Forced Expiratory Volume in One Second Predicts Length of Stay and In-Hospital Mortality in Patients Undergoing Cardiac Surgery: A Retrospective Cohort Study

Objective: An aging population and increasing use of percutaneous therapies have resulted in older patients with more co-morbidity being referred for cardiac surgery. Objective measurements of physiological reserve and severity of co-morbid disease are required to improve risk stratification. We hypothesised that FEV1 would predict mortality and length of stay following cardiac surgery. Methods: We assessed clinical outcomes in 2,241 consecutive patients undergoing coronary artery bypass grafting and/or valve surgery from 2001 to 2007 in a regional cardiac centre. Generalized linear models of the association between FEV1 and length of hospital stay and mortality were adjusted for age, sex, height, body mass index, socioeconomic status, smoking, cardiovascular risk factors, long-term use of bronchodilators or steroids for lung disease, and type and urgency of surgery. FEV1 was compared to an established risk prediction model, the EuroSCORE. Results: Spirometry was performed in 2,082 patients (93%) whose mean (SD) age was 67 (10) years. Median hospital stay was 3 days longer in patients in the lowest compared to the highest quintile for FEV1, 1.35-fold higher (95% CI 1.20–1.52; p<0.001). The adjusted odds ratio for mortality was increased 2.11-fold (95% CI 1.45–3.08; p<0.001) per standard deviation decrement in FEV1 (800 ml). FEV1 improved discrimination of the EuroSCORE for mortality. Similar associations were found after excluding people with known pulmonary disease and/or airflow limitation on spirometry. Conclusions: Reduced FEV1 strongly predicted increased length of stay and in-hospital mortality following cardiac surgery. FEV1 is a widely available measure of physiological health that may improve risk stratification of complex patients undergoing cardiac surgery and should be evaluated for inclusion in new prediction tools

An Integrated Biorefinery Concept for Conversion of Sugar Beet Pulp into Value-added Chemicals and Pharmaceutical Intermediates

Over 8 million tonnes of sugar beet are grown annually in the UK. Sugar beet pulp (SBP) is the main by-product of sugar beet processing which is currently dried and sold as a low value animal feed. SBP is a rich source of carbohydrates, mainly in the form of cellulose and pectin, including D-glucose (Glu), L-arabinose (Ara) and D-galacturonic acid (GalAc). This work describes the technical feasibility of an integrated biorefinery concept for fractionation of SBP and conversion of these monosaccharides into value-added products. SBP fractionation is initially carried out by steam explosion under mild conditions to yield soluble pectin and insoluble cellulose fractions. The cellulose is readily hydrolysed by cellulases to release Glu that can then be fermented by a commercial Yeast strain to produce bioethanol with a high yield. The pectin fraction can be either fully hydrolysed, using physico-chemical methods, or selectively hydrolysed, using cloned arabinases and galacturonases, to yield Ara-rich and GalAc-rich streams. These monomers can be separated using either Centrifugal Partition Chromatography (CPC) or ultrafiltration into streams suitable for subsequent enzymatic upgrading. Building on our previous experience with transketolase (TK) and transaminase (TAm) enzymes, the conversion of Ara and GalAc into higher value products was explored. In particular the conversion of Ara into L-gluco-heptulose (GluHep), that has potential therapeutic applications in hypoglycaemia and cancer, using a mutant TK is described. Preliminary studies with TAm also suggest GluHep can be selectively aminated to the corresponding chiral aminopolyol. Current work is addressing upgrading of the remaining SBP monomer, GalAc, and modelling of the biorefinery concept to enable economic and Life Cycle Analysis (LCA)

Investigating the transition from passive to active expiration in rodents

Under eupneic conditions, the breathing cycle is composed of three phases: inspiration (I), expiratory braking (E1) and a secondary expiratory phase (E2) during which there may be passive expiration and potentially an expiratory pause. Thus, inspiration is active and expiration is passive. With elevated respiratory drive, the abdominal muscles are recruited to exhale air forcefully from the lungs, producing active expiration (AE). Breathing is a highly integrated response, dependent on peripheral and central feedback. What is required to successfully transition from a passive to an active expiration is still unknown. The goal of this thesis was to determine what stimuli are required to recruit AE using a comparative approach. We determined which stimuli recruit AE, where within the breathing cycle AE occurs (early-expiration or late-expiration), and how the breathing cycle accommodates this new phase. Three different rat preparations (in vivo, in situ, and in vitro) were used to determine how anesthesia, afferent vagal feedback and peripheral and central chemoreceptors contribute to the production of AE. Hypoxia, anesthesia and afferent vagal feedback inhibited AE, while hypercapnia recruited AE. Central chemoreceptors were necessary to produce AE in vivo, but were insufficient to recruit AE in vitro. Within the pons, the Kölliker-Fuse actively inhibited the onset of AE activity, but did not directly initiate AE. Hypercapnia increased tidal volume (VT) and produced AE in all rodent species studied. However, there were differences in what CO₂ levels recruited AE, and where AE occurred within the breathing cycle. Most species recruited a late-expiratory AE, while agoutis, with elevated breathing frequencies and high dynamic compliance, recruited an early-expiratory AE. While AE can recruit the expiratory reserve volume to enhance VT in all species studied, the early-expiratory AE may enhance airflow to overcome an expiratory time constant that approaches the full expiratory phase duration (TE). This thesis highlights that AE is a flexible process, which can influence the breathing response in multiple ways (control of VT vs. control of TE). This suggests that the removal of the inhibitory inputs to the expiratory neural regions likely occurs through different mechanisms under different circumstances.Science, Faculty ofGraduat

Afternoon Tea

Students read the writings of Afghani women.Clinical Professor Sarah Maclay, Department of English, curator and hos

Une Promenade Pluvieuse à Paris

For my senior Honors thesis, I have created a collection of poetry inspired by Paris, France. I spent a semester living in Paris, and there is a lot of creative potential in my experience with and memories of the city. I studied the writings of expatriate American authors like Ernest Hemingway, F. Scott Fitzgerald, and Gertrude Stein, and the writings of numerous French surrealist and symbolist poets to inspire the content and style of my writing. There are also many artists who worked intimately in and with Paris like Salvador Dalí, Pablo Picasso, and André Breton whose work and conceptions are represented in my writing. I have been practically stepping into Gertrude Stein’s 1920s salon to seek advice from my favorite writers and artists. Fueled by my intense nostalgia for Paris not as a city but as a living companion for whom I yearn deeply, my goal with this collection is to create a love letter to Paris, inspired by my memory of the city and by other authors who were also inspired by Paris. I have crafted a sort of aubade for my Paris that goes beyond reflection and nostalgia to bring Paris to life in the minds and hearts of those who read my work. This intense period of reflection has made me realize just how intimately I am connected with Paris. And writing these poems has miraculously lessened the distance between us and reminded me that Paris will always be with me, even when we are apart