Experimental analysis of critical oxygen delivery

2005 ◽  
Vol 288 (3) ◽  
pp. H1071-H1079 ◽  
Author(s):  
Ivo P. Torres Filho ◽  
Bruce D. Spiess ◽  
Roland N. Pittman ◽  
R. Wayne Barbee ◽  
Kevin R. Ward

Systemic variables were evaluated with respect to O2 delivery to test the hypothesis that critical O2 delivery and critical Hb can be estimated by multiple variables collected simultaneously. Rats were subjected to transfusion with either fresh or stored blood and then subjected to stepwise isovolemic hemodilution. Critical levels were measured by the dual-regression method from plots of systemic variables against O2 delivery and Hb. Delivery was calculated from cardiac index and arterial O2 content. We found that 1) after hemodilution, O2 delivery changed in a nonlinear relationship with Hb; 2) critical delivery calculated using 30 different systemic variables was not statistically different from each other; 3) critical delivery and critical Hb were correlated but were not different between animals receiving fresh or stored blood; and 4) similar critical levels were found using a single variable from several animals and using several variables from the same subject. The best variables to estimate critical delivery were lactate, bicarbonate, base excess, O2 extraction ratio, expired CO2, pulse pressure, cardiac index, and systolic pressure. The data suggest that a multivariable analysis of critical delivery may help determine the physiological oxygenation boundary at the whole body level. This may assist in finding therapeutic triggers on an individual basis using systemic markers of the transition from aerobic to anaerobic metabolism.

2008 ◽  
Vol 396-398 ◽  
pp. 569-572
Author(s):  
Fumio Watari ◽  
Shigeaki Abe ◽  
I.D. Rosca ◽  
Atsuro Yokoyama ◽  
Motohiro Uo ◽  
...  

Nanoparticles may invade directly into the internal body through the respiratory or digestive system and diffuse inside body. The behavior of nanoparticles in the internal body is also essential to comprehend for the realization of DDS. Thus it is necessary to reveal the internal dynamics for the proper treatments and biomedical applications of nanoparticles. In the present study the plural methods with different principles such as X-ray scanning analytical microscope (XSAM), MRI and Fluorescent microscopy were applied to enable the observation of the internal diffusion of micro/nanoparticles in the (1) whole body level, (2) inner organ level and (3) tissue and intracellular level. Chemical analysis was also done by ICP-AES for organs and compared with the results of XSAM mapping.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 660.2-660
Author(s):  
J. Álvarez Troncoso ◽  
Á. Robles Marhuenda ◽  
F. Mitjavila Villero ◽  
F. J. García Hernández ◽  
A. Marín Ballvé ◽  
...  

Background:Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by multiorgan involvement. Pulmonary hypertension (PH) is an uncommon manifestation with high morbidity and mortality whose characteristics, prevalence and evolution in SLE are not completely defined.Objectives:Using data of patients from the inception cohort Registro Español de Lupus Eritematoso Sistémico (RELES), we aimed to to identify the factors associated with pulmonary hypertension (PH) in systemic lupus erythematosus (SLE).Methods:Prospective observational study on a multicenter Spanish inception cohort. Patients with SLE, diagnosed by the American College of Rheumatology (ACR) criteria, since January 2009, who had at least one transthoracic echocardiogram (TTE) performed were selected. Demographic data, diagnostic criteria, follow-ups, treatments and SLEDAI were analyzed.Results:Of 289 patients diagnosed with SLE with TTE performed, 15 (5.2%) patients were identified to have PH. Mean age was 56,9±7,7 years, of which 93,3% (14) were women and 80% (12) Caucasian. The ACR score at diagnosis was 4.66. Mean SLEDAI was 15. Only 5 patients had dyspnea at the time of diagnosis. Mean pulmonary arterial systolic pressure was 49.2±5.6 mmHg. Among the PH, 4 patients had pericarditis (26.6%), 3 (20%) valvulopathies (1 antiphospholipid syndrome), 1 patient pulmonary embolism and 1 shrinking lung. Multivariable analysis indicated that pericarditis (odds ratio (OR)=2.53), and valvulopathies (OR 8.96) were independently associated with the development of PH in SLE. Having PH was associated with older age at diagnosis (p<0.001), more dyspnea (p<0.001), higher ESR (p=0.007), more serositis (p<0.001), higher SLEDAI (p=0.011), higher SLICC (p <0.001), higher number of admissions (p=0.006) and higher mortality (p=0.003).Conclusion:PH in SLE is a serious comorbidity with high mortality. In the RELES cohort it was associated with increased disease activity, pericarditis and valvulopathies. Performing TTE in patients with SLE may favor early diagnosis and treatment.References:[1]Kim JS, Kim D, Joo YB, et al. Factors associated with development and mortality of pulmonary hypertension in systemic lupus erythematosus patients.Lupus. 2018;27(11):1769–1777.[2]Bazan IS, Mensah KA, Rudkovskaia AA, et al. Pulmonary arterial hypertension in the setting of scleroderma is different than in the setting of lupus: A review.Respir Med. 2018;134:42–46.Disclosure of Interests:Jorge Álvarez Troncoso: None declared, Ángel Robles Marhuenda: None declared, Francesca Mitjavila Villero: None declared, Francisco José García Hernández: None declared, Adela Marín Ballvé: None declared, Antoni Castro Consultant of: Actelion pharmaceuticals, GSK, MSD., Gonzalo Salvador Cervelló: None declared, Eva Fonseca: None declared, Isabel Perales Fraile: None declared, Guillermo Ruiz-Irastorza: None declared


1998 ◽  
Vol 274 (6) ◽  
pp. E978-E983 ◽  
Author(s):  
B. Mittendorfer ◽  
L. S. Sidossis ◽  
E. Walser ◽  
D. L. Chinkes ◽  
R. R. Wolfe

We have used a 3-h primed continuous infusion of [1,2-13C]acetate in five fasted (24 h) volunteers to quantify splanchnic and leg acetate metabolism ( protocol 1). Fractional extraction of acetate by both tissues was high (∼70%), and simultaneous uptake and release of acetate were observed. Labeled carbon recovery in CO2 was 37.9 ± 2.3% at the whole body level, 37.7 ± 1.5% across the splanchnic bed, and 37.3 ± 2.9% across the leg. Furthermore, we calculated whole body labeled carbon recovery during 15 h of [1,2-13C]acetate infusion in three volunteers ( protocol 2). Whole body acetate carbon recovery in CO2 was significantly higher (66.7 ± 4.5%) after 15 h of tracer infusion than after 3 h. We conclude that acetate is rapidly taken up by the leg and splanchnic tissues and that the percent recovery of CO2from the oxidation of acetate is heavily dependent on the length of acetate tracer infusion. In the postabsorptive state, labeled carbon recovery from acetate across the leg and the splanchnic region is similar to the whole body CO2 recovery.


2020 ◽  
pp. jrheum.200513
Author(s):  
Elena Gkrouzman ◽  
Ecem Sevim ◽  
Jackie Finik ◽  
Danieli Andrade ◽  
Vittorio Pengo ◽  
...  

Objective APS ACTION Registry studies long-term outcomes in persistently antiphospholipid antibody (aPL)-positive patients. Our primary objective was to determine whether clinically meaningful aPL profiles at baseline remain stable over time. Our secondary objectives were to determine a) whether baseline characteristics differ between patients with stable and unstable aPL profiles, and b) predictors of unstable aPL profiles over time. Methods Clinically meaningful aPL profile was defined as positive lupus anticoagulant (LA) test and/or anticardiolipin (aCL)/anti-β2 glycoprotein-I (aβ2GPI) IgG/M ≥40 U. Stable aPL profile was defined as a clinically meaningful aPL profile in at least two-thirds of follow-up measurements. Generalized linear mixed models with logit link were used for primary objective analysis. Results Of 472 patients with clinically meaningful aPL profile at baseline (median follow up: 5.1 years), 366/472 (78%) patients had stable aPL profiles over time, 54 (11%) unstable; and 52 (11%) inconclusive. Time did not significantly affect odds of maintaining a clinically meaningful aPL profile at follow-up in univariate (p=0.906) and multivariable analysis (p=0.790). Baseline triple aPL positivity decreased (Odds Ratio [OR] 0.25, 95% Confidence Interval [CI] 0.10-0.64, p=0.004) and isolated LA test positivity increased (OR 3.3, 95% CI 1.53-7.13, p=0.002) the odds of an unstable aPL profile over time. Conclusion Approximately 80% of our international cohort patients with clinically meaningful aPL profile at baseline maintain such at a median follow-up of five years; triple aPL-positivity increase the odds of a stable aPL profile. These results will guide future validation studies of stored blood samples through APS ACTION Core Laboratories.


2019 ◽  
Vol 20 (11) ◽  
pp. 2765 ◽  
Author(s):  
Jihwan Myung ◽  
Mei-Yi Wu ◽  
Chun-Ya Lee ◽  
Amalia Ridla Rahim ◽  
Vuong Hung Truong ◽  
...  

The kidney harbors one of the strongest circadian clocks in the body. Kidney failure has long been known to cause circadian sleep disturbances. Using an adenine-induced model of chronic kidney disease (CKD) in mice, we probe the possibility that such sleep disturbances originate from aberrant circadian rhythms in kidney. Under the CKD condition, mice developed unstable behavioral circadian rhythms. When observed in isolation in vitro, the pacing of the master clock, the suprachiasmatic nucleus (SCN), remained uncompromised, while the kidney clock became a less robust circadian oscillator with a longer period. We find this analogous to the silencing of a strong slave clock in the brain, the choroid plexus, which alters the pacing of the SCN. We propose that the kidney also contributes to overall circadian timekeeping at the whole-body level, through bottom-up feedback in the hierarchical structure of the mammalian circadian clocks.


2020 ◽  
Vol 299 ◽  
pp. 113605
Author(s):  
Diana C. Castañeda-Cortés ◽  
Jing Zhang ◽  
Agustín F. Boan ◽  
Valerie S. Langlois ◽  
Juan I. Fernandino

2013 ◽  
Vol 450 (2) ◽  
pp. 295-301 ◽  
Author(s):  
Mari Sasaki ◽  
Akihiro Tojo ◽  
Yoshifumi Okochi ◽  
Nana Miyawaki ◽  
Daisuke Kamimura ◽  
...  

Hv channels (voltage-gated proton channels) are expressed in blood cells, microglia and some types of epithelial cells. In neutrophils Hv channels regulate the production of reactive oxygen species through regulation of membrane potential and intracellular pH. Hv channels have also been suggested to play a role in sperm physiology in the human. However, the functions of the Hv channel at the whole-body level are not fully understood. In the present paper we show that Hvcn1 (voltage-gated hydrogen channel 1)-knockout mice show splenomegaly, autoantibodies and nephritis, that are reminiscent of human autoimmune diseases phenotypes. The number of activated T-cells was larger in Hvcn1-deficient mice than in the wild-type mice. Upon viral infection this was remarkably enhanced in Hvcn1-deficient mice. The production of superoxide anion in T-cells upon stimulation with PMA was significantly attenuated in the Hvcn1-deficient mice. These results suggest that Hv channels regulate T-cell homoeostasis in vivo.


2020 ◽  
Vol 9 (6) ◽  
pp. 1803
Author(s):  
Hye-Bin Kim ◽  
Sarah Soh ◽  
Young-Lan Kwak ◽  
Jae Chan Bae ◽  
Sang Hwa Kang ◽  
...  

Degradation of endothelial glycocalyx (EG) is associated with inflammation and endothelial dysfunction, which may contribute to the development of acute kidney injury (AKI). We investigated the association between a marker of EG degradation and AKI after valvular heart surgery. Serum syndecan-1 concentrations were measured at induction of anesthesia and discontinuation of cardiopulmonary bypass in 250 patients. Severe AKI was defined as Kidney Disease: Improving Global Outcomes Criteria Stage 2 or 3. Severe AKI occurred in 13 patients (5%). Receiver operating characteristic analysis of preoperative syndecan-1 to predict severe AKI showed area under curve of 0.714 (95% confidence interval (CI), 0.575–0.853; p = 0.009). The optimal cut-off value was 90 ng/mL, with a sensitivity of 61.5% and specificity of 78.5%. In multivariable analysis, both preoperative syndecan-1 ≥ 90 ng/mL and Cleveland Clinic Foundation score independently predicted severe AKI. Severe tricuspid regurgitation was more frequent (42.4% vs. 17.8%, p < 0.001), and baseline right ventricular systolic pressure (41 (33–51) mmHg vs. 33 (27–43) mmHg, p = 0.001) and TNF-α (1.85 (1.37–2.43) pg/mL vs. 1.45 (1.14–1.92) pg/mL, p <0.001) were higher in patients with high preoperative syndecan-1. Patients with high preoperative syndecan-1 had longer hospital stay (16 (12–24) days vs. 13 (11–17) days, p = 0.001). In conclusion, a high preoperative syndecan-1 concentration greater than 90 ng/mL was able to predict severe AKI after valvular heart surgery and was associated with prolonged hospitalization.


Author(s):  
Alfonso Bellia ◽  
Bruno Ruscello ◽  
Rolando Bolognino ◽  
Gianluca Briotti ◽  
Paolo Roberto Gabrielli ◽  
...  

AbstractWe investigated early effects of Whole-Body Electromyostimulation added to hypocaloric diet on metabolic syndrome features in sedentary middle-aged individuals. We randomly assigned 25 patients to Whole-Body Electromyostimulation plus caloric restriction or caloric restriction alone for 26 weeks. Anthropometrics, blood pressure, fasting glucose and insulin, HOMA-IR, glycated hemoglobin, lipids, uric acid, creatinphosphokynase, C-reactive protein were assessed. Body composition was evaluated with direct-segmental, multi-frequency Bioelectrical Impedance Analysis. Both groups lost approximately 10% of weight, with similar effects on waist circumference and fat mass. Change in free-fat mass was significantly different between groups (caloric restriction −1.5±0.2 vs. Whole-Body Electromyostimulation plus caloric restriction +1.1±0.4 kg, p=0.03). Whole-Body Electromyostimulation plus caloric restriction group experienced greater percent reductions in insulin (−45.5±4.4 vs. −28.2±3.6%, p=0.002), HOMA-IR (–51.3±3.2 vs. –25.1±1.8%, p=0.001), triglycerides (−22.5±2.9 vs. −4.1±1.6%, p=0.004) and triglycerides/HDL (p=0.028). Subjects trained with Whole-Body Electromyostimulation had also significant improvement in systolic pressure (138±4 vs. 126±7 mmHg, p=0.038). No discontinuations for adverse events occurred. In middle-aged sedentary subjects with the metabolic syndrome, Whole-Body Electromyostimulation with caloric restriction for 26 weeks can improve insulin-resistance and lipid profile compared to diet alone. Further studies are needed to ascertain long-term efficacy and feasibility of this approach in individuals with the metabolic syndrome.


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