Effect of NSAIDs and Diuretics on Nephrogenesis in an Ex Vivo Embryogenic Kidney Model

The kidney is one of the key organs in clearing foreign compounds. The effects of drugs on the developing kidney are relatively unknown. We studied the direct effect of furosemide, hydrochlorothiazide, ibuprofen, and indomethacin on kidney development in an ex vivo embryonic kidney model. At embryonic day 13, metanephroi were dissected from mice and cultured in control media or media supplemented with various clinically relevant concentrations of drugs. The ureteric tree was visualized by whole‐mount staining and branching was evaluated by counting. Additionally, gene expression levels of Wt1, Sox9, Bmp7, Fgf8, and Gdnf were investigated. No distinct differences were noted on either ureteric tip development or gene expression analysis for each drug after 24 hr of exposure. Even though short‐term exposure to clinically relevant concentrations seems not to disturb renal development, future research is needed to study prolonged or repeated exposures.     

A psychophysiological assessment battery

This research project was the first step in the development of a psychophysiological assessment battery. The battery consisted of eight tasks that have a history of use within the field of psychophysiology. These tasks were examined on a nonpathological, physically healthy sample. This sample was administered the assessment battery three times over the course of 16 weeks. The response systems of HR, SC, RR, TPA, and FPA were examined. Two major research questions were then examined. The first question was whether a subject would display a stable physiological profile on the assessment battery across the three administrations. The second question was whether there would be individual differences in physiological profiles on the assessment battery. These differences were examined in terms of individual response stereotypy (IRS) and stimulus response specificity (SRS). Depending on the task, from 30 to 100% of the subjects displayed stable physiological profiles across administrations. Twenty-five subjects displayed a high degree of SRS. Five subjects displayed a high degree of IRS.     

Protection of Ischaemic Synaptosomes from Calcium Overload by Addition of Exogenous Lactate

In depolarised anoxic synaptosomes, in which lactate production was significantly raised compared with normoxic conditions, calcium uptake, net acetylcholine release, and the intrasynaptosomal calcium concentration were all significantly lowered. In contrast, lactate production in synaptosomes incubated under aglycaemic- and ischaemic-type conditions was significantly lower and basal calcium uptake, acetylcholine release, and intrasynaptosomal calcium concentration were elevated compared with normoxia. In addition, the increase in intrasynaptosomal calcium concentration under the ischaemic-type condition appeared to be greater than could be accounted for by the rise in calcium uptake alone. Intrasynaptosomal pH reflected the lactate production under each condition investigated. Addition of exogenous lactate to normoxic synaptosomes mimicked the effects observed in anoxia, suggesting that lactate itself may have blocked the calcium uptake, inhibiting the rise in intrasynaptosomal calcium and acetylcholine release occurring in depolarised anoxic synaptosomes. When lactate was added to ischaemic synaptosomes, the large rise in intrasynaptosomal calcium concentration, calcium uptake, and acetylcholine release were decreased, suggesting that lactate may have a protective role in preventing cell death by calcium overload under ischaemic-type conditions. Evidence is presented to suggest that the effect of L-lactate was due to the lactate moiety itself rather than the associated acidosis.     

Immunofluorescence studies of neurofilaments in the rat and human peripheral and central nervous system

Localization of antisera to neurofilament antigens derived from rat peripheral nerve was carried out in tissues of rat and human peripheral and central nervous systems by indirect immunofluorescence. Unfixed and chloroform-methanol-fixed frozen sections of tissues were incubated in purified IgG of the experimental rabbit antisera and subsequently exposed to goat anti-rabbit IgG conjugated with fluorescein isothiocyanate. Control studies were conducted on identical tissue preparations incubated in the same concentrations of nonspecific rabbit IgG or in experimental rabbit IgG absorbed with extracts of rat peripheral nerve containing neurofilament antigen. Extensive immunofluorescence was observed in rat and human peripheral and central nervous systems. The distribution and configuration of immunofluorescence corresponded to neurofilament-rich structural components of these tissues. Prominent immunofluorescence was also noted in neuronal cell bodies of spinal sensory ganglia, especially in perikarya of the large neuronal type. Immunofluorescence of the central nervous system was located predominantly in myelinated axons of the white matter in cerebrum, cerebellum, brain stem, and spinal cord. Less intense immunofluorescence was also seen in neuronal perikarya and in short thin linear processes of grey matter.     

Theoretical study of enantiodifferentiation in solid state cyclodextrins

A molecular mechanics investigation of R- vs. S-phenylethanol, R- vs. S-mandelic acid, R- vs. S-flurbiprofen, and R- vs. S-fenoprofen in their cyclodextrin crystal environments was undertaken. It was found that the dominant force responsible for guesthost complexation is the short-range London force; the enantiodiscriminating forces tend to be very small and are generally, but not always, dominated by long-range electrostatic contributions. Derivatized cyclodextrins are generally more enantiodiscriminating than native cyclodextrins, perhaps due to exterior rather than interior guest-host binding. © 1993 Wiley-Liss, Inc.     

Functional and genetic interactions of TOR in the budding yeast Saccharomyces cerevisiae with myosin type II-deficiency (myo1Delta)

ABSTRACT: BACKGROUND: Yeast has numerous mechanisms to survive stress. Deletion of myosin type II (myo1Delta) in Saccharomyces cerevisiae results in a cell that has defective cytokinesis. To survive this genetically induced stress, this budding yeast up regulates the PKC1 cell wall integrity pathway (CWIP). More recently, our work indicated that TOR, another stress signaling pathway, was down regulated in myo1Delta strains. Since negative signaling by TOR is known to regulate PKC1, our objectives in this study were to understand the cross-talk between the TOR and PKC1 signaling pathways and to determine if they share upstream regulators for mounting the stress response in myo1Delta strains RESULTS: Here we proved that TORC1 signaling was down regulated in the myo1Delta strain. While a tor1Delta mutant strain had increased viability relative to myo1Delta, a combined myo1Deltator1Delta mutant strain showed significantly reduced cell viability. Synthetic rescue of the tor2-21ts lethal phenotype was observed in the myo1Delta strain in contrast to the chs2Delta strain, a chitin synthase II null mutant that also activates the PKC1 CWIP and exhibits cytokinesis defects very similar to myo1Delta, where the rescue effect was not observed. We observed two pools of Slt2p, the final Mitogen Activated Protein Kinase (MAPK) of the PKC1 CWIP; one pool that is up regulated by heat shock and one that is up regulated by the myo1Delta stress. The cell wall stress sensor WSC1 that activates PKC1 CWIP under other stress conditions was shown to act as a negative regulator of TORC1 in the myo1Delta mutant. Finally, the repression of TORC1 was inversely correlated with the activation of PKC1 in the myo1Delta strain. CONCLUSIONS: Regulated expression of TOR1 was important in the activation of the PKC1 CWIP in a myo1Delta strain and hence its survival. We found evidence that the PKC1 and TORC1 pathways share a common upstream regulator associated with the cell wall stress sensor WSC1. Surprisingly, essential TORC2 functions were not required in the myo1Delta strain. By understanding how yeast mounts a concerted stress response, one can further design pharmacological cocktails to undermine their ability to adapt and to survive.