scholarly journals Polymeric Membrane for Verteporfirin Purification

2017 ◽  
Vol 54 (1) ◽  
pp. 14-17 ◽  
Author(s):  
Stefania Simionescu ◽  
Sofia Teodorescu ◽  
Rodica Mariana Ion ◽  
Elena Voicila ◽  
Gheorghe Nechifor
Keyword(s):  
Active Substance ◽  
Polymeric Membrane ◽  
Basic Form ◽  
Polysulfone Membrane ◽  
Analytical Results ◽  
Before And After ◽  
Ophthalmic Diseases ◽  
Tumor Types ◽  
Polymer Type

Verteporfirin is the active substance of the medicine Visudyne (the basic form porphyrin of the medicine) approved and in use for ophthalmic diseases and tumor types. Because the informations from literature about degraded of this porphyrins are greatly reduced, we propose in this paper to separate the different degraded forms of this porphyrin by using polysulfone membrane polymer type. In this paper are presented some analytical results of verteporfirin before and after passing degraded form of the porphyrins over these membranes.

P0542EVALUATION OF BLOOD CELL ADHESION AND SOLUTE REMOVAL PERFORMANCE BY AN EX VIVO EXPERIMENT OF A POLYSULFONE HEMOFILTER USING AN NV POLYMER MEMBRANE FOR CONTINUOUS RENAL REPLACEMENT THERAPY

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Yoshitaka Kurihara ◽  
Shunichi Ueki ◽  
Kozue Kobayashi ◽  
Kokubo Kenichi ◽  
Hirosuke Kobayashi ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Pressure Drop ◽  
Blood Cell ◽  
Ex Vivo ◽  
Polysulfone Membrane ◽  
Molecular Weights ◽  
Performance Change ◽  
Molecular Weight Cutoff ◽  
Blood Clots ◽  
Before And After

Abstract Background and Aims Since hemofilters used for continuous renal replacement therapy (CRRT) come in prolonged contact with blood during treatment, clotting and cell adhesion induced by contact of blood with the membrane often occur, increasing the risk to the patient and burden on the staff. Suppressed platelet adhesion and better biocompatibility have been reported with the use of a dialysis membrane whose surface has been modified with an NV polymer in patients on maintenance hemodialysis. Therefore, it may be advantageous to use the NV membrane as a hemofilter for CRRT. In the present study, we evaluated the solute removal performance change and blood cell adhesion on the NV membrane after it comes in contact with blood, to clarify the characteristics of the NV membrane for long-time use. Methods A new polysulfone membrane containing the NV polymer (SNV) and a conventional polysulfone membrane (SHG) were used for the ex vivo blood filtration experiment. To compare the solute removal performance change and blood cell adhesion after blood comes in contact with the membranes, porcine blood collected from a single animal was divided into two portions, and a 24-hour of continuous hemofiltration (CHF) experiment was performed. The circulation conditions were as follows; blood flow rate, 100 mL/min; filtrate flow rate, 20 mL/min; heparin dose adjusted as appropriate to maintain the activated clotting time from 300 to 400 sec during the experiment. We evaluated the time-courses of the transmembrane pressure (TMP) and pressure drop at the hemofilter and the change in the sieving coefficients of dextran of different molecular weights (molecular weight cutoff curve) before and after the experiment, and blood cell adhesion. The amount of blood cell adhesion was evaluated based on the hemoglobin content and lactate dehydrogenase (LDH) activity in the eluate from the residual blood clots on the hemofilter 24 hours after the CHF experiment. Results The changes in the TMP and the pressure drop were significantly lower with the use of SNV as compared to SHG (n = 9, p < 0.01). From the molecular weight cutoff curves before and after the experiment, the molecular weights when the sieving coefficient was 0.1 to 0.4, which reflect the pore size of the pores through which relatively small molecules can pass, decreased to a lower extent after blood contact with SNV as compared to SHG (n = 3, SC = 0.1-0.3, p < 0.05; SC = 0.4, p < 0.01).The hemoglobin content and LDH activity in the blood clots adhering to the membrane after the experiment were significantly lower in SNV as compared to SHG (n = 9; Hb, p < 0.01; LDH, p < 0.05), indicating that blood cell adhesion on SNV was less pronounced than that on SHG. Conclusion SNV suppressed the increase in the TMP and also the pressure drop, allowed a high rate of solute removal performance to be maintained, and suppresses blood cell adhesion to a greater extent as compared to the conventional polysulfone membrane.

The Role of Dialysis Membranes on Intradialytic Selenium Removal and on Selenium Status in Patients Receiving Renal Replacement Therapy

2015 ◽  
Vol 41 (1-3) ◽  
pp. 94-99 ◽  
Author(s):  
Macroui Sonikian ◽  
Artemisia Dona ◽  
Jacob Skarakis ◽  
Sophia Trompouki ◽  
Theodora Miha ◽  
...  
Keyword(s):  
Control Group ◽  
Separate Analysis ◽  
Dialysis Session ◽  
Polysulfone Membrane ◽  
Ethylene Vinyl Alcohol ◽  
Before And After ◽  
Selenium Removal ◽  
Group A ◽  
Patient Groups ◽  
Group B

Background/Aims: Dialysis membrane has been implicated in selenium (Se) deficiency in hemodialysis (HD). Intradialytic Se removal into dialysate through different membranes was investigated. Methods: We studied 19 patients on standard HD with low-flux polysulfone membrane (group A), 10 patients on standard HD with ethylene vinyl alcohol membrane (group B), 12 patients on hemodiafiltration (HDF; group C) and 16 healthy subjects (control group D). Se was measured in blood before and after dialysis session and in effluent dialysate every hour during session. Results: In all patients together, pre-dialysis serum Se levels were lower than those in control group, but, in a separate analysis, only in standard HD. In all patient groups, there was a net Se removal into dialysate but it was greater in HDF patients who, however, had similar pre-dialysis serum Se levels to those in healthy controls. Conclusion: An intradialytic Se loss was found with all 3 membrane types, but it is not the principal factor for Se depletion in HD.

scholarly journals The Determination of Menthol in Tobacco, in Filters and in the Smoke of Mentholated Cigarettes/Untersuchungen über die Verteilung des Menthols auf Tabak, Filter und Rauch von Mentholcigaretten

1972 ◽  
Vol 6 (3) ◽  
Author(s):  
M. Brozinski ◽  
U. Dölberg ◽  
G. Lipp
Keyword(s):  
Gas Chromatography ◽  
Cellulose Acetate ◽  
Steam Distillation ◽  
Internal Standard ◽  
Polypropylene Glycol ◽  
Analytical Results ◽  
Before And After ◽  
Selective Retention ◽  
Different Origin

AbstractA method for the determination of menthol in tobacco, in filters before and after smoking as well as in the smoke of mentholated cigarettes is presented which is based on the combination of steam distillation and liquid-Iiquid partition followed by gas chromatography on polypropylene glycol in the presence of benzylpropionate as an internal standard. The procedure also permits menthone to be quantitatively determined as a characteristic constituent of peppermint oils. Analytical results concerning reproducibility, recovery and sensitivity of the method are detailed. The transfer of menthol from the tobacco rod to the acetate filter and vice versa as a function of the storing period of mentholated cigarettes has been investigated as well as the menthol distribution due to the smoking process. A considerable selective retention of menthol by cellulose acetate filters could be demonstrated. Various mentholated cigarettes of different origin and of different menthol contents have comparatively been analysed.

scholarly journals Adenovirus Receptor Expression in Cancer and Its Multifaceted Role in Oncolytic Adenovirus Therapy

2020 ◽  
Vol 21 (18) ◽  
pp. 6828
Author(s):  
Lobke C.M. Hensen ◽  
Rob C. Hoeben ◽  
Selas T.F. Bots
Keyword(s):  
Tumor Cells ◽  
Human Adenovirus ◽  
Adenovirus Type ◽  
Oncolytic Adenovirus ◽  
Receptor Expression ◽  
Future Directions ◽  
Viral Spread ◽  
Before And After ◽  
Tumor Types ◽  
Adenovirus Receptor

Oncolytic adenovirus therapy is believed to be a promising way to treat cancer patients. To be able to target tumor cells with an oncolytic adenovirus, expression of the adenovirus receptor on the tumor cell is essential. Different adenovirus types bind to different receptors on the cell, of which the expression can vary between tumor types. Pre-existing neutralizing immunity to human adenovirus species C type 5 (HAdV-C5) has hampered its therapeutic efficacy in clinical trials, hence several adenoviral vectors from different species are currently being developed as a means to evade pre-existing immunity. Therefore, knowledge on the expression of appropriate adenovirus receptors on tumor cells is important. This could aid in determining which tumor types would benefit most from treatment with a certain oncolytic adenovirus type. This review provides an overview of the known receptors for human adenoviruses and how their expression on tumor cells might be differentially regulated compared to healthy tissue, before and after standardized anticancer treatments. Mechanisms behind the up- or downregulation of adenovirus receptor expression are discussed, which could be used to find new targets for combination therapy to enhance the efficacy of oncolytic adenovirus therapy. Additionally, the utility of the adenovirus receptors in oncolytic virotherapy is examined, including their role in viral spread, which might even surpass their function as primary entry receptors. Finally, future directions are offered regarding the selection of adenovirus types to be used in oncolytic adenovirus therapy in the fight against cancer.

Emotional states before and after impulsivity

2009 ◽  
Vol 37 (6) ◽  
pp. 819-824 ◽  
Author(s):  
Shang-Ping Lin ◽  
Hui-Chuan Shih ◽  
Yu-Chen Huang
Keyword(s):  
Experimental Method ◽  
Past Research ◽  
Future Research ◽  
Emotional States ◽  
Research Directions ◽  
Analytical Results ◽  
Before And After ◽  
Future Research Directions ◽  
Paper And Pencil

Past research has demonstrated that people often feel regret and guilt after being impulsive. However, using a paper-and-pencil experimental method, the authors found people to become impulsive more easily when they feel careless, and less impulsive when feeling joy or anxiety. Post-affects of impulsivity include joy, satisfaction, and – surprisingly – lack of regret and lack of guilt. This has significant implications both theoretically and practically. Analytical results are discussed and future research directions are then suggested.

A pharmacologically active substance in mammalian tissue extracts

1963 ◽  
Vol 157 (969) ◽  
pp. 492-506 ◽  
Keyword(s):  
Guinea Pig ◽  
Active Substance ◽  
Gel Filtration ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Uridine Diphosphate ◽  
Uridine Nucleotide ◽  
Goldfish Intestine ◽  
Before And After ◽  
Pharmacologically Active

Isolated goldfish intestine may be used to detect and measure very small amounts of the pharmacologically active polypeptide known as substance P in a purified extract of mam­malian brain or intestine. However, when this test was applied to crude extracts of guinea-pig tissues, the estimate was more than 1000 times too high. The substance responsible for this effect was purified by gel filtration and anion exchange chromatography. Spectral data on the purified material, before and after hydrolysis, coupled with the appearance of a pentose sugar and uracil as products of hydrolysis, suggested that a uridine nucleotide was present. Uridine diphosphate and uridine triphosphate were both active in this test. Purified extracts were compared with authentic samples of these two nucleotides by bioassay and by optical density measurements. The active substance in liver extract was identified as uridine diphosphate since the two results agreed quantitatively when this substance was used as a standard. The effective dose is about 1 ng, which is the amount present in less than 5 μ g of guinea-pig fiver. Goldfish intestine may thus be used to estimate small amounts of either substance P or uridine diphosphate, but, if both are present, steps must be taken to separate them.

Investigation of Traffic and Evacuation Aspects at Kumamoto Earthquake and the Future Issues

2017 ◽  
Vol 12 (2) ◽  
pp. 272-286 ◽  
Author(s):  
Yosuke Kawasaki ◽  
◽  
Masao Kuwahara ◽  
Yusuke Hara ◽  
Takuma Mitani ◽  
...  
Keyword(s):  
Urban Traffic ◽  
Travel Times ◽  
End Points ◽  
Kumamoto Earthquake ◽  
Traffic Conditions ◽  
Analytical Results ◽  
Public Baths ◽  
The Future ◽  
Before And After

This study reports the results of the analysis of probe data, collected in the periods immediately before and after the foreshock in Kumamoto on April 14, 2016. Data were gathered under actual urban traffic conditions, and the traffic activity evaluated. The study also identifies any issues to be addressed in future, based on this analysis. The analytical results quantitatively show that movement from Fukuoka to central Kumamoto was impacted by closure of the Kyushu Expressway; it also shows that travel times during the day along alternative paths significantly increased, whilst congestion on highways decreased. The results show that locations such as shelters, supermarkets, and public baths were the beginning and end points of travel, thereby causing deviations from normal congestion patterns.

scholarly journals Performance of PS/PIMA/PPEES Nanofiltration Membranes before and after Alkali Treatment for Filtration of CaCl2 and NaCl

Nano Hybrids ◽  
2012 ◽  
Vol 1 ◽  
pp. 99-118 ◽  
Author(s):  
Chitrakara Hegde ◽  
Arun Mohan Isloor ◽  
B.M. Ganesh ◽  
Ahmad Fauzi Ismail ◽  
M.S. Abdullah ◽  
...  
Keyword(s):  
Membrane Filtration ◽  
Sodium Hydroxide Solution ◽  
Alkali Treatment ◽  
Composite Membranes ◽  
Size Exclusion ◽  
Polymeric Membrane ◽  
Performance Study ◽  
Before And After ◽  
Exclusion Mechanism ◽  
Contact Angle Analysis

Present article describes about the preparation of Nanofiltration (NF) composite membranes by a simple chemical treatment to the polymeric membrane composed of Poly (isobutylene-alt-maleic anhydride). After composition, anhydride functionality was converted to diacid functionality by hydrolysis using sodium hydroxide solution. Further, membrane was characterized by ATR-IR, DSC and SEM. Charge confirmation was done by IEC. Water uptake and contact angle analysis was carried out to study the hydrophilicity of the membrane. The performance study was carried out by using NaCl and CaCl2 solutions. Membranes were having higher charge density, which has resulted in better performance in terms of rejection of CaCl2 and NaCl solutions. The main focus of this research is to evaluate the effect of alkali treatment on Donnan and size exclusion mechanism during membrane filtration.

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