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McCullough, C.

Publications and source records attributed to McCullough, C..

4 recordsLinked to original sources

Discovery of Isobavachin, a natural flavonoid, as an Apolipoprotein E4 (ApoE4) structure corrector for Alzheimer's disease

Alzheimers disease (AD) is a progressive neurodegenerative disease characterized by extensive neurodegeneration and consequent severe memory loss. Apolipoprotein E4 (ApoE4) is the strongest genetic risk factor for AD, with its pathological effects linked to structural instability and altered interactions with lipids and other important disease proteins including amyloid beta (A{beta}) and tau ({tau}). Therefore, correcting and stabilizing the ApoE4 structure has emerged as a promising therapeutic strategy for mitigating its detrimental effects. In this study, we investigated naturally occurring bioavailable flavonoids as ApoE4 stabilizers, focusing on their potential to modulate ApoE4 structure and function. Comprehensive investigation of a focused database using our integrated computational and experimental screening protocol led to the identification of Isobavachin as a potential corrector and stabilizer of ApoE4 structure. In addition, a few other bioavailable flavonoids with similar stabilizing properties were identified, albeit to a much lesser extent as compared to Isobavachin. The findings support the therapeutic potential of flavonoids as ApoE4 modulators and highlight Isobavachin as a lead candidate for further preclinical evaluation. These results provide new insights into the pharmacological targeting of ApoE4 and open avenues for the development of flavonoid-based, ApoE-directed therapies for AD.

neuroscience↗

Opto2P-FCM: A MEMS based miniature two-photon microscope with two-photon patterned optogenetic stimulation

Multiphoton microscopy combined with optogenetic photostimulation is a powerful technique in neuroscience enabling precise control of cellular activity to determine the neural basis of behavior in a live animal. Two-photon patterned photostimulation has taken this further by allowing interrogation at the individual neuron level. However, it remains a challenge to implement imaging of neural activity with spatially patterned two-photon photostimulation in a freely moving animal. We developed a miniature microscope for high resolution two-photon fluorescence imaging with patterned two-photon optogenetic stimulation. The design incorporates a MEMS scanner for two-photon imaging and a second beam path for patterned two-photon excitation in a compact and lightweight design that can be head-attached to a freely moving animal. We demonstrate cell-specific optogenetics and high resolution MEMS based two-photon imaging in a freely moving mouse. The new capabilities of this miniature microscope design can enable cell-specific studies of behavior that can only be done in freely moving animals.

neuroscience↗

The Hemopurifier removes extracellular vesicles and microRNAs from renal perfusates following controlled oxygenated rewarming of discarded donor kidneys

Kidney transplantation is considered the benchmark treatment for end-stage kidney disease patients. Nevertheless, the demand for donor kidneys is continuously on the rise and the scarcity of suitable kidneys poses a significant hindrance for patients and healthcare providers. One approach is to extend the criteria for the use of kidneys from deceased brain death and deceased circulatory death donors. Use of these organs especially from these extended criteria donors is associated with ischemia reperfusion injury (IRI) and resultant delayed graft function (DGF) as well as increased rates of allograft rejection. One approach to try to lessen these complications as well as increase the time the assessment of organ viability is the use of machine perfusion on recovered kidneys. In this study we obtained perfusates from discarded organs that had undergone Controlled Oxygenated Rewarming. Perfusates were analyzed for extracellular vesicles (EVs), dsDNA associated with EVs and microRNAs. These perfusates were then pumped over the Aethlon Hemopurifier, a plasma separator with an affinity resin containing the lectin Galanthus nivalis agglutinin (GNA). Following treatment with the Hemopurifier, a diminution in extracellular vesicles, dsDNA associated with EVs and microRNAs was observed. These results support a future study of the Aethlon Hemopurifier as part of a machine perfusion circuit to explore if the device decreases these mediators in a dynamic circuit and is associated with improved function of retrieved kidneys.

molecular biology↗

Effects of a field-sprayed antibiotic on bee foraging behavior and pollination in pear orchards

Broadcast spraying of antibiotics in crops is widely used for controlling bacterial plant pathogens. The effects of antibiotics on non-target (and especially beneficial) organisms in cropping systems, however, are not well studied. Pollinators are of particular concern because in pear and apple crops, antibiotics for controlling fire blight (Erwinia amylovora) are sprayed during bloom, likely exposing pollinators. This is especially relevant as laboratory evidence suggests that antibiotics could have sublethal effects on bee foraging behavior and colony health. But to our knowledge these potential impacts have not been studied in field settings. Here, we compared the effects of two fire blight control methods, a single spray of an antibiotic (oxytetracycline) and a biological antagonist (Aureobasidium pullulans), on honey bee (Apis mellifera) foraging, pollination, and fruit set in pear orchards. Complementing these field assessments, we conducted laboratory experiments to examine the effects of these treatments on locomotion and foraging behavior of the bumble bee species, Bombus vosnesenskii. We found that honey bees visited fewer flowers and foraged longer on each flower in orchards sprayed with antibiotics than with biological product, but there were no differences in pollination and seed set. The pear cultivars we worked in, however, can self-pollinate. In the lab, we found that feeding on high doses of either the antibiotic or the biological antagonist reduced bumble bee foraging behavior relative to controls. The limited impact of antibiotics on pear pollination observed in this study suggest that antibiotics pose a low economic risk to pear growers, especially for self-compatible cultivars. Still, crops with higher pollinator dependence may be more affected by reductions in pollinator visitation. Future studies should examine the impacts of multiple antibiotic sprays within a season, which are common during warm springs, and their long-term health impacts on both individual bees and colonies. HighlightsO_LIAntibiotics are sprayed on many crops to control plant bacterial pathogens. C_LIO_LIThe impacts of antibiotics on beneficial organisms in agriculture are unknown. C_LIO_LIWe studied antibiotic impacts on bee behavior and pollination function in pears. C_LIO_LIBees exposed to antibiotics visit fewer flowers and this could impact bee fitness. C_LIO_LIDespite decreased bee visitation, we did not detect a reduction in crop pollination. C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=83 HEIGHT=200 SRC="FIGDIR/small/528407v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@17c2189org.highwire.dtl.DTLVardef@7dd952org.highwire.dtl.DTLVardef@4696beorg.highwire.dtl.DTLVardef@52b7fd_HPS_FORMAT_FIGEXP M_FIG C_FIG

animal behavior and cognition↗