Stability of ascorbate in urine: relevance to analyses for ascorbate and oxalate.

1985 ◽  
Vol 31 (10) ◽  
pp. 1703-1705 ◽  
Author(s):  
A H Chalmers ◽  
D M Cowley ◽  
B C McWhinney
Keyword(s):  
Room Temperature ◽  
Final Concentration ◽  
Disodium Edta ◽  
Ph Values ◽  
Ascorbate Concentration ◽  
The Mean ◽  
Urine Specimens

Abstract Ascorbate is unstable in urine at room temperature at pH values ranging from 1 to 12. At pH 7 and above, oxalate is generated in amounts directly proportional to the ascorbate concentration. In 12 different urines, adjusted to pH 12 and incubated for 20 h at room temperature, there was a significant correlation between the amount of oxalate formed and the initial ascorbate concentration (r = 0.97, p less than 0.01). The mean (+/- SD) concentration of oxalate (1.32 +/- 0.70 mmol/L) formed during this period approximated the initial ascorbate concentration (1.57 +/- 1.09 mmol/L). Disodium EDTA, 10 mmol/L final concentration, stabilizes ascorbate in urine and inhibits its conversion to oxalate at pH values of 4.4 to 7.0 during a 24-h period. We therefore propose that urine specimens for ascorbate and oxalate analyses be collected with disodium EDTA present such as to give about this final concentration.

SOLVOLYSABLE DEOXYCORTICOSTERONE CONJUGATES IN HUMAN URINE

1976 ◽  
Vol 68 (2) ◽  
pp. 273-281 ◽  
Author(s):  
C. L. COPE ◽  
S. LOIZOU
Keyword(s):  
Human Urine ◽  
Room Temperature ◽  
Urine Samples ◽  
Variable Ratio ◽  
The Mean ◽  
Sulphate Conjugate ◽  
Urine Specimens

SUMMARY The nature of the urinary conjugate converted by solvolysis, to free unconjugated deoxycorticosterone (DOC) was studied. A comparison of 11 solvolysis techniques has shown that the method employed in this study yielded 86% of the highest yield by any of the techniques tried. Three successive chromatographic systems on paper showed that no appreciable amounts of contaminants were present in the free DOC eluates, following solvolysis. By preparing authentic [3H]DOC sulphate and subjecting it to solvolysis it was shown that more than 90% of the tritiated DOC was recovered, after chromatography of the free DOC extract. This suggests that much of the solvolysable DOC in human urine is present in the form of the sulphate conjugate. The levels of DOC, excreted as the solvolysable conjugate in a variety of urine specimens, were shown to be much higher than those of free DOC, the former being 4·8 to 127 times higher than the amount of the latter. This highly variable ratio suggests that the site of production of solvolysable DOC is different from that for free DOC. The only correlation between free and solvolysable DOC was shown in dexamethasone-suppressed patients, in whom the mean percentage remaining after suppression was 30·6% for free DOC, 24·1% for solvolysable DOC and 22·2% for cortisol. As solvolysable DOC is present in much larger amounts in urine, care is necessary in the storage of urine samples in which free DOC estimates are to be made, as we found that urine specimens left at room temperature for 1 week could show rises of as much as 400% of their starting free DOC levels.

scholarly journals Chemical Stability of Extemporaneously Prepared Lorazepam Suspension at Two Temperatures

2004 ◽  
Vol 9 (4) ◽  
pp. 254-258
Author(s):  
Wan-Man Ellaria Lee ◽  
Ralph A. Lugo ◽  
William J. Rusho ◽  
Mark MacKay ◽  
John Sweeley
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Chemical Stability ◽  
High Performance ◽  
Room Temperature ◽  
Final Concentration ◽  
Sterile Water ◽  
Initial Concentration ◽  
Two Temperatures ◽  
The Mean

The objective of this study was to determine the chemical stability of extemporaneously prepared lorazepam suspension (1 mg/mL) stored at two temperatures (4°C and 22°C) for 3 months. Lorazepam tablets marketed by two manufacturers (Mylan Pharmaceuticals and Watson Laboratories) were used to extemporaneously formulate two independently prepared suspensions. Each suspension was prepared using sterile water, Ora-Plus® and Ora-Sweet® to achieve a final concentration of 1 mg/mL. The two brands of tablets required different volumes of vehicles to prepare a pharmaceutically optimal suspension. The suspensions were stored in amber glass bottles at 4°C and 22°C for 91 days. Samples were analyzed by high performance liquid chromatography at baseline and on days 2, 3, 7, 14, 21, 28, 42, 63, and 91. The suspensions were considered stable if the mean lorazepam concentration remained greater than 90% of the initial concentration. The chemical stabilities of these two extemporaneously prepared lorazepam suspensions were comparable throughout the study. Both lorazepam suspensions were stable for 63 days when stored at 4°C or 22°C, and both were stable for 91 days when refrigerated at 4°C. When stored at room temperature, the suspension prepared from the Watson tablet retained 88.9 ± 1.4% of the initial concentration on day 91 and was therefore considered unstable, while the suspension prepared from the Mylan tablet was stable for the entire 91-day study.

scholarly journals Appearance of Platelet-Clumping Substance after Acidification of Plasma

Blood ◽  
1968 ◽  
Vol 31 (3) ◽  
pp. 348-357 ◽  
Author(s):  
HIROH YAMAZAKI ◽  
HIROSHI MURASE ◽  
TATSUO SHIMAMOTO ◽  
TAKIO SHIMAMOTO
Keyword(s):  
Calcium Ions ◽  
Standard Error ◽  
Room Temperature ◽  
Ph Value ◽  
Platelet Rich Plasma ◽  
Final Concentration ◽  
Ringer’S Solution ◽  
Ph Values ◽  
Edta Plasma ◽  
Ph Range

Abstract 1. The pH values of heparinized plasma from ten normal rabbits were from 7.53 to 7.80. The average pH and standard error was 7.69 ± 0.03. These plasmas did not show platelet-clumping activity when exposed to the platelet-saline suspension from the same or other normal rabbits. The platelet-clumping substance was not observed in all ten cases after alkalinization of the plasma to pH values ranging from 8.32 to 9.40. On the contrary, immediately after acidification of the plasmas, the platelet-clumping substance appeared at pH values from 4.90 to 6.82 at room temperature. The range of the lower pH value, in which the platelet-clumping substance was observed, was 4.90-5.60 (5.15 ± 0.07 in average) and the upper range was 5.95-6.82 (6.27 ± 0.12 in average). The pH range at which the strongest clumping of platelets appeared was 5.22-5.95 (5.61 ± 0.07 in average). The platelet-clumping substance did not disappear after the pH of the acidified plasma was reneutralized to the original value. 2. No clumping was found after the addition of citrated, oxalated, EDTA-plasma or serum even when they were acidified. After the pH value of the citrated, oxalated or EDTA-plasma was changed from 4.85 ± 0.39 to 7.55 ± 0.03 and in the presence of calcium ions (10 mM.), platelet-clumping activity was observed. After the addition of citrate (0.38 percent in final concentration), oxalate (0.2 percent in final concentration), or EDTA (0.1 percent in final concentration) to the heparinized plasma the platelet-clumping substance did not disappear. In the case of serum, the platelet-clumping activity did not appear after the pH changes. 3. The platelet-clumping substance in the acidified plasma was heat-labile; it was detected after BaSO4-adsorption and defibrination; it was stable in storage at 4 C., and it was not dialyzable against Ringer’s solution for 72 hours. It induced platelet clumping not only in citrated platelet-rich plasma but also in the platelet-saline suspension. 4. The properties of the platelet-clumping substance in the acidified plasma were compared with that of substances known to have platelet-clumping activity and the experimental evidences showing the differences to ADP, thrombin, ADP-cofactor and thrombocyte agglutinating factors have been detailed.

scholarly journals Comparative Analysis of Different Local Anesthetic Solutions Available in Market: An In Vitro and Clinical Study

2021 ◽  
Author(s):  
Eisha Imran ◽  
Faisal Moeen ◽  
Beenish Abbas ◽  
Bakhtawar Yaqoob ◽  
Mehreen Wajahat ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Local Anesthetic ◽  
Compositional Analysis ◽  
Bacterial Activity ◽  
Similar Composition ◽  
Ph Values ◽  
Significant Difference ◽  
The Mean ◽  
The Difference

Abstract Objectives The study aimed to evaluate and compare various commercially available local anesthetic solutions. Materials and Methods A total of 150 commercially available local anesthetic cartridges of similar composition (2% lidocaine with epinephrine 1:100,000) were randomly collected and divided into 3 groups. The designations of groups were selected from their product names such that each group consisted of 60 cartridges. Group S (Septodont, France) Group M (Medicaine, Korea) and Group H (HD-Caine, Pakistan). The samples were divided into five sub-groups, each consisting of 10 cartridges from each group to investigate each parameter. Results The acquired data was statistically analyzed and compared (using SPSS version 12). Compositional analysis revealed a non-significant (P>0.05) difference when the three Groups were compared with standard lidocaine and epinephrine solutions. The mean pH values of samples from group S, M and H respectively fell within the range of pH values of commercially available solutions. Non-significant difference in EPT values of Group S and H was found when efficacy was compared (p = 0.3), however a significant difference (p < 0.01) was observed in contrast to Group M. Anti-bacterial activity was observed in all the group and a non-significant difference in cell viability values of Group S and M was found (p = 0.6), while the difference was significant in comparison to Group H. Conclusion Within the limitations of these investigations, it appears that the properties of different manufacturers fall within the recommended ranges as mentioned in literature and do not appear to be statistically different in the variables we have tested.

scholarly journals Enhanced Oil Removal by a Non-Toxic Biosurfactant Formulation

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 467
Author(s):  
Emília Mendes da Silva Santos ◽  
Isabela Regina Alvares da Silva Lira ◽  
Hugo Moraes Meira ◽  
Jaciana dos Santos Aguiar ◽  
Raquel Diniz Rufino ◽  
...  
Keyword(s):  
Room Temperature ◽  
Low Cost ◽  
Aeration Rate ◽  
Oil Removal ◽  
Central Composite Rotatable Design ◽  
Chemical Methods ◽  
Ph Values ◽  
Spectroscopic Analyses ◽  
New Formulation ◽  
Central Composite

In this study, a new formulation of low-cost, biodegradable, and non-toxic biosurfactant by Candida sphaerica UCP 0995 was investigated. The study was conducted in a bioreactor on an industrial waste-based medium, and a central composite rotatable design was used for optimization. The best results, namely a 25.22 mN/m reduction in surface tension, a biosurfactant yield of 10.0 g/L, and a critical micelle concentration of 0.2 g/L, were achieved in 132 h at an agitation speed of 175 rpm and an aeration rate of 1.5 vvm. Compositional and spectroscopic analyses of the purified biosurfactant by chemical methods, Fourier transform infrared spectroscopy, and nuclear magnetic resonance suggested that it is a glycolipid-type biosurfactant, and it showed no cytotoxicity in the MTT assay. The biosurfactant, submitted to different formulation methods as a commercial additive, remained stable for 120 days at room temperature. Tensioactive properties and stability were evaluated at different pH values, temperatures, and salt concentrations. The biosurfactant obtained with all formulation methods demonstrated good stability, with tolerance to wide ranges of pH, temperature and salinity, enabling application under extreme environmental conditions. Bioremediation tests were performed to check the efficacy of the isolated biosurfactant and the selected microbial species in removing oil from soil. The results demonstrated that the biosurfactant produced has promising properties as an agent for the bioremediation of contaminated soil.

scholarly journals The Atmosphere of the Underground Electric Railways of London: A Study of its Bacterial Content in 1920

1923 ◽  
Vol 22 (2) ◽  
pp. 123-155 ◽  
Author(s):  
J. Graham Forbes
Keyword(s):  
Body Temperature ◽  
Room Temperature ◽  
The Mean ◽  
Bacterial Content ◽  
The City

1. The bacterial content of the air of the Underground Railways, when the average of all results of the bacteriological investigations is taken, does not numerically compare unfavourably with the outside air of London.2. The ratio of the number of organisms growing at room temperature appears to be about 14 for railway air to 10 outside air. For those growing at body temperature the ratio is considerably higher, namely 2 to 1 respectively. The mean per litre, for room temperature organisms, is about 9 in railway air, 6·3 in the outside air; for body temperature organisms 4·6 for railway air, 2·2 for outside air.3. The bacterial content of platform air, except on the City and South London Railway, would appear to be higher than that of carriage air; the total mean for platform air being 52 and for carriage air 42·8 organisms per 5 litres, or a ratio of 16·4 and 13·5 respectively to 10 of the open air. The higher proportion in platform air is generally speaking to be accounted for by the greater amount of draught and dust disturbance.4. The ratios of the total bacterial content of railway carriage air and carriage and platform air on the six lines to open air are estimated in the following proportions:

Lead inclusions in aluminium

1989 ◽  
Vol 157 ◽  
Author(s):  
E. Johnson ◽  
L. Gråbaek ◽  
J. Bohr ◽  
A. Johansen ◽  
L. Sarholt-Kristensen ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Room Temperature ◽  
Noble Gas ◽  
Melting Transition ◽  
X Ray Diffraction ◽  
Free Surfaces ◽  
The Matrix ◽  
Mean Size ◽  
The Mean ◽  
Spontaneous Phase

ABSTRACTIon implantation at room temperature of lead into aluminium leads to spontaneous phase separation and formation of lead precipitates growing topotactically with the matrix. Unlike the highly pressurised (∼ 1–5 GPa) solid inclusions formed after noble gas implantations, the pressure in the lead precipitates is found to be less than 0.12 GPa.Recently we have observed the intriguing result that the lead inclusions in aluminium exhibit both superheating and supercooling [1]. In this paper we review and elaborate on these results. Small implantation-induced lead precipitates embedded in an aluminium matrix were studied by X-ray diffraction. The (111) Bragg peak originating from the lead crystals was followed during several temperature cycles, from room temperature to 678 K. The melting temperature for bulk lead is 601 K. In the first heating cycle we found a superheating of the lead precipitates of 67 K before melting occurred. During subsequent cooling a supercooling of 21 K below the solidification point of bulk lead was observed. In the subsequent heating cycles this hysteresis at the melting transition was reproducible. The full width of the hysteresis loop slowly decreased to 62 K, while the mean size of the inclusions gradually increased from 14.5 nm to 27 nm. The phenomena of superheating and supercooling are thus most pronounced for the small crystallites. The persistence of the hysteresis loop over successive heating cycles demonstrate that its cause is intrinsic in nature, and it is believed that the superheating originates from the lack of free surfaces of the lead inclusions.

Comparison of Efficacy of Refrigerated Oxytocin with Oxytocin Kept at Room Temperature for the Prevention of Post-Partum Haemorrhage in Vaginal Deliveries in a Tertiary Care Setting

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Pandey U
Keyword(s):  
Blood Loss ◽  
Low Income ◽  
Room Temperature ◽  
Postpartum Haemorrhage ◽  
Past History ◽  
Post Partum ◽  
Cold Chain ◽  
Vaginal Deliveries ◽  
History Of ◽  
The Mean

Introduction: Postpartum haemorrhage is one of the leading causes of maternal death worldwide and it accounts for nearly one-quarter of all maternal deaths and almost half of all postpartum deaths in low-income countries. Primary postpartum haemorrhage (PPH) is the most common form of major obstetric haemorrhage. Materials and Methods: The study protocol was comprised of Consent, Measurement of Pre-delivery Hemoglobin, Administration of the Intervention, Measurement of postpartum blood loss and Measurement of Post-delivery (24-48 hours) Hemoglobin. Blood loss was measured using a calibrated drape. The drape was placed beneath the parturient buttocks and secured around her abdomen with ties. Blood loss was monitored for a minimum of one hour and was continued in the second hour in case of persistent bleeding. The drape with the collected blood was weighed on a scale. The weight of the drape and the container in which it is placed was deducted from the total recorded weight in order to obtain the weight of the blood collected in the drape. Blood loss weight in grams was converted to milliliters by dividing the figure in grams by 1.06 (blood density in grams per milliliter). Results: The cross tabulations were used to study the demographic, obstetrical and medical factors in women with obstetrical haemorrhage. Table 1 shows the selected sociodemographic characteristics of the study population. The mean age of cases and controls are 26.333.559 and 26.853.873 respectively. On comparison, they are statistically insignificant. (p=0.324). The educational, occupational and socioeconomic status was comparable between cases and controls (p >0.05). Table 2 shows Antenatal, intra-partum and post-partum data in cases and controls. Discussion & Conclusion: It is a study done in North India comparing the Oxytocin kept at room temperature with failure of maintenance of cold chain during transport and storage and the refrigerated Oxytocin. It is the common understanding and general training that Oxytocin must be stored in the refrigerator, failing which its efficacy reduces i.e. it, will not be effective in controlling PPH. During the study we compared the mean blood loss and change in hemoglobin levels in cases and control and despite the fact that major risk factor for PPH for example past history of PPH, past history of D&C, prolonged third stage labour duration, manual removal of placenta were comparable in both cases and controls, still the mean blood loss and change in hemoglobin values was more in cases than controls. This could be attributed to usage of market oxytocin which had failed cold chain maintenance resulted in less effective oxytocin in prevention of PPH, Hence causing more blood loss and drop in hemoglobin values. This shows the need of room temperature stable uterotonic drug in LMIC’s like ours. Recently room temperature stable carbetocin shows the potential as an effective uterotonic drug for the prevention of PPH. However according to various studies carbetocin cannot be used for induction or augmentation of labour so it cannot replace oxytocin fully, rather it acts as a part of collective PPH reduction strategy.

Effect of Phage on Survival of Salmonella Enteritidis during Manufacture and Storage of Cheddar Cheese Made from Raw and Pasteurized Milk

2001 ◽  
Vol 64 (7) ◽  
pp. 927-933 ◽  
Author(s):  
RAJESH MODI ◽  
Y. HIRVI ◽  
A. HILL ◽  
M. W. GRIFFITHS
Keyword(s):  
Lactic Acid ◽  
Salmonella Enteritidis ◽  
Cheddar Cheese ◽  
Raw Milk ◽  
Final Concentration ◽  
Pasteurized Milk ◽  
Ph Values ◽  
Standard Procedures ◽  
Raw Milk Cheese ◽  
And Storage

The ability of Salmonella Enteritidis to survive in the presence of phage, SJ2, during manufacture, ripening, and storage of Cheddar cheese produced from raw and pasteurized milk was investigated. Raw milk and pasteurized milk were inoculated to contain 104 CFU/ml of a luminescent strain of Salmonella Enteritidis (lux) and 108 PFU/ml SJ2 phage. The milks were processed into Cheddar cheese following standard procedures. Cheese samples were examined for Salmonella Enteritidis (lux), lactic acid bacteria, molds and yeasts, coliforms, and total counts, while moisture, fat, salt, and pH values were also measured. Salmonella Enteritidis (lux) was enumerated in duplicate samples by surface plating on MacConkey novobiocin agar. Bioluminescent colonies of Salmonella Enteritidis were identified in the NightOwl molecular imager. Samples were taken over a period of 99 days. Counts of Salmonella Enteritidis (lux) decreased by 1 to 2 log cycles in raw and pasteurized milk cheeses made from milk containing phage. In cheeses made from milks to which phage was not added, there was an increase in Salmonella counts of about 1 log cycle. Lower counts of Salmonella Enteritidis (lux) were observed after 24 h in pasteurized milk cheese containing phage compared to Salmonella counts in raw milk cheese with phage. Salmonella Enteritidis (lux) survived in raw milk and pasteurized milk cheese without phage, reaching a final concentration of 103 CFU/g after 99 days of storage at 8°C. Salmonella did not survive in pasteurized milk cheese after 89 days in the presence of phage. However, Salmonella counts of approximately 50 CFU/g were observed in raw milk cheese containing phage even after 99 days of storage. In conclusion, this study demonstrates that the addition of phage may be a useful adjunct to reduce the ability of Salmonella to survive in Cheddar cheese made from both raw and pasteurized milk.

QUALITY EVALUATION OF YOGURT PRODUCED COMMERCIALLY IN ONTARIO

1972 ◽  
Vol 35 (3) ◽  
pp. 173-175 ◽  
Author(s):  
C. L. Duttschaever ◽  
D. R. Arnott ◽  
D. H. Bullock
Keyword(s):  
Quality Evaluation ◽  
Fat Content ◽  
Fat Percentage ◽  
Total Solids ◽  
Ph Values ◽  
The Mean

Analyses for fat, total solids, solids-not-fat (SNF), pH, and net weight were conducted on 152 yogurts of which 15 were unflavored. These yogurts were produced by 13 different manufacturers and sold in Ontario. The fat content of all samples varied from 0.9 to 3.6% with a mean of 1.98%. For the plain yogurt, the mean fat percentage was 2.46%. The SNF content of all samples ranged from 10.0 to 28.9% with a mean of 18.96%. For the plain yogurt, the mean SNF percentage was 13.40. The pH values for all samples varied from 3.27 to 4.53. The mean overweight for all samples was 7.2% with as much as 15% for one manufacturer.

Sign in / Sign up

Export Citation Format

Share Document