Antenatal betamethasone redistributes central blood flows and preferentially augments right ventricular output and pump function in preterm fetal lambs

2021 ◽  
Author(s):  
Joseph J. Smolich ◽  
Jonathan P. Mynard
Keyword(s):  
Right Ventricular ◽  
Regional Blood Flow ◽  
Superior Vena ◽  
Upper Body ◽  
Total Power ◽  
Body Region ◽  
Lower Body ◽  
Blood Flows ◽  
Relative Contribution ◽  
Arterial Blood

The glucocorticosteroid betamethasone, which is routinely administered prior to anticipated preterm birth to enhance maturation of the lungs and cardiovascular system, has diverse fetal regional blood flow effects ranging from increased pulmonary flow to decreased cerebral flow. The aim of this study was to test the hypothesis that these diverse effects reflect alterations in major central flow patterns which are associated with complementary shifts in left (LV) and right ventricular (RV) pumping performance. Studies were performed in anesthetized preterm fetal lambs (gestation 127±1 days, term=147 days) with (n=14) or without (n=12) preceding betamethasone treatment via maternal i.m. injection. High-fidelity central arterial blood pressure and flow signals were obtained to calculate LV and RV outputs and total hydraulic power. Betamethasone therapy was accompanied by 1) increased RV, but not LV, output, 2) a greater RV than LV increase in total power, 3) a redistribution of LV output away from the fetal upper body region, and towards the lower body and placenta, 4) a greater proportion of RV output passing to the lungs, and a lesser proportion to the lower body and placenta, 5) a change in the relative contribution of venous streams to ventricular filling, with the LV having increased pulmonary venous and decreased foramen ovale components, and the RV having lesser superior vena caval and greater inferior vena caval portions. Taken together, these findings suggest that antenatal betamethasone produces a widespread redistribution of central arterial and venous flows in the fetus, accompanied by a preferential rise in RV pumping performance.

Regional circulatory responses to hypocapnia and hypercapnia in bar-headed geese

1986 ◽  
Vol 250 (3) ◽  
pp. R499-R504 ◽  
Author(s):  
F. M. Faraci ◽  
M. R. Fedde
Keyword(s):  
Blood Flow ◽  
Regional Blood Flow ◽  
Muscle Blood Flow ◽  
Pectoral Muscle ◽  
Blood Flows ◽  
Arterial Blood ◽  
Blood Flow Reduction ◽  
Extreme Altitude ◽  
Anser Indicus ◽  
O2 Delivery

To investigate mechanisms that may allow birds to tolerate extreme high altitude (hypocapnic hypoxia), we examined the effects of severe hypocapnia and moderate hypercapnia on regional blood flow in bar-headed geese (Anser indicus), a species that flies at altitudes up to 9,000 m. Cerebral, coronary, and pectoral muscle blood flows were measured using radioactive microspheres, while arterial CO2 tension (PaCO2) was varied from 7 to 62 Torr in awake normoxic birds. Arterial blood pressure was not affected by hypocapnia but increased slightly during hypercapnia. Heart rate did not change during alterations in PaCO2. Severe hypocapnia did not significantly alter cerebral, coronary, or pectoral muscle blood flow. Hypercapnia markedly increased cerebral and coronary blood flow, but pectoral muscle blood flow was unaffected. The lack of a blood flow reduction during severe hypocapnia may represent an important adaptation in these birds, enabling them to increase O2 delivery to the heart and brain at extreme altitude despite the presence of a very low PaCO2.

Age-related changes in regional blood flow in the rat

1985 ◽  
Vol 249 (3) ◽  
pp. H485-H491 ◽  
Author(s):  
R. F. Tuma ◽  
G. L. Irion ◽  
U. S. Vasthare ◽  
L. A. Heinel
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Cardiac Index ◽  
Regional Blood Flow ◽  
Adult Rats ◽  
Blood Flows ◽  
Arterial Blood ◽  
Anesthetized Rats ◽  
Regional Blood Flows ◽  
Central Hemodynamic

The purpose of this investigation was to characterize the changes in regional blood flow and central hemodynamic measures that occur in the rat as a result of the aging process. The isotope-labeled microsphere technique was used to measure cardiac output and regional blood flows in conscious and anesthetized adult (12 mo) and senescent (24 mo) Fischer 344 virgin female rats. No significant changes were observed in central hemodynamic measurements or regional blood flows in conscious rats with the exception of a 25% reduction in splenic blood flow. Pentobarbital anesthesia significantly reduced cardiac index and heart rate but elevated total peripheral resistance and mean arterial blood pressure. There was a decrease in blood flow to skeletal muscle, spleen, duodenum, stomach, and brain tissue samples and increased hepatic arterial blood flow in both age groups. The use of anesthesia caused a greater reduction in the cardiac index and brain blood flow in the senescent anesthetized rats than in the adult rats. Heart and kidney blood flows were decreased by anesthesia in the senescent rats but not in the adult rats. Skeletal muscle blood flow, however, was significantly greater in the senescent anesthetized rats than in the younger anesthetized animals. Although body weight and organ weights of the liver, spleen, kidneys, stomach, heart, and brain were significantly greater for the senescent rats, no differences could be demonstrated in tibial length or lean body mass.

scholarly journals The Effect of Previous Wingate Performance Using one Body Region on Subsequent Wingate Performance Using a Different Body Region

2017 ◽  
Vol 56 (1) ◽  
pp. 119-126 ◽  
Author(s):  
Leonie Harvey ◽  
Matthew Bousson ◽  
Chris McLellan ◽  
Dale Lovell
Keyword(s):  
Rest Period ◽  
Cycle Ergometer ◽  
Upper Body ◽  
Body Region ◽  
Power Indices ◽  
Lower Body ◽  
Mean Power ◽  
Wingate Anaerobic Test ◽  
Sprint Exercise ◽  
Braking Force

AbstractThe 30 second Wingate Anaerobic Test (WAnT) is the gold standard measure of anaerobic performance. The present investigation aimed to determine if a previous WAnT using one body region significantly affected a subsequent WAnT using a different body region. Twelve male university students (n = 12, 23 ± 2 years, 84 ± 16.1 kg, 178.5 ± 7.4 cm) volunteered to complete two repeated WAnT protocols (either lower body WAnT followed by an upper body WAnT or vice versa) on two separate testing occasions. The upper body WAnT was conducted on a modified electromagnetically braked cycle ergometer using a flywheel braking force corresponding to 5% bodyweight. The lower body WAnT was conducted on an electronically braked cycle ergometer using a flywheel braking force corresponding to 7.5% bodyweight. Participants had a 1 minute rest period for transition between WAnTs. Data are reported as mean ± standard deviation. No significant differences were identified in power indices for the lower body between 30 s WAnTs. When the upper body WAnT was performed 2nd, absolute peak power (p < 0.01), mean power (p < 0.001) and relative mean power (p < 0.001) were significantly lower compared to when the upper body WAnT was performed 1st. The value of maximum revolutions per minute was significantly lower (p < 0.001) when the upper body WAnT was performed after the lower body WAnT, compared to when it was performed 1st (193.3 ± 11.4 1st vs 179.8 ± 14.4 2nd). Previous upper body sprint exercise does not significantly affect lower body sprint exercise; however, previous lower body sprint exercise severely compromises subsequent upper body sprint performance.

Effects of anesthetics on regional hemodynamics in normovolemic and hemorrhaged rats

1985 ◽  
Vol 249 (1) ◽  
pp. H164-H173 ◽  
Author(s):  
W. C. Seyde ◽  
L. McGowan ◽  
N. Lund ◽  
B. Duling ◽  
D. E. Longnecker
Keyword(s):  
Regional Blood Flow ◽  
Blood Gases ◽  
Anesthetic Technique ◽  
Anesthetic Techniques ◽  
Sprague Dawley ◽  
Blood Flows ◽  
Arterial Blood ◽  
Before And After ◽  
Regional Blood Flows ◽  
Anesthetic Exposure

Twenty-nine male Sprague-Dawley rats were divided into four groups based on anesthetic exposure, i.e., awake animals and those receiving anesthesia produced by chloralose-urethan, pentobarbital, or by midcollicular brain stem transsection. Before and after hemorrhage (30% of the estimated blood volume), cardiac output (CO) and regional blood flows were measured by the microsphere method. Arterial blood gases and lactate (L) and pyruvate (P) were also determined. CO and regional blood flows were greatest and the L/P ratio was least in awake animals both before and after hemorrhage. In normovolemic rats, the frequency of altered values (as compared with those in awake animals) was similar for all anesthetic techniques, whereas the CO and regional blood flow responses to hemorrhage were altered less frequently in decerebrated animals. Decerebration may be the preferable procedure if the intent is to produce responses in anesthetized animals similar to those in awake rats. If the intent is to study hemodynamics in a specific organ, the selection of an anesthetic technique should be guided by the individual anesthetic effects on that particular tissue.

Relationship between vascular reactivity in vitro and blood flows in rats with cirrhosis

1999 ◽  
Vol 97 (3) ◽  
pp. 313-318 ◽  
Author(s):  
Dominique PATERON ◽  
Frédéric OBERTI ◽  
Pascale LEFILLIATRE ◽  
Nary VEAL ◽  
Khalid A. TAZI ◽  
...  
Keyword(s):  
Blood Flow ◽  
Vascular Reactivity ◽  
Regional Blood Flow ◽  
Arterial Blood Flow ◽  
Blood Flows ◽  
Arterial Blood ◽  
Vascular Responsiveness ◽  
Microsphere Method ◽  
Radioactive Microsphere Method

In cirrhosis there is a hyperdynamic circulation, which occurs mainly in the systemic and splanchnic regions. Using isolated-vessel models, previous studies have shown reduced aortic reactivity to vasoconstrictors in rats with cirrhosis. The aim of the present study was to evaluate and compare the vascular responsiveness to phenylephrine in arterial rings and the blood flows from different regions in rats with cirrhosis and controls. Reactivity was studied in isolated thoracic aortic, superior mesenteric arterial and carotid arterial rings from sham-operated and bile-duct-ligated rats by measuring the cumulative concentration-dependent tension induced by phenylephrine (10-9–10-4 M). Blood flows were measured by the radioactive microsphere method. In rats with cirrhosis, a significant hyporeactivity to phenylephrine was observed in both the aorta and the superior mesenteric artery compared with the corresponding arteries of normal rats. This hyporesponsiveness was corrected by Nω-nitro-l-arginine (0.1 mM). In contrast, carotid artery reactivity and the responses to Nω-nitro-l-arginine were similar in the cirrhotic and control groups. In each case, cardiac output and mesenteric arterial blood flow were significantly higher in cirrhotic than in normal rats. Cerebral blood flows were not significantly different between the two groups. In cirrhotic rats, arterial hyporeactivity may be a consequence of increased regional blood flow and increased production of nitric oxide.

Effects of Sitting and Standing Work Postures on Short-Term Typing Performance and Discomfort

2016 ◽  
Vol 60 (1) ◽  
pp. 460-464 ◽  
Author(s):  
Gourab Kar ◽  
Alan Hedge
Keyword(s):  
Repeated Measures ◽  
Upper Body ◽  
Whole Body ◽  
Body Region ◽  
Lower Body ◽  
Analog Scale ◽  
Short Term ◽  
Work Posture ◽  
Body Discomfort ◽  
Typing Task

The study evaluated effects of sitting and standing work postures on objective short-term computer typing performance and perceived discomfort. A randomized, repeated measures, study design was used to assess typing performance and perceived discomfort for 12 participants on a 15-minute computer-typing task. Typing performance was measured by number of characters typed and number of errors. Perceived discomfort was measured for the whole body, as well as for upper body and lower body, using a visual analog scale. Results suggest that for a short-term computer typing task, compared to a sitting work posture a standing work posture leads to fewer typing errors without impacting typing speed. Overall levels of perceived discomfort for the whole body are similar for sitting and standing work postures. However, for perceived discomfort there is an interaction of work posture and body region - upper body discomfort is higher in the sitting work posture while lower body discomfort is higher in the standing work posture.

scholarly journals Effects of Different Doses of Caffeinated Coffee on Muscular Endurance, Cognitive Performance, and Cardiac Autonomic Modulation in Caffeine Naive Female Athletes

Nutrients ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 2
Author(s):  
Raci Karayigit ◽  
Alireza Naderi ◽  
Firat Akca ◽  
Carlos Janssen Gomes da Cruz ◽  
Amir Sarshin ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Cognitive Performance ◽  
High Frequency ◽  
Female Athletes ◽  
Upper Body ◽  
Total Power ◽  
Muscular Endurance ◽  
Lower Body ◽  
Caffeinated Coffee ◽  
Frequency Power

Caffeine is widely consumed among elite athletes for its well-known ergogenic properties, and its ability to increase exercise performance. However, studies to date have predominantly focused on the anhydrous form of caffeine in male participants. The aim of the study was to investigate the effect of caffeinated coffee ingestion on lower-upper body muscular endurance, cognitive performance, and heart rate variability (HRV) in female athletes. A total of 17 participants (mean ± standard deviation (SD): age = 23 ± 2 years, body mass = 64 ± 4 kg, height = 168 ± 3 cm) in a randomized cross-over design completed three testing sessions, following the ingestion of 3 mg/kg/bm of caffeine (3COF), 6 mg/kg/bm of caffeine (6COF) provided from coffee or decaffeinated coffee (PLA) in 600 mL of hot water. The testing results included: (1) repetition number for muscular endurance performance; (2): reaction time and response accuracy for cognitive performance; (3): HRV parameters, such as standard deviation of normal-to-normal (NN) intervals (SDNN), standard deviation of successive differences (SDSD), root mean square of successive differences (RMSSD), total power (TP), the ratio of low- and high-frequency powers (LF/HF), high-frequency power (HF), normalized HF (HFnu), low-frequency power (LF), and normalized LF (LFnu). A one-way repeated measures ANOVA revealed that 3COF (p = 0.024) and 6COF (p = 0.036) improved lower body muscular endurance in the first set as well as cognitive performance (p = 0.025, p = 0.035 in the post-test, respectively) compared to PLA. However, no differences were detected between trials for upper body muscular endurance (p = 0.07). Lastly, all HRV parameters did not change between trials (p > 0.05). In conclusion, ingesting caffeinated coffee improved lower body muscular endurance and cognitive performance, while not adversely affecting cardiac autonomic function.

scholarly journals Survey of Musculoskeletal Pain among Dental Clinician in Kulliyyah of Dentistry IIUM

2018 ◽  
Vol 17 (2) ◽  
Author(s):  
Susi Sukmasari ◽  
Ahmad Faisal Ismail ◽  
Arbaatul Arroshikin Nazirah Hamshah
Keyword(s):  
Risk Factors ◽  
Musculoskeletal Pain ◽  
Healthy Lifestyle ◽  
Pearson Correlation ◽  
Dental Students ◽  
Physical Activities ◽  
Upper Body ◽  
Body Region ◽  
Lower Body ◽  
Repetitive Movements

This study aimed to determine the prevalent site of musculoskeletal pain and its associated risk factors among dental clinicians at the Kulliyyah of Dentistry, IIUM. A validated, pilot-tested self-administered questionnaires were distributed to 160 dental clinicians between March and June 2014 using convenience sampling method. Inclusion criteria includes dentist, clinical supervisors or clinical dental students. Dental clinicians whom were diagnosed with musculoskeletal disorders were excluded. Data obtained were recorded and analyzed using statistical package for the social science (SPSS) software version 19. Pearson correlation test was used to determine the association between the risk factors and pain sites. A total of 146 participants completed the questionnaire (91.3% response rate). The sample consist of 40 dentists (27.4%), 36 Year 3 students (24.7%) and 35 participants (24%) respectively from Year 4 and Year 5. There was high prevalence of neck pain (79.5%), back shoulder pain (74.7%) and lower back pain (71.9%) among dental clinicians. Significant correlation was found between physical activities with upper body region pain sites (r = 0.170, p=0.042) and lower body region pain sites (r = 0.221, p=0.008). There was a significant association between repetitive movements and wrist bending with upper and lower body region pain sites (r = 0.320, p = <0.001) (r = 0.278, p =0.001). No correlation between awkward postures with upper and lower body pain sites. This paper will relate to the Islamic teaching on moderation in working and in maintaining healthy lifestyle. The most prevalent site of musculoskeletal pain experienced by dental clinicians was at the neck area and the least was on the left arm. Repetitive movements, wrist bending and physical activities were associated with upper and lower body region pain sites.

scholarly journals Central aortic hemodynamics following acute lower and upper-body exercise in a cold environment among patients with coronary artery disease

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Heidi E. Hintsala ◽  
Rasmus I. P. Valtonen ◽  
Antti Kiviniemi ◽  
Craig Crandall ◽  
Juha Perkiömäki ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Dynamic Exercise ◽  
Upper Body ◽  
Cold Environment ◽  
Lower Body ◽  
Static Exercise ◽  
Upper Body Exercise ◽  
Post Exercise ◽  
Artery Disease

AbstractExercise is beneficial to cardiovascular health, evidenced by reduced post-exercise central aortic blood pressure (BP) and wave reflection. We assessed if post-exercise central hemodynamics are modified due to an altered thermal state related to exercise in the cold in patients with coronary artery disease (CAD). CAD patients (n = 11) performed moderate-intensity lower-body exercise (walking at 65–70% of HRmax) and rested in neutral (+ 22 °C) and cold (− 15 °C) conditions. In another protocol, CAD patients (n = 15) performed static (five 1.5 min work cycles, 10–30% of maximal voluntary contraction) and dynamic (three 5 min workloads, 56–80% of HRmax) upper-body exercise at the same temperatures. Both datasets consisted of four 30-min exposures administered in random order. Central aortic BP and augmentation index (AI) were noninvasively assessed via pulse wave analyses prior to and 25 min after these interventions. Lower-body dynamic exercise decreased post-exercise central systolic BP (6–10 mmHg, p < 0.001) and AI (1–6%, p < 0.001) both after cold and neutral and conditions. Dynamic upper-body exercise lowered central systolic BP (2–4 mmHg, p < 0.001) after exposure to both temperatures. In contrast, static upper-body exercise increased central systolic BP after exposure to cold (7 ± 6 mmHg, p < 0.001). Acute dynamic lower and upper-body exercise mainly lowers post-exercise central BP in CAD patients irrespective of the environmental temperature. In contrast, central systolic BP was elevated after static exercise in cold. CAD patients likely benefit from year-round dynamic exercise, but hemodynamic responses following static exercise in a cold environment should be examined further.Clinical trials.gov: NCT02855905 04/08/2016.

Upper Body Aerobic Exercise as a Possible Predictor of Lower Body Performance

2015 ◽  
Vol 86 (7) ◽  
pp. 599-605 ◽  
Author(s):  
Carl J. Ade ◽  
Ryan M. Broxterman ◽  
Jesse C. Craig ◽  
Susanna J. Schlup ◽  
Samuel L. Wilcox ◽  
...  
Keyword(s):  
Aerobic Exercise ◽  
Upper Body ◽  
Lower Body
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