd modules in the degradation of chloroaromatics, each module was cloned into the medium-copy-number plasmid vector pBBR1MCS-2 under the control of the tfdR regulatory gene. These constructs were introduced into R. eutropha JMP222 (a JMP134 derivative lacking pJP4) and Pseudomonas putida KT2442, two strains able to transform 3-CB into chlorocatechols. Specific activities in cell extracts of chlorocatechol-1,2-dioxygenase (tfdC), chloromuconate cycloisomerase (tfdD), and dienelactone hydrolase (tfdE) were 2 to 50 times higher for microorganisms containing module I compared to those containing module II. In contrast, a significantly (50-fold) higher activity of maleylacetate reductase (tfdF) was observed in cell extracts of microorganisms containing module II compared to module I. The R. eutropha JMP222 derivative containing tfdR-tfdC(I)D(I)E(I)F(I) grew four times faster in liquid cultures with 3-CB as a sole carbon and energy source than in cultures containing tfdR-tfdD(II)C(II)E(II)F(II). In the case of P. putida KT2442, only the derivative containing module I was able to grow in liquid cultures of 3-CB. These results indicate that efficient degradation of 3-CB by R. eutropha JMP134(pJP4) requires the two tfd modules such that TfdCDE is likely supplied primarily by module I, while TfdF is likely supplied by module II.     

The fragile site (16) (q22)

Summary The rare fragile site at 16q22 was experimentally induced in lymphocyte cultures with various AT-specific, non-intercalating DNA-ligands. The optimum conditions for the induction of fra (16)(q22) were determined. The best expression of fra (16)(q22) was found with the aromatic diamidine berenil which is recommended for further studies on this fragile site. The results indicate that fra (16)(q22) is a region with AT-rich, late replicating DNA. The simultaneous treatment of lymphocytes with berenil and aphidicolin (inhibitor of DNA polymerase ) induces both the rare fra (16) (q22) and the common fra (16) (q23) within the same chromosome. A population study on 350 unselected individuals showed that fra (16)(q22) is the most common of all rare autosomal fragile sites in man. The frequency of individuals heterozygous for fra (16)(q22) is 5.1% no homozygosity for fra (16) (q22) was detected. Statistical analysis indicates that the population is in Hardy-Weinberg equilibrium with respect to the fragile and non-fragile chromosomes 16.     

Linkage mapping of the ovine alpha-inhibin (INHA) beta(A)-inhibin/activin (INHBA) and beta(B)-inhibin/activin (INHBB) genes

A full-sib mapping population was typed for Taql Southern blot RFLPs at the ovine alpha-inhibin (INHA), beta(A)-inhibin/activin (INHBA), and beta(B)-inhibin/activin (INHBB) loci. The most likely positions were found by genetic linkage analysis. INHA was placed on ovine chromosome 2q, between microsatellite markers BM6444 and INRA135, while INHBB was located 39 cM proximal to INHA between markers BMS1126 and BMS2626. The INHBA gene, a comparative mapping anchor locus, mapped to chromosome 4, between microsatellites OARCP26 and BMS719. These data confirm and refine previous chromosomal assignments by in situ hybridization, provide comparative mapping information, and identify microsatellite markers suitable for QTL association studies with inhibin/activin genes in ruminants.     

Biology of Acarophenax lacunatus (Cross & Krantz) (Prostigmata: Acarophenacidae) on Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and Cryptolestes ferrugineus (Stephens) (Coleoptera: Cucujidae)

The aim of the present study was to assess the effect of six different temperatures on the development of Acarophenax lacunatus (Cross & Krantz) using eggs of Tribolium castaneum (Herbst) and Cryptolestes ferrugineus (Stephens) as hosts. The temperature affected the development of A. lacunatus. The largest values for the progeny (19 mites in T. castaneum and 15 mites in C. ferrugineus) were obtained at about 30 degrees C, as also observed for the net reproductive rate (Ro), which revealed that the A. lacunatus population increased 18 times in T. castaneum and 14 times in C. ferrugineus in a generation. The intrinsic rate of increase (r m) gradually increased with temperature, reaching the maximum value at 35 degrees C in T. castaneum (1,608) and C. ferrugineus (1,289). The generation time was negatively correlated with temperature, ranging from 1,60 to 4,85 days in T. castaneum and from 1,96 to 5,34 days in C. ferrugineus. These results suggest that the mite A. lacunatus may be used in programs of biological control of T. castaneum and C. ferrugineus in the tropics.     

Vetiver grass (Vetiveria zizanioides (L.) Nash) as trap plant for Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae) and Busseola fusca (Fuller) (Lepidoptera: Noctuidae)

The preference of lepidopterous stem borer moths to oviposit on certain wild host plants can be exploited in habitat management systems by using those hosts as trap crops. Vetiver grass (Vetiveria zizanioides (L.) Nash) was evaluated for its attractiveness and suitability to the pyralid Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae) and the noctuid Busseola fusca (Fuller) (Lepidoptera: Noctuidae). Two choice tests were conducted in the laboratory and in the greenhouse to determine oviposition choice of C. partellus for maize, Vetiver and rice (Oryza sativa L.), and of B. fusca for Vetiver and maize. C. partellus larval survival was evaluated in green house studies. Results indicated that C. partellus chose Vetiver grass over maize though larval survival on Vetiver was extremely low. B. fusca did not show any host preference.     

Removal of Vanadium(III) and Molybdenum(V) from Wastewater Using Posidonia oceanica (Tracheophyta) Biomass

The use of dried and re-hydrated biomass of the seagrass Posidonia oceanica was investigated as an alternative and –low-cost biomaterial for removal of vanadium(III) and molybdenum(V) from wastewaters. Initial characterisation of this biomaterial identified carboxylic groups on the cuticle as potentially responsible for cation sorption, and confirmed the toxic-metal bioaccumulation. The combined effects on biosorption performance of equilibrium pH and metal concentrations were investigated in an ideal single-metal system and in more real-life multicomponent systems. There were either with one metal (vanadium or molybdenum) and sodium nitrate, as representative of high ionic strength systems, or with the two metals (vanadium and molybdenum). For the single-metal solutions, the optimum was at pH 3, where a significant proportion of vanadium was removed (ca. 70%) while there was ca. 40% adsorption of molybdenum. The data obtained from the more real-life multicomponent systems showed that biosorption of one metal was improved both by the presence of the other metal and by high ionic strength, suggesting a synergistic effect on biosorption rather than competition. There data ware used for the development of a simple multi-metal equilibrium model based on the non-competitive Langmuir approach, which was successfully fitted to experimental data and represents a useful support tool for the prediction of biosorption performance in such real-life systems. Overall, the results suggest that biomass of P. oceanica can be used as an efficient biosorbent for removal of vanadium(III) and molybdenum(V) from aqueous solutions. This process thus offers an eco-compatible solution for the reuse of the waste material of leaves that accumulate on the beach due to both human activities and to storms at sea.     

fra(1) (p11), fra(1) (q22) and r(1) (p11q22) in a retarded girl.

A mentally retarded girl with a 46,XX/47, XX+r(1) (p11q22q22p11)/47, XX+r(1) (p11q22) fra(1) (p31) fra(1) (p11) fra(1) (q22) karyotype who inherited the fragile sites from the normal mother was studied. The conicidence of fra(1) (p11) and fra(1) (q22) with the ring chromosome breakpoints strongly suggests a cause-effect relationship. This finding agrees with other reported associations between fragile sites and structural chromosome abnormalities and constitutes the fourth reported of a de novo structurally abnormal chromosome as a consequence of presumed in vivo fragile sites instability. Although risk figures for chromosome anomalies and cancer associated with fragile sites are lacking, carriers of fra (1) (p11) may have a higher risk for abnormalities of chromosome 1 in somatic and gonadal cells than the general population.     

tfoX (sxy)-dependent transformation of Aggregatibacter (Actinobacillus) actinomycetemcomitans

tfoX (sxy) is a regulatory gene needed to turn on competence genes. Aggregatibacter (Actinobacillus) actinomycetemcomitans has a tfoX gene that is important for transformation. We cloned this gene on an IncQ plasmid downstream of the inducible tac promoter. When this plasmid was resident in cells of A. actinomycetemcomitans and tfoX was induced, the cells became competent for transformation. Several strains of A. actinomycetemcomitans, including different serotypes, as well as rough (adherent) and isogenic smooth (nonadherent) forms were tested. Only our two serotype f strains failed to be transformed. With the other strains, we could easily get transformants with extrachromosomal plasmid DNA when closed circular, replicative plasmid carrying an uptake signal sequence (USS) was used. When a replicative plasmid carrying a USS and cloned DNA from the chromosome of A. actinomycetemcomitans was linearized by digestion with a restriction endonuclease or when genomic DNA was used directly, the outcome was allelic exchange. To facilitate allelic exchange, we constructed a suicide plasmid (pMB78) that does not replicate in A. actinomycetemcomitans and carries a region with two inverted copies of a USS. This vector gave allelic exchange in the presence of cloned and induced tfoX easily and without digestion. Using transposon insertions in cloned katA DNA, we found that as little as 78 bp of homology at one of the ends was sufficient for that end to participate in allelic exchange. The cloning and induction of tfoX makes it possible to transform nearly any strain of A. actinomycetemcomitans, and allelic exchange has proven to be important for site-directed mutagenesis.     

The antiproliferative agents trans-bis(resorcylaldoximato)copper(II) and trans-bis(2,3,4-trihydroxybenzaldoximato)copper(II) and cytopathic effects of HIV

trans-Bis(resorcylaldoximato)copper(II) and trans-bis-(2,3,4-trihydroxybenzaldoximato)copper(II) (CuRES2 and CuTRI2, respectively) have been tested for antiviral properties against HIV, using an in vitro assay that measures the ability of the test compounds to prevent the killing of susceptible human cells by HIV. In the case of CuTRI2, T4 lymphocytes (CEM-V and CEM-Z cell lines) were exposed to HIV at a virus to cell ratio approx. 0.05 in microtiter plates. In the case of CuRES2, a human leukemia cell line (MT-2) was used instead. The tetrazolium salt XTT was added to all wells, and the cultures were incubated and analyzed spectrophotometrically to quantitate formazan production and viewed microscopically for detection of viable cells. In spite of their antiproliferative properties, neither agent had any detectable ability to prevent the cytopathic effects of HIV in cultures of the target cells used. Because the test system employed was constructed in such a way as to detect antiviral agents acting at any stage of the virus reproductive cycle, the results obtained strongly suggest that neither studied agent has any value as the direct prevention of the cell destruction caused by HIV is concerned.     

Synthesis of (bis)sulfonic acid, (bis)benzamides as follicle-stimulating hormone (FSH) antagonists

Screening efforts identified (bis)sulfonic acid, (bis)benzamides (1-3) as compounds that interact with the follicle stimulating-hormone receptor (FSHR) and inhibit FSH-stimulated cAMP accumulation with IC(50) values in the low micromolar range. Structure-activity relationship studies using novel analogues of 1-3 revealed that two phenylsulfonic acid moieties were necessary for activity and that the carbon-carbon double bond of the stilbene sub-series was the optimum spacer connecting these groups. Selected analogues (2, 14, and 50) were also able to block FSHR-dependent estradiol production in rat primary ovarian granulosa cells and progesterone secretion in a clonal mouse adrenal Y1 cell line. IC(50) values for these compounds in these assays were in the low micromolar range. Optimization of the benzoic acid side chains of 1-3 led to gains in selectivity versus activity at the thyroid stimulating hormone (TSH) receptor (TSHR). For instance, while stilbene (bis)sulfonic acid congener 2 was only 10-fold selective for FSHR over TSHR, analogue 50 with an IC(50) value of 0.9 microM in the FSHR-cAMP assay was essentially inactive at 30 microM in the TSHR-cAMP assay.     

Plasticization of poly(L-lactide) with poly(propylene glycol)

A new plasticizer for poly(L-lactide) (PLA)-poly(propylene glycol) (PPG) is proposed. The advantage of using PPG is that it does not crystallize, has low glass transition temperature, and is miscible with PLA. PLA was plasticized with PPGs with nominal Mw of 425 and 1000 g/mol. Poly(ethylene glycol) (PEG), long known as a plasticizer for PLA, with nominal Mw of 600 g/mol, was also used to plasticize PLA for comparison. The thermal and tensile properties of PLA and PLA with 5-12.5 wt % of the plasticizers were studied. In blends of PLA with PPGs the glass transition temperature was lower than that of neat PLA. Both PPGs enhanced the crystallizability of PLA albeit less than PEG. All of the plasticizers increased also the ability of PLA to plastic deformation which was reflected in a decrease of yield stress and in an increase of elongation at break. The effect was enhanced by the higher PPG content and also by lower molecular weight of PPG. A phase separation occurred only in the blend containing 12.5 wt % of PPG with higher molecular weight. The evidences of crazing were found in deformed samples of PLA with low plasticizer content, whereas the samples with higher content of plasticizers crystallized due to deformation.     

Study of the interaction of cis-dichloro-(1,2 diethyl-3-aminopyrrolidine)Pt(II) complex with poly(I), poly(C) and poly(I) x poly(C)

The interaction of cis-dichloro-(1,2 diethyl-3-aminopyrrolidine)platinum(II) (Ptpyrr) with the polynucleotides poly(I), poly(C) and poly(I) x poly(C) acids was studied by circular dichroism, molecular fluorescence and (1)H NMR spectroscopies. Multivariate Curve Resolution, a factor analysis method, was applied for the analysis and interpretation of spectroscopic data obtained in mole ratio and kinetics studies. This procedure allows the determination of the number of different interaction complexes present during the experiments and the resolution of both concentration profiles and pure spectra for all of them. Two different interaction complexes were observed at the experimental conditions studied. The first one, at low Ptpyrr:polynucleotide ratio (r(Ptpyrr:poly)) values, corresponds to the interaction of Ptpyrr with hypoxanthine bases in the poly(I) moiety. This interaction leads to the destabilization and dissociation of the double-stranded conformation. The second complex was observed at higher r(Ptpyrr:poly) values and corresponds to the interaction of Ptpyrr to cytosine bases in poly(C) moiety. The formation of both complexes showed that the interaction of Ptpyrr with hypoxanthine bases occurred at the first stages of the reaction and with cytosine bases at longer reaction times. The results obtained show the utility of the Multivariate Curve Resolution approach for the analysis of data obtained by monitoring spectroscopically the interaction equilibria of platinum compounds with nucleic acids.     

Specific phosphorylase from Euglena gracilis splits diadenosine 5',5''-P(1),P(4)-tetraphosphate (Ap(4)A) and diadenosine 5',5''-P(1),P(3)-triphosphate (Ap(3)A)

1. Phosphorolytic cleavage of Ap(4),A was demonstrated in cell-free extracts from two protozoan organisms, Euglena gracilis and Acanthamoeba castellanii. 2. A specific dinucleoside oligophosphate (DNOP) alpha, beta-phosphorylase which degrades substrates with formation of corresponding nucleoside 5'-diphosphate (NDP) as one of the reaction products was purified 625-fold from Euglena gracilis cells. 3. In addition to Ap(4)A, the phosphorylase degrades AP(3)A, Ap(5)A, Gp(4)G and one of phosphonate analogs, ApppCH(2)pA. The K(m) values for Ap(4), A and Ap(3) A are 27 and 25 micron, and relative velocities 100 and 14, respectively. The K(m) for phosphate is 0.5 mM. 4. Some anions (arsenate, chromate, molybdate and vanadate) can substitute for phosphate in the catalyzed reactions and in their presence the DNOPs yield corresponding nucleoside 5'-monophosphate as one of the reactions' product. The enzyme supports also an anion-dependent dephosphorylation of NDPs. 5. Molecular weight of the native Euglena phosphorylase is 30,000. Optimum pH for its activity is at 8.0 Divalent metal cations are essential for the phosphorolysis of DNOPs but are not for the NDP dephosphorylation mentioned.     

Chemiluminescent immunoassay (CLIA) for salmon growth hormone (GH)

A highly sensitive and specific chemiluminescent immunoassay (CLIA) was developed for quantification of growth hormone (GH) in salmonid species. The CLIA for salmon GH was performed using the sandwich method with anti-GH IgG as the first antibody and chemiluminescent acridinium ester-labelled specific anti-GH F(ab′)₂ as the second antibody. The measurable range of salmon GH in the CLIA was 39–1250 pg/mL using a short assay (1 day) protocol and 3.9–125 pg/mL in a longer (2-day) assay. The dilution curve in the CLIA of serum from masu salmon (Oncorhynchus masou) was parallel to the standard curve of recombinant chum salmon (Oncorhynchus keta) GH. Seasonal changes of serum GH levels were measured in 1 year-old masu salmon cultivated in a pond from March to November. Their serum GH levels increased during smoltification from March to April, achieved a maximum level of 21 ng/mL in August, and then declined gradually to 11 ng/mL in October. © 1997 John Wiley & Sons, Ltd.     

(99m)Tc(CO)(3)-Ibritumomab tiuxetan; a novel radioimmunoimaging (RII) agent of B cell non-Hodgkin's lymphoma (NHL)

To exploit the B-lymphocyte antigen-CD20 binding capacity of the Ibritumomab tiuxetan (IBTN) monoclonal antibody (mAb) for imaging, the over-expression of B cells in non-Hodgkin's lymphoma (NHL) (a myeloproliferative disorder of the lymphatic system) was investigated. In the current investigation, we present the labeling of the IBTN with technetium-99m ((99m)Tc) through [(99m)Tc(CO)(3)](+) precursor for radioimmunoimaging (RII) of the tumor prior to its treatment with (90)Y labeled IBTN. Labeled IBTN was radiobiologically characterized in terms of radiochemical purity, in vitro stability in human plasma, immunoreactivity, binding with Raji and Ramos cells and biodistribution in a female nude mouse (FNM) model. It was observed that the reduced IBTN (rIBTN) showed more promising radiobiologic characteristics than the nonreduced IBTN. Significantly higher transchelation was seen in excess cysteine compared with histidine. The radioconjugate showed higher saturated binding affinity with CD20 antigen. Significantly higher target (tumor) to background ratios were observed 1 h post-injection (p.i.). Based on radiochemical purity, in vitro stability, immunoreactivity, binding and biodistrubtion in the FNM model, we recommend the radiolabeling of the rIBTN using tricarbonyl technique as a potential RII agent.     

Efficacy of the parasitoid,Diaeretiella rapae (McIntosh) (Hymenoptera: Braconidae) against Myzus persicae (Sulzer) (Hemiptera: Aphididae) infesting rapeseed-mustard

Efficacy of Diaeretiella rapae (McIntosh) (Hymenoptera: Braconidae) was determined by studying its biological and behavioural attributes on the aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae). Total developmental duration of the parasitoid was longer in younger instars compared to that in older instars of aphid. Host age negatively affected the oviposition period and fecundity of the ovipositing parasitoid. Survival of the immatures was higher in older than the younger instars of the aphid. Sex ratio for the parasitoid was female-biased. Longevity of female parasitoid was higher while parasitizing aphid nymphs of younger age groups (1–2 days old) compared to that of older age groups (4–5 days old). Parasitoid showed a higher preference towards second instar of M. persicae both in choice and no-choice tests. Results on mutual interference revealed that per capita searching efficiency decreased from 0.91 to 0.07 as parasitoid densities increased from 1 to 8. Logistic regression exhibited a type II functional response for D. rapae. The estimated values of search-efficiency (a) and handling time (T_h) were 0.038 h⁻¹ and 1.59 h, respectively. The maximum parasitization rate was 15.08. This investigation suggests that D. rapae could be an effective candidate for augmentative biological control of M. persicae which infests several plant species of economic importance.     

The helix-coil transitions of poly (dA)-poly (dT) and poly (dA-dT)-poly (dA-dT)

Helix–coil transition curves are calculated for poly (dA) poly(dT) and poly (dA-dT) poly (dA-dT) using the integral equation approach of Goel and Montroll.⁵ The transitions are described by the loop entropy model with the exponent of the loop entropy factor, k, remaining an arbitrary constant. The theoretical calculations are compared with experimental transition curves of the two polymers. Results indicate that the stacking energies for these two polymers differ by about 1 kcal/mole of base pairs. Also, a fit between theory and experiment was not possible for k > 1.70.