Chloroplast DNA variation and phylogeny of theRanunculaceae

Restriction site mapping of chloroplast DNA from 31 species representing 26 genera of theRanunculaceae was performed using eleven restriction endonucleases. The chloroplast genome varies in length from approximately 152 to 160 kb. Length variants are frequent in theRanunculaceae and range from usually less than 300 bp to rarely 1.5 kb. The inverted repeat is extended into the large single copy (LSC) region by 4–4.5 kb inAnemone, Clematis, Clematopsis, Hepatica, Knowltonia, andPulsatilla. Several inversions are present in the LSC-region of the cpDNA in all these genera and inAdonis. The frequency of restriction site mutations varies within the chloroplast genome in theRanunculaceae between 4 and 32 mutations per kilobase, and is lowest in the inverted repeat and the regions containing the ATPase-genes and the genespsaA, psaB, psbA, rpoB, andrbcL. A total of 547 phylogenetically informative restriction sites was utilized in cladistic analyses of the family using Wagner, Dollo, and weighted parsimony. These three parsimony analyses result in different tree topologies. Four, six, and one equally most parsimonious trees were obtained with Wagner, Dollo, and weighted parsimony, respectively. The amount of support for the monophyletic groups was evaluated using bootstrapping and decay analysis. All three parsimony methods suggest thatHydrastis is the sister group to the remainder of theRanunculaceae, and that theAnemone-Clematis group, which shares several derived cpDNA rearrangements, is monophyletic. Only a few of the traditional groups in theRanunculaceae are supported by cpDNA restriction side data. Only Dollo parsimony provides support for the hypothesis thatThalictroideae andRanunculoideae are monophyletic.     

The moss genes <Emphasis Type="Italic">PpSKI1</Emphasis> and <Emphasis Type="Italic">PpSKI2</Emphasis> encode nuclear SnRK1 interacting proteins with homologues in vascular plants

The yeast Snf1, animal AMPK, and plant SnRK1 protein kinases constitute a family of related proteins that have been proposed to serve as metabolic sensors of the eukaryotic cell. We have previously reported the characterization of two redundant SnRK1 encoding genes (PpSNF1a and PpSNF1b) in the moss Physcomitrella patens. Phenotypic analysis of the snf1a snf1b double knockout mutant suggested that SnRK1 is important for the plant’s ability to recognize and adapt to conditions of limited energy supply, and also suggested a possible role of SnRK1 in the control of plant development. We have now used a yeast two-hybrid system to screen for PpSnf1a interacting proteins. Two new moss genes were found, PpSKI1 and PpSKI2, which encode highly similar proteins with homologues in vascular plants. Fusions of the two encoded proteins to the green fluorescent protein localize to the nucleus. Knockout mutants for either gene have an excess of gametophores under low light conditions, and exhibit reduced gametophore stem lengths. Possible functions of the new proteins and their connection to the SnRK1 kinase are discussed.     

Strategies for High-Performance Resource-Efficient Compression of Neural Spike Recordings

Brain-machine interfaces (BMIs) based on extracellular recordings with microelectrodes provide means of observing the activities of neurons that orchestrate fundamental brain function, and are therefore powerful tools for exploring the function of the brain. Due to physical restrictions and risks for post-surgical complications, wired BMIs are not suitable for long-term studies in freely behaving animals. Wireless BMIs ideally solve these problems, but they call for low-complexity techniques for data compression that ensure maximum utilization of the wireless link and energy resources, as well as minimum heat dissipation in the surrounding tissues. In this paper, we analyze the performances of various system architectures that involve spike detection, spike alignment and spike compression. Performance is analyzed in terms of spike reconstruction and spike sorting performance after wireless transmission of the compressed spike waveforms. Compression is performed with transform coding, using five different compression bases, one of which we pay special attention to. That basis is a fixed basis derived, by singular value decomposition, from a large assembly of experimentally obtained spike waveforms, and therefore represents a generic basis specially suitable for compressing spike waveforms. Our results show that a compression factor of 99.8%, compared to transmitting the raw acquired data, can be achieved using the fixed generic compression basis without compromising performance in spike reconstruction and spike sorting. Besides illustrating the relative performances of various system architectures and compression bases, our findings show that compression of spikes with a fixed generic compression basis derived from spike data provides better performance than compression with downsampling or the Haar basis, given that no optimization procedures are implemented for compression coefficients, and the performance is similar to that obtained when the optimal SVD based basis is used.     

Urothelial neoplasms of the upper urinary tract. A correlation between cytologic and histologic findings in 43 patients with urothelial neoplasms of the renal pelvis or ureter.

The present study elucidates the possibilities to diagnose and classify urothelial tumors of the upper urinary tract by means of exfoliative cytology on voided urine using a membrane filter method. In a series of 30 patients with renal pelvic tumors and 13 patients with ureteral tumors an overall agreement between cytology and histopathology was obtained in 25 cases (58%). None of the Grade 1 tumors or of the non-invasive Grade 2 tumors were regarded as positive by cytology whilst two out of five invasive Grade 2 tumors had positive cytologic reports. The series included 24 patients with poorly differentiated or anaplastic tumors, 17 of whom had positive cytology (71%). By excluding from the series 13 patients with obstructed urinary passages or radiologically non-functioning kidneys on the tumor side an agreement between cytology and pathology was reached in 83 per cent of the cases, regardless of tumor grade, and in 17 out of 18 patients with Grade 3-4 tumors (94%).     

Enhanced production of glycerol in an alcohol dehydrogenase (ADH I) deficient mutant of Saccharomyces cerevisiae

Summary A partial alcohol dehydrogenase, ADH I, deficient mutant, GRF 18-2 of S. cerevisiae has been isolated. The mutant is resistant to allyl alcohol and the spec. activity of ADH I is 15-fold reduced in the mutant. In a batch fermentation the mutant overproduces glycerol. The production is enhanced 6–7 fold compared with the wildtype strain and it amounts to about 40 per cent of the ethanol produced. The yield of ethanol and glycerol is 56 and 24 per cent respectively. Another mutant possibly defect in the gene for ADH II has a reduced capacity to oxidize ethanol.     

Expression of NADH-oxidases enhances ethylene productivity in <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> expressing the bacterial EFE

Ethylene is a major petrochemical for which biotechnological production methods are an attractive alternative. Here we use a system based on a bacterial ethylene forming enzyme (EFE) expressed in Saccharomyces cerevisiae. Metabolic modelling performed in a previous study identified re-oxidation of NADH as a factor limiting ethylene production in S. cerevisiae. In line with this, we here found that strains with multicopy plasmid expression of the heterologous oxidases nox and Aox1 led to significantly increased specific ethylene productivity, up 12 and 36%, respectively, compared to the control strain with empty plasmid. However the productivity and yield was only improved in the AOX expressing strain compared to that of the control strain. Both oxidase expressing strains also exhibited increased respiration rates compared to the reference strain, with specific oxygen consumption rates being roughly doubled in both strains. The AOX strain furthermore exhibited a significant increase in the EFE substrate 2-oxoglutarate formation compared to the reference strain, linking an improvement in ethylene production to both increased respiratory capacity and increased substrate availability, thereby corroborating our previous finding.     

The effect of dehydroepiandrosterone sulfate and allopregnanolone sulfate on the binding of [(3)H]ifenprodil to the N-methyl-d-aspartate receptor in rat frontal cortex membrane

Neurosteroids have been shown to modulate the N-methyl-d-aspartate (NMDA) receptor function. Dehydroepiandrosterone sulfate (DHEAS) is shown to participate in memory and learning processes as well as preventing glutamate neurotoxicity in hippocampus. In this study we have focused on the modulatory effect of neurosteroids on ifenprodil binding to the NR2B subunit of the NMDA receptor. We show that DHEAS and allopregnanolone sulfate (ALLOPREGS) exert different effects on the [(3)H]ifenprodil binding at 10, 30 or 100 nM, corresponding to physiological concentrations. The effects include changes in the ifenprodil displacement curve, changing it from a one-site fit into a two-site fit leaving B(max), K(d) and K(off) unaffected. Our results indicate that DHEAS and ALLOPREGS induce an allosteric modulation of the NMDA receptor, an observation that might contribute to the understanding of the effects of these neurosteroids.     

The return of the pharmaceutical industry to the market of contraception

In the 1980s and 1990s, the litigious climate in the US had a catastrophic effect on sales of many major contraceptives. Although oral contraceptives escaped controversy, the intrauterine device (IUD) and Norplant(R) were two targets of damaging litigation. The IUD was withdrawn from the market in 1985. Since 1994 when the attacks began against Norplant, its US sales have dramatically declined, even though no fault has been found in the method or its development. In general, pharmaceutical companies were extremely hesitant to develop new contraceptives during this period. The bleak outlook, however, began to shift in the late 1990s, as fertility rates began to decrease worldwide and contraceptive users increased. By 2025, 2500 million women will comprise the customer base for contraception. Global pharmaceutical companies are now participating in expanding markets overseas and have launched and continue to develop a range of new long-term reversible, and highly effective, contraceptive products outside the traditional oral contraceptive field. Two new contraceptives on the way to the US market are: Mirena, a levonorgestrel-releasing intrauterine system manufactured by Schering-Leiras; and Implanon, a single implant system manufactured by Organon of the Netherlands. Other birth control methods soon to be launched include: emergency contraceptives, the contraceptive patch, monthly contraceptive injections, mifepristone for medical abortion, and modified oral contraceptives.