scholarly journals SOLUTION- 03 - Dextran solution 5% v1 (protocols.io.biyukfww)

protocols.io ◽  
2020 ◽  
Author(s):  
Marco Cosentino ◽  
Elisa Storelli ◽  
Alessandra Luini ◽  
Massimiliano Legnaro ◽  
Emanuela Rasini ◽  
...  
Keyword(s):  
Dextran Solution

High-pressure freezing and freeze substitution of teliospores of the rust fungus Gymnosporangium clavipes

1990 ◽  
Vol 48 (3) ◽  
pp. 692-693
Author(s):  
Robert W. Roberson
Keyword(s):  
High Pressure ◽  
Room Temperature ◽  
Pathogenic Fungus ◽  
Rust Fungus ◽  
Freeze Substitution ◽  
Ice Crystals ◽  
High Pressure Freezing ◽  
Thin Walled Structures ◽  
Cytological Changes ◽  
Dextran Solution

The use of cryo-techniques for the preparation of biological specimens in electron microscopy has led to superior preservation of ultrastructural detail. Although these techniques have obvious advantages, a critical limitation is that only 10-40 μm thick cells and tissue layers can be frozen without the formation of distorting ice crystals. However, thicker samples (600 μm) may be frozen well by rapid freezing under high-pressure (2,100 bar). To date, most work using cryo-techniques on fungi have been confined to examining small, thin-walled structures. High-pressure freezing and freeze substitution are used here to analysis pre-germination stages of specialized, sexual spores (teliospores) of the plant pathogenic fungus Gymnosporangium clavipes C & P.Dormant teliospores were incubated in drops of water at room temperature (25°C) to break dormancy and stimulate germination. Spores were collected at approximately 30 min intervals after hydration so that early cytological changes associated with spore germination could be monitored. Prior to high-pressure freezing, the samples were incubated for 5-10 min in a 20% dextran solution for added cryoprotection during freezing. Forty to 50 spores were placed in specimen cups and holders and immediately frozen at high pressure using the Balzers HPM 010 apparatus.

Exercise stroke volume relative to plasma-volume expansion

1988 ◽  
Vol 64 (1) ◽  
pp. 404-408 ◽  
Author(s):  
M. K. Hopper ◽  
A. R. Coggan ◽  
E. F. Coyle
Keyword(s):  
Stroke Volume ◽  
Plasma Volume ◽  
Volume Expansion ◽  
Peripheral Resistance ◽  
Submaximal Exercise ◽  
Upright Position ◽  
Plasma Volume Expansion ◽  
Trained Subjects ◽  
The Difference ◽  
Dextran Solution

The effects of plasma-volume (PV) expansion on stroke volume (SV) (CO2 rebreathing) during submaximal exercise were determined. Intravenous infusion of 403 +/- 21 ml of a 6% dextran solution before exercise in the upright position increased SV 11% (i.e., 130 +/- 6 to 144 +/- 5 ml; P less than 0.05) in untrained males (n = 7). Further PV expansion (i.e., 706 +/- 43 ml) did not result in a further increase in SV (i.e., 145 +/- 4 ml). SV was somewhat higher during supine compared with upright exercise when blood volume (BV) was normal (i.e., 138 +/- 8 vs. 130 +/- 6 ml; P = 0.08). PV expansion also increased SV during exercise in the supine position (i.e., 138 +/- 8 to 150 +/- 8 ml; P less than 0.05). In contrast to these observations in untrained men, PV expansion of endurance-trained men (n = 10), who were naturally PV expanded, did not increase SV during exercise in the upright or supine positions. When BV in the untrained men was increased to match that of the endurance-trained subjects, SV was observed to be 15% higher (165 +/- 7 vs. 144 +/- 5 ml; P less than 0.05), whereas mean blood pressure and total peripheral resistance were significantly lower (P less than 0.05) in the trained compared with untrained subjects during upright exercise at a similar heart rate. The present findings indicate that exercise SV in untrained men is preload dependent and that increases in exercise SV occur in response to the first 400 ml of PV expansion. It appears that approximately one-half of the difference in SV normally observed between untrained and highly endurance-trained men during upright exercise is due to a suboptimal BV in the untrained men.

Immobilization of Chaetomium erraticum dextranase (CED) by adsorption on carboxylated multi walled carbon nanotubes (c-MWCNT)

2021 ◽  
Author(s):  
Yakup Aslan ◽  
Barzan Ismael Ghafour
Keyword(s):  
Storage Conditions ◽  
Reducing Sugar ◽  
Solution Ph ◽  
Multi Walled Carbon Nanotubes ◽  
Activity Yield ◽  
Walled Carbon Nanotubes ◽  
Hydrolysis Of ◽  
Dextran Solution ◽  
Burk Plot

Abstract In this study, CED was immobilized onto c-MWCNT by adsorption. Optimization of immobilization conditions (immobilization buffer's pH and molarity, c-MWCNT amount, and immobilization time) was resulted in 100% immobilization yield and 114.13% activity yield. Further, characterization of FCED and ICED was also studied. After immobilization, the optimum pH shifted from 5.0 to 6.0, while the optimum temperature (55 °C) did not change. Furthermore, kinetic constants for FCED and ICED were also determined using the Lineweaver-Burk plot. The Km value for both FCED and ICED were 54.35 g / L, while Vmax values for FCED and ICED were 2.77 μmol reducing sugar / L.mg.min and 3.19 μmol reducing sugar / L.mg.min, respectively. Moreover, there was no reduction in the initial activity of ICED after 20 consecutive uses and 30 days of storage at optimal storage conditions. Finally, 17.15% and 17.53% of the dextran in 10% dextran solution (pH 6.0) were converted to reduced sugars (IMOs and Glucose) in 12 hours using FCED and ICED, respectively. Consequently, it can be concluded that ICED obtained in this study can be effectively used for industrial production of IMOs and for hydrolysis of dextran.

Urinary TCP1-eta: A Cortical Damage Marker for the Pathophysiological Diagnosis and Prognosis of Acute Kidney Injury

2019 ◽  
Vol 174 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Sandra M Sancho-Martínez ◽  
Fernando Sánchez-Juanes ◽  
Víctor Blanco-Gozalo ◽  
Miguel Fontecha-Barriuso ◽  
Laura Prieto-García ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Kidney Injury ◽  
Cortical Damage ◽  
Renal Tubular Cells ◽  
Tubular Necrosis ◽  
Diagnosis And Prognosis ◽  
A Cell ◽  
Renal Tubular ◽  
Dextran Solution

Abstract Acute kidney injury (AKI) is a serious syndrome with increasing incidence and health consequences, and high mortality rate among critically ill patients. Acute kidney injury lacks a unified definition, has ambiguous semantic boundaries, and relies on defective diagnosis. This, in part, is due to the absence of biomarkers substratifying AKI patients into pathophysiological categories based on which prognosis can be assigned and clinical treatment differentiated. For instance, AKI involving acute tubular necrosis (ATN) is expected to have a worse prognosis than prerenal, purely hemodynamic AKI. However, no biomarker has been unambiguously associated with tubular cell death or is able to provide etiological distinction. We used a cell-based system to identify TCP1-eta in the culture medium as a noninvasive marker of damaged renal tubular cells. In rat models of AKI, TCP1-eta was increased in the urine co-relating with renal cortical tubule damage. When kidneys from ATN rats were perfused in situ with Krebs-dextran solution, a portion of the urinary TCP1-eta protein content excreted into urine disappeared, and another portion remained within the urine. These results indicated that TCP1-eta was secreted by tubule cells and was not fully reabsorbed by the damaged tubules, both effects contributing to the increased urinary excretion. Urinary TCP1-eta is found in many etiologically heterogeneous AKI patients, and is statistically higher in patients partially recovered from severe AKI. In conclusion, urinary TCP1-eta poses a potential, substratifying biomarker of renal cortical damage associated with bad prognosis.

Antishock effects of corticosterone on dextran-induced shock in rats

1986 ◽  
Vol 251 (5) ◽  
pp. E569-E575 ◽  
Author(s):  
K. Kogure ◽  
M. Ishizaki ◽  
M. Nemoto ◽  
T. Nakamura ◽  
M. Suzuki
Keyword(s):  
Control Group ◽  
Shock State ◽  
Vascular Activity ◽  
The Status ◽  
Cutaneous Tissue ◽  
Group A ◽  
Shock Experiment ◽  
Group B ◽  
Dextran Solution ◽  
Chemical Mediators

To study the effects of glucocorticoid on the shock state, dextran-induced shock in rats was used as an experimental model system. The rats were divided into three groups, viz., control (group A), adrenalectomized (group B), and adrenalectomized corticosterone supplemented (2 mg/rat for 4 days; group C), and 5% dextran solution was given intravenously to each rat. In group B, remarkable increases in the histamine levels in both plasma and the paw cutaneous tissue, hemoconcentration, and intractable hypotension were observed. Most rats in group B died during the shock experiment without showing any recovery when the cannulas were inserted into the left carotid artery for the measurement of blood pressure. But in group C, most rats eventually survived and recovered to a normal state within 2 h, so that corticosterone clearly ameliorated the shock state of adrenalectomized rats by dextran administration. These results suggested that the ameliorating effects of corticosterone in the dextran-induced shock states are due to the acceleration of the rate of clearance of circulating chemical mediators that are represented by histamine and are due to the alteration of overall responsiveness of the animals to a complex array of factors that threaten the status of the animals, as represented by the amelioration of the vascular activity.

The Rate of the 86RbCl Escape from Blood in Different States of Circulation in Rabbits

1971 ◽  
Vol 10 (03) ◽  
pp. 216-222
Author(s):  
Jan Kasalický
Keyword(s):  
Pulmonary Embolism ◽  
Blood Flow ◽  
Blood Level ◽  
Blood Concentration ◽  
Haemorrhagic Shock ◽  
Organ Blood Flow ◽  
Radioactivity Measurement ◽  
Experimental Animals ◽  
Organ Uptake ◽  
Dextran Solution

SummaryRabbits with haemorrhagic shock, normovolaemic anaemia, hypervolaemia caused by infusion of isotonic dextran solution and with shock resulting from pulmonary embolism were used for the examination of the 86Rb blood level up to 5 minutes after the intravenous injection of the radioisotope. The highest amount of 86Rb circulated in shock states, especially after pulmonary embolism; nevertheless in other groups the total amount of the circulating radioisotope was still twice as high as in the controls even 3 minutes after application. The author emphasizes that in states of severe haemodynamic alterations it is not advisable to kill experimental animals earlier than 3 minutes after application when examining the organ blood flow by means of Sapirstein’s method of 86Rb organ uptake. At this time the radioisotope blood concentration is generally not too high, so that the blood contained in the blood vessels of the measured organs or tissues does not cause any significant distortion of the tissue radioactivity measurement.

CARDIORENAL EFFECTS OF LARGE INFUSIONS OF DEXTRAN IN DOGS

1954 ◽  
Vol 32 (1) ◽  
pp. 559-566 ◽  
Author(s):  
C. W. Gowdey ◽  
I. E. Young
Keyword(s):  
Cardiac Output ◽  
Peripheral Resistance ◽  
The Body ◽  
Arterial Blood ◽  
High Output Heart Failure ◽  
Mean Pressure ◽  
Anesthetized Dogs ◽  
The Right ◽  
Dextran Solution ◽  
High Output

The production of hypervolemic dilution anemia in intact, anesthetized dogs by the continuous intravenous infusion of 6% dextran solution caused large increases in the cardiac output and urine flow. No consistent changes were observed in pulse rate or arterial blood pressure. The right auricular mean pressure usually increased early in the infusion, but later there was no consistent relation between right auricular pressure and cardiac output. The total peripheral resistance, glomerular filtration rate, and renal blood flow decreased. With infusion volumes exceeding 10% of the body weight, acute high-output heart failure occurred. The observed hemodilution was consistently greater than that expected from the volume of the infusion, because the dextran solution was, presumably, hypertonic.

Ultrastructure of the Infection of Poinsettia by Oidium SP. using High Pressure Freezing and Freeze Substitution

2000 ◽  
Vol 6 (S2) ◽  
pp. 690-691
Author(s):  
G. J. Celio ◽  
E. A. Richardson ◽  
C. W. Mims
Keyword(s):  
High Pressure ◽  
Freeze Substitution ◽  
Uranyl Acetate ◽  
Euphorbia Pulcherrima ◽  
High Pressure Freezing ◽  
Thin Sections ◽  
Transmission Electron ◽  
Dextran Solution ◽  
Leaf Disks ◽  
Diamond Knife

Cryofixation is becoming more widely used to study host-pathogen relationships in fungal diseases of plants. This presentation describes results we have obtained using high pressure freezing and freeze substitution to study powdery mildew disease of poinsettia ﹛Euphorbia pulcherrima) caused by Oidium sp.Approximately 0.5 mm leaf disks bearing sporulating colonies of Oidium sp. were excised and placed in a 15% dextran solution contained in brass planchets. Samples were frozen using a Balzer's HPM 010 High Pressure Freezing Machine and substituted according to the procedures of Hoch.6 Thin sections of embedded leaves were cut using a diamond knife, collected on gold slot grids, and placed on formvar-coated racks. Sections were poststained with uranyl acetate and lead citrate and examined using a Zeiss EM 902A transmission electron microscope.Outstanding preservation of haustoria, the specialized nutrient-absorbing structures produced in host epidermal cells by Oidium, was obtained. Both young, unlobed (Fig. 1) as well as mature, highly lobed (Fig. 2) haustoria were observed.

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