261 research outputs found
Comparative chromosome painting discloses homologous Segments in distantly related mammals
Comparative chromosome painting, termed ZOO-FISH, using DNA libraries from flow
sorted human chromosomes 1,16,17 and X, and mouse chromosome 11 discloses the
presence of syntenic groups in distantly related mammalian Orders ranging from
primates (Homo sapiens), rodents (Mus musculus), even-toed ungulates (Muntiacus
muntjak vaginalis and Muntiacus reevesi) and whales (Balaenoptera physalus). These
mammalian Orders have evolved separately for 55-80 million years (Myr). We conclude
that ZOO-FISH can be used to generate comparative chromosome maps of a large
number of mammalian species
Micro-pharmacokinetics: quantifying local drug concentration at live cell membranes
Fundamental equations for determining pharmacological parameters, such as the binding afnity of a ligand for its target receptor, assume a homogeneous distribution of ligand, with concentrations in the immediate vicinity of the receptor being the same as those in the bulk aqueous phase. It is, however, known that drugs are able to interact directly with the plasma membrane, potentially increasing local ligand concentrations around the receptor. We have previously reported an infuence of ligand-phospholipid interactions on ligand binding kinetics at the β2-adrenoceptor, which resulted in distinct “micro-pharmacokinetic” ligand profles. Here, we directly quantifed the local concentration of BODIPY630/650-PEG8-S-propranolol (BY-propranolol), a fuorescent derivative of the classical β-blocker propranolol, at various distances above membranes of single living cells using fuorescence correlation spectroscopy. We show for the frst time a signifcantly increased ligand concentration immediatel adjacent to the cell membrane compared to the bulk aqueous phase. We further show a clear role of both the cell membrane and the β2-adrenoceptor in determining high local BY-propranolol concentrations at the cell surface. These data suggest that the true binding afnity of BY-propranolol for the β2-adrenoceptor is likely far lower than previously reported and highlights the critical importance of understanding the “micro-pharmacokinetic” profles of ligands for membrane-associated proteins
The impact of open versus closed format ICU admission practices on the outcome of high risk surgical patients: a cohort analysis
<p>Abstract</p> <p>Background</p> <p>In the year 2000, the organizational structure of the ICU in the Zaandam Medical Centre (ZMC) changed from an open to a closed format ICU. The objective of this study was to evaluate the effect of this organizational change on outcome in high risk surgical patients.</p> <p>Methods</p> <p>The medical records of all consecutive high risk surgical patients admitted to the ICU from 1996 to 1998 (open format) and from 2003 to 2005 (closed format), were reviewed. High-risk patients were defined according to the Identification of Risk in Surgical patients (IRIS) score. Parameters studied were: mortality, morbidity, ICU length of stay (LOS) and hospital LOS.</p> <p>Results</p> <p>Mortality of ICU patients was 25.7% in the open format group and 15.8% in the closed format group (p = 0.01). Morbidity decreased from 48.6% to 46.1% (p = 0.6). The average length of hospital stay was 17 days in the open format group, and 21 days in the closed format group (p = 0.03).</p> <p>Conclusions</p> <p>High risk surgical patients in the ICU are patients that have undergone complex and often extensive surgery. These patients are in need of specialized treatment and careful monitoring for maximum safety and optimal care. Our results suggest that closed format is a more favourable setting than open format to minimize the effects of high risk surgery, and to warrant safe outcome in this patient group.</p
Device Thrombogenicity Emulation: A Novel Method for Optimizing Mechanical Circulatory Support Device Thromboresistance
Mechanical circulatory support (MCS) devices provide both short and long term hemodynamic support for advanced heart failure patients. Unfortunately these devices remain plagued by thromboembolic complications associated with chronic platelet activation – mandating complex, lifelong anticoagulation therapy. To address the unmet need for enhancing the thromboresistance of these devices to extend their long term use, we developed a universal predictive methodology entitled Device Thrombogenicity Emulation (DTE) that facilitates optimizing the thrombogenic performance of any MCS device – ideally to a level that may obviate the need for mandatory anticoagulation
Surgeon-Performed Ultrasound as Preoperative Localization Study in Patients with Primary Hyperparathyroidism
Background: Minimally invasive parathyroidectomy is the treatment of choice for single-gland primary hyperparathyroidism. However, the exact location of the abnormal gland has to be established. Sestamibi scintigraphy, computed tomography and ultrasound (US) are commonly used modalities. We describe our experience in a non-academic center with surgeon-performed US (S-US) of the neck as preoperative localization study in patients with primary hyperparathyroidism (PHPT). Methods: Patients with a biochemically proven diagnosis of PHPT and preoperative S-US were included. Data were recorded prospectively. Perioperative gland location was compared to the preoperative S-US to determine sensitivity, specificity and accuracy rates. Results: Two of the 50 patients who underwent S-US were not subjected to surgery. In 85% of the patients analyzed by S-US, the appropriate abnormal gland(s) were identified. In 11%, no gland was identified, but abnormal glands were found during surgery. Sensitivity of S-US in our hospital is 85%, with a positive predictive value of 97%. Conclusions: We achieved a satisfactory sensitivity rate. S-US provides anatomic information to the surgeon which enables a more detailed operation planning, and it is a valuable diagnostic modality for patients with PHPT in our opinion. We hope that our data encourage other centers to implement this technique as well. Copyrigh
The relationship between patient physiology and cancer-specific survival following curative resection of colorectal cancer
The impact of patient physiology on cancer-specific survival is poorly documented. Patient physiology predicted overall, cancer-specific (Physiology Score>30; HR 8.64 (95% CI 3.00–24.92); P=0.0005) and recurrence-free survival (Physiology Score >30; HR 7.44 (95% CI 1.99–27.73); P=0.003) independent of Dukes stage following potentially curative surgery for colorectal cancer. This independent negative association with survival is a novel observation
Learning HCI Across Institutions, Disciplines and Countries: A Field Study of Cognitive Styles in Analytical and Creative Tasks
Human-computer interaction (HCI) is increasingly becoming a subject taught in universities around the world. However, little is known of the interactions of the HCI curriculum with students in different types of institutions and disciplines internationally. In order to explore these interactions, we studied the performance of HCI students in design, technology and business faculties in universities in UK, India, Namibia, Mexico and China who participated in a common set of design and evaluation tasks. We obtained participants’ cognitive style profiles based on Allinson and Hayes scale in order to gain further insights into their learning styles and explore any relation between these and performance. We found participants’ cognitive style preferences to be predominantly in the adaptive range, i.e. with combined analytical and intuitive traits, compared to normative data for software engineering, psychology and design professionals. We further identified significant relations between students’ cognitive styles and performance in analytical and creative tasks of a HCI professional individual. We discuss the findings in the context of the distinct backgrounds of the students and universities that participated in this study and the value of research that explores and promotes diversity in HCI education
Discussing life expectancy with surgical patients: Do patients want to know and how should this information be delivered?
<p>Abstract</p> <p>Background</p> <p>Predicted patient life expectancy (LE) and survival probability (SP), based on a patient's medical history, are important components of surgical decision-making and informed consent. The objective of this study was to assess patients' interpretation of and desire to know information relating to LE, in addition to establishing the most effective format for discussion.</p> <p>Methods</p> <p>A cross sectional survey of 120 patients (mean age = 68.7 years, range 50–90 years), recruited from general urological and surgical outpatient clinics in one District General and one Teaching hospital in Southwest England (UK) was conducted. Patients were included irrespective of their current diagnosis or associated comorbidity. Hypothetical patient case scenarios were used to assess patients' desire to know LE and SP, in addition to their preferred presentation format.</p> <p>Results</p> <p>58% of patients expressed a desire to know their LE and SP, if it were possible to calculate, with 36% not wishing to know either. Patients preferred a combination of numerical and pictorial formats in discussing LE and SP, with numerical, verbal and pictorial formats alone least preferred. 71% patients ranked the survival curve as either their first or second most preferred graph, with 76% rating facial figures their least preferred. No statistically significant difference was noted between sexes or educational backgrounds.</p> <p>Conclusion</p> <p>A proportion of patients seem unwilling to discuss their LE and SP. This may relate to their current diagnosis, level of associated comorbidity or degree of understanding. However it is feasible that by providing this information in a range of presentation formats, greater engagement in the shared decision-making process can be encouraged.</p
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