New open frameworks based on metal pyridylphosphonates.

A family of new 1D, 2D, and 3D coordination networks based on metal-pyridylphosphonates have been synthesized under hydro(solvo)thermal conditions. Zn(3-pyridylphosphonate)(bromide), 1, adopts a 1D ladder structure, while Co(4-pyridylphosphonate)(H(2)O)(3), 2, adopts a 2D grid structure. [Cu(2)(4-pyridylphosphonate)(2)]-2H(2)O, 3, [Cd(3-pyridylphosphonate)(2)]-DMSO, 4, Cd(4-pyridylphosphonate)(2), 5, and Cd(ethyl 4-pyridylphosphonate)(2), 6, all adopt 3D framework structures. While 3 possesses open channels that are occupied by water molecules, 4 exhibits cavities that accommodate DMSO guest molecules. The present work demonstrates that interesting open frameworks can be readily synthesized on the basis of metal pyridylphosphonates. Crystal data for 1: monoclinic space group C2/c; a = 15.267(4), b = 11.903(2), c = 10.380(2) A; beta = 98.68(2) degrees; Z = 8. Crystal data for 2: monoclinic space group P2(1)/c; a = 9.634(12), b = 7.611(9), c = 11.901(1) A; beta = 97.830(2) degrees; Z = 4. Crystal data for 3: triclinic spacegroup P one macro; a = 7.464(8), b = 9.203(1), c = 11.602(2) A; alpha = 100.289(1) degrees; beta = 104.532(1) degrees, gamma = 94.569(1) degrees; Z = 2. Crystal data for 4: tetragonal space group I4(1)/a; a = 15.114(2), b = 15.114(2), c = 13.128(3) A; Z = 8. Crystal data for 5: monoclinic space group P2(1)/c; a = 8.344(2), b = 10.589(2), c = 14.384(3) A; beta = 91.77(3) degrees; Z = 4. Crystal data for 6: monoclinic space group P2(1)/n; a = 5.606(1), b = 11.198(1), c = 14.176(2) A; beta = 94.518(1) degrees; Z = 2.

Aqua(benzene-1,3-dicarboxylato)zinc(II).

The title compound, poly[[aquazinc(II)]-mu-benzene-1,3-dicarboxylato-O1:O1':O2], [Zn(C8H4O4)(H2O)]n, forms a metal-organic coordination network that consists of tetrahedral Zn atoms bonded to one water molecule and three carboxylate groups. Isophthalate groups bridge the four-coordinate Zn centers to generate two-dimensional architectures in the ac plane. These planar zinc isophthalate motifs are linked by infinite C=O...H-O-H interactions along the a axis to form a chiral framework. The observed polar structural pattern originates due to the distorted tetrahedral Zn centers [O-Zn-O 100.7 (2)-136.0 (1) degrees ] and the alignment of the water molecules. Bridging isophthalate groups align to form approximate centrosymmetric motifs.

Synthesis and biological evaluation of novel pyrazoles and indazoles as activators of the nitric oxide receptor, soluble guanylate cyclase.

Database searching and compound screening identified 1-benzyl-3-(3-dimethylaminopropyloxy)indazole (benzydamine, 3) as a potent activator of the nitric oxide receptor, soluble guanylate cyclase. A comprehensive structure-activity relationship study surrounding 3 clearly showed that the indazole C-3 dimethylaminopropyloxy substituent was critical for enzyme activity. However replacement of the indazole ring of 3 by appropriately substituted pyrazoles maintained enzyme activity. Compounds were evaluated for inhibition of platelet aggregation and showed a general lipophilicity requirement. Aryl-substituted pyrazoles 32, 34, and 43 demonstrated potent activation of soluble guanylate cyclase and potent inhibition of platelet aggregation. Pharmacokinetic studies in rats showed that compound 32 exhibits modest oral bioavailability (12%). Furthermore 32 has an excellent selectivity profile notably showing no significant inhibition of phosphodiesterases or nitric oxide synthases.

Bone marrow transplantation versus chemotherapy in the treatment of very high-risk childhood acute lymphoblastic leukemia in first remission: results from Medical Research Council UKALL X and XI.

The role of bone marrow transplantation (BMT) in first remission of children with high-risk acute lymphoblastic leukemia (ALL) remains unclear. There were 3676 patients (aged 1 to 15 years) entered into the United Kingdom (UK) Medical Research Council (MRC) trials UKALL X and XI from 1985 to 1997. Of these patients, 473 patients (13%) were classified as very high (VH) risk and were eligible for a transplantation from a matched histocompatible sibling donor (MSD). We tissue-typed 286 patients; 99 patients had a matched related donor, and 76 patients received transplantations. Additionally, 25 children received transplantations from a matched unrelated donor (MUD) despite trial guidelines for MSD transplantations only. The median time to transplantation was 5 months (range, 2 to 19 months), and the median follow-up was 8 years. The 10-year event-free survival (EFS) adjusted for the time to transplantation, diagnostic white blood cell (WBC) count, Ph chromosome status, and ploidy was 6. 0% higher (95% confidence interval (CI), -10.5% to 22.5%) for 101 patients who received a first-remission transplantation (MSD and MUD) than for the 351 patients treated with chemotherapy (transplantation, 45.3%, vs chemotherapy, 39.3%). The transplantation group had fewer relapses (31%) compared to relapses in the chemotherapy group (55%); however, the transplantation group had more remission deaths (18%) compared to remission deaths in the chemotherapy group (3%). In contrast the adjusted 10-year EFS was 10. 7% higher (95% CI, -2.6% to 24.0%) for patients without a human leukocyte antigen (HLA)-matched donor than for those patients with a donor (no donor, 50.4%, vs donor, 39.7%). In conclusion, for the majority of children with VH-risk ALL, the first-remission transplantation has not improved EFS.

The slow step of folding of Staphylococcus aureus PC1 beta-lactamase involves the collapse of a surface loop rate limited by the trans to cis isomerization of a non-proline peptide bond.

We wished to test the hypothesis that the non proline cis to trans isomerization of the peptide bond at position 167 in the S. aureus beta-lactamase PC1 exerts a significant controlling effect on the folding pathway of this enzyme. The previous data presented in support of this hypothesis could not rule out the effect of factors unrelated to non-proline cis/trans isomerization. We have used the plasmid pET9d to direct soluble overproduction of the S. aureus beta-lactamase PC1 and a site-directed mutant (Ile 167 to Pro) in Escherichia coli. Following purification the proteins were subjected to a comparative analysis of the kinetics of unfolding and refolding using the techniques of near- and far-UV circular dichroism spectroscopy and fluorescence spectroscopy in conjunction with "double-jump" experiments. Results show that the fully-unfolded I167P mutant enzyme retains 20% of molecules in a fast-refolding form and that slower-refolding molecules fold faster than the recombinant wild-type enzyme. The final stage of folding involves folding of the omega-loop into a conformation essential for enzymatic activity. In support of the original hypothesis, the folding of this omega-loop is rate limited by the isomerization of the Glu 166-Ile 167 peptide bond.

Control of metabolic flux through the quinate pathway in Aspergillus nidulans.

The quinic acid ulitization (qut) pathway in Aspergillus nidulans is a dispensable carbon utilization pathway that catabolizes quinate to protocatechuate via dehydroquinate and dehydroshikimate(DHS). At the usual in vitro growth pH of 6.5, quinate enters the mycelium by means of a specific permease and is converted into PCA by the sequential action of the enzymes quinate dehydrogenase, 3-dehydroquinase and DHS dehydratase. The extent of control on metabolic flux exerted by the permease and the three pathway enzymes was investigated by applying the techniques of Metabolic Control Analysis. The flux control coefficients for each of the three quinate pathway enzymes were determined empirically, and the flux control coefficient of the quinate permease was inferred by use of the summation theorem. There measurements implied that, under the standard growth conditions used, the values for the flux control coefficients of the components of the quinate pathway were: quinate permease, 0.43; quinate dehydrogenase, 0.36; dehydroquinase, 0.18; DHS dehydratase, <0,03. Attempts to partially decouple quinate permease from the control over flux by measuring flux at pH 3.5 (when a significant percentage of the soluble quinate is protonated and able to enter the mycelium without the aid of a permease) led to an increase of approx. 50% in the flux control coefficient for dehydroquinase. Taken together with the fact that A. nidulans has a very efficient pH homeostasis mechanism, these experiments are consistent with the view that quinate permease exerts a high degree of control over pathway flux under the standard laboratory growth conditions at pH 6.5. The enzymes quinate dehydrogenase and 3-dehydroquinase have previously been overproduced in Escherichia coli, and protocols for their purification published. The remaining qut pathway enzyme DHS dehydratase was overproduced in E. coli and a purification protocol established. The purified DHS dehydratase was shown to have a K(m) of 530 microM for its substrate DHS and a requirement for bivalent metal cations that could be fulfilled by Mg(2+), Mn(2+) or Zn(2+). All three qut pathway enzymes were purified in bulk and their elasticity coefficients with respect to the three quinate pathway intermediates were derived over a range of concentrations in a core tricine/NaOH buffer, augmented with necessary cofactors and bivalent cations as appropriate. Using these empirically determined relative values, in conjunction with the connectivity theorem, the relative ratios of the flux control coefficients for the various quinate pathway enzymes, and how this control shifts between them, was determined over a range of possible metabolic concentrations. These calculations, although clearly subject to caveates about the relationswhip between kinetic measurements in vitro and the situation in vivo, were able to successfully predict the hiearchy of control observed under the standard laboratory growth conditions. The calculations imply that the hierarchy of control exerted by the quinate pathway enzymes is stable and relatively insensitive to changing metabolite concentrations in the ranges most likely to correspond to those found in vivo. The effects of substituting the type I 3-dehydroquinases from Salmonella typhi and the A. nidulans AROM protein (a pentadomain protein catalysing the conversion of 3-deoxy-D-arabinoheptulosonic acid 7-phosphate into 5-enolpyruvylshikimate 3 phosphate), and the Mycobacterium tuberculosis type II 3-dehydroquinase, in the quinate pathway were investigated and found to have an effect. In the case of S. typhi and A. nidulans, overproduction of heterologous dehydroquinase led to a diminuation of pathway flux caused by a lowering of in vivo quinate dehydrogenase levels increased above those of the wild type. We speculate that these changes in qu

Comparative analysis of the QUTR transcription repressor protein and the three C-terminal domains of the pentafunctional AROM enzyme.

The AROM protein is a pentadomain protein catalysing steps two to six in the prechorismate section of the shikimate pathway in microbial eukaryotes. On the basis of amino acid sequence alignments and the properties of mutants unable to utilize quinic acid as a carbon source, the AROM protein has been proposed to be homologous throughout its length with the proteins regulating transcription of the genes necessary for quinate catabolism. The QUTR transcription repressor protein has been proposed to be homologous with the three C-terminal domains of the AROM protein and one-fifth of the penultimate N-terminal domain. We report here the results of experiments designed to overproduce the QUTR and AROM proteins and their constituent domains in Escherichia coli, the purpose being to facilitate domain purification and (in the case of AROM), complementation of E. coli aro- mutations in order to probe the degree to which individual domains are stable and functional. The 3-dehydroquinate dehydratase domain of the AROM protein and the 3-dehydroquinate dehydratase-like domain of the QUTR spectroscopy and fluorescence emission spectroscopy. The CD spectra were found to be virtually superimposable. The fluorescence emission spectra of both domains had the signal from the tryptophan residues almost completely quenched, giving a tyrosine-dominated spectrum for both the AROM- and QUTR-derived domains. This unexpected observation was demonstrated to be due to a highly unusual environment provided by the tertiary structure, as addition of the denaturant guanidine hydrochloride gave a typical tryptophan-dominated spectrum for both domains. The spectroscopy experiments had the potential to refute the biologically-based proposal for a common origin for the AROM and QUTR proteins; however, the combined biophysical data are consistent with the hypothesis. We have previously reported that the AROM dehydroquinate synthase and 3-dehydroquinate dehydratase are stable and functional as individual domains, but that the 5-enol-pyruvylshikimate-3-phosphate synthase is only active as part of the complete AROM protein or as a bi-domain fragment with dehydroquinate synthase. Here we report that the aromA gene (encoding the AROM protein) of Aspergillus nidulans contains a 53 nt intron in the extreme C-terminus of the shikimate dehydrogenase domain. This finding accounts for the previously reported observation that the AROM protein was unable to complement aroE- (lacking shikimate dehydrogenase) mutations in E. coli. When the intron is removed the correctly translated AROM protein is able to complement the E. coli aroE- mutation. An AROM-derived shikimate dehydrogenase domain is, however, non-functional, but function is restored in a bi-domain protein with e-dehydroquinate dehydratase. This interaction is not entirely specific, as substitution of the 3-dehydroquinate dehydratase domain with the glutathione S-transferase protein partially restores enzyme activity. Similarly an AROM-derived shikimate kinase domain is non-functional, but is functional as part of the complete AROM protein, or as a bi-domain protein with 3-dehydroquinate dehydratase.

The normal mycoflora of commodities from Thailand. 2. Beans, rice, small grains and other commodities.

Part of a comprehensive study of fungi occurring in commodities in Thailand, this paper reports results from 276 samples of mung beans, rice, sorghum and soybeans as well as other minor crops. Samples for major commodities were taken from farmers' stocks, middlemen and retail outlets, while those for minor crops were mostly from retail. Each sample was divided into two portions, one being examined in Bangkok and the second at North Ryde. Mycological examinations were carried out by direct plating after surface disinfection in chlorine. Media used were dichloran rose bengal chloramphenicol agar, dichloran 18% glycerol agar, Aspergillus flavus and parasiticus agar and dichloran chloramphenicol peptone agar. Fungi were identified to species level and percentage infection of samples calculated. The dominant fungus found in mung beans was Fusarium semitectum, which was present in 40% of samples and at a high level (18% of all seeds) overall. Aspergillus flavus was also found in 40% of samples, but only in 2% of seeds overall. Lasiodiplodia theobromae was the only other fungus exceeding 1% total infection. The major fungi found in soybeans were A. flavus (67% of samples; 6% overall) and Cladosporium cladosporioides (49% of samples; 9% overall). Storage fungi were more common in soybeans than the other commodities, indicating longer or adverse storage. Paddy rice contained high levels of a wide variety of field fungi, notably Fusarium semitectum, Bipolaris oryzae, and Curvularia, Phoma and Colletotrichum species. However, probably due to the heat generated by milling, milled rice contained very few fungi, which were mostly of storage origin. Only 3% of particles examined contained internal fungi. Infection in sorghum was typical of oilseeds, dominated by Aspergillus flavus, which was present in 86% of samples, with an overall infection rate of 12%. Beans other than soybeans were infected by a wide range of field fungi, but at low levels, with less than half of seeds examined being infected internally. With the exception of sorghum, the levels of mycotoxigenic fungi encountered were much lower than observed previously in nuts and oilseeds.

The normal mycoflora of commodities from Thailand. 1. Nuts and oilseeds.

A comprehensive study was carried out of the fungi occurring in commodities normally traded in Thailand. Samples of major commodities were obtained from farmers' stocks and middlemen in major producing areas throughout the country. Retail samples were obtained from outlets in and around Bankok. Samples were divided into two portions, one being examined in Bangkok, and the second in Sydney. After surface disinfection, fungi were enumerated by direct plating on dichloran rose bengal chloramphenicol agar, dichloran 18% glycerol agar, Aspergillus flavus and parasiticus agar and dichloran chloramphenicol peptone agar. Figures for percentage infection were calculated, and fungi were isolated and identified to species level. In all 602 samples were examined, and at North Ryde about 18,000 fungal isolates identified. Data obtained from 329 samples are reported here, comprising maize (154), peanuts (109), cashews (45) and copra (21). Major fungi in maize included Fusarium moniliforme (present in 97% of samples), Aspergillus flavus (85%), Penicillium citrinum (67%), Aspergillus niger (64%), Lasiodiplodia theobromae (58%) and Fusarium semitectum (45%). In peanuts, the major fungi were Aspergillus flavus (95% of samples), Aspergillus niger (86%), Rhizopus oryzae (60%), Eurotium rubrum (51%), Macromina phaseolina (49%), Penicillium citrinum (46%) and Eurotium chevalieri (46%). Invasion in cashews was lower, major fungi being Aspergillus flavus (60%), Nigrospora oryzae (58%), Aspergillus niger (53%), Chaetomium globosum (47%) and Eurotium chevalieri (40%). Aspergillus flavus (86% of samples) was again dominant in copra, with Rhizopus oryzae (52%), Aspergillus niger (43%), Eurotium chevalieri (43%) the only other species exceeding 40% infection. Aspergillus parasiticus was rarely seen, and Aspergillus nomius was reported from foods for the first time.

Participation of the SOS system in producing deletions in E. coli plasmids.

The participation of the SOS response in the deletion of palindromic and non-palindromic inserts of about 66 and 100 bp cloned within the EcoR1 site of the chloramphenicol acetyl transferase (cat) gene of plasmid pBR325 was tested after introducing the derived plasmids into strains containing different combinations of lexA, recA and umuC alleles and the auxotrophic mutation trpE65. This allowed for a comparison of deletion frequency in the plasmids, measured as the reversion of chloramphenicol sensitivity to resistance (Cms-->Cmr), to point-mutation frequency measured from the reversion of trpE65 to tryptophan independence (Trp(-)-->Trp+). We found that the spontaneous deletion frequency of palindromic inserts was increased by the overproduction of activated RecA* and UmuC+ in lexA (Def) backgrounds but the deletion of the non-palindromic inserts was unaltered. Overproduction of RecA+ had no significant effect on deletion incidence but it did increase Trp(-)-->Trp+ reversions. The SOS stimulation of palindrome deletions paralleled the SOS mutator effect of certain recA and umuC alleles on Trp(-)-->Trp+ reversions, suggesting that some form of SOS processing was responsible for the observed increases. The results further suggest that the SOS effect on deletions depends on the distinction between palindromy vs. non-palindromy, rather than on the sizes or sequences of the inserts or those of the terminal homologies bracketing them.

Interactions among xerophilic fungi associated with dried salted fish.

Interactions were investigated among five xerophilic fungi, Polypaecilum pisce, Basipetospora halophila, Eurotium rubrum, Aspergillus wentii and A. penicillioides, isolated from Indonesian dried salted fish. A range of water activities (aw) (0.98, 0.95, 0.90 and 0.84) and temperatures (15 degrees, 25 degrees and 30 degrees C) were studied on agar media in Petri dishes, and with dried fish as a substrate at 0.90 and 0.84 aw at 30 degrees C. Generally, the fungi exhibited one of two interaction types: mutual inhibition on contact, or inhibition of one or both species on contact, with the inhibited species continuing to grow at a significantly reduced rate. On glucose-based agar media A. wentii and E. rubrum were most competitive at all aw values and temperatures studied, while on NaCl media P. pisce and B. halophila were usually most competitive. The Petri dish system was a useful model, but did not completely simulate the interactions observed on dried fish. Polypaecilum pisce and B. halophila were able to compete more strongly on fish than on agar media, especially at 0.90 aw. This study provides some evidence that each species examined had a niche in which it was dominant, and that species interactions as well as environmental factors are important in determining the dominant fungal species on dried salted fish.

Comparison of cartridge insulin Penmix 50:50/Isophane with soluble/Isophane in type I diabetic adolescents using a multiple injection regimen.

This study investigated the effect on blood sugar control and weight gain of a multiple injection therapy (MIT) regimen in 22 established adolescent diabetics using a pre-prandial 50:50 mixture of Isophane/soluble insulin with night-time Isophane. This regimen was compared in a cross-over study with MIT using pre-prandial soluble insulin and night-time Isophane. After 4 wk for stabilization, there were 2 periods of 16 wk on each regimen. Throughout the study, blood sugar control was monitored by regular HbA1 and fructosamine measurements. The total daily dose of insulin was unchanged throughout the study, 1.0 +/- 0.3 iu/kg/day for Penmix/Isophane and 1.1 +/- 0.3 iu/kg/day for soluble/Isophane. The mean HbA1 and fructosamine did not alter significantly on either regimen. There was no significant weight gain during the Penmix therapy, despite the increased proportion of longer-acting despite the increased proportion of longer-acting insulin. Lean body mass (LBM) measured by skinfold thickness and electrical impedance only changed marginally on either regimen; the correlation between the 2 measuring techniques for LBM was good. Patient acceptance of the 50:50 Penmix insulin was high, 13 of 19 children preferring it to the conventional regimen.

Influence of pH on the growth of some toxigenic species of Aspergillus, Penicillium and Fusarium.

The effect of pH on the growth rates of 61 isolates belonging to 13 important toxigenic fungi are reported here: four species each of Aspergillus and Fusarium, and five of Penicillium, over the pH range 2 to 11 at 25, 30 and 37 degrees C. Nearly all species studied were able to grow over the entire range examined on a laboratory agar medium. However, in general, Aspergillus species were more tolerant of alkaline pH while Penicillium species appeared to be more tolerant of acidic pH.

Influence of Doppler sample volume location on the assessment of changes in mitral inflow velocity profiles.

Previous studies that have validated Doppler indexes of mitral inflow have used pulsed wave sample volume locations either at the level of the mitral valve anulus or at the tips of the mitral valve leaflets. Although significant differences between absolute values for peak velocities and velocity time integrals at these sample volume locations have previously been reported, no information exists that has compared changes in inflow profiles after an intervention to improve left ventricular filling. To address this question, 13 patients with severe pulmonary hypertension (mean pulmonary artery pressure, 50 +/- 13 mm Hg) caused by chronic thromboembolic disease were studied with use of Doppler echocardiography immediately before and after surgical reduction of pulmonary hypertension (pulmonary vascular resistance decreased from 916 +/- 413 to 233 +/- 89 dynes.sec.cm5). This clinical model has been shown to have abnormal mitral inflow velocity profiles that improve markedly after surgery. Doppler measures of early and late peak velocities were significantly lower both before and after surgery when sampling at the mitral anulus compared with the leaflet tips, although late filling parameters and the deceleration of early flow velocity tended to differ little. With surgery, the significant increase in peak early velocity and the ratio of early to late velocity was present regardless of the sample volume location (peak E at leaflet tips, 47.1 +/- 16.0 to 68.9 +/- 15.4 [p less than 0.001], and at anulus, 40.7 +/- 11.3 to 56.2 +/- 14.6 cm/sec [p less than 0.001]; peak E/A at leaflet tips, 0.95 +/- 0.4 to 1.55 +/- 0.9, and at anulus, 0.78 +/- 0.3 to 1.32 +/- 0.7 [both p less than 0.02]).(ABSTRACT TRUNCATED AT 250 WORDS)

Water relations of Paecilomyces variotii, Eurotium amstelodami, Aspergillus candidus and Aspergillus sydowii, xerophilic fungi isolated from Indonesian dried fish.

The water relations of four xerotolerant fungi, Paecilomyces variotii, Eurotium amstelodami, Aspergillus candidus and Aspergillus sydowii, isolated from dried salt fish, were examined at 25 degrees C, on media in which water activity (aW) was controlled by NaCl or a glucose/fructose mixture. All fungi were less tolerant of NaCl than glucose/fructose at low aW. P. variotii grew 2 to 3 times faster on glucose/fructose media than on NaCl. The minimum aW permitting germination varied from 0.753 for E. amstelodami and, 0.776 for A. candidus and A. sydowii to 0.793 for P. variotii. At low aW germination was not always followed by growth. In most cases the minimum for growth was 0.02 aW units above that for germination.

Double blind trial of bezafibrate in familial hypercholesterolaemia.

A six month, double blind, crossover controlled trial of bezafibrate was conducted in 14 children with familial hypercholesterolaemia all of whom had a strong family history of early coronary heart disease. The bezafibrate was given twice daily in a dose of 10 to 20 mg/kg/day. The mean plasma total cholesterol concentration on bezafibrate was 22% lower than during the period on placebo and there was a moderate rise in high density lipoprotein cholesterol. Bezafibrate may be a useful adjunct to treatment in these children.

Preorgasmic group treatment: assertiveness, marital adjustment and sexual function in women.

Five measures were used in this study to assess preorgasmic group treatment: Gambill-Richey Assertiveness Scale, Dyadic Adjustment Scale, Sexual Arousal Inventory, Survey of Sexual Activity, and General Information Questionnaire. The total sample (N = 70) was made up of two groups: a control group of 32 women and a treatment group of 38 women who had completed preorgasmic group treatment. Analysis of the data showed that the treatment group women were having orgasms more frequently, had developed significantly more positive feelings about themselves, and established better communication with their partners. In assertiveness, the treatment group was somewhat higher, while no significant differences were found on the Dyadic Adjustment Scale. Of most significance for future research was the finding of increased sexual arousal for treatment group women.