Recent studies showed that nasal high flow (NHF) with or without supplemental oxygen can assist ventilation of patients with chronic respiratory and sleep disorders. The hypothesis of this study was ...to test whether NHF can clear dead space in two different models of the upper nasal airways. The first was a simple tube model consisting of a nozzle to simulate the nasal valve area, connected to a cylindrical tube to simulate the nasal cavity. The second was a more complex anatomically representative upper airway model, constructed from segmented CT-scan images of a healthy volunteer. After filling the models with tracer gases, NHF was delivered at rates of 15, 30, and 45 l/min. The tracer gas clearance was determined using dynamic infrared CO2 spectroscopy and 81mKr-gas radioactive gamma camera imaging. There was a similar tracer-gas clearance characteristic in the tube model and the upper airway model: clearance half-times were below 1.0 s and decreased with increasing NHF rates. For both models, the anterior compartments demonstrated faster clearance levels (half-times < 0.5 s) and the posterior sections showed slower clearance (half-times < 1.0 s). Both imaging methods showed similar flow-dependent tracer-gas clearance in the models. For the anatomically based model, there was complete tracer-gas removal from the nasal cavities within 1.0 s. The level of clearance in the nasal cavities increased by 1.8 ml/s for every 1.0 l/min increase in the rate of NHF. The study has demonstrated the fast-occurring clearance of nasal cavities by NHF therapy, which is capable of reducing of dead space rebreathing.
Gold nanoparticles (AuNP) provide many opportunities in imaging, diagnostics, and therapy in nanomedicine. For the assessment of AuNP biokinetics, we intratracheally instilled into rats a suite of ...198Au-radio-labeled monodisperse, well-characterized, negatively charged AuNP of five different sizes (1.4, 2.8, 5, 18, 80, 200 nm) and 2.8 nm AuNP with positive surface charges. At 1, 3, and 24 h, the biodistribution of the AuNP was quantitatively measured by gamma-spectrometry to be used for comprehensive risk assessment. Our study shows that as AuNP get smaller, they are more likely to cross the air–blood barrier (ABB) depending strongly on the inverse diameter d –1 of their gold core, i.e., their specific surface area (SSA). So, 1.4 nm AuNP (highest SSA) translocated most, while 80 nm AuNP (lowest SSA) translocated least, but 200 nm particles did not follow the d –1 relation translocating significantly higher than 80 nm AuNP. However, relative to the AuNP that had crossed the ABB, their retention in most of the secondary organs and tissues was SSA-independent. Only renal filtration, retention in blood, and excretion via urine further declined with d –1 of AuNP core. Translocation of 5, 18, and 80 nm AuNP is virtually complete after 1 h, while 1.4 nm AuNP continue to translocate until 3 h. Translocation of negatively charged 2.8 nm AuNP was significantly higher than for positively charged 2.8 nm AuNP. Our study shows that translocation across the ABB and accumulation and retention in secondary organs and tissues are two distinct processes, both depending specifically on particle characteristics such as SSA and surface charge.
Nasal high flow reduces dead space Möller, Winfried; Feng, Sheng; Domanski, Ulrike ...
Journal of applied physiology (1985),
01/2017, Volume:
122, Issue:
1
Journal Article
Peer reviewed
Open access
Recent studies show that nasal high flow (NHF) therapy can support ventilation in patients with acute or chronic respiratory disorders. Clearance of dead space has been suggested as being the key ...mechanism of respiratory support with NHF therapy. The hypothesis of this study was that NHF in a dose-dependent manner can clear dead space of the upper airways from expired air and decrease rebreathing. The randomized crossover study involved 10 volunteers using scintigraphy with
Krypton (
Kr) gas during a breath-holding maneuver with closed mouth and in 3 nasally breathing tracheotomized patients by volumetric capnography and oximetry through sampling CO
and O
in the trachea and measuring the inspired volume with inductance plethysmography following NHF rates of 15, 30, and 45 l/min. The scintigraphy revealed a decrease in
Kr gas clearance half-time with an increase of NHF in the nasal cavities Pearson's correlation coefficient cc = -0.55, P < 0.01, the pharynx (cc = -0.41, P < 0.01), and the trachea (cc = -0.51, P < 0.01). Clearance rates in nasal cavities derived from time constants and MRI-measured volumes were 40.6 ± 12.3 (SD), 52.5 ± 17.7, and 72.9 ± 21.3 ml/s during NHF (15, 30, and 45 l/min, respectively). Measurement of inspired gases in the trachea showed an NHF-dependent decrease of inspired CO
that correlated with an increase of inspired O
(cc = -0.77, P < 0.05). NHF clears the upper airways of expired air, which reduces dead space by a decrease of rebreathing making ventilation more efficient. The dead space clearance is flow and time dependent, and it may extend below the soft palate.
Clearance of expired air in upper airways by nasal high flow (NHF) can be extended below the soft palate and de facto causes a reduction of dead space. Using scintigraphy, the authors found a relationship between NHF, time, and clearance. Direct measurement of CO
and O
in the trachea confirmed a reduction of rebreathing, providing the actual data on inspired gases, and this can be used for the assessment of other forms of respiratory support.
Chronic rhinosinusitis (CRS) is a common chronic disease of the upper airways and has considerable impact on quality of life. Topical delivery of drugs to the paranasal sinuses is challenging, ...therefore the rate of surgery is high. This study investigates the delivery efficiency of a pulsating aerosol in comparison to a nasal pump spray to the sinuses and the nose in healthy volunteers and in CRS patients before and after sinus surgery.
(99m)Tc-DTPA pulsating aerosols were applied in eleven CRSsNP patients without nasal polyps before and after sinus surgery. In addition, pulsating aerosols were studied in comparison to nasal pump sprays in eleven healthy volunteers. Total nasal and frontal, maxillary and sphenoidal sinus aerosol deposition and lung penetration were assessed by anterior and lateral planar gamma camera imaging.
In healthy volunteers nasal pump sprays resulted in 100% nasal, non-significant sinus and lung deposition, while pulsating aerosols resulted 61.3+/-8.6% nasal deposition and 38.7% exit the other nostril. 9.7+/-2.0 % of the nasal dose penetrated into maxillary and sphenoidal sinuses. In CRS patients, total nasal deposition was 56.7+/-13.3% and 46.7+/-12.7% before and after sinus surgery, respectively (p<0.01). Accordingly, maxillary and sphenoidal sinus deposition was 4.8+/-2.2% and 8.2+/-3.8% of the nasal dose (p<0.01). Neither in healthy volunteers nor in CRS patients there was significant dose in the frontal sinuses.
In contrast to nasal pump sprays, pulsating aerosols can deliver significant doses into posterior nasal spaces and paranasal sinuses, providing alternative therapy options before and after sinus surgery. Patients with chronic lung diseases based on clearance dysfunction may also benefit from pulsating aerosols, since these diseases also manifest in the upper airways.
Single-cell oil (SCO) produced by oleaginous microorganisms is potentially a more land-efficient and sustainable alternative to vegetable oil. The cost of SCO production can be reduced by value-added ...co-products like squalene, a highly relevant compound for the food, cosmetic, and pharmaceutical industry. For the first time, squalene in the oleaginous yeast Cutaneotrichosporon oleaginosus was analyzed, reaching 172.95 ± 61.31 mg/100 g oil in a lab-scale bioreactor. Using the squalene monooxygenase inhibitor terbinafine, cellular squalene was significantly increased to 2169 ± 262 mg/100 g SCO, while the yeast remained highly oleaginous. Further, SCO from a 1000 L scale production was chemically refined. The squalene content in the deodorizer distillate (DD) was found to be higher than that in DD from typical vegetable oils. Overall, this study demonstrates squalene as a value-added compound in SCO from C. oleaginosus for application in food and cosmetics without the use of genetic modifications.
The aim of this study was to determine the prevalence and the predictive factors of vitamin D deficiency in pregnancy and the compliance with "The National Vitamin D Support Program" at Turkey's ...easternmost and westernmost provinces.
Lifestyles of women at 24-28 weeks of pregnancy were assessed using a questionnaire form, and serum 25-hydroxyvitamin D3 (25(OH)D3) levels were measured.
Vitamin D deficiency (≤20 ng/mL) in pregnant women had a prevalence of 27.8% in İzmir and 76.3% in Erzurum. The compliance of "The National Vitamin D Support Program" was 8% in İzmir and 32.6% in Erzurum. Clothing style, fish consumption, seaside holiday duration, and 1200 IU/day vitamin D replacement had an effect on 25(OH)D3 levels in pregnant subjects in İzmir, whereas only holiday duration and 1200 IU/day vitamin D replacement affected 25(OH)D3 levels in Erzurum. However, when a threshold for 25(OH)D3 level was considered ≥32 ng/mL, lifestyles did not affect 25(OH)D3 level.
The effect of lifestyle on 25(OH)D3 level in pregnancy is limited, especially in cold regions. We recommended increasing the compliance with "The National Vitamin D Support Program" at the follow-up of all pregnant women, irrespective of region and season.
Lung cancer is a common pathology with high mortality due to late diagnosis. Glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST), catalase (CAT), xanthine oxidase (XO), Cu–Zn superoxide ...dismutase (Cu–Zn SOD) activities, total glutathione (TGSH), nitric oxide (NO
), and malondialdehyde (MDA) levels were investigated in erythrocytes of patients with non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC), and healthy control group. We aimed to investigate serum GSH, GSH-dependent enzymes activities (GSH-Px and GST), XO, CAT, Cu–Zn SOD activity, and NO
, and MDA levels in patients with NSCLC and with SCLC and correlate with the cancer stage.
Erythrocyte MDA, NO
, TGSH levels and erythrocyte SOD, CAT and XO activities were significantly higher in patients with NSCLC and SCLC than in controls. Slightly increased erythrocyte GSH-Px and GST activities were not significantly different from the controls. Erythrocyte MDA level positively correlated with erythrocyte NO
levels in patients with early stage (I+II) in NSCLC groups. Erythrocyte MDA level positively correlated with erythrocyte XO activity in patients with advanced stage (III+IV) in NSCLC groups. However, no other correlation could be found among the parameters in healthy controls and patients with NSCLC and with SCLC.
Results obtained in this study indicate significant changes in antioxidant defence system in NSCLC and SCLC patients, which may lead to enhanced action of oxygen radical, resulting in lipid peroxidation.
Background: The management of fluid balance in the intensive care unit (ICU) is an indispensable part of the care and treatment process. Especially, changes in the level of consciousness may make it ...difficult to manage fluid balance. Purpose: This study was conducted to determine the relationship between fluid balance and level of consciousness in ICU. Methods: This cross-sectional and observational study included 209 patients hospitalized in ICU. An input-output monitoring form was used to assess the fluid balance of the patients, while the Glasgow Coma Scale (GCS) was used to assess their levels of consciousness. Results: Among the patients who were monitored for a week, the mean fluid balance value was 689.90±101.37 ml on the first day and 1141.53±1188.28 ml on the seventh day. where a significant increase occurred in positive fluid balance within the week (p<0.01). While there was no significant relationship between the patients' levels of consciousness and their fluid balance on the first day (p>0.05), on the seventh day; the mean fluid balance value of the patients who were categorized as 'coma' in the GCS was significantly higher than others (p<0.05). Conclusions: It was observed that the ICU patients had a positive fluid balance, while an increase in positive fluid balance was observed in time in the patients who were in a coma. Nurses are recommended to pay more importance to the monitoring of the fluid balance of patients who are experiencing advanced changes in consciousness like a coma.
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