Plasma Colloid Research Articles

A new strategy to improve the performance of MoS2-based 2D photodetector by synergism of colloidal CuInS2 quantum dots and surface plasma resonance of noble metal nanoparticles

Owing to their extraordinary optoelectronic properties, 2D transition metal dichalcogenides (TMDs) are proved to be promising materials for photodetectors. However, they suffered from poor absorptivity due to their atomically thin profile. Herein, CuInS2 quantum dots (QDs) and plasmonic Au nanoparticles (AuNPs) were adopted to achieve a MoS2-CuInS2-AuNPs 2D–0D hybrid by simultaneous deposition of CuInS2 QDs and AuNPs on the MoS2 nanosheet. In this configuration, MoS2 is used as a high mobility carrier transport channel, while CuInS2 QDs act as an efficient light absorber, and the AuNPs serve as a light sensitizer to enhance the local electric field around MoS2 and CuInS2 QDs via surface plasmon resonance (SPR). With such synergism of CuInS2 QDs and Au NPs, the highest responsivity of 16.65AW−1 and D* as high as 2.27×1012Jones are achieved for the MoS2-CuInS2-AuNPs hybrid devices under 635 nm laser, which is two orders of magnitude higher than the pristine MoS2 devices and outperformed most of the other MoS2-based photodetectors. Finally, the synergistic effect of the CuInS2 QDs and Au nanoparticles is illustrated by Finite-Difference Time-domain(FDTD) simulation. The underlying synergism strategy for such a 2D–0D configuration may also be applied to other photo-electric devices.

Low albumin levels are associated with mortality in the critically ill: A retrospective observational study in a multidisciplinary intensive care unit.

Background Albumin is a determinant of plasma colloid oncotic pressure and buffering capacity. It is a carrier protein for drugs and is important for normal functioning of the glycocalyx. Hypoalbuminaemia is common in the critically ill and has been associated with adverse outcomes. The association between hypoalbuminaemia and outcome has not been specifically explored in the South African context. Objectives To determine whether albumin levels on admission and changes in albumin levels were associated with intensive care unit (ICU) mortality in a heterogenous critically ill population. Methods This was a retrospective observational study of 247 adult patients who were admitted to a multidisciplinary ICU. Albumin levels were measured on admission and 48 hours later, alongside other biochemical and clinical parameters to determine whether they were predictive of ICU mortality. Results The lowest level of albumin on admission was 8 g/L and the highest was 43 g/L. The incidence of hypoalbuminaemia (using the laboratory reference range) was 93.9% on admission and 99.4% at 48 hours. Receiver operating characteristic curve analysis provided an optimal albumin cut-off of 18.5 g/L. Using this cut-off, hypoalbuminaemia at admission and at 48 hours was associated with increased ICU mortality. Hypoalbuminaemia at admission was an independent predictor of mortality using multivariable analysis (OR 3.74; 95% confidence interval 1.87 - 4.48). Conclusion Hypoalbuminaemia is associated with increased ICU mortality. There is currently no evidence to support the use of albumin replacement therapy. Further research is required to determine its role in critically ill patients. Contributions of the study Hypoalbuminaemia is common in critically ill South African (SA) patients and is associated with increased ICU mortality. This has not been well explored in the SA setting. We found that an optimal albumin cut-off was 18.5 g/L, which was much lower than the limits of the laboratory reference range.

Effects of different plasma expanders on rats subjected to severe acute normovolemic hemodilution

BackgroundPlasma expanders are widely used for acute normovolemic hemodilution (ANH). However, existing studies have not focused on large-volume infusion with colloidal plasma expanders, and there is a lack of studies that compare the effects of different plasma expanders.MethodsThe viscosity, hydrodynamic radius (Rh) and colloid osmotic pressure (COP) of plasma expanders were determined by a cone-plate viscometer, Zetasizer and cut-off membrane, respectively. Sixty male rats were randomized into five groups with Gelofusine (Gel), Hydroxyethyl Starch 200/0.5 (HES200), Hydroxyethyl Starch 130/0.4 (HES130), Hydroxyethyl Starch 40 (HES40), and Dextran40 (Dex40), with 12 rats used in each group to build the ANH model. ANH was performed by the withdrawal of blood and simultaneous infusion of plasma expanders. Acid-base, lactate, blood gas and physiological parameters were detected.ResultsGel had a lower intrinsic viscosity than HES200 and HES130 (P < 0.01), but at a low shear rate in a mixture of colloids, red cells and plasma, Gel had a higher viscosity (P < 0.05 or P < 0.01, respectively). For hydroxyethyl starch plasma expanders, the COP at a certain concentration decreases from 11.1 mmHg to 6.1 mmHg with the increase of Rh from 10.7 nm to 20.2 nm. A severe ANH model, with the hematocrit of 40% of the baseline level, was established and accompanied by disturbances in acid-base, lactate and blood gas parameters. At the end of ANH and 60 min afterward, the Dex40 group showed a worse outcome in maintaining the acid-base balance and systemic oxygenation compared to the other groups. The systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) decreased significantly in all groups at the end of ANH. The DBP and MAP in the Dex40 group further decreased 60 min after the end of ANH. During the process of ANH, the Dex40 group showed a drop and recovery in SBP, DBP and MAP. The DBP and MAP in the HES200 group were significantly higher than those in the other groups at some time points (P < 0.05 or P < 0.01).ConclusionGel had a low intrinsic viscosity but may increase the whole blood viscosity at low shear rates. Rh and COP showed a strong correlation among hydroxyethyl starch plasma expanders. Dex40 showed a worse outcome in maintaining the acid-base balance and systemic oxygenation compared to the other plasma expanders. During the process of ANH, Dex40 displayed a V-shaped recovery pattern for blood pressure, and HES200 had the advantage in sustaining the DBP and MAP at some time points.

The Effect of Hemodialysis on Axial Length, Ocular Surface, and Intraocular Pressure in Patients with End-Stage Renal Failure.

PurposeTo evaluate the changes in intraocular pressure (IOP), central corneal thickness (CCT), axial length, and ocular surface in patients with end-stage renal failure after single-session hemodialysis treatment and to examine the correlation of these findings with systemic hemodynamic parameters.Patients and MethodsA total of 112 eyes of 112 patients enrolled in a hemodialysis treatment program for three times a week (approximately four hours per session) for at least three months in our hospital between December 2019 and March 2020 were included in the study. Approximately 30 minutes before and after hemodialysis, the best-corrected visual acuity measurement, slit-lamp examination, IOP measurement, and dilated fundus examination with the Goldmann applanation tonometer were performed in all patients. The axial length measurement was undertaken by ultrasonic biometry, and the CCT measurement by ultrasonic pachymetry. The ocular surface evaluation was performed based on the tear breakup time (BUT), basal secretion time (BST) and keratoepitheliopathy score. Blood pressure, serum osmolarity, and body weight were measured before and after hemodialysis.ResultsThe mean IOP decreased from 12.2 ± 3.5 to 10.8 ± 2.2 mmHg, and the mean decrease was 1.4 ± 2 mmHg, indicating statistical significance (p<0.001). The mean CCT dropped from 502 ± 41.2 to 494.1 ± 35.4 μm, and the mean decrease was 8.1 ± 7.7 μm, which also indicated a statistically significant change (p<0.001). The mean axial length was reduced from 23.1 ± 0.8 to 22.9 ± 0.8 mm. The reduction in the axial length was significant with an average value of 0.26 ± 0.15 mm (p<0.001). When the ocular surface changes were examined, BUT decreased from 7.4 ± 3.1 to 6.3 ± 2.5 s, BST from 8.6 ± 1.7 to 6.6 ± 1.3 mm, and the keratoepitheliopathy score increased from 0.36 ± 0.61 to 1.59 ± 0.93, and all these changes were statistically significant (p<0.001). There was a significant correlation between the axial length change and the IOP change (r=0.202, p=0.03). A significant correlation was also observed between BST and plasma colloid osmotic pressure (r=−0.268, p=0.004). In addition, there was a strong correlation between serum osmolarity and the keratoepitheliopathy score (r=−0.437, p<0.001).ConclusionHemodialysis causes significant changes in IOP, CCT, axial length, and ocular surface. These changes should be considered in the ophthalmological examination of patients after the hemodialysis session.

Plasma replacement solutions in the intensive care unit of shock for acute spontaneous canine babesiosis

The article presents the results of studies on the study of secondary processes that develop during acute spontaneous babesiosis in dogs, as well as on the use of infusion therapy with plasma substitutes for the development of shock as a complication of the underlying disease. It is shown that acute blood parasitic disease is accompanied by the development of moderate subcompensated shock, which determines the state of unstable equilibrium and the tendency to avalanche-like disorders due to the transition of the process to the decompensated phase. The basis for the diagnosis of the shock state was the establishment of the following hemodynamic and hemorheological changes: hypovolemia with a decrease of all blood components (shaped elements and plasma components) in the circulation, a significant decrease in the specific volume of circulating blood, hematocrit value, a significant increase in spontaneous aggregation of shaped blood elements (platelets and red blood cells), hypotension, an increase in the Alghöver shock index by almost 2 times. There was a significant deficit in the volume of circulating blood (the degree of blood loss), which was about 30 %. It is shown that the presence of a state of shock in the subcompensation stage poses a threat to the life of the animal in the event of transition to the terminal stage. In order to stop the development of shock, infusion therapy was used with the most common plasma–substituting solutions – Rheopolyglucin and Rheosorbylact at a dose of 5 ml/kg of body weight intravenously drip per day for 3 days. A comparative assessment of the effect of drugs on the correction of major hemodynamic and hemorheological shifts was carried out. It was found that Rheopolyglucin as a colloidal plasma substitute has a better effect on the normalization of hemodynamic disorders – hypovolemia and hypotension, and Rheosorbylact as a crystalloid plasma substitute turned out to be the best disaggregant and reducing agent of hemorheological disorders. Both drugs provided a complete recovery of hemodynamic and hemorheological parameters in 72 hours. As a result, it is recommended to use a combination of drugs with the priority of Rheopolyglucin in the first hours of treatment and combine it with an infusion of Rheosorbylact in subsequent days.

Evaluation of the effects of hydroxyethyl starch (130/0.4) administration as a constant rate infusion on plasma colloid osmotic pressure in hypoabluminemic dogs.

To evaluate the effects of 2 constant rate infusions of hydroxyethyl starch (HES) 130/0.4 on plasma colloid osmotic pressure (COP) in hypoalbuminemic dogs. Prospective, randomized clinical trial. A total of 24 client-owned dogs. Hypoalbuminemic euvolemic dogs (albumin<20g/L[<2g/dL]) with normal perfusion parameters requiring IV fluid therapy were enrolled. In addition to crystalloid, HES 130/0.4 was administered as a constant rate infusion over 24hours at 1mL/kg/h (group 1, n=15) or at 2mL/kg/h (group 2, n=9), in order to support plasma COP. Before infusion, a blood sample was collected to perform CBC, serum electrophoresis, and serologic tests for some infective diseases. Plasma COP, albumin concentration, PCV, and total plasma protein concentration were evaluated serially at baseline (T0) and then at 6, 12, and 24hours after the start of infusion, and a multilevel model was performed for these parameters to detect statistically significant differences between the 2 groups. Twenty-four dogs were included. No statistically significant differences in COP werefound between the 2 groups; however, a high level of variability has been identified within the single individual. Among the other laboratory analyses, PCV was significantly decreased in group 1 at T12 and T24 compared with T0 (P<0.001) and total plasma protein concentration was significantly increased in group 2 at T12 and T24 compared with T0 (P<0.008). No significant effect on plasma COP was found following infusion with HES 130/0.4 at doses of 1mL/kg/h and 2mL/kg/h for 24hours to hypoalbuminemic dogs. The administered concomitant dose of crystalloids, underlying disease, and small sample size were all potential confounding factors.

L’hypo-albuminémie contribue-t-elle à l’aggravation de l’insuffisance cardiaque ?

BackgroundHypoalbuminemia has now emerged as a powerful prognosticator in heart failure regardless of age, clinical presentation, left ventricular ejection fraction and usual prognostic markers. Growing evidence is that this prognostic value persists after adjusting for causative factors for hypoalbuminemia such as malnutrition, inflammation and liver dysfunction. ObjectiveTo address the prognostic relevance of hypoalbuminemia in frail elderly patients with well-characterized cardiogenic pulmonary edema at high risk for adverse outcome, beyond causative factors for low serum albumin levels. Serum albumin was measured after clinical stabilization to avoid hypervolemia. ResultsIn all, 67 patients with a mean age of 86 years were included. Hospital mortality was 30%. Patients who died and who survived were similar in age, ejection fraction, BNP concentration, serum creatinine, serum hemoglobin, total bilirubin and prealbumin. Patients who died had lower serum albumin levels (P<0.001), higher blood urea nitrogen (P=0.03) and higher C-reactive protein (P=0.02). In multivariate analysis, serum albumin was the sole independent predictor of hospital death (P<0.01), after adjusting for malnutrition (prealbumin P=ns), inflammation (C-reactive protein P=ns) and liver dysfunction (total bilirubin P=ns). ConclusionSerum albumin is a powerful prognosticator in frail elderly patients with acute cardiogenic pulmonary edema even after adjusting for main causative factors. These results suggest that hypoalbuminemia may contribute to the worsening of heart failure given the physiological properties of serum albumin that includes antioxidant activity and plasma colloid osmotic pressure action. Further studies are critically needed to address the relevance of prevention and correction of hypoalbuminemia in heart failure.

Dynamic Effects of Laser Action on Quasi-Two-Dimensional Dusty Plasma Systems of Charged Particles.

We present the results of an experimental study of the behavior of a colloidal plasma system formed by copper-coated and uncoated polymer particles under the action of laser irradiation. A comparative study of particle velocity distribution profiles depending on the power of the pushing laser was conducted. In the case of uncoated melamine-formaldehyde (MF) particles, we observed the well-known action of light pressure, causing shear stress in the colloidal plasma structure and leading to the occurrence of a laminar flow within the affected area. For the copper-coated MF particles, we revealed some additional patterns of behavior for the dust particles, i.e., kinetic temperature growth due to laser radiation absorption by the copper coating, as well as the appearance of chaotic particle motion. We believe that this happens due to the existence of defects in the coating, causing asymmetric heating of the particles, which in turn leads to chaotic deviations of the photophoretic force pushing the particles in different directions.

P1090DETERMINATION OF ABSOLUTE BLOOD VOLUME USING ONLINE DIALYSATE DILUTION: WHEN SHOULD BE MEASURED?

Abstract Background and Aims Current on-line haemodiafiltration (HDF) machines equipped with a blood volume monitor (BVM) and an on-line bolus function have the potential for measuring absolute blood volume (aBV). Recently, we developed a simple method to determine absolute BV in everyday dialysis sessions. The aim of the present study was to evaluate the reproducibility of measurements. Method Intra-individual reproducibility was studied in 10 patients during a single dialysis session by 4 measurements of absolute BV: immediately after beginning before ultrafiltration (UF) was started, and after one, two and three hours. ABV was determined by indicator dilution. A defined volume bolus of 240 mL dialysate was infused into the venous blood line by pressing the emergency button of the HDF machine 5008 (FMC). For this reason, total UF volume was increased by 1L. UF was automatically stopped during and after the infusion. The resulting increase in relative blood volume (RBVpost-RBVpre) was measured by the ultrasonic relative BVM incorporated in the dialysis machine. ABV was measured in hourly intervals and for assessment of reproducibility the volume at treatment start (t=0) where RBV is 100% was calculated for all measurements as: aBV in mL = bolus volume 240 mL x 100% / increase RBV in % ABV data were normalized for body mass at dry weight (in mL/kg). Additionally, in 5 patients the RBV graph was monitored immediately at the beginning of dialysis without UF in a separate dialysis session. Results ABV at t=0 were consistently larger when calculated from measurements done immediately after the beginning compared to measurements obtained after 1 h (6.52 ± 1.40 L or 80.6 ± 14.5 mL/kg vs. 5.16 ± 1.40 L or 63.9 ± 14.3 mL/kg). Specific BV derived from 2 and 3 h measurements did not significantly differ from the measured volumes after 1 hour (61.4 ± 13.8 mL/kg, and 60.9 ± 13.9 mL/kg). The standard deviations of the 3 examinations in the same study patient during a further course of dialysis were between 0.6 and 5.3 ml/kg (ø 2.6 ml/kg). In a separate session, RBV decreases without UF at the beginning of dialysis in the first 3 minutes by 0.5 % and in 5 minutes by 0.6 %. Conclusion If BV is diluted by additional priming volume and bolus volume, a part of this volume will leave the circulation. This represented the time frame where the bolus was initially infused and the measurements were carried out. This loss is caused by the reduction in plasma colloid osmotic pressure induced by the dilution thereby changing the microvascular filtration equilibrium. The increase in RBV display is not solely caused by the bolus volume in this time and, and therefore, calculated BV would be overestimated by about 17 mL/kg. If measurement is performed at a later time, UF will take place and, consequently, refilling. This inward drive matches the outward bolus escape as a counterforce. BV measurement during a further course of dialysis is well reproducible with a deviation of only ± 2.6 ml/kg. The method would therefore be sufficiently precise in clinical practice. Therefore, we propose the determination of aBV only after 1 hour dialysis when a sufficient refilling takes place. With a software modification, the BV measurement could be routinely automated during each dialysis treatment. Manufacturers are asked to implement this technology in their devices.

Rapid calcification propensity testing in blood using a temperature controlled microfluidic polymer chip.

Phosphate toxicity is a major threat to cardiovascular health in chronic kidney disease. It is associated with oxidative stress, inflammation and the accumulation of calcium phosphate commonly known as calcification in soft tissues leading to functional disorders of blood vessels. An improved calcification propensity test for the assessment of phosphate toxicity was developed, which measures the velocity of calcium phosphate mineralization from colloidal precursors in vitro. This so called T50 test measures the transformation from a primary into a secondary form of nanosized colloidal plasma protein-calcium phosphate particles known as calciprotein particles. The T50 test in its previous form required a temperature controlled nephelometer and several hours of continuous measurement, which precluded rapid bed side testing. We miniaturized the test using microfluidic polymer chips produced by ultrasonic hot embossing. A cartridge holder contained a laser diode for illumination, light dependent resistor for detection and a Peltier element for thermo control. Increasing the assay temperature from 37°C to 75°C reduced the T50 test time 36-fold from 381 ± 10 min at 37°C to 10.5 ± 0.3 min at 75°C. Incorporating sputtered micro mirrors into the chip design increased the effective light path length, and improved signal-to-noise ratio 9-fold. The speed and reproducibility of the T50 chip-based assay run at 75°C suggest that it may be suitable for rapid measurements, preferably in-line in a dialyser or in a portable microfluidic analytic device with the chip inserted as a disposable cartridge.

Clinical Study on the Effects of Different Infusion Solutions on Colloid Osmotic Pressure During Major Abdominal Surgery and Perioperative Albumin in Elderly Patients

Objective: To explore the effects of different infusion schemes on colloid osmotic pressure during major abdominal surgery and perioperative albumin in elderly patients. Methods: 140 elderly patients of 65-80 years old undergoing major abdominal surgery were divided into 4 groups according to the method of random number table , and different proportions of crystals and colloids were given to different groups (group A: whole crystal, group B: crystal-colloid ratio 1 : 1, group C: crystal-colloid ratio 2: 1, Group D: crystal-colloid ratio 1: 2). The plasma colloid osmotic pressure and level of albumin during perioperative period were monitored. Simultaneously observe the arterial blood pH, blood glucose, extubating time of endotracheal tube, postoperative feeding time, et al. Results: The total amount of liquid inputted in the group of whole crystal was 3056ml (3056 ± 253), which was significantly increased compared with other groups (P&lt;0.01). At the same time, the colloid osmotic pressure decreased by 11.9 mmHg (11.9 ± 2.8), which was more obviously decreased than that of the other groups( B group3.9 ± 1.3, C group 1.5 ± 0.3, D group 4.7±2.1). The difference was a statistically significant(P&lt;0.01). On the other day after surgery, the level of albumin decreased by an average of 4.3 g / L (4.5 ± 1.9) compared with that in group B before surgery, and group C decreased by 2.9 g / L (2.9 ± 1.2) in average, which was significantly different (P&lt;0.05) from group A 10.2 g / L (10.2 ± 1.8). There was no statistically significant difference between group A and group D (P&gt;0.05). And the other indexes were not significantly different between the two groups. Conclusion: This study found that different infusion solutions with different crystal-colloid ratios had an effect on perioperative colloid osmotic pressure and level of albumin.

Dimensional-dependent antibacterial behavior on bioactive micro/nano polyetheretherketone (PEEK) arrays

Abstract Polyetheretherketone (PEEK) is a biocompatible polymer but the poor bacteria resistance and bioactivity have hampered its wider application to orthopedics. Inspired by the natural antibacterial structure on insect wings, cone/pillar-like micro/nano-arrays are fabricated controllably on PEEK by colloidal lithography and plasma etching and the resulting bacterial resistance and biocompatibility are investigated. The surface-engineered PEEK possesses enhanced antibacterial properties and the underlying mechanism depends on the surface topography and dimensions of the surface structures. With regard to the microarrays, both the early mechanical stretching effect and subsequent dimensional effect contribute to the overall antibacterial effects. On the other hand, the nanoarrays that mimic cicada wings kill bacteria solely by the penetration effect. Enhanced proliferation of osteoblasts is also observed from the modified PEEK rendering it suitable for implant materials. The antibacterial principles concluded from this work provide insights into the design and fabrication of bio-inspired biomaterials with improved bacteria resistance and biocompatibility.

Effect of Coagulation Factor Concentrates on Markers of Endothelial Cell Damage in Experimental Hemorrhagic Shock.

Plasma-based resuscitation showed protective effects on the endothelial glycocalyx compared with crystalloid resuscitation. There is paucity of data regarding the effect of coagulation factor concentrates (CFC) on the glycocalyx in hemorrhagic shock (HS). We hypothesized that colloid-based resuscitation supplemented with CFCs offers a therapeutic value to treat endothelial damage following HS. Eighty-four rats were subjected to pressure-controlled (mean arterial pressure (MAP) 30-35 mm Hg) and lab-guided (targeted cutoff: lactate >2.2. mmol/L and base deficit > 5.5 mmol/L) HS. Animals were resuscitated with fresh frozen plasma (FFP), human albumin (HA) or Ringer's lactate (RL) and RL or HA supplemented with fibrinogen concentrate (FC) or prothrombin complex concentrate (PCC). Serum epinephrine and the following markers of endothelial damage were assessed at baseline and at the end-of-observation (120 min after shock was terminated): syndecan-1, heparan sulfate, and soluble vascular endothelial growth factor receptor 1 (sVEGFR 1). Resuscitation with FFP had no effect on sVEGFR1 compared with crystalloid-based resuscitation (FFP: 19.3 ng/mL vs. RL: 15.9 ng/mL; RL+FC: 19.7 ng/mL; RL+PCC: 18.9 ng/mL; n.s.). At the end-of-observation, syndecan-1 was similar among all groups. Interestingly, HA+FC treated animals displayed the highest syndecan-1 concentration (12.07 ng/mL). Resuscitation with FFP restored heparan sulfate back to baseline (baseline: 36 ng/mL vs. end-of-observation: 36 ng/mL). The current study revealed that plasma-based resuscitation normalized circulating heparan sulfate but not syndecan-1. Co-administration of CFC had no further effect on glycocalyx shedding suggesting a lack of its therapeutic potential. VExperimental in vivo study.

Colloid Oncotic Pressure in Children with Nephrotic Syndrome

To evaluate the correlation between plasma protein concentration and colloid oncotic pressure (COP) and their influence on clinical symptom of edema, we studied 30 children with nephrotic syndrome (NS). Total plasma protein concentration (TP), albumm, globulin and COP were measured in all patients in edema forming state (EF) and m steady state phase (SS), except for COP, only 16 samples in SS phase.&#x0D; COP TP plasma albumin and globulin contents in EF group were 8. 7 ± 2. 7 mmHg, 4.07 '± 0.68 g/dl; 2.57 ± 0.50 g/dl and 1.51 ± 0.32 g/dl, respectively. In SS group these figures rose significantly to 16.7 ± 3.9 mmHg for COP; 5. 70 ± 0.99 g/dl for TP; 3.46 ± 0.52 g!dl and 2.06 ± 0.56 g/dl for plasma albumin and globulin, respectively. We also found the high correlation both between COP and albumin content (r= +0.58; p &lt; 0.01) and between COP and TP (r= +0.54; P &lt; 0.01) .&#x0D; A strong negative correlation was also found between COP and the degree of edema (r = _ 0.55; p &lt;0.01). On the other hand a very low grade correlation was noticed between plasma albumin content and the degree of edema (r= - 0.26; P &lt; 0.05) and no correlation at all was found between edema and TP (r= - 0.19; P &gt; 0.05).&#x0D; We conclude that COP has the highest correlation with plasma protein concentration and the degree of edema, and can be used as a diagnostic tool. It is even more sensitive and simple compared with the TP or albumin content determination.

Oncotic pressure and the effects of water deprivation in healthy captive Asian elephants.

We evaluated the oncotic pressure (plasma colloid osmotic pressure, πc) in a group of healthy, captive Asian elephants (Elephas maximus; n = 21) with a colloid osmometer with a membrane cutoff of >20,000 daltons. The median πc for these elephants was 26.3 mm Hg with an interquartile interval of 25.5-26.8 mm Hg. The mean πc value was 26.0 mm Hg ± SD 1.1. We found moderate correlation between albumin measured by electrophoresis and πc (r = 0.622; p = 0.003). After a 16-h water deprivation test in a subset of elephants (n = 16), a difference in πc was not detected, despite a significant increase in serum total proteins, urea, and osmolality. These results indicate that πc is not a sensitive indicator of hydration status in elephants after a short period of water deprivation. Use of oncotic pressure as a diagnostic tool in diseased Asian elephants warrants further investigation.

A polymeric micelle with an endosomal pH-sensitivity for intracellular delivery and enhanced antitumor efficacy of hydroxycamptothecin

Amphiphilic poly(ethylene glycol)-imino-poly(benzyl-l-aspartate) (PIPA) and poly(ethylene glycol)-poly(benzyl-l-aspartate) (PPA) block copolymers were synthesized as pH-responsive and pH-nonresponsive copolymers, respectively. Polymer micelles were fabricated by the film dispersion method, and hydroxycamptothecin (HCPT) was physically encapsulated into the micelles. The average diameter of the HCPT-loaded PIPA micelles (PIPAH micelles) was approximately 230 nm, which was slightly smaller than that of the HCPT-loaded PPA micelles (PPAH micelles, approximately 260 nm). The drug-loading content and encapsulation efficiency of the PIPAH micelles (3.33% and 68.89%, respectively) were slightly higher than those of the PPAH micelles (2.90% and 59.68%, respectively). The PIPAH micelles exhibited better colloid stability, storage stability, and plasma stability than the PPAH micelles. Drug release from the PIPAH micelles with imino groups was pH dependent, and more than 75% or 65% of the loaded HCPT was released within 24 h in weakly acidic media (pH 5.0 or 6.0, respectively). An in vitro cell assay demonstrated that the pH-sensitive micelles exhibited potent suppression of cancer cell proliferation and little cytotoxicity on normal cells. Additionally, these micelles could be efficiently internalized by the tumor cells through macropinocytosis- and caveolin-mediated endocytotic pathways. HCPT-loaded micelles had longer circulation time than the HCPT solution in a pharmacokinetic study. In vivo antitumor experiments indicate that the PIPAH micelles had better antitumor efficacy than the pH-insensitive PPAH micelles and the HCPT solution. Therefore, the pH-responsive PIPAH micelles have great potential for high-efficiency delivery of HCPT. Statement of SignificanceIn this study, a new type of pH-responsive amphiphilic copolymer, poly(ethylene glycol)-imino-poly(benzyl-l-aspartate) (PIPA) block copolymer, was synthesized. This copolymer had then self-assembled to form nanomicelles for tumor intracellular delivery of hydroxycamptothecin (HCPT) for the first time. In in vitro test, the PIPAH micelles exhibited adequate stability and pH-dependent drug release. To one's excitement, the PIPAH micelles exhibited better antitumor efficacy and biosafety than the pH-insensitive micelles (PPAH) and the HCPT solution in in vitro and in vivo antitumor experiments. Therefore, the pH-responsive micelles in this study have significant potential to be used for high-performance delivery of HCPT and potentially for the targeted delivery of other cancer therapeutic agents. The polymer designed in this study can be used as a carrier of poorly soluble drugs or other active ingredients.

Semisynthetic supra plasma expanders: a new class of therapeutics to improve microcircualtion in sickle cell anaemia

Compromised microcirculation and endothelial dysfunction are hallmarks of sickle cell disease (SCD). EAF PEG Haemoglobin (Hb) and EAF PEG Albumin (Alb) represent a novel class of semisynthetic colloidal supra plasma expanders that improve microcirculation. The therapeutic activity of supra plasma expanders to attenuate vaso-occlusion and restore the haemodynamic functions in patients with SCD has been investigated using NY1DD, a transgenic mouse model of mild SCD without anaemia. Vaso-occlusion and perturbation of haemodynamics are amplified in NY1DD by hypoxia-reoxygenation protocol. EAF P5K6 Alb and Alb T12 (Alb conjugated with 12 copies of antioxidant tempo) attenuate vaso-occlusion when infused at the start of reoxygenation. However, only EAF PEG Alb restores haemodynamics close to levels in control C57BL. EAF P5K6 Alb-T12, active plasma expander conjugated with antioxidant, completely clears vaso-occlusion and restores normal haemodynamics. EAF PEG Hb also completely clears vaso-occlusion and restores normal haemodynamics. Pretreating NY1DD with EAF PEG Hb protects it from hypoxia reoxygenation-induced damages. EAF P5K6 Alb T12 attenuates the endothelial dysfunction in S + S Antilles mice as reflected by the vasodilatory response of its arteries and arterioles to vaso-dilators. Active plasma expanders are novel therapeutics to restore normal haemodynamics in SCD patients to improve tissue oxygenation during episodes of painful vaso-occlusive crisis. Abbreviations: 2-IT: 2-immothiolane; Mal-T: 4-Maleimido tempo; Alb: human serum albumin (HSA); Alb-T12: human albumin conjugated with 12 copies of tempo; EAF: extension arm facilitated; EAF PEG Hb: extension arm facilitated PEGylated haemoglobin; EAF PEG Alb: extension arm facilitated PEGylated albumin; EAF P3K6 Hb: extension arm facilitated PEGylated haemoglobin conjugated with 6 copies of PEG3K; EAF P5K6 Alb T12: extension arm facilitated PEGylated albumin conjugated with 6 copies of PEG5K and 12 copies of tempo; Hb: haemoglobin; HAS: human serum albumin (Alb); PEG: polyethylene glycol; MP4: MalPEG Hb, is formulated at 4.2 g/dL in lactated Ringer's solution, a product of Sangart; SCD: sickle cell disease; NO: nitric oxide; SEC: size exclusive chromatography; Vrbc: red cell velocity; Q: volumetric flow rates, Q; SNP: sodium nitroprusside

Evolutionary Characteristics of Morphogenetic Types of Moss Litter in Swamp Spruce Forests

We identified five types of moss litter in a green moss–hypnum spruce forest during alloevolution (metamorphosis) according to the habitat: peat, peaty, reduced peaty, high-ash peaty, and reduced high-ash peaty litters. During the self-development (autoevolution) of the litter, the transformation of plant matter occurs in four stages: (1) leaf (background) stage, (2) peat- and peaty-fermentative stage (browning, destruction of the litter fall and formation of platy macroaggregates), (3) humified-fermentative stage (formation of colloidal humus plasma and granular organogenic macroaggregates), and (4) the black mold humus stage (formation of colloidal humus plasma and organo-mineral humus nutty and granular macroaggregates). It was found that peat litters undergo only the initial stages of plant substrate transformation (1 and 2). The genetic profile of peaty litter is formed by three unidirectional processes (1, 2, and 3). High-ash peaty litter undergoes all the stages of plant matter transformation. The reduced analogs of peaty and high-ash peaty litter bedding were found to bypass the transitional stage 2.

Thermoelectric and Thermoelectrokinetic Phenomena in Liquid Biological Systems

Thermoelectric and thermoelectrokinetic phenomena have been studied in liquids that could serve as analogs for biological liquids, namely, physiological (Ringer’s) solution that is isotonic to blood plasma and iron (III) hydroxide colloid solution. The thermoelectric (Seebeck) coefficient and thermoelectrokinetic coefficient have been measured. The results indicate that the above phenomena are associated with the electrical properties of bioliquids representing charged colloids and may play an essential role in them.

Synthetic colloid fluids (6% hydroxyethyl starch 130/0.4 and 4% succinylated gelatin) interfere with total plasma protein measurements in vitro.

High molecular weight (MW) synthetic colloids interfere with refractometry. The effect of low MW synthetic colloids on refractometry is unknown. To investigate the effect of 6% hydroxyethyl starch 130/0.4 (HES) and 4% succinylated gelatin (GELO) on the refractometric measurement of total plasma protein (TPP) and colloid osmotic pressure (COP) in canine plasma. Heparinized plasma from 10 dogs was diluted with 0.9% saline (NaCl), HES, and GELO in ratios of plasma:fluid, 9:1, 8:2, 7:3, 6:4, and 5:5. The biuret TPP (TPPb), refractometric TPP (TPPr), and COP assays were performed for all dilutions. Agreement (bias, 95% limits of agreement (LOA)) was tested between the TPPb (NaCl) and the TPPr of the NaCl, HES, and GELO plasma dilutions, and between the TPPb (NaCl) and the TPPb of the HES and GELO plasma dilutions. A small bias (0.06 g/dL, 95% LOA -0.51 to 0.39 g/dL) existed between TPPb (NaCl) and TPPr (NaCl). A large bias was found between TPPb (NaCl) and TPPr (HES) (1.38 g/dL, 95% LOA 0.30 to 3.10 g/dL), and TPPr (GELO) (1.18 g/dL, 95% LOA 0.53 to 2.88 g/dL). A small bias was found between TPPb (NaCl) and TPPb (HES) (0.08 g/dL, 95% LOA -2.04 to 2.20 g/dL), and a large bias was found between TPPb (NaCl) and TPPb (GELO) (1.00 g/dL, 95% LOA -0.59 to 2.60 g/dL). Increasing overestimation of TPPb (NaCl) by TPPr (HES and GELO) and TPPb (GELO) occurred with increasing colloid volumes. HES and GELO interfered with TPPr, and GELO also interfered with TPPb, in vitro. These variables should be interpreted with caution for dogs that have received these synthetic colloids.