Date Palm DNA Mini-Preparation without Liquid Nitrogen

We have developed a new mini-procedure for isolation of total cellular DNA from date palm (Phoenix dactylifera L.). The procedure, which does not use liquid nitrogen, has proved useful due to temporary disruptions in supplies of liquid nitrogen that occur in countries where date palm trees are cultivated. DNA suitable for RFLP and PCR analyses is obtained.     

Determination of stereochemistry in the fatty acid hydroperoxide products of lipoxygenase catalysis

High-performance liquid chromatography has been found to be an effective method for the determination of absolute configuration in the products of the lipoxygenase-catalyzed oxygenation of polyunsaturated fatty acids. Methyl esters of fatty acid hydroperoxides that had been reduced to the corresponding alcohols were converted into (+)-alpha-methoxy-alpha-trifluoromethylphenylacetic acid esters. Enantiomeric alcohols were converted into diastereomeric esters that were readily resolved by normal-phase HPLC. The instrumental requirements for the technique are an isocratic HPLC and a uv absorbance monitor. The method was found to be effective in the determination of stereochemistry in the products derived from the action of plant lipoxygenases on linoleic acid. In addition, the chromatography of the derivatives obtained from lipoxygenase catalysis on arachidonic acid was found to be effective for the assignment of stereochemistry in those products. A comparison of the chromatography of these derivatives with that for the corresponding menthyloxycarbonyl derivatives demonstrated the superiority of this approach for the resolution of the diastereomeric pairs. The technique was applied to the determination of stereochemistry in the products derived from soybean lipoxygenase isoenzymes under a variety of experimental conditions.     

cAMP-dependent protein phosphorylation of membrane proteins in the parotid gland, platelets and liver. Comparison of a 22-kDa phosphoprotein from rat parotid microsomes (protein III) with phosphoproteins of similar molecular size from platelet and liver membranes

Stimulation of secretion in exocrine secretory glands leads to the phosphorylation of a 22-kDa membrane protein (protein III) whose function is still unknown [Jahn et al. (1980) Eur. J. Biochem. 112, 345-352; Jahn & S?ling (1980) Proc. Natl Acad. Sci. USA 78, 6903-6906]. This report describes the comparison of this protein with phosphorylated membrane proteins of similar molecular mass in platelets and liver. Incubation of platelets with agents which raise the intracellular cAMP concentration results in the phosphorylation of a 22-kDa protein which is also phosphorylated in membrane preparations by endogenous kinases or by exogenous cAMP-dependent protein kinase. It is shown that this protein is distinct from protein III although both proteins have the same molecular mass and are substrates of cAMP-dependent protein kinase. In contrast to platelets, protein III could be demonstrated in liver microsomes. This indicates that the function of protein III is not exclusively linked to the stimulus-secretion coupling in exocrine cells.     

A comparative study of chromatin from lymphocyte nuclei upon activation of transcription by irradiation from an He-Ne-laser or phytohemagglutinin]

The influence of He-Ne laser radiation (632.8 nm, 56 J/m2, t = 10 s) and phytohaemagglutinin (PHA, 2 micrograms/ml) on chromatin structure in human lymphocytes was studied by electron microscopy using ultrathin cell sections. Morphometric analysis of extranuclear condensed chromatin masses was performed 1 h after the irradiation or after the beginning of PHA treatment. In the irradiated cells the following insignificant changes were revealed: decrease in the relative area of the nucleoplasmic chromatin, increase in the relative area of decondensation zones as well as increase in the number of clumps of nucleoplasmic chromatin and relative length at their boundary with nucleoplasma. The tendency of these morphological changes may be interpreted as functional activation of extranucleolar RNA synthesis in response to irradiation by red laser light. Action of PHA results in significant changes of the surfaces of chromatin clumps, namely increase in relative length of nucleoplasmic chromatin boundary and decrease in relative length of perimembranous chromatin boundary with nucleoplasma as well as some less expressed delamination of the chromatin masses from the nuclear membrane. These essential changes may reflect chromatin activation by proliferative stimulus. Peculiarities of the ultrastructural reorganisation in the condensed chromatin after irradiation and PHA-treatment probably reflect the differences in the processes of gene activation caused by the two agents.     

Dissociating Two Stages of Preparation in the Stop Signal Task Using fMRI

Often we must balance being prepared to act quickly with being prepared to suddenly stop. The stop signal task (SST) is widely used to study inhibitory control, and provides a measure of the speed of the stop process that is robust to changes in subjects’ response strategy. Previous studies have shown that preparation affects inhibition. We used fMRI to separate activity that occurs after a brief (500 ms) warning stimulus (warning-phase) from activity that occurs during responses that follow (response-phase). Both of these phases could contribute to the preparedness to stop because they both precede stop signals. Warning stimuli activated posterior networks that signal the need for top-down control, whereas response phases engaged prefrontal and subcortical networks that implement top-down control. Regression analyses revealed that both of these phases affect inhibitory control in different ways. Warning-phase activity in the cerebellum and posterior cingulate predicted stop latency and accuracy, respectively. By contrast, response-phase activity in fronto-temporal areas and left striatum predicted go speed and stop accuracy, in pre-supplementary motor area affected stop accuracy, and in right striatum predicted stop latency and accuracy. The ability to separate hidden contributions to inhibitory control during warning-phases from those during response-phases can aid in the study of models of preparation and inhibitory control, and of disorders marked by poor top-down control.     

Tauchbeobachtungen an Plankton und an Echostreuschichten

Zusammenfassung 1. Das Tauchen als Methode zur Untersuchung von Plankton und Echostreuschichten wird durch vier Beispiele erläutert: (a) Visuelle Beobachtungen an Wasserschichtungen und Grenzschichten durch Schwimmtaucher. (b) Untersuchung von Echostreuschichten durch Freitaucher, wobei sich ergab, daß angesammeltes biogenes Material in den untersuchten Sprung- beziehungsweise Streuschichten die Schallreflektion nicht beeinflußt. (c) Beobachtung von Großplankton und Feststellung von Planktonund Sestonkonzentrationen beim Tauchen mit dem Bathyscaph. (d) Untersuchung der Tiefenstreuschicht (deep scattering layer) durch Beobachtung der Vertikalwanderung bestimmter Arten des Großplanktons mit den Tauchbooten Bathyscaph und Soucoupe Plongeante. Physonectide Siphonophoren und Myctophiden standen in deutlicher Beziehung zur Tiefenstreuschicht und wurden als Echogeber erkannt.2. Die Möglichkeiten, von Tauchbooten aus quantitative und qualitative Proben von Plankton und auch vom Benthos zu nehmen, sind zur Zeit noch unzureichend. Die Entwicklung entsprechender Geräte für den wahlweisen und mehrfachen Einsatz bei demselben Tauchgang wird empfohlen.

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Diving observations on plankton and on scattering layers

Diving techniques are employed as a research tool in plankton investigations carried out in shallow water of the western Baltic Sea. Observations and samplings were made by skin divers on scattering layers corresponding to the discontinuity layers. Biogene materials, sometimes concentrated at the thermocline, are not responsible for this special kind of scattering, but rather discontinuity of salinity and temperature (Lenz 1965). For observations in deep water the use of undersea vehicles is recommended. From the Bathyscaph and the diving saucer, single plankton organisms and plankton concentrations were observed (e. g.Bernard 1958); investigations on the deep scattering layer have shown physonectid siphonophores and myctophids to be scatterers (Barham 1966). The equipment for sampling plankton and benthos from undersea vehicles is poorly developed. We need urgently gear for quantitative and qualitative sampling and for manifold use during single dives, i. e., multiple sampling gear and magazins for storage of samples.

     

Blastomycosis in wild wolves

Blastomycosis was fatal to a wild wolf in Minnesota, and serologic evidence of blastomycosis was found in a Wisconsin wolf. No unusual movements were detected in the Minnesota animal from October 1983 through October 1985. However, by early December 1985, this wolf was weak and debilitated, and it perished on 14 December after approaching a human residence.     

Chrysonila sitophila (TFB-27441): A hyperlignolytic strain

Summary C. sitophila strain TFB-27441 showed 2–3 times higher lignolytic activity thanPhanerochaete chrysosporium (BKM-F-1767 strain). Lignin had a marked effect on the ligninase activity indicating that some induction or activation mechanism is involved in lignin degradation byC. sitophila.