Unbiased automated quantitation of ROS signals in live retinal neurons of Drosophila using Fiji/ImageJ

Numerous imaging modules are utilized to study changes that occur during cellular processes. Besides qualitative (immunohistochemical) or semiquantitative (Western blot) approaches, direct quantitation method(s) for detecting and analyzing signal intensities for disease(s) biomarkers are lacking. Thus, there is a need to develop method(s) to quantitate specific signals and eliminate noise during live tissue imaging. An increase in reactive oxygen species (ROS) such as superoxide (O2•-) radicals results in oxidative damage of biomolecules, which leads to oxidative stress. This can be detected by dihydroethidium staining in live tissue(s), which does not rely on fixation and helps prevent stress on tissues. However, the signal-to-noise ratio is reduced in live tissue staining. We employ the Drosophila eye model of Alzheimer's disease as a proof of concept to quantitate ROS in live tissue by adapting an unbiased method. The method presented here has a potential application for other live tissue fluorescent images.

Saving the Last Unicorns: The Genetic Rescue of Florida’s Pillar Corals

As stony coral tissue loss disease (SCTLD) swept through the Florida Reef Tract, one of the most severely impacted species was the iconic pillar coral, Dendrogyra cylindrus. As the species’ population experienced a precipitous decline, a collaborative rescue project collected colony fragments for safekeeping at onshore and offshore nursery facilities. Between 2015 and 2019, a total of 574 fragments representing 128 genotypes were collected. These are currently dispersed among five facilities where they continue to provide opportunities to (1) refine best husbandry practices for D. cylindrus, (2) develop treatment options for SCTLD that have been adapted for use on other species, (3) maximize growth and fragmentation to provide the live tissue needed for eventual restoration, and (4) provide a source of parent colonies for assisted sexual reproduction and new genetic diversity. With the wild pillar coral population in Florida at the end of 2020 at less than 6% of its known 2014 population and continuing to decline, the rescued ex situ colonies represent the entirety of the restoration potential for this species in Florida.

Macrocirculatory Parameters and Oxygen Debt Indices in Pigs During Propofol Or Alfaxalone Anesthesia When Subjected to Experimental Stepwise Hemorrhage

Background: Pigs are anesthetized when used for emergency procedures live tissue training (LTT) of civilian and military medical personnel or for experimental purposes, but there is a paucity in the literature regarding anesthesia of pigs for this purpose.Objective(s): The main goals of the study were to compare oxygen debt, macrocirculatory parameters, and time to cardiac arrest between pigs in hemorrhagic shock and anesthetized with propofol-ketamine-dexmedetomidine or alfaxalone-ketamine-dexmedetomidine.Design: A prospective, non-blinded randomized study design was used. Sixteen pigs were randomized in blocks of four to be anesthetized with either propofol-ketamine-dexmedetomidine (n = 8) or alfaxalone-ketamine-dexmedetomidine (n = 8) as a continuous infusion.Interventions: Premedication with ketamine 15 mg kg−1 and midazolam 1 mg kg−1 was given i.m. Anesthesia was maintained with propofol 8 mg kg−1 h−1 or alfaxalone 5 mg kg−1 h−1 combined with ketamine 5 mg kg−1 h−1 and dexmedetomidine 4 μg kg−1 h−1 i.v. A stepwise, volume-controlled model for hemorrhage was created by exsanguination.Main Outcome Measures: Indices of oxygen debt (lactate, base excess, and oxygen extraction), macrocirculatory (PR, SAP, DAP, MAP, and CI, SVI, and TPR) variables, and time to death was compared between groups.Results: Pigs in the alfaxalone group had significantly higher SAP than pigs given propofol. No difference in other macrocirculatory variables or indices of oxygen debt could be found. A blood loss of 50% of the total blood volume or more was possible in most pigs with both anesthetic regimes.Conclusions: Pigs anesthetized with propofol or alfaxalone combined with ketamine and dexmedetomidine tolerated substantial blood loss.

Parrotfish target large relocated corals causing restoration bottleneck

Large (30–45 cm in diameter) corals from three species relocated onto a reef in Miami, Florida, USA, experienced significant predation by parrotfish, with several colonies loosing >50% of their live tissue in less than 2 weeks, representing a major source of mortality for restored corals.

A red-emissive two-photon fluorescent probe for mitochondrial sodium ions in live tissue

A cyclocyanine (CC)-based organic small molecule two-photon (TP) fluorescent probe (CCNa1) was developed for mitochondrial sodium ion sensing. CCNa1 exhibits a low solvatochromic shift and strong TP fluorescence enhancement at...

Recovery from finfish predation on newly outplanted boulder coral colonies on three reefs in the Florida Keys

Corals throughout the Caribbean have experienced major declines since the 1970s. In response, many agencies have focused their conservation and restoration efforts on outplanting nursery-grown coral fragments onto degraded reefs. Predation on newly outplanted corals can be an important but often unmonitored factor contributing to the declining health and survival of these fragments. In this study, we outplanted 360 boulder coral fragments (Montastraea cavernosa, Orbicella faveolata, Pseudodiploria clivosa), sourced from both ex situ and in situ nurseries, at three locations in the Florida Keys. Each location included one inshore and one offshore site. Ten fragments of each species and source were outplanted at each site (60 corals per site). Transplants were monitored for finfish predation, live tissue area, and survival at 1, 2, 6, and 12 wks post-outplanting. We found the highest finfish predation for all species during the first week monitoring period. Predation during this first week varied by location and reef type, with two locations showing higher predation on offshore sites and one location experiencing increased predation on the inshore site. We also found that coral fragments produced in the ex situ nursery experienced higher initial predation compared to fragments produced in the in situ nursery. However, overall coral survival at 12 wks post-outplanting was 96%, suggesting there was no effect of initial predation on survival. Our results indicate that coral restoration efforts may be affected by intense, initial predation on newly-outplanted boulder coral colonies, but this initial predation may not lead to an increase in mortality.

Microdissected “cuboids” for microfluidic drug testing of intact tissues

A microfluidic platform permits multiple drug testing of uniformly-sized microscale “cuboids” of live tissue with well-preserved microenvironments.

Single molecule imaging reveals a slice of life

JGP study describes method to trace the real-time movements of individual membrane proteins in live tissue slices.