The Spirodela polyrhiza genome reveals insights into its neotenous reduction fast growth and aquatic lifestyle.

The subfamily of the Lemnoideae belongs to a different order than other monocotyledonous species that have been sequenced and comprises aquatic plants that grow rapidly on the water surface. Here we select Spirodela polyrhiza for whole-genome sequencing. We show that Spirodela has a genome with no signs of recent retrotranspositions but signatures of two ancient whole-genome duplications, possibly 95 million years ago (mya), older than those in Arabidopsis and rice. Its genome has only 19,623 predicted protein-coding genes, which is 28% less than the dicotyledonous Arabidopsis thaliana and 50% less than monocotyledonous rice. We propose that at least in part, the neotenous reduction of these aquatic plants is based on readjusted copy numbers of promoters and repressors of the juvenile-to-adult transition. The Spirodela genome, along with its unique biology and physiology, will stimulate new insights into environmental adaptation, ecology, evolution and plant development, and will be instrumental for future bioenergy applications.

Digital microscopy for multiparameter FISH imaging.

Fluorescence in situ hybridization (FISH) allows the direct localization of DANN and RNA sequences on chromosomes, in cells and in tissue. The technique is based on hybridization between target sequences of single-strand DNA of chromosomes or cell nuclei with marked complementary specimens. The signal is amplified using fluorochrome-marked specific antibodies and made visible under a microscope. Signals from painted chromosomes, stained subchromosomal regions or localized single probes are generally visible when an epifluorescence microsope is used. In order to view and display different fluorochromes, single filter sets, as well as double and triple bandpass filters, are in use. For multiple fluoroscence imaging, lenses with high numerical aperture, mostly oil immersion systems, are recommended. In conventional photomicrography, triple exposure on high-speed film (e.g., 400-1,000 ASA) is more or less the limitation. Opto=electronic methods using a CCD and laser summing techniques have considerably extended the application range of multiple fluorescence techniques. By means of digitized images, simultaneous detection of multiple-labelled objects and ratio imaging up to 24 colors are possible today. Current FISH approaches are based on chromosome-painting probes to distinguish all 24 chromosomes by their unique spectral signatures.

Summary statement on quantitative cytochemistry (DNA and molecular biology): Task Force 8.

OBJECTIVE: To reach consensus on the application of quantitative cytochemical analysis of chromosomal and DNA aneuploidy in cervical cytopathology. CONCLUSION: The current Pap test has limited specificity to predict cancer and its truly progressive pre-malignant lesions. Infection with human papillomavirus may trigger genetic instability, hyperproliferation and immortalization of the cervical mucosa and cause cervical cancer. Several related molecular markers have been shown to be informative about this neoplastic process. Quantitative analysis of chromosomal and DNA aneuploidy has been shown to be an important tool for identifying (progression to) high grade squamous intraepithelial lesions. A high degree of standardization (material handling, calibration and quality control, measurement and interpretation of results) is required for accurate and reproducible measurements. Areas for further study are presented.

Induction of 12-oxo-phytodienoic acid in wounded plants and elicited plant cell cultures.

Jasmonic acid (JA) is rapidly biosynthesized from alpha-linolenic acid in plants upon contact with pathogens or wounding, and triggers gene activation, leading to the synthesis of defensive secondary metabolites and proteins. Despite the recent finding that its precursor, 12-oxo-phytodienoic acid (PDA), is a more powerful inducer of gene activation, interest has focused so far almost exclusively on JA. A validated negative chemical ionization-gas chromatography-mass spectrometry method has been developed that allows the simultaneous quantification of endogenous 12-oxo-PDA and JA in plant tissues. In six out of eight plant species tested maximal levels of 12-oxo-PDA exceeded peak levels of JA by approximately 3- to 5-fold after elicitation with a yeast cell wall preparation or when plants were wounded. These experiments support the hypothesis that 12-oxo-PDA acts as the predominant jasmonate signal in most plants, whereas JA remains an active metabolite of its precursor. Furthermore, JA but not 12-oxo-PDA was shown to be secreted into the medium from cultured plant cells, suggesting that JA may also act as an intercellular signal.

[Not Available]. / Faktor Mensch im Krieg. Der Eintritt der Psychologie und Psychotechnik in den Krieg.

In the First World War representatives of the university discipline of psychology took the opportunity to apply their expertise in the armed forces. The initial undertakings in the German Empire and in the USA show some similarities and marked disparities. A comparison of events and circumstances in these principal belligerent states is linked with a sketch of their importance for the further development of psychology as an academic specialty and an emerging profession.

Jasmonic acid is a signal transducer in elicitor-induced plant cell cultures.

To deter pathogenic microorganisms and herbivores, plants have developed an inducible chemical defense system. It is known that the induced synthesis of low molecular weight compounds can be provoked by exposing cultured cells to fungal cell wall fragments. In this study we show that endogenous jasmonic acid and its methyl ester accumulate rapidly and transiently after treatment of plant cell suspension cultures of Rauvolfia canescens and Eschscholtzia californica with a yeast elicitor. Thirty-six plant species tested in cell suspension culture could be elicited with respect to the accumulation of secondary metabolites by exogenously supplied methyl jasmonate. Addition of methyl jasmonate initiates de novo transcription of genes, such as phenylalanine ammonia lyase, that are known to be involved in the chemical defense mechanisms of plants. These data demonstrate the integral role of jasmonic acid and its derivatives in the intracellular signal cascade that begins with interaction of an elicitor molecule with the plant cell surface and results, ultimately, in the accumulation of secondary compounds.

Working with the confocal scanning UV-laser microscope: specific DNA localization at high sensitivity and multiple-parameter fluorescence.

The use of fast-staining DNA-specific dyes such as DAPI or Hoechst 33342/33258 has been a major problem for confocal scanning laser microscopy (CSLM) studies of intranuclear chromatin organization. Moreover, the availability of a confocal ultraviolet scanning laser microscope configuration, which allows an excitation at wavelengths of 364 nm as well as 488, 514 and 543 nm, is a prerequisite for single as well as multiple fluorescence parameter studies, especially if these studies are concerned with the precise localization of intranuclear signals. Here we report the characteristics and application of a CSLM, which was adapted for UV-excitation and therefore enables comparison of the spatial distribution of several types of signals within one preparation. In addition to multiple-parameter studies, we have also investigated the sensitivity of the system with regard to the identification of the double-stranded DNA of lampbrush chromosome loops in germinal vesicles of amphibian oocytes.

Elicitation of benzophenanthridine alkaloid synthesis in Eschscholtzia cell cultures.

Quaternary benzophenanthridine alkaloids (sanguinarine, chelerythrine, chelirubine, chelilutine and macarpine) are specifically induced by cell wall components of Penicillium and Saccharomyces in a colorless strain of Eschscholtzia californica cell suspension cultures. Classical elicitors such as the Phytophthora megasperma elicitor are inactive. The alkaloid synthesis is, however, strongly induced by certain polypeptide antibiotics. Out of 190 tested plant species the yeast elicitor provoked benzophenanthridine synthesis in 13 cultures. One of the branch point enzymes, namely the berberine bridge enzyme, catalysing the formation of (S)-scoulerine from (S)-reticuline, is strongly stimulated during the elicitation process. These results clearly demonstrate the induction of the benzophenanthridine biosynthetic pathway by microbial elicitors.

Late enzymes of vindoline biosynthesis. Acetyl-CoA: 17-O-deacetylvindoline 17-O-acetyl-transferase.

From differentiated plants of Catharanthus roseus (L.) G. Don, a specific enzyme was isolated and named acetyl-CoA : 17-O-deacetylvindoline 17-O-acetyltransferase, acting on the biosynthetic formation of the Aspidosperma type alkaloid vindoline.The enzyme shows a high selectivity towards different substrates. The acetyl-CoA-dependent transferase also catalyses the reverse reaction by hydrolysis of the 17-O-acetyl group of vindoline in the presence of free CoA. This enzyme is localized only in vindoline-containing plant parts, but was so far not detectable in cell suspension cultures of C. roseus. The enzyme allows the synthesis of labelled vindoline with high specific activity, applicable for instance as tracer for radioimmunoassays of vindoline.

Direct evaluation of fluorescence in single renal epithelial cells using a mitochondrial probe (DASPMI).

The study of distribution and quantitation of a fluorescent probe in living epithelia with the aid of an inverted microscope requires that individual cells can be analysed without optical interference from adjacent cells. This report describes the application of fluorescence microscopy and fluorometry to a recently developed in vitro culture system of renal epithelial cells. Epithelial cells derived from the mammalian renal cortical collecting tubule (CT) and the thick ascending loop of Henle (TAL) are cultivated as continuous monolayers in serum-free, hormone-supplemented media. A specific mitochondrial marker (DASPMI) is added to the medium and incorporated into the cytoplasm. The microscopic image reveals that the mitochondrial fluorescence distribution differs between CT and TAL cultures. The fluorometric quantitation shows a normally distributed histogram of medium-range intensity in TAL cell cultures while CT cultures exhibit a two-peak pattern of mitochondrial fluorescence distribution among epithelial cells.

[Bacterial elimination and antibiotic concentration in the gall-bladder during biliary tract infections treated with mezlocillin (author's transl)]. / Keimelimination und Konzentrationsbestimmungen unter Mezlocillin in der Galle bei Gallenwegsinfektionen.

A transpapillary indwelling catheter was placed in 15 patients with choledocholithiasis and threatened occlusion by stone. Ten of the 15 patients had marked biliary stasis, four had signs of acute cholangitis. In all patients E. coli was present in the gall-bladder in a concentration of greater than or equal to 10(5)/ml when the catheter was first inserted. The bacteria were sensitive to mezlocillin, at a minimal inhibitor concentration between 1.5 and 16 micrograms/ml. All patients received mezlocillin, 5 g twice daily, in a short-term infusion. Immediately before and regularly thereafter bile samples were taken to measure antibiotic concentration and bacterial counts (by membrane filtration). Mezlocillin was excreted in the bile in very high concentrations in patients without biliary stasis. But while the concentrations were markedly lower in those with stasis, they were still 10 to 100 times the minimum inhibitory concentration of mezlocillin against the appropriate strains. In keeping with the high mezlocillin concentration, bacterial counts fell much more quickly in the patients without stasis than in those with alkaline phosphatase concentration above 250 U/l. These differences were even more marked after two or three days. Bacterial elimination from bile was complete in two of three patients with normal alkaline phosphatase activity, but in only one of five in whom it was elevated.

Application of differential interference contrast with inverted microscopes to the in vitro perfused nephron.

The study of in vitro perfused individual nephron segments requires a microscope which provides: (1) easy access to the specimen for measurement of cellular solute flux and voltage; (2) an image with high resolution and contrast; (3) optical sectioning of the object at different levels; and (4) rapid recording of the morphological phenomena. This paper describes an example of commercially available apparatus meeting the above requirements, and illustrates its efficiency. The microscope is of the inverted type (Zeiss IM 35) equipped with differential-interference-contrast (DIC) with a long working distance, and an automatically controlled camera system. The microscopic image exhibits cellular and intercellular details in the unstained transporting mammalian nephron segments despite their tubular structure and great thickness and makes obvious function-structure correlations (e.g. cell volume changes); luminal and contraluminal cell borders are well resolved for controlled microelectrode impalement.

[Comparative experimental animal studies of the effects of various nuclear pharmaceuticals on the EEG]. / Vergleichende tierexperimentelle Untersuchungen zur Wirkung verschiedener Nuklearpharmaka auf das EEG.

Some of the radiopharmaceuticals presently recommended for cisternoscintigraphy were compared, in experiments on animals, for their effects upon bioelectric activity. On relaxed cats, electroencephalography did not show any effects upon bioelectric activity for 198 Au and 169 Yb Ca DTPA. One test animal each of seven and six cats examined using 169 Yb DTPA and 131 J HSA showed changes in the electroencephalogram subsequent to suboccipital application.