Search results for "oxygenation"

8 Å cryo-TEM and single particle analysis of Nautilus pompilius hemocyanin under two states of oxygenation

2007

Extended abstract of a paper presented at MC 2007, 33rd DGE Conference in Saarbrücken, Germany, September 2 – September 7, 2007

Histologic effects of university of wisconsin two-layer method preservation of rat pancreas.

2013

Marginal donors represent a poorly utilized source of organs for transplantation despite their availability. The key is to reduce the ischemic damage in the effort to improve organ quality. This study investigated the histologic effects after in situ perfusion of preservation with a two-layer method compared with the classic University of Wisconsin preservation in term of tissue integrity and number of viable exocrine cells in the rat pancreas both after exsanguination and at 8 weeks of cryopreservation. Pancreata harvested from 60 rats were collected using 3 methods: two-layer method following University of Wisconsin perfusion; exsanguination; and classic University of Wisconsin perfusion/…

Microenvironmental adaptation of experimental tumours to chronic vs acute hypoxia

2004

This study investigated long-term microenvironmental responses (oxygenation, perfusion, metabolic status, proliferation, vascular endothelial growth factor (VEGF) expression and vascularisation) to chronic hypoxia in experimental tumours. Experiments were performed using s.c.-implanted DS-sarcomas in rats. In order to induce more pronounced tumour hypoxia, one group of animals was housed in a hypoxic atmosphere (8% O(2)) for the whole period of tumour growth (chronic hypoxia). A second group was acutely exposed to inspiratory hypoxia for only 20 min prior to the measurements (acute hypoxia), whereas animals housed under normal atmospheric conditions served as controls. Acute hypoxia reduced…

Novel technologies to detect atelectotrauma in the injured lung

2010

ABSTRACTCyclical recruitment and derecruitment of lung parenchyma (R/D) remains a serious problem in ALI/ARDS patients, defined as atelectotrauma. Detection of cyclical R/D to titrate the optimal respiratory settings is of high clinical importance. Image-based technologies that are capable of detecting changes of lung ventilation within a respiratory cycle include dynamic computed tomography (dCT), synchrotron radiation computed tomography (SRCT), and electrical impedance tomography (EIT). Time-dependent intra-arterial oxygen tension monitoring represents an alternative approach to detect cyclical R/D, as cyclical R/D can result in oscillations of PaO2 within a respiratory cycle. Continuous…

An Atypical Case of Taravana Syndrome in Mediterraneo

2010

Dysbaric accidents are usually referred to compressed air-supplied diving. Nonetheless, diving accidents are known to have occurred among breath-hold divers also and some cases are reported in medical literature. A male professional breath hold diver (57 year old) presented neurological disorders as dizziness, sensory numbness, blurred vision and left phronto-parietal pain after many dives to a 30-35 meters seawater depth. He went home after the regression of the symptoms and runned 8 Km the following morning. Pain, sensory numbness and dizziness occurred after running. He went by himself to the hospital where he had a grand mal seizure and lost consciousness. A magnetic resonance imaging o…

The Effects of Flow Waveform on Oxygenation in Pediatric Patients

2015

Polarization-sensitive hyperspectral imaging of human skin: From system design to clinical validation (Conference Presentation)

2020

We present the development and validation of a new approach for quantitative functional imaging of human skin based on the machine learning technique for the analysis of the hyperspectral skin images. The considered skin parameters include blood volume fraction, blood oxygenation, melanin content, and the epidermal layer thickness. Additionally, the degree of residual polarization of the reflected light has been analyzed. The validity of the approach has been confirmed by the initial preclinical tests with the tissue-mimicking phantoms, functional in-vivo skin tests, and pilot clinical study of type II diabetic patients. The proposed technique has great potential to be implemented in clinic…

Impact of oxygenation status and patient age on DNA content in cancers of the uterine cervix.

2003

Abstract Purpose In carcinomas of the uterine cervix, the tumor oxygenation status has been shown to be a prognostic indicator that is independent of treatment modality. In vitro studies suggest gene amplification and polyploidization to be among the major consequences of hypoxia (with or without consecutive reoxygenation) and to be associated with treatment resistance and tumor progression. This study analyzed whether hypoxia alters net DNA content in uterine cervix cancer cells to the extent that it is identifiable by DNA image cytometry. Methods and materials In 64 patients with primary cervical cancer, tumor oxygenation was assessed polarographically and correlated with cell DNA content…

Shallow ocean oxygen decline during the end-Triassic mass extinction

2022

The end-Triassic mass extinction (ETME) was associated with intensified deep-water anoxia in epicontinental seas and mid-depth waters, yet the absolute oxygenation state in the shallow ocean is uncharacterized. Here we report carbonate-associated iodine data from the peritidal Mount Sparagio section (Southern Italy) that documents the ETME (~ 200 Ma) in the western Tethys. We find a sharp drop in carbonate I/(Ca + Mg) ratios across the extinction horizon and persisting into the Early Jurassic. This records local dissolved oxygen and iodate decline in the near-surface ocean of low-latitude Tethys due to the development of depleted oxygen concentrations. Consequently, during the ETME even sha…

Multiple sulfur and carbon isotope composition of sediments from the Belingwe Greenstone Belt (Zimbabwe): A biogenic methane regulation on mass indep…

2013

Abstract To explore the linkage between mass-independent sulfur isotope fractionation (MIF-S) and δ13Corg excursions during the Neoarchean, as well as the contemporary redox state and biogeochemical cycling of carbon and sulfur, we report the results of a detailed carbon and multiple sulfur (δ34S, δ33S, δ36S) isotopic study of the ∼2.7 Ga Manjeri and ∼2.65 Ga Cheshire formations of the Ngezi Group (Belingwe Greenstone Belt, Zimbabwe). Multiple sulfur isotope data show non-zero Δ33S and Δ36S values for sediments older than 2.4 Ga (i.e. prior to the Great Oxidation Event, GOE), indicating MIF-S thought to be associated with low atmospheric oxygen concentration. However, in several 2.7–2.5 Ga …