scholarly journals Factors affecting the concentration of ascorbic acid in the crystalline lens of cattle and rabbits

1956 ◽  
Vol 63 (1) ◽  
pp. 52-56 ◽  
Author(s):  
M. E. Langham ◽  
Kathleen Heald
Keyword(s):  
Ascorbic Acid ◽  
Crystalline Lens ◽  
Factors Affecting

Maturation, iron deficiency, and ligands in enteric radioiron transport in vitro

1963 ◽  
Vol 204 (1) ◽  
pp. 171-175 ◽  
Author(s):  
W. S. Ruliffson ◽  
J. M. Hopping
Keyword(s):  
Ascorbic Acid ◽  
Iron Deficiency ◽  
Iron Absorption ◽  
Deficiency Anemia ◽  
Anaerobic Incubation ◽  
Reverse Effect ◽  
Factors Affecting ◽  
Everted Gut Sac

The effects in rats, of age, iron-deficiency anemia, and ascorbic acid, citrate, fluoride, and ethylenediaminetetraacetate (EDTA) on enteric radioiron transport were studied in vitro by an everted gut-sac technique. Sacs from young animals transported more than those from older ones. Proximal jejunal sacs from anemic animals transported more than similar sacs from nonanemic rats, but the reverse effect appeared in sacs formed from proximal duodenum. When added to media containing ascorbic acid or citrate, fluoride depressed transport as did anaerobic incubation in the presence of ascorbic acid. Anaerobic incubation in the presence of EDTA appeared to permit elevated transport. Ascorbic acid, citrate, and EDTA all enhanced the level of Fe59 appearing in serosal media. These results appear to agree with previously established in vivo phenomena and tend to validate the in vitro method as one of promise for further studies of factors affecting iron absorption and of the mechanism of iron absorption.

Other Factors Affecting Ascorbic Acid Needs

Vitamin C ◽  
2018 ◽  
pp. 291-307
Author(s):  
C. Alan B. Clemetson
Keyword(s):  
Ascorbic Acid ◽  
Factors Affecting

​Short-term changes in and preoperative factors affecting vaulting after posterior chamber phakic Implantable Collamer Lens implantation

2020 ◽  
Author(s):  
Qiujian Zhu ◽  
Wen-Jing Chen ◽  
Wei-Jian Zhu ◽  
Hai-Xiang Xiao ◽  
Man-Hui Zhu ◽  
...  
Keyword(s):  
Multiple Regression ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Crystalline Lens ◽  
Stepwise Multiple Regression ◽  
Multiple Regression Equation ◽  
Posterior Chamber ◽  
Key Factors ◽  
Implantable Collamer Lens ◽  
Factors Affecting

Abstract Background: To describe the very early changes in vault in the first month after Implantable Collamer Lens (ICL) implantation and to evaluate the effect of preoperative biometric factors on vault.Methods: A total of 83 eyes from 83 subjects with complete data who met follow-up requirements were recruited in this retrospective study between May 2019 and March 2020. We quantitatively assessed postoperative vault at 2 hours, 1 day, 1 week, and 1 month following implantation. Associations between postoperative vault and age, ICL size, spherical equivalent (SE), axial length (AL), central corneal thickness (CCT), flat K, steep K, mean K, anterior chamber depth (ACD), crystalline lens thickness (LT), white-to-white (WTW) diameter obtained by three devices, horizontal and vertical sulcus-to-sulcus (STS) diameter, bright and dark pupil sizes (BPS and DPS) and DPS-BPS were investigated using Spearman’s correlation analysis and stepwise multiple regression analysis.Results: The mean vault values at 2 hours, 1 day, 1 week, and 1 month after ICL implantation were 672.05 ± 30.72, 389.15 ± 28.33, 517.23 ± 30.76 and 530.12 ± 30.22 μm, respectively. There were significant differences in vault values between 2 hours, 1 day and 1 week after the operation. ICL size (β = 0.942; p < 0.001), followed by horizontal STS (β = -0.517; p < 0.001), crystalline LT (β = -0.376; p < 0.001) and vertical STS (β = -0.257; p = 0.017), significantly influenced vault at 1 month after the operation. The multiple regression equation was expressed as follows: central vault (μm) = -1369.05+ 657.121 × ICL size- 287.408 × horizontal STS - 432.497 × crystalline LT - 137.33 × vertical STS (adjusted R2 = 0.643).Conclusions: After ICL implantation, vault decreased and then increased, but it did not return to the vault value at 2 hours after surgery. ICL size, horizontal and vertical STS and crystalline LT were key factors for predicting postoperative vaulting.

scholarly journals ELECTROCHEMICAL EVALUATION OF THE STABILITY OF ASCORBIC ACID IN WHEY FROM CHEESE AND RICOTTA

2017 ◽  
Vol 14 (27) ◽  
pp. 51-55
Author(s):  
Lucélia HOEHNE ◽  
Adriano GENNARI ◽  
Eduardo Miranda ETHUR ◽  
Maurício HILGEMANN ◽  
Claucia Fernanda Volken SOUZA ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Cyclic Voltammetry ◽  
Vitamin C ◽  
Antioxidant Capacity ◽  
Electrochemical Techniques ◽  
Factors Affecting ◽  
Oxidative Reactions ◽  
Antioxidant Evaluation ◽  
The Stability ◽  
Electrochemical Evaluation

Ascorbic acid has aroused particular interest due to its antioxidant capacity, which can prevent oxidative reactions. Cyclic voltammetry stands out as one of the main electrochemical techniques for antioxidant evaluation. The cheese and ricotta whey are subproducts of the dairy, and have several components that allow its use in various foods. The enrichment of subproducts with essential substances in food may make its use even more attractive by industries. Therefore, the aim of this study was to evaluate the stability of ascorbic acid in cheese and ricotta whey using cyclic voltammetry. For this, the cheese and ricotta whey were collected from a dairy industry of the Vale do Taquari-RS and were fortified with ascorbic acid and its stability was evaluated according to the electrochemical profiles of the samples. With the data obtained, it was concluded that one of the factors affecting directly the stability of ascorbic acid was the pH, but more studies are needed to evaluate other interfering stability of vitamin C.

Effect of Some Drugs on Clinical Laboratory Values as Determined by the Technicon SMA 12/60

1972 ◽  
Vol 18 (2) ◽  
pp. 137-144 ◽  
Author(s):  
H P Singh ◽  
M A Hebert ◽  
M H Gault
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Laboratory Tests ◽  
Clinical Laboratory ◽  
Relative Importance ◽  
Factors Affecting ◽  
Biochemical Laboratory ◽  
In Vitro Effects ◽  
Therapeutic Doses

Abstract We examined the quantitative in vitro effects of 45 drugs on 12 automated biochemical laboratory tests done on the Technicon SMA 12/60. Of these, 25 drugs in 1 mmol/liter concentration interfered in one or more of the assays. However, only eight drugs (N-acetyl-p-aminophenol, p-aminosalicylate, isoniazid, L-dopa, α-methyldopa, 6-mercaptopurine, sulfathiazole, and ascorbic acid) reacted positively with the test reagents at concentrations likely to occur in plasma after administration of maximum single therapeutic doses. A slight false elevation of plasma uric acid and a major false increase in urine values occurred in patients after ingestion of N-acetyl-p-aminophenol and phenacetin, corresponding to the greater concentrations of these drugs and their metabolites in urine. The relative importance of various factors affecting the influence of drugs on biochemical test values is discussed.

Factors affecting measurement of urinary oxalate.

1984 ◽  
Vol 30 (8) ◽  
pp. 1339-1343 ◽  
Author(s):  
B C Mazzachi ◽  
J K Teubner ◽  
R L Ryall
Keyword(s):  
Ascorbic Acid ◽  
Room Temperature ◽  
Alkaline Ph ◽  
Ascorbic Acid Concentration ◽  
Factors Affecting ◽  
The Stability ◽  
Gas Chromatographic Method ◽  
And Storage ◽  
Urine Specimens ◽  
Positive Interference

Abstract Using a gas-chromatographic method, we examined the effects of phosphate concentration, added calcium chloride, and pH on precipitation of oxalate from urine. All three factors are important, but the pH of precipitation is particularly so, especially in the presence of even normal concentrations of ascorbic acid. At pH 8, increases in measured oxalate ranged from 20% at an ascorbic acid concentration of 1 mmol/L to more than 300% at 15 mmol/L. Ascorbic acid is rapidly converted to oxalate at alkaline pH. We also investigated the stability of both untreated and acidified urine containing ascorbic acid during storage for up to one month at -70, -20, and 4 degrees C, and room temperature. After one month, untreated collections were stable at -70 degrees C and acidified collections at -20 and -70 degrees C. We recommend conditions for assay and storage of urine specimens that are to be assayed for oxalate under which positive interference by ascorbic acid is minimized.

Factors affecting formulation characteristics and stability of ascorbic acid in water-in-oil creams

2014 ◽  
Vol 36 (5) ◽  
pp. 494-504 ◽  
Author(s):  
M. A. Sheraz ◽  
M. F. Khan ◽  
S. Ahmed ◽  
S. H. Kazi ◽  
S. Rehman Khattak ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Factors Affecting
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