In Vitro Interaction between Venous Blood Clots and Radiopharmaceuticals

1985 ◽  
Vol 24 (04) ◽  
pp. 173-179 ◽  
Author(s):  
B. R. R. Persson ◽  
V. Kempi
Keyword(s):  
Room Temperature ◽  
Venous Blood ◽  
Gel Chromatography ◽  
Time Intervals ◽  
Ph Values ◽  
Blood Clots ◽  
Glass Tubes ◽  
Ph Range ◽  
In Vitro Interaction

SummaryClots of 1 ml venous blood formed in glass tubes after 10 min at room temperature were incubated at 37° C with the radiopharmaceutical to be studied. Methods for quality control of the radiopharmaceuticals were compared. Gel chromatography scanning was found to give reliable information. The incorporation into the clot was studie’d at different pH values and after various time intervals. The highest incorporation was found for 125I-fibrinogen and for 99mTc-mac-roaggregates of albumin, followed by 99mTc-sulphur colloid and 99mTc-strep-tokinase at pH less than 2. The titrated initial dose of 99mTc-streptoki-nase was studied at various pH levels. The lysing effect was less in the pH range 1-2.5, where the best labeling yield was obtained. The inactivation of streptokinase by the labeling procedure was also studied with im-munoelectrophoresis and decomposition of casein. In vitro studies of the interaction of radiopharmaceuticals with clots add information for the clinical use of radiopharmaceuticals for thrombus localization.

Differences between in vitro and in vivo degradation of LHRH by rat brain and other organs

1987 ◽  
Vol 253 (3) ◽  
pp. E317-E321 ◽  
Author(s):  
F. A. Carone ◽  
M. A. Stetler-Stevenson ◽  
V. May ◽  
A. LaBarbera ◽  
G. Flouret
Keyword(s):  
Degradation Products ◽  
Venous Blood ◽  
Simultaneous Action ◽  
Pituitary Cells ◽  
Time Intervals ◽  
Luteinizing Hormone Releasing Hormone ◽  
Hydrolysis Of ◽  
The Brain

Homogenates of brain, pituitary, liver, lung, ovary, and testes were incubated with [pyro Glu1-3,4-3H]luteinizing hormone-releasing hormone ([3H]LHRH), and the profiles of metabolites generated as a function of time were determined. After 5 min of incubation, 5 was the predominant metabolite in most homogenates. Although the profiles of metabolites varied at different time intervals, metabolites 2, 3, 4, and 5, and in some instances 7 and 9, appeared to form simultaneously and were detectable at 10 min. Neither metabolite 6 nor other larger metabolites formed initially as dominant degradation products. The findings suggest cleavage of LHRH by the simultaneous action of several endopeptidases. After a single vascular transit of [3H]LHRH, metabolites were determined in the venous blood of liver, lung, and brain of rats in vivo. There were no metabolites of [3H]LHRH in venous blood of liver and lung; however, metabolites 2-4 were present in venous blood of the brain. Incubation of rat anterior pituitary cells with [3H]LHRH yielded metabolites 1-4 but not metabolites 5 or 9 as in homogenates. Incubation of [3H]LHRH with porcine follicular granulosa cells resulted in the generation of metabolites 2-7 and 9, similar to the profile in homogenates. Thus, since homogenates contain enzymes of disrupted cells, they do not always reflect mechanisms for in vivo hydrolysis of circulating LHRH. Brain degraded 12.1% of LHRH during a single vascular transit and may account for substantial degradation of the circulating hormone.

Survival of Bacillus cereus Vegetative Cells and Spores during In Vitro Simulation of Gastric Passage

2012 ◽  
Vol 75 (4) ◽  
pp. 690-694 ◽  
Author(s):  
SIELE CEUPPENS ◽  
MIEKE UYTTENDAELE ◽  
KATRIEN DRIESKENS ◽  
ANDREJA RAJKOVIC ◽  
NICO BOON ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Acid Resistance ◽  
In Vitro Experiments ◽  
Vegetative Cells ◽  
Ph Values ◽  
Constant Ph ◽  
In Vitro Simulation ◽  
Ph Range

The enteric pathogen Bacillus cereus must survive gastric passage in order to cause diarrhea by enterotoxin production in the small intestine. The acid resistance and the survival after gastric passage were assessed by in vitro experiments with acidified growth medium and gastric simulation medium with B. cereus NVH 1230-88 vegetative cells and spores. First, batch incubations at constant pH values for 4 h, which represented different physiological states of the stomach, showed that spores were resistant to any gastric condition in the pH range of 2.0 to 5.0, while vegetative cells were rapidly inactivated at pH values of ≤4.0. Second, a dynamic in vitro gastric experiment was conducted that simulated the continuously changing in vivo conditions due to digestion dynamics by gradually decreasing the pH from 5.0 to 2.0 and fractional emptying of the stomach 30 to 180 min from the start of the experiment. All of the B. cereus spores and 14% (±9%) of the vegetative cells survived the dynamic simulation of gastric passage.

Long-term in vitro transformation of 2-line ferrihydrite to goethite/hematite at 4, 10, 15 and 25°C

Clay Minerals ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 433-438 ◽  
Author(s):  
U. Schwertmann ◽  
H. Stanjek ◽  
H.-H. Becher
Keyword(s):  
Zero Point ◽  
Transformation Rate ◽  
Ambient Temperatures ◽  
Ph Values ◽  
In Vitro Transformation ◽  
Zero Point Of Charge ◽  
Ph Range ◽  
Increasing Temperature

Abstract2-line ferrihydrite stored in water at ambient temperatures from 4 to 25°C and at ten different pH values between 2.5 and 12 for up to 10–12 y transformed to both goethite and hematite at all temperatures and pH values except at pH 12 where only goethite was formed. The rate and degree of transformation (20–100%) increased with increasing pH and temperature. The hematite/ (hematite+goethite) ratio varied between 0 and ~0.8, increased with increasing temperature and showed a strong maximum at pH 7–8 which increased from 0.1–0.2 at 4°C to 0.7–0.8 at 25°C. The maximum coincides with the zero point of charge of ferrihydrite where its solubility and, thus, its via-solution transformation rate to goethite are minimal. We assume, therefore, that in this pH-range the (slower) via-solution transformation to hematite can more efficiently compete with that to goethite.

Survival and Multiplication of Vibrio cholerae Serotype Ogawa in Reconstituted Infant Milk

1990 ◽  
Vol 53 (12) ◽  
pp. 1071-1072 ◽  
Author(s):  
M. O. ODUGBO ◽  
S. I. ONUORAH ◽  
A. A. ADESIYUN
Keyword(s):  
Adverse Effect ◽  
Vibrio Cholerae ◽  
Room Temperature ◽  
Milk Formula ◽  
Competitive Growth ◽  
Ambient Conditions ◽  
Survival And Growth ◽  
Effects Of Temperature ◽  
Ph Range

In vitro studies were conducted to determine the effects of temperature, pH, and competitive growth of other microorganisms on the viability and multiplication of Vibrio cholerae serotype Ogawa in reconstituted infant milk (nonsterile). Following inoculation of milk sample (at a pH range of 6.0 to 6.4), the V. cholerae population detected on thiosulfate-citrate-bile sucrose (TCBS) agar increased from 9.5 × 103 per g to 7.4 × 104, 2.6 × 108, and 1.9 × 109 per g after 12 h at 4°C, 25°C (room temperature) and 37°C, respectively. At a pH of 5.5, an approximate 100-fold rise in V. cholerae was observed after 12 h at 25°C, while within a pH range of 6.5 to 8.5, a five logarithmic increase in numbers was detected. The presence of other microorganisms did not appear to have any adverse effect on V. cholerae survival and growth in milk. The study demonstrates that at ambient conditions V. cholerae contamination of infant milk formula by carriers or infected mothers could lead to multiplication of the organism and hence pose serious health risk to infants.

scholarly journals One cell–one immunoglobin. Origin of limited heterogeneity of myeloma proteins

1970 ◽  
Vol 116 (2) ◽  
pp. 241-248 ◽  
Author(s):  
Z. L. Awdeh ◽  
A. R. Williamson ◽  
Brigitte A. Askonas
Keyword(s):  
Isoelectric Focusing ◽  
Light Chain ◽  
Time Intervals ◽  
Myeloma Protein ◽  
Heavy Chains ◽  
Serum Component ◽  
Isoelectric Points ◽  
Ph Range ◽  
A Charge

Plasma-cell tumour 5563 forms a single molecular species of immunoglobulin IgG2a, i.e. one variant of heavy chain and one variant of light chain. The molecules formed are labile and undergo alterations in charge properties, which rapidly lead to heterogeneity of the myeloma protein after synthesis. The single immunoglobulin species originally formed is found only after the shortest time-intervals tested, i.e. 10min incubation. Two types of changes in charge properties take place: (1) The originally formed protein (component o) is converted via an intermediate o′ into the most basic form of 5563 myeloma protein found in serum (component a). Charge differences between these components are suppressed at pH8.9, but can be studied by chromatography at pH6.5 or by analysis of isoelectric points by isoelectric focusing in polyacrylamide gel. The conversion of components o and o′ into component a apparently commences soon after assembly of the molecules and proceeds to completion extracellularly. (2) The second type of charge difference that distinguishes components a, b, c and d is exhibited over the pH range 6.0–8.9, but not at acid pH, and has been studied by electrophoresis at pH8.9, by chromatography and by isoelectric focusing. Conversion of component a into components b, c, d and e is only partial so that all five components can be found at decreasing concentrations in serum. Both types of charge alteration can be effected in vitro in the presence of serum, with optimum pH8.0. None of the charge differences could be attributed to the secretion process, since a component with the same isoelectric point as component o was found in secreted myeloma protein (1h). We have found no evidence to support the idea that the first type of change from component o to component a is due to ring formation of N-terminal [14C]glutamine into pyrrolid-2-one-5-carboxylic acid; however, our findings do not exclude this process happening very rapidly to a precursor of component o, possibly the polypeptide chain during or immediately after synthesis. In studying this point we noted that not only the heavy chains but also the κ-type light chain of mouse 5563 myeloma protein have a blocked N-terminus.

Preanalytical stability of [-2]proPSA in whole blood stored at room temperature before separation of serum and plasma: implications to Phi determination

2019 ◽  
Vol 57 (4) ◽  
pp. 521-531 ◽  
Author(s):  
Ruggero Dittadi ◽  
Aline S.C. Fabricio ◽  
Giulia Rainato ◽  
Edoardo Peroni ◽  
Fulvio Di Tonno ◽  
...  
Keyword(s):  
Whole Blood ◽  
Room Temperature ◽  
Specific Antigen ◽  
Free Psa ◽  
Glass Tubes ◽  
Edta Plasma ◽  
Total Psa ◽  
Clot Activator ◽  
Over Time

Abstract Background [-2]proPSA seems to outperform free/total prostate-specific antigen (PSA) ratio in prostate cancer diagnosis. However, [-2]proPSA stability remains an underestimated issue. We examined [-2]proPSA stability over time in whole blood before separation of serum and plasma and its implications for prostate health index (Phi) determination. Total PSA (tPSA) and free PSA (fPSA) stabilities were also assessed. Methods Blood was drawn from 26 patients and separated in two tubes for plasma (K2EDTA and K2EDTA plus protease inhibitors – P100) and one for serum (clot activator plus gel separator). Tubes were stored at room temperature before centrifugation 1, 3 and 5 h for serum and EDTA plasma or 1 and 5 h for P100 plasma. To investigate the influence of gel separator on markers’ stability, blood was collected from 10 patients in three types of tubes to obtain serum: tubes with clot activator plus gel separator, with silica particles or glass tubes. Biomarkers were assayed with chemiluminescent immunoassays. Results [-2]proPSA and Phi levels significantly and progressively increased over time in serum (+4.81% and +8.2% at 3 h; +12.03% and +14.91% at 5 h, respectively, vs. 1 h; p<0.001). Conversely, [-2]proPSA levels did not change in plasma (EDTA or P100). tPSA levels did not change over time in serum or plasma, whereas fPSA decreased in serum. All markers were higher in plasma than in serum at any time point. This difference did not seem to be attributable to the use of gel for serum preparation. Conclusions EDTA prevented spurious in vitro modifications in PSA-related isoforms, confirming that a stabilized blood sample is a prerequisite for [-2]proPSA measurement and Phi determination.

scholarly journals In vitro evaluation of the safety and probiotic and technological potential of Pediococcus pentosaceus isolated from sheep milk

2018 ◽  
Vol 39 (1) ◽  
pp. 113 ◽  
Author(s):  
Mayara Leal Fernandes ◽  
Luana Martins Perin ◽  
Svetoslav Dimitrov Todorov ◽  
Luís Augusto Nero ◽  
Ernandes Rodrigues de Alencar ◽  
...  
Keyword(s):  
Penicillin G ◽  
Pediococcus Pentosaceus ◽  
Ph Values ◽  
Sheep Milk ◽  
Technological Potential ◽  
Amoxicillin Trihydrate ◽  
Limited Application ◽  
Acidification Capacity ◽  
Ph Range

Six isolates (Ac1Pd, Ac3Pd, Ac4Pd, Ac5Pd, Ac7Pd, and Ac22Pd) of Pediococcus pentosaceus from sheep milk were tested for safety and for probiotic and technological potential. The results showed that none of the isolates were able to produce biogenic amines or virulence factors. The isolates tested showed low hydrophobicities, high auto-aggregation capacities and co-aggregation with L. monocytogenes ATCC 7644, L. sakei ATCC 15521 and E. faecalis ATCC 19444, but none produced ?-galactosidase and bacteriocins. The isolates did not show growth at pH values 3 and 12, while in a pH range from 4 to 10 the growth was variable. In the absence of bile, all the isolates showed growth, with suppression at bile concentrations of 0.1%, 0.3%, 0.6% and 1.0%. In the disc-diffusion test, the isolates tested were resistant to oxacillin, sulfatrimethoprim and vancomycin but were sensitive to chloramphenicol and tetracycline. The isolates showed variable responses to penicillin G and were resistant to most of the drugs tested, except for amoxicillin trihydrate and ibuprofen. All cultures showed a high milk-acidification capacity after 24 hours and none produced exopolysaccharides. The isolates of P. pentosaceus were able to produce diacetyl; however, no culture showed extracellular proteolytic activity and the autolysis varied from 21.3% to 30.5% after 24 h. The isolates grew at NaCl concentrations of 4.0 and 6.0%, but the growth was lower at 10.0%. Finally, all the isolates were found to be safe but had limited application as probiotics and in some technological uses.

scholarly journals Toxicity and Resistance Potential of Selected Fungicides to Galactomyces and Penicillium spp. Causing Postharvest Fruit Decays of Citrus and Other Crops

Plant Disease ◽  
2012 ◽  
Vol 96 (1) ◽  
pp. 87-96 ◽  
Author(s):  
A. H. McKay ◽  
H. Förster ◽  
J. E. Adaskaveg
Keyword(s):  
Mycelial Growth ◽  
Single Spore ◽  
Ph Values ◽  
Highly Active ◽  
Green Mold ◽  
Dmi Fungicides ◽  
Ph Range ◽  
Penicillium Spp ◽  
Twofold Decrease

A diverse collection of isolates of Galactomyces citri-aurantii and G. geotrichum, the causal pathogens of sour rots of citrus and other fruit crops, respectively, was evaluated for sensitivity to demethylation-inhibiting (DMI) fungicides of the triazole group. Propiconazole was found to be highly effective in reducing mycelial growth of both species in vitro. For 139 isolates of G. citri-aurantii, a mean effective concentration for 50% reduction of mycelial growth (EC50 value) of 0.34 μg/ml was determined; whereas, for 33 isolates of G. geotrichum, this value was 0.14 μg/ml. In a comparison of additional DMI fungicides, mean EC50 values for 60 isolates of G. citri-aurantii and 20 isolates of G. geotrichum, were 0.27 and 0.17 μg/ml for cyproconazole, 0.25 and 0.14 μg/ml for metconazole, and 1.16 and 0.73 μg/ml for tebuconazole, respectively. Propiconazole was also highly active against mycelial growth of imazalil-sensitive isolates of Penicillium digitatum, the pathogen that causes green mold of citrus, with a mean EC50 value of 0.008 μg/ml for 63 isolates. Imazalil-resistant isolates of this fungus were cross-resistant to propiconazole. When G. citri-aurantii and P. digitatum were grown at selected pH values between 3 and 9, inhibition by propiconazole occurred over the entire pH range. The fungicide was most effective at pH 5 when compared with the non-fungicide-amended control grown at the same pH. In laboratory mass platings of single-spore isolates sensitive to propiconazole onto selective media, isolates with an up to 81.6-fold decrease in sensitivity to the fungicide were recovered for P. digitatum. For G. geotrichum, isolates with an approximately twofold decrease in sensitivity were obtained. No isolates with reduced sensitivity were recovered for G. citri-aurantii. Propiconazole is currently being registered for postharvest use on citrus and other crops, and the information provided will be valuable in monitoring of fungicide resistance and in designing effective fungicide application strategies.

Evaluate the Effect of pH on the Mixed Brine and Chemical Solutions

2016 ◽  
Author(s):  
Cody Chancellor ◽  
Connor Kirby ◽  
Mahmoud Elsharafi
Keyword(s):  
Calcium Ions ◽  
Oil Well ◽  
Superabsorbent Polymer ◽  
Time Intervals ◽  
Ph Values ◽  
Blocking High ◽  
Polymer Volume ◽  
Chemical Solutions ◽  
Ph Range ◽  
Kinetics Of

The purpose of this study is to observe the effects of a superabsorbent polymer (SAP) when it is introduced to brine solutions containing Calcium ions at varying pH values. When injected into an oil well, a superabsorbent polymer will swell, blocking high permeability zones. The swelled polymer will decrease reservoir heterogeneity, diverting injected water to oil rich zones/areas of the formation. Understanding the kinetics of an SAP is crucial to its proper employment. However, when the polymer is introduced to brine solutions containing calcium, reactions involving the ionization of the sodium crosslinker of the polymers result in the destruction of the polymers and the formation of a precipitate. In an attempt to solve this problem, pH values of various concentrations of Calcium Chloride and Sodium Chloride in deionized water solutions will be varied and introduced to polymer samples to determine if lowering the pH can prevent precipitation. The procedure includes first introducing hydrochloric acid to brine mixtures, mixing and agitating the polymer with the brine solution, and lastly recording the results. The measurements to be recorded will include the volume of the polymers before, during, and after the swelling process. From this data, the swelling ratios of the polymer samples will be calculated, graphed, and contrasted appropriately according to time intervals and the pH of each sample. By following this procedure, the data shows that a very low pH can significantly inhibit the extent to which the polymer precipitates out with Calcium ions. Temperature tends to decrease polymer volume in brines with pH values above the 1–2 pH range, while pH values in or below said range increase in volume substantially.

Rational design of porous binary Pt-based nanodendrites as efficient catalysts for direct glucose fuel cells over a wide pH range

2017 ◽  
Vol 7 (13) ◽  
pp. 2819-2827 ◽  
Author(s):  
Kamel Eid ◽  
Yahia H. Ahmad ◽  
Siham Y. AlQaradawi ◽  
Nageh K. Allam
Keyword(s):  
Catalytic Activity ◽  
Oxidation Reaction ◽  
Rational Design ◽  
Glucose Oxidation ◽  
Room Temperature ◽  
Ph Values ◽  
Wide Ph Range ◽  
One Step ◽  
Ph Range ◽  
Glucose Oxidation Reaction

Porous binary PtPd, AuPt, PtCu, and PtNi nanodendrites prepared by a facile one-step reduction under ultrasonic irradiation at room temperature, exhibited a substantial catalytic activity towards glucose oxidation reaction at different pH values relative to a commercial Pt/C catalyst.

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