scholarly journals Measurement of Retinal Microvascular Blood Velocity Using Erythrocyte Mediated Velocimetry

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Breanna M. Tracey ◽  
Lakyn N. Mayo ◽  
Christopher T. Le ◽  
Victoria Y. Chen ◽  
Julian Weichsel ◽  
...  
Keyword(s):  
Average Diameter ◽  
Retinal Blood Flow ◽  
Direct Visualization ◽  
Ocular Diseases ◽  
Novel Technique ◽  
Retinal Microvasculature ◽  
The Mean ◽  
Pharmacologic Agents

AbstractChanges in retinal blood flow may be involved in the pathogenesis of glaucoma and other ocular diseases. Erythrocyte mediated velocimetry (EMV) is a novel technique where indocyanine green (ICG) dye is sequestered in erythrocyte ghosts and autologously re-injected to allow direct visualization of erythrocytes for in vivo measurement of speed. The purpose of this study is to determine the mean erythrocyte speed in the retinal microvasculature, as well as the intravisit and intervisit variability of EMV. Data from 23 EMV sessions from control, glaucoma suspect, and glaucoma patients were included in this study. In arteries with an average diameter of 43.11 µm ± 6.62 µm, the mean speed was 7.17 mm/s ± 2.35 mm/s. In veins with an average diameter of 45.87 µm ± 12.04 µm, the mean speed was 6.05 mm/s ± 1.96 mm/s. Intravisit variability, as measured by the mean coefficient of variation, was 3.57% (range 0.44–9.68%). Intervisit variability was 4.85% (range 0.15–8.43%). EMV may represent reliable method for determination of retinal blood speed, potentially allowing insights into the effects of pharmacologic agents or pathogenesis of ocular diseases.

Determination of the pH of Hemolyzed Packed Red Cells from Arterial Blood

1961 ◽  
Vol 7 (5) ◽  
pp. 536-541 ◽  
Author(s):  
May K Purcell ◽  
Gertrude M Still ◽  
Theodore Rodman ◽  
Henry P Close
Keyword(s):  
Blood Cell ◽  
Normal Subjects ◽  
The Body ◽  
Red Cell ◽  
Arterial Blood ◽  
Fiducial Probability ◽  
The Mean ◽  
Red Cell Ph

Abstract A technic is described for the determination of the in vivo pH of red blood cell hemolysates. The mean arterial red cell pH of 20 normal subjects was 7.19 with a range of 7.15 to 7.22. The fiducial probability at the 0.95 level is 7.13 to 7.25. The mean difference in pH between plasma and cells was 0.21, with a range of 0.15 to 0.23. It is suggested that changes in pH of erythrocytes may reflect changes in other less accessible cells of the body and that the determination may be a useful research and clinical procedure in the study of metabolic and respiratory derangements.

In Vivo Determination of Elastic Modulus of Canine Cardiac Muscle

1972 ◽  
Vol 94 (4) ◽  
pp. 912-916 ◽  
Author(s):  
J. F. Lafferty ◽  
E. P. McCutcheon ◽  
J. E. Funk ◽  
A. M. Higgins
Keyword(s):  
Elastic Modulus ◽  
Left Ventricle ◽  
Circumferential Stress ◽  
Isotonic Saline ◽  
Strain Analysis ◽  
Volume Data ◽  
Rapid Injection ◽  
The Mean

A practical technique was developed for in vivo determinations of the mechanical properties of canine left ventricle. A “quick stretch” was accomplished by rapid injection of isotonic saline into the ventricle during isovolumetric systole. The experimental pressure-volume data and a stress-strain analysis of the left ventricle as a thick-walled sphere permitted determination of the effective elastic modulus as a function of the mean circumferential stress. The elastic modulus E was found to be a linear function of the mean tangential stress σ throughout the isovolumetric systolic period; the slope (K, modulus of stiffness) of the Eversus σ curve was 18.8 with a standard deviation of 0.9.

scholarly journals Solubility Determination of c-Met Inhibitor in Solvent Mixtures and Mathematical Modeling to Develop Nanosuspension Formulation

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 390
Author(s):  
Maharjan Ravi ◽  
Tripathi Julu ◽  
Nam Ah Kim ◽  
Kyeung Eui Park ◽  
Seong Hoon Jeong
Keyword(s):  
Mole Fraction ◽  
Effect Study ◽  
Solvent Mixtures ◽  
Water Mixture ◽  
The Mean ◽  
Met Inhibitor ◽  
Solubility Determination ◽  
Low Solubility

The solubility and dissolution thermodynamics of new c-Met inhibitor, ABN401, were determined in eleven solvents and Transcutol® HP–water mixture (TWM) from 298.15 to 318.15 K. The experimental solubilities were validated using five mathematical models, namely modified Apelblat, van’t Hoff, Buchowski–Ksiazaczak λh, Yalkowsky, and Jouyban–Acree van’t Hoff models. The experimental results were correlated and utilized further to investigate the feasibility of nanosuspension formation using liquid anti-solvent precipitation. Thermodynamic solubility of ABN401 increased significantly with the increase in temperature and maximum solubility was obtained with Transcutol® HP while low solubility in was obtained water. An activity coefficient study indicated that high molecular interaction was observed in ABN401–Transcutol® HP (THP). The solubility increased proportionately as the mole fraction of Transcutol® HP increased in TWM, which was also supported by a solvent effect study. The result suggested endothermic and entropy-driven dissolution. Based on the solubility, nanosuspension was designed with Transcutol® HP as solvent, and water as anti-solvent. The mean particle size of nanosuspension decreased to 43.05 nm when the mole fraction of ABN401 in THP, and mole fraction of ABN401 in TWM mixture were decreased to 0.04 and 0.1. The ultrasonicated nanosuspension appeared to give comparatively higher dissolution than micronized nanosuspension and provide a candidate formulation for in vivo purposes.

scholarly journals Use of an aiming drill guide and ankle arthroscopy for reduction of depressed articular surface in posterior malleolar fractures

2021 ◽  
Vol 29 (3) ◽  
pp. 230949902110558
Author(s):  
Hyo-Jin Lee ◽  
Sung Jae Kim ◽  
Young Uk Park ◽  
Jintak Hyun ◽  
Hyong Nyun Kim
Keyword(s):  
Soft Tissue ◽  
Articular Surface ◽  
Ankle Arthroscopy ◽  
Direct Visualization ◽  
Novel Technique ◽  
Drill Guide ◽  
Posterior Malleolus ◽  
Soft Tissue Dissection ◽  
Tissue Dissection ◽  
The Mean

Purpose We describe a novel technique that uses an aiming drill guide and ankle arthroscopy for direct visualization and reduction of the depressed articular surface located between the posterior tibia and the fractured posterior malleolus. This technique requires less soft tissue dissection to visualize and reduce the depressed articular surface. Methods Between June 2014 and May 2019, 126 patients were surgically treated for trimalleolar fractures. Among them, 11 had depressed articular fragment between the posterior tibia and the fractured posterior malleolus reduced using our novel technique. The study included six men and five women, with a mean age of 46.5 (range: 23–62) years. Results In eight (73%) cases, the articular surface was reduced, with the articular surface step-off being less than 2 mm, as noted on postoperative computed tomography (CT). Syndesmosis congruity within an anterior-to-posterior difference of less than 2 mm was confirmed in nine (82%) cases via postoperative CT. The mean 100-mm visual analog scale (VAS) and the mean Olerud-Molander ankle score at the final follow-up were 16.6 ± 14.5 and 87.7 ± 7.5, respectively. Conclusions The depressed articular fragment located between the posterior tibia and the fractured posterior malleolus can be treated using an aiming drill guide and ankle arthroscopy. Ankle arthroscopy is used for direct visualization of the depressed articular surface, and the aiming drill guide can guide the bone plunger precisely to the depressed articular surface for reduction. This technique requires less soft tissue dissection than conventional techniques to visualize and reduce the depressed articular surface.

scholarly journals Tissue Penetration and Pharmacokinetics of Tigecycline in Diabetic Patients with Chronic Wound Infections Described by Using In Vivo Microdialysis

2010 ◽  
Vol 54 (12) ◽  
pp. 5209-5213 ◽  
Author(s):  
Catharine C. Bulik ◽  
Dora E. Wiskirchen ◽  
Ashley Shepard ◽  
Christina A. Sutherland ◽  
Joseph L. Kuti ◽  
...  
Keyword(s):  
Steady State ◽  
Protein Binding ◽  
Subcutaneous Tissue ◽  
Diabetic Patients ◽  
Tissue Penetration ◽  
Tissue Concentrations ◽  
Time Curve ◽  
The Mean

ABSTRACT Tissue penetration of systemic antibiotics is an important consideration for positive outcomes in diabetic patients. Herein we describe the exposure profile and penetration of tigecycline in the interstitial fluid of wound margins versus that of uninfected thigh tissue in 8 adult diabetic patients intravenously (IV) administered 100 mg and then 50 mg of tigecycline twice daily for 3 to 5 doses. Prior to administration of the first dose, 2 microdialysis catheters were inserted into the subcutaneous tissue, the first within 10 cm of the wound margin and the second in the thigh of the same extremity. Samples for determination of plasma and tissue concentrations were simultaneously collected over 12 h under steady-state conditions. Tissue concentrations were corrected for percent in vivo recovery by the retrodialysis technique. Plasma samples were also collected for determination of protein binding at 1, 6, and 12 h postdose for each patient. Protein binding data were corrected using a fitted polynomial equation. The mean patient weight was 95.1 kg (range, 63.6 to 149.2 kg), the mean patient age was 63.5 ± 9.4 years, and 75% of the patients were males. The mean values for the plasma, thigh, and wound free area under the concentration-time curve from 0 to 24 h (fAUC0-24) were 2.65 ± 0.33, 2.52 ± 1.15, and 2.60 ± 1.02 μg·h/ml, respectively. Protein binding was nonlinear, with the percentage of free drug increasing with decreasing serum concentrations. Exposure values for thigh tissue and wound tissue were similar (P = 0.986). Mean steady-state tissue concentrations for the thigh and wound were similar at 0.12 ± 0.02 μg/ml, and clearance from the tissues appeared similar to that from plasma. Tissue penetration ratios (tissue fAUC/plasma fAUC) were 99% in the thigh and 100% in the wound (P = 0.964). Tigecycline penetrated equally well into wound and uninfected tissue of the same extremity.

Evaluation of Potential Analytical Approach for Determination of Polychlorinated Biphenyls in Serum: Interlaboratory Study

1983 ◽  
Vol 66 (4) ◽  
pp. 956-968
Author(s):  
Virlyn W Burse ◽  
Larry L Needham ◽  
Chester R Lapeza ◽  
Margaret P Korver ◽  
John A Liddle ◽  
...  
Keyword(s):  
Polychlorinated Biphenyls ◽  
Ethyl Ether ◽  
Analytical Approach ◽  
Chromatographic Determination ◽  
Electron Capture Detection ◽  
Coefficients Of Variation ◽  
The Mean

Abstract Forty-four laboratories participated in evaluation of a method for determining polychlorinated biphenyls (PCBs) as AR 1254 in serum at the parts per billion level. The method involves deproteinating serum with methanol, extracting with hexane-ethyl ether, and eluting PCBs from deactivated silica gel for gasliquid chromatographic determination with electron capture detection. Compounds are quantitated by using the Webb-McCall factors. Five serum pools, 4 containing in vivo-fortified PCBs (as AR 1254) or 8 in vitro-f ortif ied chlorinated hydrocarbons (CHs), or both, were used. For PCB fortification levels of 9.89 (EP 2), 24.74 (EP 3), and 74.20 ppb (EP 4), interlaboratory coefficients of variation (CVs) for collaborators that adhered to protocol were 92.7, 67.6, and 25.8%, respectively. CVs on the same pools analyzed by the Centers for Disease Control (CDC) were 7.4, 7.8, and 4.6%, respectively. Average interlaboratory recoveries for pools EP 2, EP 3, and EP 4 were 138.1,111.2, and 91.1%, respectively, and 99.8,89.6, and 90.4%, respectively, for CDC on the same pools. There was a general decrease in the mean error for those laboratories that had participated in an earlier study in which they were allowed to use their own methods.

scholarly journals Determination of Freeway Space in Completely Edentulous Patients Using Lateral Profile Photographs—In Vivo Study

2019 ◽  
Vol 05 (01) ◽  
pp. 006-009
Author(s):  
Monika Dagdiya ◽  
Ashok Pakhan ◽  
Surekha Dubey ◽  
Seema Sathe ◽  
Manish Dagdiya
Keyword(s):  
Significant Negative Correlation ◽  
Reference Points ◽  
Simple Linear Regression ◽  
Prediction Formula ◽  
Independent Variable ◽  
The Mean ◽  
Edentulous Patients ◽  
Lateral Profile

Abstract Objective This study aims to determine the freeway space (FWS) using lateral profile photograph (LPP) as an adjunct in completely edentulous patients. Materials and Methods In this study, 30 patients in the age group of 45 to 60 years who met with the criteria were included. LPPs were taken for all participants using standard protocol and a duplicate copy was obtained, on which three soft tissue reference points—porion (Stp), gnathion (Stgn), and gonion (Stg)—were marked and joined to form an angle Stp-Stg-Stgn. This angle was correlated with the mean FWS obtained using swallowing. Simple linear regression model was used to develop a prediction formula for FWS using Stp-Stg-Stgn angle as the independent variable. Result This study shows that the angle Stp-Stg-Stgn had a significant negative correlation with FWS.

Statistical constraints on microvascular measurements using fluorescent erythrocytes

1985 ◽  
Vol 248 (4) ◽  
pp. H577-H586 ◽  
Author(s):  
I. H. Sarelius ◽  
S. M. McKinlay
Keyword(s):  
Simultaneous Determination ◽  
Coefficient Of Variation ◽  
Fluorescent Cell ◽  
Cell Counts ◽  
Cell Velocity ◽  
In Vivo Sampling ◽  
Sampling Intervals ◽  
The Mean

We show that two separate estimators of microvessel hematocrit (H) using the same fluorescent cell technique are not equally precise. The precision of H (indicated by the coefficient of variation, CV) depends on in vivo labeled cell counts (m), the labeled fraction (p), and for time-averaged H estimates, the mean cell velocity (v). Thus, for length-dependent estimates of H, CV2(HL) = 1/E(m) + CV2(p) and for time-averaged H estimates, CV2(Ht) = 1/E(m) + CV2(p) + CV2(v). Because CV(p) can be made small arbitrarily and independently, the precision of H is principally dependent on the expected value of m. Practical sampling constraints and minimum sampling intervals are identified and used to define strategies to minimize CV(H). We show that Ht is preferable to HL because it is more precise and the useful in vivo sampling range of m and p is more flexible. In addition, Ht allows simultaneous determination of cell flux and mean cell velocity.

scholarly journals Tritium effect in peroxidation of ehtanol by liver catalase

1977 ◽  
Vol 167 (1) ◽  
pp. 77-86 ◽  
Author(s):  
S E Damgaard
Keyword(s):  
Isotope Effect ◽  
Ethanol Concentration ◽  
Mean Value ◽  
Wide Range ◽  
H2o2 Generation ◽  
State Generation ◽  
The Mean ◽  
Galactose Dehydrogenase

1. Simultaneous determination of the rate of appearance of 3H in water from [(1R)-1-3H1] ethanol and the rate of acetaldehyde formation in the presence of rat or ox liver catalase under conditions of steady-state generation of H2O2 allowed calculation of the 3H isotope effect. The mean value of 2.52 obtained for rat liver catalase at 37 degrees C and pH 6.3-7.7 was independent of both ethanol concentration and the rate of H2O2 generation over a wide range. At 25 degrees C a slightly lower mean value of 2.40 was obtained with the ox liver catalase. 2. Neither the product, acetaldehyde, nor 4-methylpyrazole influenced the two rates measured in the assay. 3. Relating the value obtained for the 3H isotope effect to a known value for the 2H isotope effect strongly supports the view that both values are close to the true isotope effect with the respective substituted compounds on the rate constant in the catalytic step involving scission of the C-H bond. 4. The constancy of the isotope effect under various conditions makes it possible to use it for interpretations in vivo. 5. It was established that beta-D-galactose dehydrogenase exhibits B-specificity towards the nicotinamide ring in NAD.

A Molecular Approach to Immunoscintigraphy: A Study of the T-Antigen Conformation on the Surface of Tumors

1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Cell ◽  
T Antigen ◽  
Human Carcinomas ◽  
Animal Tumor ◽  
Synthetic Antigens

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.

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