First-In-Human Study in Cancer Patients Establishing the Feasibility of Oxygen Measurements in Tumors Using Electron Paramagnetic Resonance With the OxyChip

ObjectiveThe overall objective of this clinical study was to validate an implantable oxygen sensor, called the ‘OxyChip’, as a clinically feasible technology that would allow individualized tumor-oxygen assessments in cancer patients prior to and during hypoxia-modification interventions such as hyperoxygen breathing.MethodsPatients with any solid tumor at ≤3-cm depth from the skin-surface scheduled to undergo surgical resection (with or without neoadjuvant therapy) were considered eligible for the study. The OxyChip was implanted in the tumor and subsequently removed during standard-of-care surgery. Partial pressure of oxygen (pO2) at the implant location was assessed using electron paramagnetic resonance (EPR) oximetry.ResultsTwenty-three cancer patients underwent OxyChip implantation in their tumors. Six patients received neoadjuvant therapy while the OxyChip was implanted. Median implant duration was 30 days (range 4–128 days). Forty-five successful oxygen measurements were made in 15 patients. Baseline pO2 values were variable with overall median 15.7 mmHg (range 0.6–73.1 mmHg); 33% of the values were below 10 mmHg. After hyperoxygenation, the overall median pO2 was 31.8 mmHg (range 1.5–144.6 mmHg). In 83% of the measurements, there was a statistically significant (p ≤ 0.05) response to hyperoxygenation.ConclusionsMeasurement of baseline pO2 and response to hyperoxygenation using EPR oximetry with the OxyChip is clinically feasible in a variety of tumor types. Tumor oxygen at baseline differed significantly among patients. Although most tumors responded to a hyperoxygenation intervention, some were non-responders. These data demonstrated the need for individualized assessment of tumor oxygenation in the context of planned hyperoxygenation interventions to optimize clinical outcomes.

Refining the use of oxygen consumption as a proxy corrosion rate measure for archaeological and historic iron

Since its introduction to the field of heritage science, oxygen consumption has found multiple applications in the assessment of artefact stability and the examination of conservation treatment efficiencies. Early papers identified various factors affecting oxygen measurements and produced preliminary data on their effects. This paper follows on from the early research by other workers and presents guidance on the application of oxygen consumption as a proxy corrosion rate measurement based on a decade of experience at Cardiff University. It examines the rationale for key aspects of the Cardiff protocols for oxygen consumption and presents data to underpin these. Finally, it provides instructional guidance for heritage scientists adopting oxygen consumption for their research applications.

Peripheral oxygen measurements in suspected elderly COVID-19 patients can be an effective tool for alerting physicians

Since December 2019 the world has been facing a newly identified coronavirus named SarsCov-2 which is the causative agent of COVID-19 that produces different symptoms. One of these symptoms is asymptomatic hypoxia, particularly in elderly patients. Despite the absence of signs of respiratory distress, many patients evolve to respiratory failure. The cause of this asymptomatic hypoxia remains unclear; therefore our goal was to evaluate the utility of peripheral oxygen measurements using oximetry in elderly patients with suspected COVID-19 and with no apparent signs of shortness of breath, during 10 consecutive days. Every elderly patient with suspected COVID-19 who sought medical care at one of the 12 Primary Health Unit (PHU) in the South-West area of Campinas, Sao Paulo State was enrolled in the 10-days monitoring report. Each patient had the levels of oxygen saturation (SpO2) monitored by pulse oximeter from the fifth to the tenth days after the onset of symptoms and, when possible, twice a day; 1297 patients (pts) were followed during the period from August 2020 to February 2021. A total of 9023 measurements were carried out using a SpO2 pulse oximeter. 163 (12.5%) cases were referred to the Emergency Room and 37 (3%) had to be hospitalized. The highest frequencies of symptoms occurred during the 6th and 8th day and included cough (16.8%), fatigue (12.8%), headache (9.7%), loss of taste and/or smell (6.8%). Among the patients who were hospitalized, 13 died (1%). The asymptomatic hypoxia remains unclear; however, the measurement of SpO2 levels appears to be a cheap and effective tool to be used as an alert system for further evaluation.

Kelkit Çayı (Tokat) Epilitik Diyatomeleri

In this study, monthly variations of epilithic diatoms in Kelkit Creek (Tokat) were studied from stone samples taken from two stations between March - December 2018: one station below the settlement area and the other one below agricultural areas. During this study, 18 taxa which belong to epilithic diatoms were recorded. Cymbella (3 taxa) and Nitzschia (3 taxa) were the diatoms mostly represented by the taxa, and Ulnaria ulna had the highest relative density recorded in both stations throughout the months. Sorensen Similarity Index was calculated as %56.41 between the two station diatoms. Also, temperature and dissolved oxygen measurements were done on the water samples taken from the stations. The measured variables were confirmed to make positive effects on the growth of diatoms in epiliton. Relative densities of the types of diatoms that were found in the epilithic flora were determined. In hand according to the results, the lowest relative density was recorded as 4.76 in march (Cymbella affinis) at Station 1 and 2.83 in march (Lindavia glomerata) at Station 2. Considering the highest relative density values, Navicula radiosa and Ulnaria ulna species were determined in december (13.56) at Station 1 and in march (9.43) for Ulnaria ulna at Station 2.