Leak measurements in spontaneously breathing premature newborns by using the flow-through technique

1998 ◽  
Vol 85 (3) ◽  
pp. 1187-1193 ◽  
Author(s):  
B. Foitzik ◽  
M. Schmidt ◽  
D. Windstetter ◽  
R. R. Wauer ◽  
G. Schmalisch
Keyword(s):  
Measurement Errors ◽  
Face Mask ◽  
Maximum Error ◽  
Air Leaks ◽  
The Face ◽  
Flow Through ◽  
Spontaneously Breathing ◽  
Suction Flow

A new method for measuring and correcting air leaks during lung-function testing in infants has been validated in vitro and in vivo by using a flow-through system that measured the inflow and outflow of a face mask. An adjustable leak was quantified by using suction flow to validate the accuracy of leak measurements. To validate the leak correction, the volume of a pump was measured with different air leaks (0–30%). The method developed was tested in 67 infants breathing spontaneously. There was good agreement between measured and simulated leaks ( r = 0.998, P < 0.001; 95% limits of agreement were −0.3 and 0.1%, respectively). The volume was generally underestimated because of leaks, and the volume error was up to 94% compared with the maximum error of 5% after leak correction. With continuous leak measurements in vivo, there were <4% actual leaks (median 2.6%), and we did not observe any leaks in >7% of cases. The leak correction improved the accuracy of ventilatory measurements. The monitoring of leaks is helpful for airtight placement of the face mask and for prevention of serious measurement errors caused by leaks.

scholarly journals Antibacterial and In Vivo Studies of a Green, One-Pot Preparation of Copper/Zinc Oxide Nanoparticle-Coated Bandages

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 462
Author(s):  
Archana R. Deokar ◽  
Ilana Perelshtein ◽  
Melissa Saibene ◽  
Nina Perkas ◽  
Paride Mantecca ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Metal Oxide ◽  
Ultrasound Irradiation ◽  
Face Mask ◽  
In Vivo Studies ◽  
One Pot ◽  
The Face ◽  
Bulk Scale ◽  
Particle Size And Shape

Simultaneous water and ethanol-based synthesis and coating of copper and zinc oxide (CuO/ZnO) nanoparticles (NPs) on bandages was carried out by ultrasound irradiation. High resolution-transmission electron microscopy demonstrated the effects of the solvent on the particle size and shape of metal oxide NPs. An antibacterial activity study of metal-oxide-coated bandages was carried out against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative). CuO NP-coated bandages made from both water and ethanol demonstrated complete killing of S. aureus and E. coli bacteria within 30 min., whereas ZnO NP-coated bandages demonstrated five-log reductions in viability for both kinds of bacteria after 60 min of interaction. Further, the antibacterial mechanism of CuO/ZnO NP-coated bandages is proposed here based on electron spin resonance studies. Nanotoxicology investigations were conducted via in vivo examinations of the effect of the metal-oxide bandages on frog embryos (teratogenesis assay—Xenopus). The results show that water-based coatings resulted in lesser impacts on embryo development than the ethanol-based ones. These bandages should therefore be considered safer than the ethanol-based ones. The comparison between the toxicity of the metal oxide NPs prepared in water and ethanol is of great importance, because water will replace ethanol for bulk scale synthesis of metal oxide NPs in commercial companies to avoid further ignition problems. The novelty and importance of this manuscript is avoiding the ethanol in the typical water:ethanol mixture as the solvent for the preparation of metal oxide NPs. Ethanol is ignitable, and commercial companies are trying the evade its use. This is especially important these days, as the face mask produced by sonochemistry (SONOMASK) is being sold all over the world by SONOVIA, and it is coated with ZnO.

CD200 is a novel p53-target gene involved in apoptosis-associated immune tolerance

Blood ◽  
2004 ◽  
Vol 103 (7) ◽  
pp. 2691-2698 ◽  
Author(s):  
Michael D. Rosenblum ◽  
Edit Olasz ◽  
Jeffery E. Woodliff ◽  
Bryon D. Johnson ◽  
Marja C. Konkol ◽  
...  
Keyword(s):  
Target Gene ◽  
Molecular Mechanisms ◽  
Apoptotic Cell ◽  
Immune Reactivity ◽  
Biochemical Processes ◽  
The Face ◽  
P53 Target Gene ◽  
Self Antigens

Abstract During apoptotic cell death, biochemical processes modify self-proteins and create potential autoantigens. To maintain self-tolerance in the face of natural cell turnover, the immune system must prevent or control responses to apoptosis-associated autoantigens or risk autoimmunity. The molecular mechanisms governing this process remain largely unknown. Here, we show that expression of the immunoregulatory protein CD200 increases as murine dendritic cells (DCs) undergo apoptosis. We define CD200 as a p53-target gene and identify both p53- and caspase-dependent pathways that control CD200 expression during apoptosis. CD200 expression on apoptotic DCs diminishes proinflammatory cytokine production in response to self-antigens in vitro and is required for UVB-mediated tolerance to haptenated self-proteins in vivo. Up-regulation of CD200 may represent a novel mechanism, whereby immune reactivity to apoptosis-associated self-antigens is suppressed under steady state conditions. (Blood. 2004;103: 2691-2698)

Does actin produce the force that moves a chromosome to the pole during anaphase?

1985 ◽  
Vol 63 (6) ◽  
pp. 585-598 ◽  
Author(s):  
Arthur Forer
Keyword(s):  
Spindle Fibre ◽  
Apparent Contradiction ◽  
Spindle Poles ◽  
Ultraviolet Microbeam ◽  
The Face ◽  
Spindle Fibres ◽  
Rule Out ◽  
Do So

Chromosomes move towards spindle poles because of force produced by chromosomal spindle fibres. I argue that actin is involved in producing this force. Actin is present in chromosomal spindle fibres, with consistent polarity. Physiological experiments using ultraviolet microbeam irradiations suggest that the force is due to an actin and myosin (or myosin-equivalent) system. Other physiological experiments (using inhibitors in "leaky" cells or antibodies injected into cells) that on the face of it would seem to rule out actin and myosin on closer scrutiny do not really do so at all. I argue that in vivo the "on" ends of chromosomal spindle fibre microtubules are at the kinetochores; I discuss the apparent contradiction between this conclusion and those from experiments on microtubules in vitro. From what we know of treadmilling in microtubules in vitro, the poleward movements of irradiation-induced areas of reduced birefringence (arb) can not be explained as treadmilling of microtubules: additional assumptions need to be made for arb movements toward the pole to be due to treadmilling. If arb movement does indeed represent treadmilling along chromosomal spindle fibre microtubules, treadmilling continues throughout anaphase. Thus I suggest that chromosomal spindle fibres shorten in anaphase not because polymerization is stopped at the kinetochore (the on end), as previously assumed, but rather because there is increased depolymerization at the pole (the "off" end).

Quantification of in vitro and in vivo energy metabolism of the gastrointestinal tract of fed or fasted sheep

1993 ◽  
Vol 73 (4) ◽  
pp. 855-868 ◽  
Author(s):  
J. M. Kelly ◽  
B. G. Southorn ◽  
C. E. Kelly ◽  
L. P. Milligan ◽  
B. W. McBride
Keyword(s):  
Blood Flow ◽  
Gastrointestinal Tract ◽  
Portal Blood Flow ◽  
Whole Body ◽  
Hepatic Portal Vein ◽  
Flow Through ◽  
Hepatic Portal ◽  
Ouabain Inhibition

The effect of level of nutrition on in vitro and in vivo O2 consumption by the gastrointestinal tract in four nonlactating, nonpregnant ewes catheterized in the anterior mesenteric vein, hepatic portal vein and mesenteric artery with duodenal cannulae was investigated. Animals were fed a pelleted ration at maintenance (M) or twice maintenance (2M) or fasted (F) subsequent to the M measurement. Duodenal in vitro O2, ouabain-sensitive O2 (OSO2) and cycloheximide-sensitive O2 (CSO2) consumption was determined polarographically using a YSI O2 monitor; whole-gut O2 consumption was determined as (arterio-venous difference of O2 concentration) × (blood flow through the PV). Whole-body O2 consumption was determined using indirect calorimetry. Ewes fed 2M exhibited higher (P < 0.10) whole-body O2 consumption than either M or F ewes. Ewes fed M and 2M had higher (P < 0.10) duodenal in vitro O2 and ouabain-insensitive O2 (OIO2) consumption than F ewes. Hepatic portal blood flow was directly proportional to level of intake (P < 0.10): it was lowest for F ewes (81.0 L h−1), intermediate for M ewes (97.7 L h−1) and highest for 2M ewes (122.5 L h−1). Ouabain inhibition of O2 consumption by portal-drained viscera (PDV) was highest in M ewes and lowest in 2M ewes (P < 0.10). CSO2 consumption by the entire PDV was not affected by level of intake, corresponding to no change in OIO2 consumption by the PDV. As a proportion of whole-body O2 consumption, total O2, OSO2 and cycloheximide-insensitive O2 consumption by the PDV was higher in F ewes than in 2M ewes (P < 0.10). Fasted ewes expended a greater proportion of whole-body O2 consumption on gastrointestinal energetics than did 2M ewes. Key words: Sheep, gastrointestinal oxygen consumption, sodium–potassium ATPase, protein synthesis

scholarly journals Escaping High Viral Load Exhaustion

2002 ◽  
Vol 195 (9) ◽  
pp. 1089-1101 ◽  
Author(s):  
Stephanie Reignat ◽  
George J.M. Webster ◽  
David Brown ◽  
Graham S. Ogg ◽  
Abigail King ◽  
...  
Keyword(s):  
Viral Infections ◽  
Low Frequency ◽  
High Viral Load ◽  
Functional Impairments ◽  
Cd8 Cells ◽  
Cell Dysfunction ◽  
Chronic Hepatitis B Virus ◽  
The Face

Deletion, anergy, and a spectrum of functional impairments can affect virus-specific CD8 cells in chronic viral infections. Here we characterize a low frequency population of CD8 cells present in chronic hepatitis B virus (HBV) infection which survive in the face of a high quantity of viral antigen. Although they do not appear to exert immunological pressure in vivo, these CD8 cells are not classically “tolerant” since they proliferate, lyse, and produce antiviral cytokines in vitro. They are characterized by altered HLA/peptide tetramer reactivity, which is not explained by TCR down-regulation or reduced functional avidity and which can be reversed with repetitive stimulation. CD8 cells with altered tetramer binding appear to have a specificity restricted to envelope antigen and not to other HBV antigens, suggesting that mechanisms of CD8 cell dysfunction are differentially regulated according to the antigenic form and presentation of individual viral antigens.

Detection of allergen-induced airway hyperresponsiveness in isolated mouse lungs

2006 ◽  
Vol 291 (3) ◽  
pp. L466-L472 ◽  
Author(s):  
Martin Witzenrath ◽  
Birgit Ahrens ◽  
Stefanie M. Kube ◽  
Armin Braun ◽  
Heinz G. Hoymann ◽  
...  
Keyword(s):  
Airway Hyperresponsiveness ◽  
Ex Vivo ◽  
Whole Body ◽  
Strongly Correlated ◽  
Ex Vivo Model ◽  
Isolated Lungs ◽  
Spontaneously Breathing

Airway hyperresponsiveness (AHR) is a hallmark of bronchial asthma. Important features of this exaggerated response to bronchoconstrictive stimuli have mostly been investigated in vivo in intact animals or in vitro in isolated tracheal or bronchial tissues. Both approaches have important advantages but also certain limitations. Therefore, the aim of our study was to develop an ex vivo model of isolated lungs from sensitized mice for the investigation of airway responsiveness (AR). BALB/c mice were sensitized by intraperitoneal ovalbumin (Ova) and subsequently challenged by Ova inhalation. In vivo AR was measured in unrestrained animals by whole body plethysmography after stimulation with aerosolized methacholine (MCh) with determination of enhanced pause ( Penh). Twenty-four hours after each Penh measurement, airway resistance was continuously registered in isolated, perfused, and ventilated lungs on stimulation with inhaled or intravascular MCh or nebulized Ova. In a subset of experiments, in vivo AR was additionally measured in orotracheally intubated, spontaneously breathing mice 24 h after Penh measurement, and lungs were isolated further 24 h later. Isolated lungs of allergen-sensitized and -challenged mice showed increased AR after MCh inhalation or infusion as well as after specific provocation with aerosolized allergen. AR was increased on days 2 and 5 after Ova challenge and had returned to baseline on day 9. AHR in isolated lungs after aerosolized or intravascular MCh strongly correlated with in vivo AR. Pretreatment of isolated lungs with the β2-agonist fenoterol diminished AR. In conclusion, this model provides new opportunities to investigate mechanisms of AHR as well as pharmacological interventions on an intact organ level.

Pressor response to a postural change in cirrhosis: an experimental study in the CCI4-treated rat

1992 ◽  
Vol 82 (2) ◽  
pp. 147-156 ◽  
Author(s):  
Arieh Bomzon ◽  
Avraham Weinbroum ◽  
Laurence M. Blendis
Keyword(s):  
Pressor Response ◽  
Contributory Factor ◽  
Postural Change ◽  
Systemic Hypotension ◽  
Arterial Blood ◽  
The Face ◽  
Cirrhotic Patients

1. Systemic hypotension, blunted cardiovascular responsiveness to noradrenaline and an abnormal hypertensive pressor response to a postural change have been described in cirrhotic patients. 2. We have examined the role of blunted responsiveness in these abnormalities by studying basal arterial blood pressure and its response to a postural change (vertical head-up 90° tilting) in conscious and pithed CCl4-treated (cirrhotic) rats, as well as assessing the pressor response to noradrenaline in vivo and the vascular contractile response to noradrenaline in vitro. 3. A diminished hypotensive response to a change in posture was found in pre-cirrhotic portal hypertensive rats, whereas an inverted hypertensive pressor response in the face of systemic hypotension occurred in the cirrhotic rats with portal hypertension. 4. The inverted pressor response was abolished in the pithed portal hypertensive cirrhotic rats. 5. The pressor response to noradrenaline in vivo in conscious cirrhotic rats and the vascular contractile responsiveness to noradrenaline in vitro were intact. 6. We conclude that blunted responsiveness to noradrenaline is not a contributory factor to the development of systemic hypotension or the inverted pressor response to a change in posture in cirrhosis.

scholarly journals Energy metabolism in trout red cells: consequences of adrenergic stimulation in vivo and in vitro

1989 ◽  
Vol 143 (1) ◽  
pp. 133-147 ◽  
Author(s):  
R. A. Ferguson ◽  
B. L. Tufts ◽  
R. G. Boutilier
Keyword(s):  
Ph Regulation ◽  
Red Cells ◽  
Red Cell ◽  
Adrenergic Stimulation ◽  
Beta Adrenergic ◽  
Extracellular Acidosis ◽  
Metabolic Functions ◽  
The Face

beta-Adrenergic stimulation of salmonid red cells results in a rapid decrease (within 5 min) in the nucleotide triphosphate:haemoglobin ratio (NTP:Hb), which is thereafter maintained at a constant level, presumably through increased ATP turnover via matched aerobic metabolism and energy-consuming processes. Addition of the beta-adrenergic agonist isoproterenol to rainbow trout red cells in vitro leads to a rise in intracellular pH (pHi), a corresponding decrease in extracellular pH (pHe) and an increase in red cell oxygen consumption (MO2). Moreover, the extent to which red cell pHi is maintained constant in the face of an acute extracellular acidosis in vitro or in vivo is proportional to the adrenergically stimulated increase in red cell MO2. In the absence of oxygen, these red cells remain capable of pH regulation, but cannot maintain NTP:Hb constant. As a result, membrane and metabolic functions become uncoupled in the stimulated deoxygenated cells.

scholarly journals Interactions between Babesia microti merozoites and rat kidney cells in a short-term in vitro culture and animal model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marta Albertyńska ◽  
Hubert Okła ◽  
Krzysztof Jasik ◽  
Danuta Urbańska-Jasik ◽  
Przemysław Pol
Keyword(s):  
Epithelial Cells ◽  
Cross Sections ◽  
Rat Kidney ◽  
Babesia Microti ◽  
Renal Tubules ◽  
Renal Epithelial Cells ◽  
Transmission Electron ◽  
Flow Through

AbstractBabesiosis is one of the most common infections in free-living animals and is rapidly becoming significant among human zoonoses. Cases of acute renal failure in humans caused by Babesia spp. have been described in the literature. The kidneys are characterised by intense blood flow through the blood vessels, which increases the likelihood of contact with the intra-erythrocyte parasite. The aim of this study was to observe the influence of B. microti (ATCC 30221) on renal epithelial cells in vitro cultured (NRK-52E line) and Wistar rats’ kidney. Both NRK-52E cells and rats’ kidney sections were analysed by light microscopy, transmission electron microscopy (TEM) and fluorescence in situ hybridization (FISH). Necrotic changes in renal epithelial cells have been observed in vitro and in vivo. In many cross-sections through the rats’ kidney, adhesion of blood cells to the vascular endothelium, accumulation of erythrocytes and emboli were demonstrated. In NRK-52E culture, elements with a distinctly doubled cell membrane resembling B. microti were found inside the cytoplasm and adjacent to the cell layer. The study indicates a chemotactic tendency for B. microti to adhere to the renal tubules' epithelium, a possibility of piroplasms entering the renal epithelial cells, their proliferation within the cytoplasm and emboli formation.

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