scholarly journals Early microvascular modifications in patients previously hospitalized for COVID-19: comparison with healthy individuals

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
P Malerba ◽  
C Agabiti Rosei ◽  
M Nardin ◽  
A Gaggero ◽  
G Chiarini ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Healthy Individuals ◽  
Cross Sectional ◽  
Retinal Arterioles ◽  
Wide Range ◽  
Baseline Characteristics ◽  
Microvascular Alterations

Abstract Background SARS-CoV2 infection has been associated to a wide range of clinical scenarios, named COVID-19, ranging from acute respiratory distress syndrome to blood coagulation abnormalities and vascular manifestations related to hyper-inflammation. Recent focus has been addressed to study of microvascular alterations which may explain COVID-19 pathophysiology. Alterations in microvascular structure, identified as increased wall to lumen ratio (WLR) of retinal arterioles, have been extensively described in patients with cardiovascular diseases, such as hypertension or diabetes mellitus. Both inflammation and immune system dysregulation seem to play a role in the pathogenesis of these morphological changes. Purpose Aim of this study was to evaluate through Adaptive Optics microvascular differences of retinal arterioles between patients experienced COVID-19 and controls. Methods Patients were hospitalized between 28th February and 15th April at a Internal Medicine ward in a tertiary care hospital. All patients tested positive for a SARS-CoV-2 nasopharyngeal swab at admission and showed signs of pneumonia and respiratory insufficiency. Adaptive Optics, which allows a non-invasive evaluation of retinal arteriole structure, and blood chemistry exams were performed as part of follow up visits between 2 to 3 months after hospitalization. Baseline characteristics were collected through medical records. COVID-19 patients were compared to age- and sex-matched healthy subjects referred to our center between 2018 and 2019. Results A total of 80 patients were included in this study (of which 40 were COVID-19 patients). Apart from smoking habit, other baseline characteristics (sex, age, cardiovascular risk factors and main comorbidities) did not differ between the two groups. At follow up visit COVID-19 patients showed lower values for leukocytes (6.2 vs. 7.5x103/μL, p=0.015) and lymphocytes (1.9 vs. 2.8x103/μL, p=0.002). Creatinine values were higher in patients who suffered from COVID-19 (1.0 vs 0.8 mg/dl, p=0.004 – Figure 1, panel A). Adaptive Optics showed no differences in terms of internal lumen, wall thickness and WLR of retinal arterioles. However, the wall cross-sectional area (WCSA) was found to be higher in COVID-19 patients (p=0.039 – Figure 1, panel B). Hypertension significantly affected both WCSA and WLR between COVID-19 and healthy individuals, while diabetes only impacted on WLR (Figure 2). Conclusion Previous studies described the presence of leukopenia and lymphopenia during the acute phase of SARS-CoV2 infection. Our study demonstrates that these alterations persist several weeks after symptoms onset. Adaptive Optics showed microvascular alterations occurring in these patients: in particular, higher wall cross-sectional area of retinal arterioles were observed in patients after COVID-19 hospitalization, reflecting the complex pathogenic mechanisms which may explain the wide range of symptoms and clinical severity. FUNDunding Acknowledgement Type of funding sources: None. Figure 1 Figure 2

scholarly journals Cross-sectional area of the paraspinal muscles and its association with muscle strength among fighter pilots: a 5-year follow-up

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Tuomas Honkanen ◽  
Matti Mäntysaari ◽  
Tuomo Leino ◽  
Janne Avela ◽  
Liisa Kerttula ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Paraspinal Muscles ◽  
Cross Sectional

Relationships between Muscle Strength and Cross-Sectional Area in Healthy Individuals

1982 ◽  
Vol 63 (3) ◽  
pp. 5P-5P ◽  
Author(s):  
R.J. Maughan ◽  
Jennifer S. Watson ◽  
J. Weir
Keyword(s):  
Muscle Strength ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Healthy Individuals ◽  
Cross Sectional

scholarly journals Downstream Morphologic Characteristics of the Alluvial Section of Lower River Ogun, Nigeria

2015 ◽  
Vol 8 (1-2) ◽  
pp. 1-10 ◽  
Author(s):  
Olutoyin A. Fashae ◽  
Adetoye Faniran
Keyword(s):  
Cross Sections ◽  
Morphological Characteristics ◽  
Scientific Basis ◽  
River Channel ◽  
Cross Sectional Area ◽  
Correlation Technique ◽  
Sectional Area ◽  
Cross Sectional ◽  
Wide Range ◽  
Wetted Perimeter

Abstract Rivers constitute an important focus of attention in surface water studies because of their dynamic nature. Therefore, natural rivers develop a wide range of channel forms whose characteristics vary as a function of the position within the fluvial systems. This study examined the river channel morphologic parameters along the alluvial section of River Ogun in South western Nigeria. Data on the channel morphologic variables were collected through field measurement of the bankfull cross sectional characteristics of the river from where the longitudinal characteristics were defined. 48 cross sections were randomly established at bankfull stage along the river channel stretch of 90 km. Bankfull depth and width at each of the cross sections were determined using sonar (electronic sounding machine) that was mounted to a boat. Velocity was measured with the aid of a current meter, while other morphological parameters were estimated from the field data. Analysis of variance revealed that downstream morphological characteristics of the river varies distinctively at each cross section with bedslope as the most significantly varied among all other morphologic parameters (F=91.18; P=0.00). Pearson product moment correlation technique revealed that bankfull width had a correlation of 0.8 and 0.9 with wetted perimeter and cross sectional area respectively while bankfull depth (maximum) had correlations of 0.9, 0.8 and 0.78 with hydraulic radius, wetted perimeter and cross sectional area respectively. The research also revealed that gradient affects the discharge with a positive correlation of 0.9. The study ascertains the extent of variability in the morphologic characteristic of River Ogun which provides scientific basis for river maintenance and management.

scholarly journals Variability of the Suspended Particle Cross-Sectional Area in the Bohai Sea and Yellow Sea

2019 ◽  
Vol 11 (10) ◽  
pp. 1187 ◽  
Author(s):  
Qiong Tang ◽  
Shengqiang Wang ◽  
Zhongfeng Qiu ◽  
Deyong Sun ◽  
Muhammad Bilal
Keyword(s):  
Optical Properties ◽  
Yellow Sea ◽  
Bohai Sea ◽  
Suspended Particles ◽  
Cross Sectional Area ◽  
The Yellow Sea ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Bohai Sea ◽  
Wide Range

A cross-sectional area (CSA) is a key element in the optical properties of suspended particles. The seasonal evolution of CSA has great potential for use in mapping total suspended particles, and such mapping plays an important role in water quality monitoring. In this study, the spatiotemporal variations in CSA in the Bohai Sea and the Yellow Sea were studied using temperature, salinity and chlorophyll-a data collected by four cruises. The CSA field data covered a wide range of spatiotemporal variabilities in the Bohai Sea and the Yellow Sea. The results revealed that the largest CSA (>2 m−1) was found in the coastal area, while the CSA (≤1 m−1) on the outer shelf was much smaller. Large values of CSA (>15 m−1) were observed in winter, whereas the smallest values of CSA (0~2 m−1) were observed in summer. These results suggest that vertical mixing and ocean stratification might be important physical mechanisms that influences the CSA seasonal distribution in the surface layer. The results also showed that phytoplankton played an important role in the CSA, with an R2 value of 0.601. The seasonal patterns of CSA documented in this study provide a fundamental theory for research on optical properties, mapping transparency, and photosynthetically active radiation.

scholarly journals Childhood hydrocephalus secondary to posterior fossa tumor is both an intra- and extraaxial process

2016 ◽  
Vol 18 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Grant A. Bateman ◽  
Mark Fiorentino
Keyword(s):  
Posterior Fossa ◽  
Postoperative Period ◽  
Cross Sectional Area ◽  
Venous Sinus ◽  
Third Ventriculostomy ◽  
Adaptation Period ◽  
Sectional Area ◽  
Cross Sectional ◽  
Childhood Hydrocephalus

OBJECTIVE Ventricular dilation secondary to tumor obstruction of the posterior fossa CSF outflow in childhood is an intraaxial process. However, third ventriculostomy or complete tumor removal often fails to reduce the pressure in some children, and in others there is a delayed reduction in intracranial pressure; this is termed the adaptation period. The cause of this adaptation period has not been studied. Venous sinus compression is highly correlated with other forms of childhood hydrocephalus, and this study seeks to follow the changes that occur in sinus cross-sectional area after surgery. METHODS Twelve children with posterior fossa tumors underwent MRI examination that included standard T2-weighted and 3D contrast-enhanced images obtained preoperatively, in the immediate postoperative period, and after several months. The volumes of the lateral and third ventricles and the minimum cross-sectional area of the transverse and sigmoid sinuses were measured. Patients were categorized by 1) shunt status (those who required a shunt vs those who did not) and 2) by age (those younger than 3 years vs those older than 3 years at diagnosis). RESULTS There was a significant reduction in ventricular volume in both the immediate and secondary follow-up periods for all patients. There was preoperative venous sinus compression in all groups, which did not change significantly in the immediate postoperative period but did improve in the secondary follow-up period. The younger children had larger ventricles and smaller sinuses before surgery compared with the older children. CONCLUSIONS In children with obstructed hydrocephalus caused by tumor, there is secondary compression of venous outflow, indicating both an intra- and extraaxial process. The expansion of the sinuses following decompression of the posterior fossa is delayed and may correlate with the adaptation period. Younger children have greater sinus compression than older ones.

scholarly journals Caecilian jaw-closing mechanics: integrating two muscle systems

2008 ◽  
Vol 5 (29) ◽  
pp. 1491-1504 ◽  
Author(s):  
Thomas Kleinteich ◽  
Alexander Haas ◽  
Adam P Summers
Keyword(s):  
Bite Force ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Lever Arm ◽  
Mandibular Joint ◽  
Wide Range ◽  
Jaw Joint ◽  
Muscle Groups ◽  
Using Data

Caecilians (Lissamphibia: Gymnophiona) are unique among vertebrates in having two sets of jaw-closing muscles, one on either side of the jaw joint. Using data from high-resolution X-ray radiation computed tomography scans, we modelled the effect of these two muscle groups ( mm. levatores mandibulae and m. interhyoideus posterior ) on bite force over a range of gape angles, employing a simplified lever arm mechanism that takes into account muscle cross-sectional area and fibre angle. Measurements of lever arm lengths, muscle fibre orientations and physiological cross-sectional area of cranial muscles were available from three caecilian species: Ichthyophis cf. kohtaoensis ; Siphonops annulatus ; and Typhlonectes natans . The maximal gape of caecilians is restricted by a critical gape angle above which the mm. levatores mandibulae will open the jaw and destabilize the mandibular joint. The presence of destabilizing forces in the caecilian jaw mechanism may be compensated for by a mandibular joint in that the fossa is wrapped around the condyle to resist dislocation. The caecilian skull is streptostylic; the quadrate–squamosal complex moves with respect to the rest of the skull. This increases the leverage of the jaw-closing muscles. We also demonstrate that the unusual jaw joint requires streptostyly because there is a dorsolateral movement of the quadrate–squamosal complex when the jaw closes. The combination of the two jaw-closing systems results in high bite forces over a wide range of gape angles, an important advantage for generalist feeders such as caecilians. The relative sizes and leverage mechanics of the two closing systems allow one to exert more force when the other has a poor mechanical advantage. This effect is seen in all three species we examined. In the aquatic T. natans , with its less well-roofed skull, there is a larger contribution of the mm. levatores mandibulae to total bite force than in the terrestrial I . cf. kohtaoensis and S. annulatus .

Cross-sectional area of the posterior extensor muscles of the cervical spine in whiplash injury patients versus healthy volunteers – 10year follow-up MR study

Injury ◽  
2012 ◽  
Vol 43 (6) ◽  
pp. 912-916 ◽  
Author(s):  
Morio Matsumoto ◽  
Daisuke Ichihara ◽  
Eijiro Okada ◽  
Kazuhiro Chiba ◽  
Yoshiaki Toyama ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Healthy Volunteers ◽  
Whiplash Injury ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Extensor Muscles ◽  
Mr Study

Increased carotid cross-sectional area is a marker of organ damage in young hypertensive patients

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M De Marco ◽  
C Mancusi ◽  
G Canciello ◽  
M.G Losi ◽  
B Trimarco ◽  
...  
Keyword(s):  
Atherosclerotic Plaque ◽  
Carotid Plaque ◽  
Organ Damage ◽  
Left Ventricular ◽  
Cross Sectional Area ◽  
Prognostic Impact ◽  
Sectional Area ◽  
Cross Sectional ◽  
Hypertensive Patients

Abstract Background Common Carotid artery (CA) cross sectional area (CCSA) is strictly related to vessel remodelling stimulated by mechanical stress due to arterial hypertension. Accordingly, increased CCSA might represent an early marker of vascular target organ damage independently of presence of atherosclerotic plaque. Purpose To assess early correlates and prognostic impact of CCSA in a large population of young treated HTN patients. Methods We selected 970 hypertensive patients, 18 to 40 years old (mean age 34±5 yrs; 30% women) of the Campania Salute Network registry with available CA ultrasound and follow-up data, free of overt cardiovascular (CV) disease. CCSA was computed as: CCSA = π [(CAd/2 + IMT)2 – (CAd/2)2] where CAd = CA diameter and IMT = mean intima media thickness. Participants were compared by CCSA tertiles. Results Compared to the lowest and intermediate tertiles, patients in the highest tertile were more often male, smokers, older, and had higher body mass index (BMI), diastolic blood pressure (BP), higher fasting glucose, triglycerides, LDL cholesterol and uric acid, with lower level of HDL cholesterol. They also exhibited higher left ventricular mass index and IMT and had more often carotid atherosclerotic plaque (all p<0.05). During a median follow-up of 45 months, 22 incident composite CV events occurred. In Cox-Regression analyses, adjusting for the above covariates, presence of carotid plaque and classes of antihypertensive medications, increased CCSA was significantly associated with increased CV risk (HR 1.08/mm2; 95% CI 1.02–1.13; p<0.01). Conclusions In a population of young hypertensive patients, increased CCSA is related to metabolic and atherosclerotic disease and is associated with increased CV risk, also independently of overt carotid plaque. Funding Acknowledgement Type of funding source: None

scholarly journals POS0593 THE REDUCTION OF RETINAL MICROVASCULAR ALTERATIONS AND THE DECREASE OF A POTENTIALLY RELATED T-CELL SUBSET IN PATIENTS WITH ACTIVE RHEUMATOID ARTHRITIS TREATED WITH ABATACEPT

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 530.1-530
Author(s):  
S. Piantoni ◽  
F. Regola ◽  
S. Masneri ◽  
C. Nalli ◽  
C. Bazzani ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Risk Factors ◽  
T Cells ◽  
T Cell ◽  
Cell Number ◽  
Sectional Area ◽  
Microvascular Damage ◽  
Cross Sectional ◽  
Retinal Arterioles ◽  
Microvascular Alterations

Background:T-cells play a pivotal role in the pathogenesis of rheumatoid arthritis (RA) and in its cardiovascular (CV) comorbidities, acting at microvascular level [1]. Since small artery remodeling is the earliest form of target organ damage in hypertension, the evaluation of microvascular alterations might provide clinically useful information. The evaluation of retinal arterioles is a non-invasive technique to identify a precocious microvascular damage, which is related to an increase of the wall-to-lumen ratio (WLR) [2]. CD3+CD31+CXCR4+ T-cells may be involved in damaged endothelium repair and are increased in patients with morphological microvascular alterations [3]. In addition to its effect on disease activity, abatacept (ABA), a co-stimulator blocker which is approved for the treatment of RA, may have specific CV protective action, modulating the numbers of certain subtypes of lymphocytes [4].Objectives:To non-invasively investigate morphological characteristics of retinal arterioles and to evaluate CD3+CD31+CXCR4+T-cells in a cohort of RA patients treated with ABA.Methods:Eleven RA patients [median (25th-75thpercentile) age=58 (50-65) years, baseline C-reactive protein (CRP)-DAS28=4.4 (3.8-4.6), body mass index (BMI)=23.4 (21.6-25.6) kg/m2, rheumatoid factor (RF) positive:45%, anti-citrullinated peptide autoantibodies (ACPA) positive:73%] without known CV risk factors (arterial hypertension, diabetes, hypercholesterolemia, previous CV events, smoking) were evaluated by adaptive optics, a validated technique quantifying microvascular damage [5], before and every 6 months of therapy with ABA (T0, T6 and T12). Phenotypic analysis of peripheral blood T lymphocytes was made by flow-cytometry in 5 patients of the cohort at T0 and T6.Results:A progressive significant reduction of the WLR of retinal arterioles was observed [T0=0.28 (0.25-0.30), T6=0.27 (0.24-0.31), T12=0.23 (0.23-0.26); p T0 vs T6=0.4; p T6 vs T12=0.01; p T0 vs T12=0.01] (Figure 1), without significant variations in the other parameters [internal diameter: T0=94.4 (84.1-104.0), T6=94.8 (84.6-107.7), T12=99.2 (89.1-109.1) µm; external diameter: T0=125.8 (111.1-131.0), T6=122.4 (109.1-134.5), T12=125.6 (113.9-134.4) µm; wall thickness: T0=13.2 (12.2-14.4), T6=13.4 (11.7-14.4), T12=12.5 (11.6-13.0) µm; wall cross-sectional area: T0=4581.0 (3788.7-5263.7), T6=4563.3 (3788.5-5295.2), T12=4099.7 (3899.0-5145.7) µm2)]. In 5 patients evaluated also for T-cell immunophenotyping a negative correlation was observed between CD3+CD31+CXCR4+ T-cell number and the retinal wall thickness at baseline (R=0.871;p=0.05). After ABA therapy a trend for reduction of CD3+CD31+CXCR4+T-cells [19.0 (13.8-38.3) vs 12.4 (5.2-18.0) % of CD3+], was observed as well as of significant reduction of retinal wall cross-sectional area [5123.3 (4385.0-5470.3) vs 4852.3 (4118.3-5228.0) µm2;p=0.04].Conclusion:In a cohort of RA patients without known CV risk factors, a reduction in retinal microvascular alterations arterioles was demonstrated after treatment for 12 months with ABA. CD3+CD31+CXCR4+T-cell number was inversely related to the possible presence of subclinical CV involvement. These results may suggest the possibility of microvascular abnormalities regression induced by the immune system modulation.References:[1]Dessein PH, J Rheumatol 2005.[2]Rizzoni D, Am J Hypertens. 2018.[3]Hur J, Circulation 2007.[4]Kallikourdis M, Nat Commun 2017.[5]De Ciuceis C, J Hypertens 2018.Acknowledgements:Bristol-Myers-Squibb Italy provided an unrestricted research grant for the study conduct.Figure 1.Disclosure of Interests:None declared

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