Characterization of 4-hydroxycinnamic acid: CoA ligase, anthocyanins and pathogen ingress in resistant and susceptible maize cultivars

Phenylpropanoid metabolism in maize cultivars B73\sb{Ht} (susceptible) and B73\sb{Ht\ rhm} (resistant) is conspicuously affected following inoculation with the fungus Bipolaris maydis race O. The purpose of this research was to examine the role of 4-hydroxycinnamic acid: CoA ligase (4CL) in the disease interaction from infected host tissues and to establish whether isozymes are induced. Anion exchange and hydrophobic interaction chromatography of protein preparations extracted in bulk from maize leaves infected with B. maydis resulted in over a 600-fold purification of 4CL. The native enzyme had an estimated molecular weight of 51.6 kDa. Kinetic analysis of enzyme activities with various phenylpropanoid substrates demonstrated there is little preferential substrate-specificity among phenylpropanoids tested. The enzyme exhibited no activity when assayed with sinapic acid. No evidence for multiple forms was found in the present investigation, suggesting that the maize 4CL is not responsible for metabolic channeling of phenylpropanoids and their distribution within the cell which occurs in response to infection. The second goal of this research was to chemically characterize anthocyanin pigments which often accumulate in uninfected cells adjacent to restricted lesions in the resistant B73\sb{Ht\ rhm} cultivar. Results showed that anthocyanins begin to accumulate by 32 hours post-inoculation and continue to accumulate through 72 hours. Plasma Desorption Mass Spectrometry (PDMS) of anthocyanins that accumulate in the healthy leaf sheath tissues revealed a major ion with a molecular mass of 621. A search of the literature identified this 621 ion as a cyanidin 3-dimalonylglucoside. Importantly, PDMS of anthocyanins isolated from infected tissues showed the identical 621 ion. The final goal of this research was to use fluorescent staining and microscopic examination of B. maydis hyphae at various times after infection to delineate the time when fungal ingress is arrested. Computer analysis revealed that the growth of B. maydis in the resistant cultivar is restricted prior to 18 hours post-inoculation. However, analysis of the susceptible tissues showed an almost linear growth of fungal hyphae. Importantly, this investigation shows that the cessation of pathogen ingress in the resistant cultivar occurs much earlier than the previously reported accumulation of phenylpropanoids

Definitely NOT Just Another Hernia

n/a images in emergency medicin

Definitely NOT Just Another Hernia

[West J Emerg Med. 2012;13(6):492-493

Development and implementation of a multicenter registry for resuscitation-focused transesophageal echocardiography

Study objective:To evaluate the clinical effect, safety, and clinical outcomes of focused transesophageal echocardiography (TEE) in the evaluation of critically ill patients in the emergency department (ED) and ICUs. Methods:We established a prospective, multicenter, observational registry involving adult critically ill patients in whom focused TEE was performed for evaluation of out-of-hospital cardiac arrest (OHCA), inhospital cardiac arrest, evaluation of undifferentiated shock, hemodynamic monitoring, and/or procedural guidance in the ED, ICU, or operating room setting. The primary objective of the current investigation was to evaluate the clinical influence and safety of focused, point-of-care TEE in critically ill patients. Data elements included patient and procedure characteristics, laboratory values, timing of interventions, clinical outcomes, and TEE video images. Results:A total of 1,045 focused TEE studies were collected among 916 patients from 28 hospitals, including 585 (64%) intraarrest and postarrest OHCA and inhospital cardiac arrest, 267 (29%) initial evaluation of undifferentiated shock, 101 (11%) procedural guidance, and 92 (10%) hemodynamic monitoring. TEE changed management in 85% of patients with undifferentiated shock, 71% of patients with inhospital cardiac arrest, and 62% of patients with OHCA. There were no reported esophageal perforations or oropharyngeal injuries, and other procedural complications were rare. Conclusions:A prospective, multicenter, and multidisciplinary TEE registry was successfully implemented, and demonstrated that focused TEE is safe and clinically impactful across multiple critical care applications. Further studies from this research network will accelerate the development of outcome-oriented research and knowledge translation on the use of TEE in emergency and critical care settings

Keratinocyte expression of inflammatory mediators plays a crucial role in substance P-induced acute and chronic pain

<p>Abstract</p> <p>Tibia fracture in rats followed by cast immobilization leads to nociceptive, trophic, vascular and bone-related changes similar to those seen in Complex Regional Pain Syndrome (CRPS). Substance P (SP) mediated neurogenic inflammation may be responsible for some of the signs of CRPS in humans. We therefore hypothesized that SP acting through the SP receptor (NK1) leads to the CRPS-like changes found in the rat model. In the present study, we intradermally injected rats with SP and monitored hindpaw mechanical allodynia, temperature, and thickness as well as tissue levels of tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), interleukin 6 (IL-6), and nerve growth factor-β (NGF) for 72 h. Anti-NGF antibody was utilized to block the effects of SP-induced NGF up-regulation. Fracture rats treated with the selective NK1 receptor antagonist LY303870 prior to cast removal were assessed for BrdU, a DNA synthesis marker, incorporation in skin cells to examine cellular proliferation. Bone microarchitecture was measured using micro computed tomography (μCT). We observed that: (1) SP intraplantar injection induced mechanical allodynia, warmth and edema as well as the expression of nociceptive mediators in the hindpaw skin of normal rats, (2) LY303870 administered intraperitoneally after fracture attenuated allodynia, hindpaw unweighting, warmth, and edema, as well as cytokine and NGF expression, (3) LY303870 blocked fracture-induced epidermal thickening and BrdU incorporation after fracture, (4) anti-NGF antibody blocked SP-induced allodynia but not warmth or edema, and (5) LY303870 had no effect on bone microarchitecture. Collectively our data indicate that SP acting through NK1 receptors supports the nociceptive and vascular components of CRPS, but not the bone-related changes.</p