Kinetic PCR analysis: real-time monitoring of DNA amplification reactions

We describe a simple, quantitative assay for any amplifiable DNA sequence that uses a video camera to monitor multiple polymerase chain reactions (PCRs) simultaneously over the course of thermocycling. The video camera detects the accumulation of double-stranded DNA (dsDNA) in each PCR using the increase in the fluorescence of ethidium bromide (EtBr) that results from its binding duplex DNA. The kinetics of fluorescence accumulation during thermocycling are directly related to the starting number of DNA copies. The fewer cycles necessary to produce a detectable fluorescence, the greater the number of target sequences. Results obtained with this approach indicate that a kinetic approach to PCR analysis can quantitate DNA sensitively, selectively and over a large dynamic range. This approach also provides a means of determining the effect of different reaction conditions on the efficacy of the amplification and so can provide insight into fundamental PCR processes.     

Recognizing, assessing, and intervening with problems of professional competence.

Working collaboratively, psychologist educators and trainers at the doctoral, internship, and postdoctoral levels; credentialers; practitioners; and students offer 8 proposals for psychologists to consider in recognizing, assessing, and intervening with problems of professional competence in students and practicing professionals. In the proposals, the authors address the following topics: definitions and categories; preparing the system; self-assessment; remediation; diversity; communication across various levels of the system; confidentiality; and ethical, regulatory, and legal underpinnings. They also propose future directions for the assessment of problems in professional competence in both students and practicing psychologists. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The live cell irradiation and observation setup at SNAKE

We describe a new setup at the ion microprobe SNAKE (Superconducting Nanoscope for Applied nuclear (Kern-) physics Experiments) at the Munich 14 MV Tandem accelerator that facilitates both living cell irradiation with sub micrometer resolution and online optical imaging of the cells before and after irradiation by state of the art phase contrast and fluorescence microscopy. The cells are kept at standard cell growth conditions at 37 °C in cell culture medium. After irradiation it is possible to switch from single ion irradiation conditions to cell observation within 0.5 s. First experiments were performed targeting substructures of a cell nucleus that were tagged by TexasRed labeled nucleotides incorporated in the cellular DNA by 55 MeV single carbon ion irradiation. In addition we show first online sequences of short time kinetics of Mdc1 protein accumulation in the vicinity of double strand breaks after carbon ion irradiation.     

Hydrogen microscopy – Distribution of hydrogen in buckled niobium hydrogen thin films

Hydrogen absorption in thin metal films clamped to rigid substrates results in mechanical stress that changes the hydrogen's chemical potential by Δμ_H(σ) = −1.124σ kJ/mol_H for σ measured in [GPa]. In this paper we show that local stress relaxation by the detachment of niobium hydrogen thin films from the substrate affects the chemical potential on the local scale: using coincident proton–proton scattering at a proton microprobe, the hydrogen concentration is determined with μm resolution, revealing that hydrogen is not homogenously distributed in the film. The local hydrogen solubility of the film changes with its local stress state, mapping the buckled film fraction. In niobium hydrogen thin films loaded up to nominal concentrations in the two-phase coexistence region, the clamped film fraction remains in the solid solution phase, while the buckles represent the hydride phase. These results are compared to a simple model taking the stress impact on the chemical potential into account.     

Beitrag zur Kenntnis der Magen-Darm-Parasitenfauna des Rehwildes der Nordostschweiz

Zusammenfassung In den Verdauungsapparaten von 64 Rehen aus den schweizerischen Kantonen Aargau, St. Gallen, Thurgau und Zürich wurden 23 verschiedene Nematoden- und eine Cestodenart festgestellt. Im Labmagen waren dies:Trichostrongylus axei, T. capricola, Ostertagia circumcincta, O. leptospicularis, O. ostertagi, Skrjabinagia kolchida, S. lyrata, Rinadia mathevossiani, Spiculopteragia böhmi undHaemonchus contortus; im Dünndarm:Moniezia expansa, Strongyloides papillosus, Capillaria bovis, Bunostomum trigonocephalum, Trichostrongylus capricola, T. colubriformis, T. longispicularis, Cooperia oncophora, C. punctata, Nematodirus filicollis, N. spathiger, Skrjabinema ovis, im Dickdarm:Trichuris sp. (soweit bestimmt:T. capreoli), Oesophagostomum venulosum, Chabertia ovina.Befallsfrequenz und Befallsintensität der einzelnen Parasitenarten werden dargestellt. Im Anschluß wird die epizootologische Rolle des Rehwildes für Parasitosen landwirtschaftlicher Nutztiere diskutiert, wobei auf Grund der Unterschiede im Parasitenspektrum und der sich nur teilweise deckenden Biotope angenommen wird, daß die Bedeutung des Rehwildes für gastrointestinale Helminthosen der Hauswiederkäuer in der Regel gering ist.Für die Beschaffung des Materials danke ich den Angehörigen der Arbeitsgruppe für Wildforschung der Universität Zürich, insbesondere Herrn Dr.A. Krämer sowie den Mitgliedern der Jagdgesellschaften Littenheid, Bazenheid, Grabs und Staffelbach, für die technische Assistenz den Laborantinnen unseres Institutes, Frau Ch.Böni, Frl.S. Bleuler, FrauR. Magnin und FrauF. Schiess.

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Summary The digestive tracts of 64 roe deer from the Swiss cantons Aargau, St. Gallen, Thurgau and Zurich were examined, and 23 different kinds of nematodes and one cestode were found.The varieties found in the Abomasus were:Tricostrongylus axei, T. capricola, Ostertagia circumcincta, O. leptospicularis, O. ostertagi, Skrjabinagia kolchida, S. lyrata, Rinadia mathevossiani, Spiculopteragia böhmi andHaemonchus contortus; in the small intestine:Moniezia expansa, Strongyloides papillosus, Capillaria bovis, Bunostomum trigonocephalum, Trichostrongylus capricola, T. colubriformis, T. longispicularis, Cooperia oncophora, C. punctata, Nematodirus filicollis, N. spathiger, Skrjabinema ovis; and in the large intestine:Trichuris sp. (T. capreoli), Oesophagostomum venulosum, Chabertia ovina.The frequency and intensity of parasitic infection are presented. Finally, the epizootic role of roe deer with respect to parasitism of domestic animals is discussed. It is hereby assumed that the significance of roe deer for the gastrointestinal helminths of domesticated ruminants is usually small. This is because of the difference in the parasitic spectrum and a only partially overlapping biotop.

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Résumé Dans l'appareil digestif de 64 chevreuils issus des cantons Suisses de l'Argovie, Saint Gall, Thurgovie et Zurich la présence de 23 espèces de Nématodes et Cestodes a été constatée. En ce qui concerne la caillette, il s'agissait des espèces suivantes:Trichostrongylus axei, T. capricola, Ostertagia circumcincta, O. leptospicularis, O. ostertagi, Skrjabinagia kolchida, S. lyrata, Rinadia mathevossiani, Spiculopteragia böhmi etHaemonchus contortus.Das l'intestin grêle on a trouvé:Moniezia expansa, Strongyloides papillosus, Capillaria bovis, Bunostomum trigonocephalum, Trichostrongylus capricola, T. colubriformis, T. longispicularis, Cooperia oncophora, C. punctata, Nematodirus filicollis, N. spathiger, Skrjabinema ovis.Enfin dans le gros intestin, il s'agissait de:Trichuris sp. (dans la majorité des casT. capreoli), Oesophagostomum venulosum, Chabertia ovina.La fréquence et l'intensité de l'infection parasitaire est donnée. On fait ensuite état du rôle épizootique du Chevreuil sur les parasitoses des espèces domestiques: compte tenu de la différence du spectre parasitaire et du recouvrement très partiel des biotopes, il semble que la signification du Chevreuil pour les helminthoses gastrointestinales des animaux domestiques soit, en règle générale, assez faible.

     

A 2-methyleneoxetane analog of orlistat demonstrating inhibition of porcine pancreatic lipase

The 2-methyleneoxetane analog 2 of orlistat (OLS, 1) has been synthesized and tested against porcine pancreatic lipase (PPL). Despite the loss of the carbonyl group, a potential site for hydrogen bonding interaction with the enzyme and the key element in the acylation by OLS, 2 has activity comparable to 1.     

Classical light scattering quantitation of protein aggregates: off-line spectroscopy versus HPLC detection

This paper describes the development and validation of a new off-line approach to quantitate both covalent and noncovalent, in-solution aggregates present in protein formulations and compares the new assay to established HPLC methods. This off-line analysis is well suited for use in QC release testing, formulation development and stability indicating applications. An inexpensive, continuous source HPLC fluorometer has been adapted with the addition of second order filters for use as a sensitive right-angle scatterometer which can determine the molecular weight of protein aggregates in solution. When used as an HPLC detector, right-angle light scattering is a sensitive method which can determine the molecular weight of peaks separable by HPLC, thus discriminating between monomers of different conformations and aggregates. The weight-averaged molecular weight of aggregate peaks can be calculated with system calibration, yielding the average number of monomers per aggregate. If the protein concentration is high enough for an adequate signal, the off-line technique of right-angle light scattering of protein formulations has advantages of convenience and speed over the HPLC approach. Samples are placed in standard fluorometer cuvettes and toluene is used as a calibrator. Data are presented which show the off-line (static) method to be extremely rapid, rugged and precise. The accuracy of this approach is demonstrated through cross-validation to traditional GPC analysis of protein aggregate distributions. This non-invasive light scattering approach is particularly useful when non-covalent protein aggregation is reversible and readily altered by chromatographic separations typically used for characterizing aggregates.     

Scanning electron microscopy of injection replicas of the chick embryo circulatory sytem

The injection replication procedure has been modified for study of the thin and very delicate blood vessels of young embryos. Batson's corrosion compound (a polyester resin) modified for rapid polymerization (20:3.0:0.25, monomer: catalyst: promoter) was effective in replicating even very small blood vessels without excessive distension. Since injection of plastic induced violent heart spasms with eventual expulsion of plastic from the ventricular lumen, contractility of the heart was inhibited by injection of a 2% (w/v) aqueous solution of KNO₃ prior to injection with polyester resin. Following polymerization of the injected resin, the tissues were macerated and removed, leaving a solid three-dimensional cast of the lumen of the circulatory system. The casts were photographed with the scanning electron microscope to produce accurate micrographs for study of the developmental anatomy of the circulatory system.     

Nipple attachment in rats during the first 24 hours of life.

Investigated nipple attachment in 49 Purdue-Wistar laboratory rat pups during the 1st 24 hrs of life and identified determinants that influenced its expression. In Exp I, nipple attachment was shown to be age dependent: 1-hr-old pups exhibited a low percentage of attachment, and 12- and 24-hr-old pups exhibited high percentages when tested against an anesthetized lactator. Exps II–VI established the time course of nipple attachment as age related. Exps VII–X explored the behavioral mechanism responsible for the increase in attachment from Hr 1 to Hr 12. They showed that nipple experience, independent of milk acquisition, was the responsible factor for the increase. The findings suggest that learning is employed as a behavioral strategy by the newborn, and they reemphasize the value of using species-relevant measures in the assessment of behavioral development. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A case report of dissociative neurosis (depersonalization disorder) in an adolescent treated with family therapy and behavior modification.

Describes the use of behavioral procedures within the context of systems-oriented family therapy in the treatment of a 15-yr-old girl's functional blackouts. Despite fairly clear psychosexual issues, treatment successfully eliminated blackouts without directly addressing such issues. The matter is discussed with reference to conceptualizing etiology and treatment. Working with the adolescent's family is advocated, the importance of client attributions for therapeutic gain is noted, and issues of validity and generalizability are discussed. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)