Vascular architecture and hypoxic profiles in human head and neck squamous cell carcinomas

Tumour oxygenation and vasculature are determinants for radiation treatment outcome and prognosis in patients with squamous cell carcinomas of the head and neck. In this study we visualized and quantified these factors which may provide a predictive tool for new treatments. Twenty-one patients with stage III–IV squamous cell carcinomas of the head and neck were intravenously injected with pimonidazole, a bioreductive hypoxic marker. Tumour biopsies were taken 2 h later. Frozen tissue sections were stained for vessels and hypoxia by fluorescent immunohistochemistry. Twenty-two sections of biopsies of different head and neck sites were scanned and analysed with a computerized image analysis system. The hypoxic fractions varied from 0.02 to 0.29 and were independent from T- and N-classification, localization and differentiation grade. No significant correlation between hypoxic fraction and vascular density was observed. As a first attempt to categorize tumours based on their hypoxic profile, three different hypoxia patterns are described. The first category comprised tumours with large hypoxic, but viable, areas at distances even greater than 200 μm from the vessels. The second category showed a typical band-like distribution of hypoxia at an intermediate distance (50–200 μm) from the vessels with necrosis at greater distances. The third category demonstrated hypoxia already within 50 μm from the vessels, suggestive for acute hypoxia. This method of multiparameter analysis proved to be clinically feasible. The information on architectural patterns and the differences that exist between tumours can improve our understanding of the tumour micro-environment and may in the future be of assistance with the selection of (oxygenation modifying) treatment strategies. © 2000 Cancer Research Campaig

Effect of the Implantable Atrial Defibrillator on the Natural History of Atrial Fibrillation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75480/1/j.1540-8167.1999.tb00296.x.pd

The Selectivity of Milking of Dunaliella salina

The process of the simultaneous production and extraction of carotenoids, milking, of Dunaliella salina was studied. We would like to know the selectivity of this process. Could all the carotenoids produced be extracted? And would it be possible to vary the profile of the produced carotenoids and, consequently, influence the type of carotenoids extracted? By using three different D. salina strains and three different stress conditions, we varied the profiles of the carotenoids produced. Between Dunaliella bardawil and D. salina 19/18, no remarkable differences were seen in the extraction profiles, although D. salina 19/18 seemed to be better extractable. D. salina 19/25 was not “milkable” at all. The milking process could only be called selective for secondary carotenoids in case gentle mixing was used. In aerated flat-panel photobioreactors, extraction was much better, but selectiveness decreased and also chlorophyll and primary carotenoids were extracted. This was possibly related to cell damage due to shear stress

Radiographic rib fracture nonunion and association with fracture classification in adults with multiple rib fractures without flail segment:A multicenter prospective cohort study

Background: Rib fracture nonunion is a probable cause of chronic pain following chest trauma, although its prevalence remains unknown. The aims of this study were to determine rib fracture nonunion prevalence following nonoperative management and to determine if presence of nonunion was associated with the number of rib fractures, or the rib fracture classification of anatomical location, type, and displacement. Methods: This multicenter prospective cohort study included trauma patients with three or more fractured ribs but without a flail segment, who participated in the nonoperative management group of the FixCon trial between January 2019 and June 2022. The number and classification of rib fractures were assessed on trauma chest CT. Chest CTs conducted six months post-trauma were evaluated for the presence of nonunion. Radiological characteristics of nonunions were compared with normally healed rib fractures using the Mann-Whitney U, χ2 test, and Fisher's exact test as appropriate. A generalized linear model adjusted for multiple observations per patient when assessing the associations between nonunion and fracture characteristics. Results: A total of 68 patients were included with 561 post-traumatic fractures in 429 ribs. Chest CT after six months revealed nonunions in 67 (12 %) rib fractures in 29 (43 %) patients with a median of 2 (P25-P75 1–3) nonunions per patient. Nonunion was most commonly observed in ribs seven to 10 (20–23 %, p &lt; 0.001, adjusted p = 0.006). Nonunion occurred in 14 (5 %) undisplaced, 22 (19 %) offset, and 20 (23 %) displaced rib fractures (p &lt; 0.001). No statistically significant association between rib fracture type and nonunion was found. Conclusions: Forty-three percent of patients with multiple rib fractures had radiographic nonunion six months after trauma. Fractures in ribs seven to 10 and dislocated fractures had an increased risk of rib fracture nonunion.</p

Radiographic rib fracture nonunion and association with fracture classification in adults with multiple rib fractures without flail segment:A multicenter prospective cohort study

Background: Rib fracture nonunion is a probable cause of chronic pain following chest trauma, although its prevalence remains unknown. The aims of this study were to determine rib fracture nonunion prevalence following nonoperative management and to determine if presence of nonunion was associated with the number of rib fractures, or the rib fracture classification of anatomical location, type, and displacement. Methods: This multicenter prospective cohort study included trauma patients with three or more fractured ribs but without a flail segment, who participated in the nonoperative management group of the FixCon trial between January 2019 and June 2022. The number and classification of rib fractures were assessed on trauma chest CT. Chest CTs conducted six months post-trauma were evaluated for the presence of nonunion. Radiological characteristics of nonunions were compared with normally healed rib fractures using the Mann-Whitney U, χ2 test, and Fisher's exact test as appropriate. A generalized linear model adjusted for multiple observations per patient when assessing the associations between nonunion and fracture characteristics. Results: A total of 68 patients were included with 561 post-traumatic fractures in 429 ribs. Chest CT after six months revealed nonunions in 67 (12 %) rib fractures in 29 (43 %) patients with a median of 2 (P25-P75 1–3) nonunions per patient. Nonunion was most commonly observed in ribs seven to 10 (20–23 %, p &lt; 0.001, adjusted p = 0.006). Nonunion occurred in 14 (5 %) undisplaced, 22 (19 %) offset, and 20 (23 %) displaced rib fractures (p &lt; 0.001). No statistically significant association between rib fracture type and nonunion was found. Conclusions: Forty-three percent of patients with multiple rib fractures had radiographic nonunion six months after trauma. Fractures in ribs seven to 10 and dislocated fractures had an increased risk of rib fracture nonunion.</p

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Current transport versus continental inputs in the eastern Indian Ocean: Radiogenic isotope signatures of clay size sediments

Analyses of radiogenic neodymium (Nd), strontium (Sr), and lead (Pb) isotope compositions of clay-sized detrital sediments allow detailed tracing of source areas of sediment supply and present and past transport of particles by water masses in the eastern Indian Ocean. Isotope signatures in surface sediments range from −21.5 (ɛNd), 0.8299 (87Sr/86Sr), and 19.89 (206Pb/204Pb) off northwest Australia to +0.7 (ɛNd), 0.7069 (87Sr/86Sr), and 17.44 (206Pb/204Pb) southwest of Java. The radiogenic isotope signatures primarily reflect petrographic characteristics of the surrounding continental bedrocks but are also influenced by weathering-induced grain size effects of Pb and Sr isotope systems with superimposed features that are caused by current transport of clay-sized particles, as evidenced off Australia where a peculiar isotopic signature characterizes sediments underlying the southward flowing Leeuwin Current and the northward flowing West Australian Current (WAC). Gravity core FR10/95-GC17 off west Australia recorded a major isotopic change from Last Glacial Maximum values of −10 (ɛNd), 0.745 (87Sr/86Sr), and 18.8 (206Pb/204Pb) to Holocene values of −22 (ɛNd), 0.8 (87Sr/86Sr), and 19.3 (206Pb/204Pb), which documents major climatically driven changes of the WAC and in local riverine particle supply from Australia during the past 20 kyr. In contrast, gravity core FR10/95-GC5 located below the present-day pathway of the Indonesian throughflow (ITF) shows a much smaller isotopic variability, indicating a relatively stable ITF hydrography over most of the past 92 kyr. Only the surface sediments differ significantly in their isotopic composition, indicating substantial changes in erosional sources attributed to a change of the current regime during the past 5 kyr

Uncertainties in steric sea level change estimation during the satellite altimeter era: concepts and practices

This article presents a review of current practice in estimating steric sea level change, focussed on the treatment of uncertainty. Steric sea level change is the contribution to the change in sea level arising from the dependence of density on temperature and salinity. It is a significant component of sea level rise and a reflection of changing ocean heat content. However tracking these steric changes remains still a significant challenge for the scientific community. We review the importance of understanding the uncertainty in estimates of steric sea level change. Relevant concepts of uncertainty are discussed and illustrated with the example of observational uncertainty propagation from a single profile of temperature and salinity measurements to steric height. We summarise and discuss the recent literature on methodologies and techniques used to estimate steric sea level in the context of the treatment of uncertainty. Our conclusions are that progress in quantifying steric sea level uncertainty will benefit from: greater clarity and transparency in published discussions of uncertainty, including exploitation of international standards for quantifying and expressing uncertainty in measurement; and the development of community ‘recipes’ for quantifying the error covariances in observations and from sparse sampling, and for estimating and propagating uncertainty across spatio-temporal scales