scholarly journals Size Distribution of Colistin Delivery by Different Type Nebulizers and Concentrations During Mechanical Ventilation

Pharmaceutics ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 459 ◽  
Author(s):  
Ching-Yi Liu ◽  
Hsin-Kuo Ko ◽  
James Fink ◽  
Gwo-Hwa Wan ◽  
Chung-Chi Huang ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Size Distribution ◽  
Mechanical Ventilators ◽  
High Concentration ◽  
Low Concentration ◽  
Dose Volume ◽  
Jet Nebulizer ◽  
Similar Range ◽  
Colistin Methanesulfonate

Although aerosol delivery through mechanical ventilators has been used to administer various medications, little is known of administration with colistin. This in vitro evaluation aimed to evaluate size distribution of colistin delivery by different types of nebulizers and concentrations during mechanical ventilation. Colistin methanesulfonate (colistin) for injection was dissolved in 6 mL of distilled water to produce a low concentration (L; 156 mg) and a high concentration (H; 312 mg). A dose volume of 6 mL was placed in a vibrating mesh nebulizer (VMN) and a jet nebulizer (JN). The inhaled mass (mean ± SD) of the VMN-L (53.80 ± 14.79 mg) was greater than both the JN-L (19.82 ± 3.34 mg, P = 0.001) and JN-H (31.72 ± 4.48 mg, P = 0.017). The nebulization time of the VMN-L (42.35 ± 2.30 min) was two times longer than the JN-L (21.12 ± 0.8 min) or JN-H (21.65 ± 0.42 min; P < 0.001). The mass median aerodynamic distal to the endotracheal tube was within a similar range at 2.03 to 2.26 μm (P = 0.434), independent of neb or formulation concentration. In conclusion, the VMN-L yields greater inhaled mass than the JN with either concentration. Therefore, a standard nominal dose of colistin results in a higher delivered dose during mechanical ventilation with a VMN compared with a JN and may be considered the preferred device. If JN must be used, multiple doses of low concentration colistin may compensate for poor delivery performance.

Polyethylene glycol diacrylate scaffold filled with cell-laden methacrylamide gelatin/alginate hydrogels used for cartilage repair

2021 ◽  
pp. 088532822110448
Author(s):  
Xiang Zhang ◽  
Zhenhao Yan ◽  
Guotao Guan ◽  
Zijing Lu ◽  
Shujie Yan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Polyethylene Glycol ◽  
Cartilage Tissue Engineering ◽  
Cartilage Tissue ◽  
High Concentration ◽  
Polyethylene Glycol Diacrylate ◽  
Low Concentration ◽  
Glycol Diacrylate

Natural cartilage tissue has excellent mechanical properties and has certain cellular components. At this stage, it is a great challenge to produce cartilage scaffolds with excellent mechanical properties, biocompatibility, and biodegradability. Hydrogels are commonly used in tissue engineering because of their excellent biocompatibility; however, the mechanical properties of commonly used hydrogels are difficult to meet the requirements of making cartilage scaffolds. The mechanical properties of high concentration polyethylene glycol diacrylate (PEGDA) hydrogel are similar to those of natural cartilage, but its biocompatibility is poor. Low concentration hydrogel has better biocompatibility, but its mechanical properties are poor. In this study, two different hydrogels were combined to produce cartilage scaffolds with good mechanical properties and strong biocompatibility. First, the PEGDA grid scaffold was printed with light curing 3D printing technology, and then the low concentration GelMA/Alginate hydrogel with chondral cells was filled into the PEGDA grid scaffold. After a series of cell experiments, the filling hydrogel with the best biocompatibility was screened out, and finally the filled hydrogel with cells and excellent biocompatibility was obtained. Cartilage tissue engineering scaffolds with certain mechanical properties were found to have a tendency of cartilage formation in in vitro culture. Compared with the scaffold obtained by using a single hydrogel, this molding method can produce a tissue engineering scaffold with excellent mechanical properties on the premise of ensuring biocompatibility, which has a certain potential application value in the field of cartilage tissue engineering.

Cleanroom Mats: An Investigation of Particle Removal

1996 ◽  
Vol 39 (4) ◽  
pp. 19-27
Author(s):  
W. Whyte ◽  
T. Shields ◽  
T. Prvan
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Removal Efficiency ◽  
Adhesive Strength ◽  
Particle Removal ◽  
High Concentration ◽  
Low Concentration

The variables that influence the particle removal efficiency of cleanroom mats were investigated. The removal efficiency was generally found to be greater if the mat was of a softer type, the particles smaller, the particle size distribution more homogeneous, the distance between the particles greater, and the adhesive strength of the mat surface greater. One application of a mat surface was sufficient to remove a low concentration of similarly sized particles from a surface but it could require up to four mat surfaces to remove a high concentration of heterogeneously sized particles. It was found with heterogeneously sized particles that larger particles were removed first, thus allowing access to the smaller particles which could then be removed. If the mat was soft, it allowed larger particles to sink into it and smaller particles than normal to be picked up.

Protective effect of glutathione against oxidative injury in intestinal epithelial cells of piglet in vitro

2009 ◽  
Vol 59 (3) ◽  
pp. 263-272 ◽  
Author(s):  
Qun Chen ◽  
Ying-Qiu Li ◽  
Shu-Ming Zhang ◽  
Hai-Yan Liu
Keyword(s):  
Oxidative Stress ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Oxidative Injury ◽  
Control Group ◽  
Dependent Manner ◽  
Intestinal Epithelial ◽  
High Concentration ◽  
Low Concentration

AbstractOxidative stress of intestinal epithelium is involved in inflammatory bowel disease. To investigate protective effects of glutathione (GSH) on xanthine/xanthine oxidase (X/XO)-induced oxidative injury in intestinal epithelial cells (IECs). We employed in vitro cell culture supplemented with X/XO. IECs were cultured for 72 h, and then divided into seven groups with various concentrations of X/XO and GSH supplementation in the medium. Agarose gel electrophoresis lanes indicated that X/XO induced DNA injury by the high concentration of XO (40, 70 U/L)-treated groups. The X/XO supplementation significantly increased the production of malondialdehyde (MDA) in a dose-dependent manner. There was a slight increase in total radical-trapping antioxidant potential (TRAP) value by the low concentration of XO (10U/L) alone-treated group (P > 0.05) while supplementation of a high concentration of XO (40, 70 U/L) significantly decreased TRAP value compared with XO (10 U/L) and the control group (P < 0.05). Addition of GSH decreased the production of MDA and DNA fragmentations (P < 0.05), but enhanced TRAP value (P < 0.05). These results suggest that IECs of piglet have the ability of enduring mild oxidative stress induced by a low concentration of XO. Although high concentrations of XO resulted in oxidation injury and lipid peroxidation in the IECs, additions of GSH to the medium showed significant protection against the X/XO-induced oxidative stress.

scholarly journals Epilobium angustifolium L.: A medicinal plant with therapeutic properties

2017 ◽  
Vol 1 (2) ◽  
pp. 126-131
Author(s):  
Halyna Ostrovska ◽  
Oleksandra Oleshchuk ◽  
Samuele Vannini ◽  
Samuela Cataldi ◽  
Elisabetta Albi ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Medicinal Plant ◽  
Antioxidant Properties ◽  
Carcinoma Cells ◽  
High Concentration ◽  
Mitochondrial Potential ◽  
Low Concentration ◽  
Epilobium Angustifolium ◽  
Human Hepatocellular Carcinoma Cells

Abstract Epilobium angustifolium L. is a medicinal plant belonging to the Onagraceae family, which includes more than 200 different species from all over the world. Traditional medicinal applications include treatment of prostate, gastrointestinal, menstrual disorders and recently it has been used for its analgesic and anti-inflammatory activity. In this investigation E. angustifolium was collected in Ternopil region of Ukraine. The obtained data demonstrated that E. angustifolium herb extract, rich in polyphenolic compounds such as flavonoids and tannins, display high antioxidant properties. In addition the potential anticancer activity has been investigated in vitro on human hepatocellular carcinoma cells (HepG2). Furthermore the cytotoxic and genotoxic effects of E. angustifolium have been investigated respectively by MTT and Comet assay. Results showed that at low concentration, up to 25 μg/mL, the cytotoxic effect was not observed. Increasing concentration from 50 to 75 μg/mL reduced significantly cell viability and induced an important DNA damage in hepatocellular carcinoma. These promising data were also confirmed with mitochondrial potential test. It is possible to conclude that E. angustifolium has beneficial properties in low concentration, in term of antioxidant activity, and it could be a potential antitumoral natural product if it will be used at high concentration

THE EFFECT OF OUABAIN ON ALDOSTERONE PRODUCTION IN THE RAT

1971 ◽  
Vol 68 (3) ◽  
pp. 477-484 ◽  
Author(s):  
Kathleen Sz. Szalay
Keyword(s):  
Chronic Treatment ◽  
High Concentration ◽  
Low Concentration ◽  
Aldosterone Production ◽  
The Media ◽  
Renin Content

ABSTRACT Chronic treatment with ouabain increases aldosterone production in the rat but has no effect on the renal renin content. The effect of ouabain in vitro on aldosterone depends on its concentration and the K content of the media: 10−8 m ouabain and 4 and 8 meq./l K and 10−4 m and 4 meq./l K intensify, while 10−3 m at 6 and 8 meq./l K inhibits production. In the present experiments, ouabain at low concentration increased and at high concentration reduced aldosterone production.

scholarly journals State of antioxidant system in urogenital trichomoniasis and membranotropic effect of metronidazole

2021 ◽  
pp. 8-11
Author(s):  
H. K. Kondakova ◽  
◽  
H. O. Semko ◽  
O. V. Levytska ◽  
V. M. Tsymbal ◽  
...  
Keyword(s):  
Glutathione Peroxidase ◽  
Glutathione Reductase ◽  
Antioxidant System ◽  
Sulfhydryl Groups ◽  
High Concentration ◽  
Vitro Experiment ◽  
Low Concentration ◽  
In Vitro Experiment ◽  
Hypotonic Hemolysis

The objective of this work was to study the activity of glutathione peroxidase, glutathione reductase and the level of sulfhydryl groups in erythrocytes of patients with urogenital trichomoniasis and the effect of metronidazole on the degree of osmotic and peroxide resistance of erythrocytes from healthy donors. We examined 15 patients with urogenital trichomoniasis and 20 healthy volunteers. We studied native preparations, and also carried out a culture method using the Johnson-Trussel nutrient medium (CPLM) to identify Trichomona vaginalis. The activity of glutathione reductase, glutathione peroxidase and the level of total sulfhydryl groups were determined in erythrocytes of peripheral blood. The membrane effect of metronidazole was evaluated in in vitro experiment by the degree of osmotic and peroxide resistance of erythrocytes from healthy people. It has been established that a significant decrease in glutathione reductase and glutathione peroxidase activities in erythrocytes is observed, which indicates a violation of the antioxidant system in this pathology. It was shown in vitro experiment, that metronidazole in low concentration (80 μmol /l) has the ability to inhibit erythrocyte hypotonic hemolysis, and high concentration (250 μmol/l) leads to a decrease in osmotic and peroxide resistance of erythrocytes. Thus, inhibition of the activity of the enzymatic link of the antioxidant defense is observed in urogenital trichomoniasis, which is one of the mechanisms for the development of pathology at the cellular level in this disease. It has been shown that the isolated membranotropic action of metronidazole depends on its concentration – the drug at low concentration is able to inhibit hypotonic hemolysis of erythrocytes, and high concentration makes them more sensitive to the osmotic and peroxide hemolysis. The obtained results should be taken into account in the development of complex methods of therapy for urogenital trichomoniasis.

scholarly journals The bacteriostatic effect and mechanism of berberine on Methicillin resistant Staphylococcus aureus in vitro

2019 ◽  
Author(s):  
Lei Wang ◽  
Fangfang Zhou ◽  
Minyi Xu ◽  
Wei Gong ◽  
Shuiying Ji
Keyword(s):  
Cell Wall ◽  
Rna Sequencing ◽  
Differentially Expressed Genes ◽  
Differentially Expressed ◽  
Control Group ◽  
High Concentration ◽  
Bacteriostatic Effect ◽  
Low Concentration ◽  
Kinetics Of

Abstract Background: To observe the bacteriostatic effect of berberine on MRSA, while also exploring the bacteriostatic mechanism of BBR on MRSA. Methods: The MIC of BBR, gentamicin, levofloxacin，amikacin was determined by broth microdilution, while the MICs of BBR combined with gentamicin, levofloxacin，amikacin against MRSA were determined using microdilution checkerboard. Time-killing test were used to determine the kinetics of BBR combined with antibiotics for MRSA. We used conductivity to assess the changes in membrane permeability in response to BBR on MRSA, while also investigating the changes in MRSA morphology by TEM. RNA-sequencing was used to analyze the expression of differentially expressed genes in USA300 after its treatment with BBR. Results: The MICs range of BBR on MRSA was 32-256 µg/mL. The range of FICIs of BBR combined with gentamicin, levofloxacin，amikacin were 0.53-1.06, 0.62-1.5, 0.16-1.25. After co-culturing MRSA with BBR at 512 ug/mL, 64 ug/mL,8 ug/mL, respectively, the conductivity of these group increased by 8.14%,13.08% and 12.01%, respectively. Using TEM, we found that low-concentration of BBR had no significant effect on MRSA structure, medium-concentration of BBR thinned the cell wall of MRSA, while high-concentration of BBR destroyed cell wall, leading to bacterial lysis. RNA-sequencing results showed that there were 754 differentially expressed genes in the high-concentration group compared with the control group, of which 561 genes were up-regulated and 193 genes were down-regulated. Compared with the low-concentration group, there were 590 differentially expressed genes, of which 402 genes were up-regulated and 188 genes were down-regulated. Compared with the control group, 19 genes were differentially expressed in the low-concentration group, of which 11 genes were up-regulated,8 genes were down-regulated. Conclusions: BBR displayed an excellent bacteriostatic effect on MRSA. BBR combined with antibiotics significantly enhanced the bacteriostatic effect on MRSA. BBR inhibited bacteria by destroying the structure of cell wall. RNA-sequencing results demonstrated that the expression of cell wall hydrolysis genes and virulence factor were significantly differentially expressed on MRSA.

scholarly journals Effect of exogenous abscisic acid on accumulation of raffinose family oligosaccharides and galactosyl cyclitols in tiny vetch seeds (Vicia hirsuta [L.] S.F. Gray)

2011 ◽  
Vol 73 (4) ◽  
pp. 277-283 ◽  
Author(s):  
Lesław B. Lahuta ◽  
Ryszard J. Górecki ◽  
Ewa Gojło ◽  
Marcin Horbowicz
Keyword(s):  
Abscisic Acid ◽  
Seed Development ◽  
Acid Concentration ◽  
Raffinose Family Oligosaccharides ◽  
High Concentration ◽  
Low Concentration ◽  
Vicia Hirsuta ◽  
Galactosyl Cyclitols

The role of the abscisic acid (ABA) in biosynthesis of raffinose family oligosaccharides (RFOs) and galactosyl cyclitols (Gal-C) in tiny vetch (<em>Vicia hirsuta</em> [L.] S.F. Gray) seeds was investigated. The ABA was applied through incubation of seed at various stage of its development. The level of RFOs and Gal-C was determined in seed maturing on plant and in seed maturing in vitro. In early stages of <em>V. hirsuta</em> seed development, the ABA activated the biosynthesis of galactinol, although the level of arisen galactinol quickly declined. In the later stages of <em>V. hirsuta</em> seed development ABA had stimulatory effect of RFOs and Gal-C biosynthesis. Influence of ABA on biosynthesis of a-galactosides in <em>Vicia hirsuta</em> seed seems to be dependent on abscisic acid concentration. Low concentration of ABA had stimulatory effect on a-galactosides biosynthesis, but high concentration of ABA inhibited the process.

Bacterial Colonization in Humidifying Cascade Reservoirs After 24 and 48 Hours of Continuous Mechanical Ventilation

1987 ◽  
Vol 8 (5) ◽  
pp. 200-203 ◽  
Author(s):  
Theresa A. Goularte ◽  
Marie Manning ◽  
Donald E. Craven
Keyword(s):  
Mechanical Ventilation ◽  
Bacterial Colonization ◽  
Heated Humidifier ◽  
Mechanical Ventilator ◽  
Reservoir Temperature ◽  
Mechanical Ventilators ◽  
Cascade Reservoirs ◽  
Reservoir Fluid ◽  
Bacterial Aerosols

AbstractWe evaluated levels of bacterial colonization in the humidifying cascade reservoirs of 466 mechanical ventilators; 326 reservoirs were cultured after 24 hours and 140 were cultured after 48 hours of continuous mechanical ventilation. Bacterial colonization was absent in 284 (87.1%) of the humidifier reservoirs sampled at 24 hours and 125 (89.3%) of the reservoirs cultured at 48 hours. Levels of bacterial colonization in the remaining humidifiers were low (<100 organisms/mL). The median temperature recorded in the reservoir fluid of 30 different ventilators was 50°C (range 40° to 60°C). In vitro seeding of reservoir fluid at 50°C with 106 organisms/mL of four different species of nosocomial gram-negative bacilli and Staphylococcus aureus demonstrated rapid killing of all five strains over a 6-hour incubation period, and no significant bacterial aerosols were detected. Rates and levels of bacteria in heated humidifier reservoirs are low and nosocomial pathogens survive poorly at the median reservoir temperature of 50°C. We conclude that the heated humidifier reservoir on a mechanical ventilator is an unlikely source of colonization or bacterial aerosols, and therefore it can be changed every 48 hours with the ventilator tubing.

scholarly journals In-vitro and in-vivo comparisons of high versus low concentrations of inhaled epoprostenol to adult intubated patients

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jie Li ◽  
Ashley E. Augustynovich ◽  
Payal K. Gurnani ◽  
James B. Fink
Keyword(s):  
Pulmonary Hypertension ◽  
Clinical Study ◽  
In Vitro Study ◽  
Vitro Study ◽  
Invasive Ventilation ◽  
High Concentration ◽  
Low Concentration ◽  
Low Concentrations ◽  
Clinical Scenarios

Abstract Background Inhaled epoprostenol (iEPO) has been shown to reduce pulmonary artery pressure and improve oxygenation. iEPO is mainly delivered via a syringe pump with feed tubing connected to a vibrating mesh nebulizer with high or low formulation concentration delivery. Methods An in vitro study and a two-period retrospective case–control study were implemented. The in vitro study compared iEPO delivery via invasive ventilation at low concentrations of 7.5, and 15 mcg/mL and high concentration at 30 mcg/mL, to deliver the ordered dose of 30 and 50 ng/kg/min for three clinical scenarios with predicted body weight of 50, 70 and 90 kg. While in the clinical study, adult patients receiving iEPO via invasive ventilation to treat refractory hypoxemia, pulmonary hypertension, or right ventricular failure were included. 80 patients received low concentration iEPO at multiple concentrations (2.5, 7.5, and 15 mcg/mL, depending on the ordered dose) from 2015 to 2017, while 84 patients received high concentration iEPO at 30 mcg/mL from 2018 to 2019. Results In the in vitro study, there were no significant differences in aerosol deposition between high vs low concentrations of iEPO at a dose of 50 ng/kg/min. In the clinical study, age, gender, ethnicity, and indications for iEPO were similar between high and low concentration groups. After 30–120 min of iEPO administration, both delivery strategies significantly improved oxygenation in hypoxemic patients and reduced mean pulmonary arterial pressure (mPAP) for patients with pulmonary hypertension. However, no significant differences of the incremental changes were found between two delivery groups. Compared to low concentration, high concentration delivery group had better adherence to the iEPO weaning protocol (96% vs 71%, p < 0.001), fewer iEPO syringes utilized per patient (5 [3, 10] vs 12 [6, 22], p = 0.001), and shorter duration of invasive ventilation (6 [3, 12] vs 9 [5, 18] days, p = 0.028). Intensive care unit length of stay and mortality were similar between two groups. Conclusion Compared to low concentration delivery of iEPO, high concentration iEPO via a vibrating mesh nebulizer maintained clinical benefits and increased clinician compliance with an iEPO weaning protocol, required less medication preparation time, and shortened duration of invasive ventilation.

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