scholarly journals Optic disc centered imaging versus quadrant imaging in retinal oximetry

2018 ◽  
Author(s):  
Ashwin Mohan ◽  
Rohit Shetty ◽  
Padmamalini Mahendradas ◽  
Carroll AB Webers ◽  
Tos TJM Berendschot
Keyword(s):  
Oxygen Saturation ◽  
Optic Disc ◽  
Negative Correlation ◽  
Healthy Subjects ◽  
Retinal Vessel ◽  
Positive Correlation ◽  
Retinal Oximetry

AbstractWe aimed to compare intra eye quadrant variation in retinal vessel oxygen saturation in optic disc centered versus quadrant imaging. Forty two consecutive healthy subjects were included in the study. Fifty degree optic disc centered images and images of 4 quadrants (supero-temporal - ST, supero-nasal - SN, infero-nasal - IN and infero-temporal - IT) were taken. The thickest arteriole and venule were chosen in each quadrant in the optic disc centered images. For quadrant images averaged values of 3 segments of thickest arterioles and venules, each above 100µm were chosen. The intra-eye variation between quadrants for arteriolar and venous saturation (%) was compared between optic disc centered and quadrant images. Smaller vessels (70 – 100 µm) in the quadrant images were selected to study the effect of vessel calibre on oxygen saturation. Optic disc centered images gave average arteriolar saturation (%) of 90, 94, 93 and 89 and venous saturation of 58, 60, 60 and 52 in the ST, SN, IN and IT respectively. For quadrant images the average arteriolar saturation was 94, 95, 94 and 91 and the venous saturation was 62, 60, 61 and 60 in the ST, SN, IN and IT respectively. Temporally, the saturation values were significantly different (p<0.001) between optic disc centered and quadrant images. We found no differences nasally. The average intra eye range for arterioles was 11.9 in optic disc centered versus 7.1 in quadrant images (p<0.001) and for venules was 11.6 in optic disc centered versus 7.5 in quadrant images (p<0.001). We found a positive correlation of r=0.18 between saturation and vessel calibre for arteries (p=0.001) and a negative correlation of r=-0.52 for venes (p<0.001). Quadrant imaging significantly reduced intra eye variation between quadrant measurements indicating that maybe the larger variation observed in optic disc centered images are artefactual. Differences in saturation between optic disc centered and quadrant imaging were only seen temporally. We also see physiologically reducing saturation from large arterioles to small arterioles to small venules to large venules.

scholarly journals Automation improves repeatability of retinal oximetry measurements

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260120
Author(s):  
Robert Arnar Karlsson ◽  
Olof Birna Olafsdottir ◽  
Vedis Helgadottir ◽  
Soumaya Belhadj ◽  
Thorunn Scheving Eliasdottir ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Intraclass Correlation ◽  
Retinal Vessel ◽  
Vessel Diameter ◽  
Automated Measurements ◽  
Automation Of Measurements ◽  
Image Pairs ◽  
The Right ◽  
Measurement Area ◽  
Retinal Oximetry

Purpose Retinal oximetry is a technique based on spectrophotometry where images are analyzed with software capable of calculating vessel oxygen saturation and vessel diameter. In this study, the effect of automation of measurements of retinal vessel oxygen saturation and vessel diameter is explored. Methods Until now, operators have had to choose each vessel segment to be measured explicitly. A new, automatic version of the software automatically selects the vessels once the operator defines a measurement area. Five operators analyzed image pairs from the right eye of 23 healthy subjects with semiautomated retinal oximetry analysis software, Oxymap Analyzer (v2.5.1), and an automated version (v3.0). Inter- and intra-operator variability was investigated using the intraclass correlation coefficient (ICC) between oxygen saturation measurements of vessel segments in the same area of the retina. Results For semiautomated saturation measurements, the inter-rater ICC was 0.80 for arterioles and venules. For automated saturation measurements, the inter-rater ICC was 0.97 for arterioles and 0.96 for venules. For semiautomated diameter measurements, the inter-rater ICC was 0.71 for arterioles and venules. For automated diameter measurements the inter-rater ICC was 0.97 for arterioles and 0.95 for venules. The inter-rater ICCs were different (p < 0.01) between the semiautomated and automated version in all instances. Conclusion Automated measurements of retinal oximetry values are more repeatable compared to measurements where vessels are selected manually.

scholarly journals Macular Retinal Vessel Oxygen Saturation Elevation in Chinese Central Serous Chorioretinopathy

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Cheng Li ◽  
Xiaoxiao Feng ◽  
Xin Wen ◽  
Xiaobing Qian ◽  
Qishan Zheng ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Optic Disc ◽  
Central Serous Chorioretinopathy ◽  
Retinal Vessel ◽  
Chinese Patients ◽  
Retinal Arteriole ◽  
Retinal Blood Vessels ◽  
Disc Area ◽  
The Mean ◽  
Arteriovenous Difference

Purpose. To evaluate the retinal vessel oxygen saturation in central serous chorioretinopathy (CSC) cases among the Chinese. Methods. Relative oxygen saturation of retinal blood vessels was measured in 33 Chinese patients with single-eye CSC using the Oxymap T1 retinal oximeter. The contralateral eyes were the control. The mean saturation of the retinal arteriole (AS) and venule (VS), arteriovenous difference (AVS), and arteriole and venule diameters (AD, VD) was analyzed in the optic disc area and macular region. Results. In the optic disc area, the inferotemporal quadrant (TI) AS (93.2 ± 10.2%) and inferonasal quadrant (NI) VS (61.3 ± 7.3%) were higher in the affected eyes than in the contralateral eyes (88.7 ± 7.7% and 56.9 ± 6.5%) and AVS in NI (36.7 ± 10.4%) decreased compared to the contralateral eyes (41.5 ± 11.2%). The VD in TI was expanded (19.9 ± 2.5 pixels versus 18.1 ± 3.4 pixels). Around the macular region, AS was 93.6 ± 7.6%, higher than in the contralateral eyes (89.5 ± 6.3%). No other significant changes were found. Conclusions. AS increased in the TI, and VS decreased in the NI in the eyes with CSC. In addition, AS also increased around the macular region, suggesting that these are contributors to CSC pathophysiology.

scholarly journals Automation improves repeatability of retinal oximetry measurements

2021 ◽  
Author(s):  
Robert Arnar Karlsson ◽  
Olof Birna Olafsdottir ◽  
Soumaya Belhadj ◽  
Vedis Helgadottir ◽  
Thorunn Scheving Eliasdottir ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Intraclass Correlation ◽  
Retinal Vessel ◽  
Vessel Diameter ◽  
Automated Measurements ◽  
Automation Of Measurements ◽  
Image Pairs ◽  
The Right ◽  
Measurement Area ◽  
Retinal Oximetry

AbstractPurposeRetinal oximetry is a technique based on spectrophotometry where images are analyzed with software capable of calculating vessel oxygen saturation and vessel diameter. In this study, the effect of automation of measurements of retinal vessel oxygen saturation and vessel diameter is explored.MethodsUntil now, operators have had to choose each vessel segment to be measured explicitly. A new, automatic version of the software automatically selects the vessels once the operator defines a measurement area.Five operators analyzed image pairs from the right eye of 23 healthy subjects with semiautomated retinal oximetry analysis software, Oxymap Analyzer (v2.5.1), and an automated version (v3.0). Inter- and intra-operator variability was investigated using the intraclass correlation coefficient (ICC) between oxygen saturation measurements of vessel segments in the same area of the retina.ResultsFor manual saturation measurements, the inter-rater ICC was 0.80 for arterioles and venules. For automated saturation measurements, the inter-rater ICC was 0.97 for arterioles and 0.96 for venules. For manual diameter measurements, the inter-rater ICC was 0.71 for arterioles and venules. For automated diameter measurements the inter-rater ICC was 0.97 for arterioles and 0.95 for venules. The inter-rater ICCs were different (p < 0.01) between the semiautomated and automated version in all instances.ConclusionAutomated measurements of retinal oximetry values are more repeatable compared to measurements where vessels are selected manually.

Correlation of Phraseological Semantic Fields in Russian Study of Aphorisms

2020 ◽  
pp. 60-71
Author(s):  
Anshelika Korolkova
Keyword(s):  
Negative Correlation ◽  
Semantic Field ◽  
Positive Correlation ◽  
Classical Study ◽  
Semantic Fields ◽  
Zero Correlation ◽  
Russian Study

The article deals with the interconnection and interdependence of phraseological semantic fields of Russian study of aphorisms in synchronic and in diachronic approaches. The correlation of phraseological semantic fields of Russian study of aphorisms is considered as their interdependence due to various factors (linguistic and extra-linguistic ones). The correlation of the phraseological semantic fields of Russian study of aphorisms is manifested in the existence of many antinomies. The natural linguistic antinomies of life / death / immortality or war / peace, or good / evil, or friend / enemy, or villainy / nobility are reflected in Russian aphorisms and have entered the corresponding phraseological semantic fields. The corpus of Russian study of aphorisms containsnot only antinomic aphorisms, but also antinomic relations that extend to the level of language and speech. Therefore, in Russian study of aphorisms there are phraseological semantic fields that implement these antinomies. In addition to the antinomic phraseological semantic fields in the corpus of classical Russian study of aphorisms there are other types of correlations. The keywords (concepts) of many phraseological semantic fields are closely thematically connected. When the number of units from one field is changed, the number of units in another phraseological semantic field also changes. Most phraseological semantic fields of Russian study of aphorisms do not show a zero correlation in either synchronic or diachronic approaches. This is due to, first of all, the universality of the aphoristic theme, with all the ideological and thematic uniqueness of the sayings used by Russian writers. However, a few phraseological and semantic fields of aphorisms by Russian writers may show a negative correlation, which is due to the diversity of the thematic groups that comprise them. A positive correlation of phraseological semantic fields, the most significant in the number of their constituent components, shows deep internal linguistic systemic connections in Russian classical study of aphorisms.

scholarly journals Correlates of SARS-CoV-2 Variants on Deaths, Case Incidence and Case Fatality Ratio among the Continents for the Period of 1 December 2020 to 15 March 2021

Genes ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 1061
Author(s):  
Wajdy J. Al-Awaida ◽  
Baker Jawabrah Al Hourani ◽  
Samer Swedan ◽  
Refat Nimer ◽  
Foad Alzoughool ◽  
...  
Keyword(s):  
Negative Correlation ◽  
Significant Positive Correlation ◽  
Vaccine Development ◽  
Case Fatality ◽  
Significant Negative Correlation ◽  
Reference Sequence ◽  
Genome Sequences ◽  
Positive Correlation ◽  
Case Fatality Ratio ◽  
Epidemiological Surveys

The outbreak of coronavirus disease 2019 (COVID-19), by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has quickly developed into a worldwide pandemic. Mutations in the SARS-CoV-2 genome may affect various aspects of the disease including fatality ratio. In this study, 553,518 SARS-CoV-2 genome sequences isolated from patients from continents for the period 1 December 2020 to 15 March 2021 were comprehensively analyzed and a total of 82 mutations were identified concerning the reference sequence. In addition, associations between the mutations and the case fatality ratio (CFR), cases per million and deaths per million, were examined. The mutations having the highest frequencies among different continents were Spike_D614G and NSP12_P323L. Among the identified mutations, NSP2_T153M, NSP14_I42V and Spike_L18F mutations showed a positive correlation to CFR. While the NSP13_Y541C, NSP3_T73I and NSP3_Q180H mutations demonstrated a negative correlation to CFR. The Spike_D614G and NSP12_P323L mutations showed a positive correlation to deaths per million. The NSP3_T1198K, NS8_L84S and NSP12_A97V mutations showed a significant negative correlation to deaths per million. The NSP12_P323L and Spike_D614G mutations showed a positive correlation to the number of cases per million. In contrast, NS8_L84S and NSP12_A97V mutations showed a negative correlation to the number of cases per million. In addition, among the identified clades, none showed a significant correlation to CFR. The G, GR, GV, S clades showed a significant positive correlation to deaths per million. The GR and S clades showed a positive correlation to number of cases per million. The clades having the highest frequencies among continents were G, followed by GH and GR. These findings should be taken into consideration during epidemiological surveys of the virus and vaccine development.

scholarly journals Study of Short Latency Somatosensory and Brain Stem Auditory Evoked Potentials Patients with Acute Ischemic Stroke Involving Middle Cerebral Artery Territory

2021 ◽  
Author(s):  
Abhishek Miryala ◽  
Mahendra Javali ◽  
Anish Mehta ◽  
Pradeep R. ◽  
Purushottam Acharya ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Evoked Potentials ◽  
Middle Cerebral Artery ◽  
Acute Ischemic Stroke ◽  
Brain Stem ◽  
Functional Outcome ◽  
Cerebral Artery ◽  
Negative Correlation ◽  
Auditory Evoked Potentials ◽  
Positive Correlation

Abstract Background The precise timings of evoked potentials in evaluating the functional outcome of stroke have remained indistinct. Few studies in the Indian context have studied the outcome of early prognosis of stroke utilizing evoked potentials. Objective The aim of this study was to determine somatosensory evoked potentials (SSEPs) and brain stem auditory evoked potentials (BAEPs), their timing and abnormalities in acute ischemic stroke involving the middle cerebral artery (MCA) territory and to correlate SSEP and BAEP with the functional outcome (National Institutes of Health Stroke Scale (NIHSS), modified Rankin scale (mRS) and Barthel’s index) at 3 months. Methods MCA territory involved acute ischemic stroke patients (n = 30) presenting consecutively to the hospital within 3 days of symptoms onset were included. Details about clinical symptoms, neurological examination, treatment, NIHSS score, mRS scores were collected at the time of admission. All patients underwent imaging of the brain and were subjected to SSEP and BAEP on two occasions, first at 1 to 3 days and second at 4 to 7 days from the onset of stroke. At 3 months of follow-up, NIHSS, mRS, and Barthel’s index were recorded. Results P37 and N20 amplitude had a strong negative correlation (at 1–3 and 4–7 days) with NIHSS at admission, NIHSS at 3 months, mRS at admission, and mRS at 3 months and a significant positive correlation with Barthel’s index (p < 0.0001). BAEP wave V had a negative correlation (at 1–3 and 4–7 days) with NIHSS at admission, NIHSS at 3 months, mRS at admission, and mRS at 3 months and a positive correlation with Barthel’s index (p < 0.0001). Conclusion SSEP abnormalities recorded on days 4 to 7 from onset of stroke are more significant than those recorded within 1 to 3 days of onset of stroke; hence, the timing of 4 to 7 days after stroke onset can be considered as better for predicting functional outcome.

scholarly journals Evaluation of serum adropin and irisin levels and its association with anthropometric obesity indices and biochemical parameters in Type 2 diabetic patients

2021 ◽  
pp. 1-8
Author(s):  
Foad Alzoughool ◽  
Huda Al Hourani ◽  
Manar Atoum ◽  
Sajedah Bateineh ◽  
Hanan Alsheikh ◽  
...  
Keyword(s):  
Negative Correlation ◽  
Biochemical Parameters ◽  
Significant Positive Correlation ◽  
Glycosylated Hemoglobin ◽  
Significant Negative Correlation ◽  
Diabetic Patients ◽  
Positive Correlation ◽  
Obesity Indices ◽  
Group Serum

BACKGROUND/AIM: The newly described proteins adropin and irisin are a highly conserved polypeptide that plays essential roles in metabolic and energy homeostasis, insulin resistance, and fat browning. The aim of this study is to evaluate the circulating levels of serum adropin and irisin in type 2 diabetes mellitus (T2DM) patients and also to elucidate possible relationships between serum adropin and irisin levels with anthropometric obesity indices and biochemical parameters. SUBJECTS AND METHODS: Single-center prospective observational study included 90 T2DM patients referred to the diabetes outpatient clinic. Height, weight, and waist circumference (WC) were measured. Body mass index (BMI) and waist to height ratio (WHtR) were calculated. Fasting blood glucose, glycosylated hemoglobin, serum lipids, creatinine, urea, and blood urea nitrogen were evaluated. Estimated glomerular filtration rate (GFR) was calculated, serum adropin and irisin were evaluated. RESULTS: The results showed a significant positive correlation between adropin and irisin in females but not in males (r = 0.311; P = 0.042). In males’ group, serum adropin levels showed significant negative correlation with serum glucose (–0.423, P = <  0.05), HbA1C (–0.364, P = <  0.05), and GFR (–0.355, P = <  0.05). In contrast, creatinine was showed a significant positive correlation with adropin in males (0.381, P = <  0.05). In females’ group, adropin showed a significant negative correlation with weight (–0.371, P = <  0.05), BMI (–0.349, P = <  0.05), WC (–0.402, P = <  0.01), and WHtR (–0.398, P = <  0.01). Contrary, in males’ group, serum irisin levels showed significant positive correlation with weight (0.338, P = <  0.05), BMI (0.332, P = <  0.05), WC (0.409, P = <  0.01), and WHtR (0.432, P = <  0.01). CONCLUSION: This study demonstrated that, in T2DM patients, circulating serum adrpoin correlated negatively with anthropometric obesity indices of obesity in females, while serum irisin was positively correlated with anthropometric obesity indices of obesity in males.

Increased plasma kynurenine and its relationship to neopterin and tryptophan in Tourette's syndrome

1996 ◽  
Vol 26 (4) ◽  
pp. 857-862 ◽  
Author(s):  
H. Rickards ◽  
S. M. Dursun ◽  
G. Farrar ◽  
T. Betts ◽  
J. A. Corbett ◽  
...  
Keyword(s):  
Tourette Syndrome ◽  
Negative Correlation ◽  
Plasma Levels ◽  
Significant Positive Correlation ◽  
Significant Negative Correlation ◽  
Healthy Controls ◽  
Positive Correlation ◽  
Control Value ◽  
Cellular Immune ◽  
Patient Value

SynopsisFasting plasma levels of tryptophan, kynurenine and the pteridines, neopterin and tetrahydrobiopterin were measured in seven patients with Gilles de la Tourette syndrome (GTS) and 10 healthy controls. Plasma kynurenine was significantly elevated in the GTS patients. The lowest patient value was higher than the highest control value. Values for tryptophan, neopterin and tetrahydrobiopterin were similar in TS patients and controls. However, in TS patients only, there was a significant negative correlation between tryptophan and neopterin and a significant positive correlation between kynurenine and neopterin when controlling for tryptophan. This finding indicates that activation of cellular immune processes is a possible explanation for the rise in plasma kynurenine.

Effect of Age on Oxygen-Binding in Normal Human Subjects

1976 ◽  
Vol 51 (2) ◽  
pp. 185-188
Author(s):  
P. M. Tweeddale ◽  
R. J. E. Leggett ◽  
D. C. Flenley
Keyword(s):  
Oxygen Saturation ◽  
Oxygen Tension ◽  
Inorganic Phosphate ◽  
Human Subjects ◽  
Oxygen Binding ◽  
Corpuscular Haemoglobin ◽  
Positive Correlation ◽  
Normal Human ◽  
Mean Corpuscular Haemoglobin ◽  
Effect Of Age

1. Oxygen-binding, plasma and intra-erythrocytic pH, and haemoglobin, 2,3-diphosphoglycerate and inorganic phosphate concentrations were measured in sixty-two healthy non-smokers aged between 18 and 89 years. 2. P50 (oxygen tension at 50% oxygen saturation) expressed at plasma pH 7·40 and Pco2 5·33 kPa showed a positive correlation with age. 3. This correlation of P50 with age was closer when P50 was expressed at a constant intra-erythrocytic pH 7·20. On average P50 at intra-erythrocytic pH 7·20 increased from 3·59 kPa at 20 years to 3·96 kPa at 90 years of age. 4. 2,3-Diphosphoglycerate, inorganic phosphate, haemoglobin and mean corpuscular haemoglobin concentrations did not correlate with P50 or with age.

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