In Vivo Assessment of Cold Adaptation in Insect Larvae by Magnetic Resonance Imaging and Magnetic Resonance Spectroscopy

Background Temperatures below the freezing point of water and the ensuing ice crystal formation pose serious challenges to cell structure and function. Consequently, species living in seasonally cold environments have evolved a multitude of strategies to reorganize their cellular architecture and metabolism, and the underlying mechanisms are crucial to our understanding of life. In multicellular organisms, and poikilotherm animals in particular, our knowledge about these processes is almost exclusively due to invasive studies, thereby limiting the range of conclusions that can be drawn about intact living systems. Methodology Given that non-destructive techniques like 1H Magnetic Resonance (MR) imaging and spectroscopy have proven useful for in vivo investigations of a wide range of biological systems, we aimed at evaluating their potential to observe cold adaptations in living insect larvae. Specifically, we chose two cold-hardy insect species that frequently serve as cryobiological model systems–the freeze-avoiding gall moth Epiblema scudderiana and the freeze-tolerant gall fly Eurosta solidaginis. Results In vivo MR images were acquired from autumn-collected larvae at temperatures between 0°C and about -70°C and at spatial resolutions down to 27 µm. These images revealed three-dimensional (3D) larval anatomy at a level of detail currently not in reach of other in vivo techniques. Furthermore, they allowed visualization of the 3D distribution of the remaining liquid water and of the endogenous cryoprotectants at subzero temperatures, and temperature-weighted images of these distributions could be derived. Finally, individual fat body cells and their nuclei could be identified in intact frozen Eurosta larvae. Conclusions These findings suggest that high resolution MR techniques provide for interesting methodological options in comparative cryobiological investigations, especially in vivo

Wound healing in glaucoma filtering surgery

Successful glaucoma filtering surgery is characterized by the passage of aqueous humor from the anterior chamber to the subconjunctival space, which results in the formation of a filtering bleb. Aqueous in the subconjunctival space may then exit by multiple pathways. Bled failure most often results from fibroblast proliferation and subconjunctival fibrosis. Factors associated with an increased risk of bleb failure include youth, aphakia, active anterior segment neovascularization, inflammation, previously failed glaucoma filtering surgery, and, possibly, race. Several surgical and pharmacologic techniques have recently been introduced to enhance success in eyes with poor surgical prognoses. To elucidate the scientific rationale of these methods, we summarize the process of wound healing after glaucoma filtering surgery and describe postoperative clinical and histopathologic features, factors which may affect success, and specific methods to improve surgical success.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26516/1/0000054.pd

Sarcoid uveitis: A look beyond the eyes

Background: Bilateral acute uveitis can cause significant morbidity, and a complete workup is often warranted. This report illustrates a case of sarcoid uveitis definitively diagnosed by skin biopsy in a patient with red tattoo ink. Case Report: A 40-year-old African American male presented with bilateral photophobia and intraocular pressures of 26 mmHg in both eyes, 1þ grade cell and flare in both eyes, and granulomatous (mutton fat) keratic precipitates in both eyes. Serum angiotensin-converting enzyme level was elevated at 146 U/mL (normal valu

Sulfanegen sodium treatment in a rabbit model of sub-lethal cyanide toxicity.

The aim of this study is to investigate the ability of intramuscular and intravenous sulfanegen sodium treatment to reverse cyanide effects in a rabbit model as a potential treatment for mass casualty resulting from cyanide exposure. Cyanide poisoning is a serious chemical threat from accidental or intentional exposures. Current cyanide exposure treatments, including direct binding agents, methemoglobin donors, and sulfur donors, have several limitations. Non-rhodanese mediated sulfur transferase pathways, including 3-mercaptopyruvate sulfurtransferase (3-MPST) catalyze the transfer of sulfur from 3-MP to cyanide, forming pyruvate and less toxic thiocyanate. We developed a water-soluble 3-MP prodrug, 3-mercaptopyruvatedithiane (sulfanegen sodium), with the potential to provide a continuous supply of substrate for CN detoxification. In addition to developing a mass casualty cyanide reversal agent, methods are needed to rapidly and reliably diagnose and monitor cyanide poisoning and reversal. We use non-invasive technology, diffuse optical spectroscopy (DOS) and continuous wave near infrared spectroscopy (CWNIRS) to monitor physiologic changes associated with cyanide exposure and reversal. A total of 35 animals were studied. Sulfanegen sodium was shown to reverse the effects of cyanide exposure on oxyhemoglobin and deoxyhemoglobin rapidly, significantly faster than control animals when administered by intravenous or intramuscular routes. RBC cyanide levels also returned to normal faster following both intramuscular and intravenous sulfanegen sodium treatment than controls. These studies demonstrate the clinical potential for the novel approach of supplying substrate for non-rhodanese mediated sulfur transferase pathways for cyanide detoxification. DOS and CWNIRS demonstrated their usefulness in optimizing the dose of sulfanegen sodium treatment

Heart transplantation and in-hospital outcomes in adult congenital heart disease patients with Fontan: A decade nationwide analysis from 2004 to 2014

INTRODUCTION: Treatment of adult congenital heart disease patients who require advanced therapies remains challenging due to high perioperative and wait-list mortality and limited donors. Patients palliated with Fontan are at the highest risk of early mortality due to multiorgan involvement and few centers able to safely transplant them. We sought to evaluate the early outcomes of heart transplants in these adult Fontan patients. METHODS: Using the Nationwide Inpatient Sample database, we identified all adults aged at least 18 years old who underwent heart transplantation across U.S. hospitals from 2004 to 2014. We then identified those with specific ICD-9 codes to include tricuspid atresia, hypoplastic left heart syndrome and common ventricle. Multivariate regression models were created to adjust for potential confounders. RESULTS: A total of 93 Fontan patients underwent heart transplant during the study time (0.5% of all heart transplants). Compared to non-Fontan heart transplantations, Fontan patients were younger, with a higher incidence of liver disease and coagulopathy. Fontan patients receiving heart transplant had higher mortality during transplant hospitalization compared to non-Fontan patients (26.3% vs 5.3% OR, 18.10, CI, 5.06-65.0 P \u3c .001). Extracorporeal membrane oxygenator (ECMO) usage and bleeding were also higher in the Fontan cohort with an OR of 5.30 (P = .016) and 5.32 (P = .015) for ECMO and bleeding, respectively. The remaining outcomes were similar for both cohorts. CONCLUSION: Adults with Fontan palliation undergoing heart transplantation have exceptionally high inpatient mortality, which is nearly five times that of non-Fontan heart transplant recipients, perhaps related to a delayed referral, surgical complexity, and coexistent, underrecognized liver failure