Rheological effects of hypertonic saline and sodium bicarbonate solutions on cystic fibrosis sputum in vitro

Abstract Background Cystic fibrosis (CF) is a life-threatening multiorgan genetic disease, particularly affecting the lungs, where recurrent infections are the main cause of reduced life expectancy. In CF, mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein impair transepithelial electrolyte and water transport, resulting in airway dehydration, and a thickening of the mucus associated with abnormal viscoelastic properties. Our aim was to develop a rheological method to assess the effects of hypertonic saline (NaCl) and NaHCO3 on CF sputum viscoelasticity in vitro, and to identify the critical steps in sample preparation and in the rheological measurements. Methods Sputum samples were mixed with hypertonic salt solutions in vitro in a ratio of either 10:4 or 10:1. Distilled water was applied as a reference treatment. The rheological properties of sputum from CF patients, and the effects of these in vitro treatments, were studied with a rheometer at constant frequency and strain, followed by frequency sweep tests, where storage modulus (G′), loss modulus (G″) and loss factor were determined. Results We identified three distinct categories of sputum: (i) highly elastic (G′ > 100,000 Pa), (ii) elastic (100,000 Pa > G′ > 1000 Pa), and (iii) viscoelastic (G′ < 1000). At the higher additive ratio (10:4), all of the added solutions were found to significantly reduce the gel strength of the sputum, but the most pronounced changes were observed with NaHCO3 (p < 0.001). Samples with high elasticity exhibited the greatest changes while, for less elastic samples, a weakening of the gel structure was observed when they were treated with water or NaHCO3, but not with NaCl. For the viscoelastic samples, the additives did not cause significant changes in the parameters. When the lower additive ratio (10:1) was used, the mean values of the rheological parameters usually decreased, but the changes were not statistically significant. Conclusion Based on the rheological properties of the initial sputum samples, we can predict with some confidence the treatment efficacy of each of the alternative additives. The marked differences between the three categories suggest that it is advisable to evaluate each sample individually using a rheological approach such as that described here.

Download Full-text

Impact of systemic cryotherapy on the rheological properties of the blood in women with rheumatoid arthritis

Rehabilitacja Medyczna ◽

10.5604/01.3001.0010.4815 ◽

2017 ◽

Vol 21 (2) ◽

pp. 4-9

Author(s):

Bartłomiej Ptaszek ◽

Aneta Teległów ◽

Jakub Marchewka

Keyword(s):

Rheumatoid Arthritis ◽

Rheological Properties ◽

Treatment Time ◽

Venous Blood ◽

Body Height ◽

Rheological Parameters ◽

Study Group ◽

Mean Values ◽

Chamber Temperature ◽

The Mean

Study aim: The aim of this study was to assess the effects of systemic cryotherapy on the rheological properties of the blood in women with rheumatoid arthritis. Study group: The study group consisted of 10 women with rheumatoid arthritis, aged 57.2 ± 9.4, who underwent systemic cryotherapy treatments (3 min treatment time, -120 °C chamber temperature, 10 treatment sessions - 5 times a week). Their average body height was 165.5 ± 4.6 cm, weight 68.5 ± 4.9 kg and BMI 24.8 ± 2.2 kg/m2. In order to analyze morphological and rheological parameters of the blood, venous blood samples were drawn from the participants of the study twice. The first study was held on the day of beginning treatments and the second test was conducted after a series of 10 treatments. Methodology: The morphological blood test - measurements were taken using the ABX MICROS 60 (USA) hematology analyser. Erythrocyte deformability and aggregation were tested using the LORCA analyser (Laser-assisted Optical Rotational Cell Analyser RR Mechatronics, The Netherlands). The results were obtained as the index of elongation and aggregation according to the Hardeman method (2001). Results: Analysing the average values of morphological and rheological parameters of the blood in women with rheumatoid arthritis in the study group, the mean values of RBC, Hct and AI following the series of 10 treatments were significantly higher after cryotherapy in comparison to the measurements taken before treatments. Analysing the mean concentrations of T½, there was statistically significant reduction after the series of 10 treatments. Conclusions: Regular usage of cryotherapy treatments may affect the levels of morphological and rheological parameters of the blood in women with rheumatoid arthritis - RBC, Hct and AI (increase) and T½ (reduction) in the blood. null

Download Full-text

Rheological properties of cholesteric liquid crystals as lubricant additives

International Journal of Modern Physics B ◽

10.1142/s0217979219500140 ◽

2019 ◽

Vol 33 (05) ◽

pp. 1950014 ◽

Cited By ~ 1

Author(s):

A. Bindu Madhavi ◽

S. Sreehari Sastry

Keyword(s):

Shear Rate ◽

Rheological Properties ◽

Loss Modulus ◽

Flow Behavior ◽

Lubricant Additives ◽

Rheological Parameters ◽

Practical Applications ◽

Phase Transition Temperatures ◽

Frequency Independent ◽

Temperature Shear

Rheological properties of Cholesteryl n-valerate, Cholesteryl decanoate and Cholesteryl myristate which are esters of cholesterol have been studied. Phase transition temperatures and rheological parameters such as viscosity, elastic modulus G[Formula: see text], loss modulus G[Formula: see text] as functions of temperature, shear rate and time are investigated. In frequency sweep test, a higher transition crossover region has occurred for Cholesteryl myristate, whereas for Cholesteryl n-valerate a frequency-independent plateau prevailed for both the moduli. The occurrence of blue phase in Cholesteryl decanoate during temperature sweep measurements is an indication for the rheological support. The results for steady state have informed that cholesteric esters are having non-Newtonian flow behavior in their respective cholesteric phases. The power-law model has explained well the shear rate dependence of shear stress. A few practical applications of these esters as lubricant additives are discussed, too.

Download Full-text

MANAGEMENT OF ENDOCRINE DISEASE: Cystic fibrosis-related diabetes: novel pathogenic insights opening new therapeutic avenues

Acta Endocrinologica ◽

10.1530/eje-14-0644 ◽

2015 ◽

Vol 172 (4) ◽

pp. R131-R141 ◽

Cited By ~ 26

Author(s):

Raquel Barrio

Keyword(s):

Cystic Fibrosis ◽

Insulin Secretion ◽

Synergistic Effects ◽

Ionic Composition ◽

Cell Mass ◽

Β Cell ◽

Gene Encoding ◽

Mutant Proteins ◽

Cf Transmembrane Conductance Regulator

Cystic fibrosis (CF) is a recessive genetic disease caused by mutations in the CF transmembrane conductance regulator (CFTR).CFTRis primarily present in epithelial cells of the airways, intestine and in cells with exocrine and endocrine functions. Mutations in the gene encoding the channel protein complex (CFTR) cause alterations in the ionic composition of secretions from the lung, gastrointestinal tract, liver, and also the pancreas. CF-related diabetes (CFRD), the most common complication of CF, has a major detrimental impact on pulmonary function, nutrition and survival. Glucose derangements in CF seem to start from early infancy and, even when the pathophysiology is multifactorial, insulin insufficiency is clearly a major component. Consistently, recent evidence has confirmed that CFTR is an important regulator of insulin secretion by islet β-cells. In addition, several other mechanisms were also recognized from cellular and animals models also contributing to either β-cell mass reduction or β-cell malfunction. Understanding such mechanisms is crucial for the development of the so-called ‘transformational’ therapies in CF, including the preservation of insulin secretion. Innovative therapeutic approaches aim to modify specific CFTR mutant proteins or positively modulate their function. CFTR modulators have recently shownin vitrocapacity to enhance insulin secretion and thereby potential clinical utility in CFDR, including synergistic effects between corrector and potentiator drugs. The introduction of incretins and the optimization of exocrine pancreatic replacement complete the number of therapeutic options of CFRD besides early diagnosis and implementation of insulin therapy. This review focuses on the recently identified pathogenic mechanisms leading to CFRD relevant for the development of novel pharmacological avenues in CFRD therapy.

Download Full-text

Rheological Properties of Cystic Fibrosis Bronchial Secretion and in Vitro Drug Permeation Study: The Effect of Sodium Bicarbonate

Journal of Aerosol Medicine and Pulmonary Drug Delivery ◽

10.1089/jamp.2015.1228 ◽

2016 ◽

Vol 29 (4) ◽

pp. 337-345 ◽

Cited By ~ 15

Author(s):

Mariateresa Stigliani ◽

Michele Dario Manniello ◽

Olga Zegarra-Moran ◽

Luis Galietta ◽

Laura Minicucci ◽

...

Keyword(s):

Cystic Fibrosis ◽

Sodium Bicarbonate ◽

Rheological Properties ◽

Bronchial Secretion ◽

Drug Permeation ◽

Permeation Study

Download Full-text

Analysis of the Magnetic Field Influence on the Rheological Properties of Healthy Persons Blood

BioMed Research International ◽

10.1155/2013/490410 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Anna Marcinkowska-Gapinska ◽

Honorata Nawrocka-Bogusz

Keyword(s):

Magnetic Field ◽

Rheological Properties ◽

Blood Viscosity ◽

Flow Curve ◽

Rheological Parameters ◽

Blood Samples ◽

The Magnetic Field ◽

Field Influence ◽

Healthy Persons

The influence of magnetic field on whole blood rheological properties remains a weakly known phenomenon. Anin vitroanalysis of the magnetic field influence on the rheological properties of healthy persons blood is presented in this work. The study was performed on blood samples taken from 25 healthy nonsmoking persons and included comparative analysis of the results of both the standard rotary method (flow curve measurement) and the oscillatory method known also as the mechanical dynamic analysis, performed before and after exposition of blood samples to magnetic field. The principle of the oscillatory technique lies in determining the amplitude and phase of the oscillations of the studied sample subjected to action of a harmonic force of controlled amplitude and frequency. The flow curve measurement involved determining the shear rate dependence of blood viscosity. The viscoelastic properties of the blood samples were analyzed in terms of complex blood viscosity. All the measurements have been performed by means of the Contraves LS40 rheometer. The data obtained from the flow curve measurements complemented by hematocrit and plasma viscosity measurements have been analyzed using the rheological model of Quemada. No significant changes of the studied rheological parameters have been found.

Download Full-text