scholarly journals An in vitro method for the determination of protein turnover in incubated proximal tubule segments

1993 ◽  
Vol 43 (5) ◽  
pp. 1156-1159 ◽  
Author(s):  
Robert May ◽  
Brian Logue ◽  
Byrad Edwards ◽  
Swati Patel
2009 ◽  
Vol 366 (1-2) ◽  
pp. 111-116 ◽  
Author(s):  
Simon Gaisford ◽  
Anthony E. Beezer ◽  
Alistair H. Bishop ◽  
Michael Walker ◽  
David Parsons

Author(s):  
D. I. Zybin ◽  
A. S. Seregin ◽  
A. D. Askretkov ◽  
N. V. Orlova ◽  
Yu. A. Seregin ◽  
...  

Objectives. Developing reliable and accurate analytical methods is necessary for comparative pharmaceutical analysis using physicochemical, biological (in vitro), preclinical, and clinical trials. The main objective of this study was to develop and validate an in vitro method for determining the specific activity of the recombinant monoclonal antibody eculizumab.Methods. The method of indirect enzyme immunoassay was used in the study.Results. A method for determining the specific activity of the humanized recombinant monoclonal antibody eculizumab was described and validated for the first time. A comparative evaluation of the specific activity of Soliris® (Alexion Pharmaceuticals Inc., USA), and its biosimilar PRK-001 (Pharmapark, Russia) was performed using the developed method.Conclusions. The similarity of PRK-001 and the original Soliris® in relation to their specific activity, that is, binding to the human complement system C5 protein, was proved. 


2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
Yalda Mirzaei ◽  
Kerstin Hagemeister ◽  
Martina Hüffel ◽  
Timo Schwandt ◽  
René H. Tolba ◽  
...  

Background. Tissue glues can minimize treatment invasiveness, mitigate the risk of infection, and reduce surgery time; ergo, they have been developed and used in surgical procedures as wound closure devices beside sutures, staples, and metallic grafts. Regardless of their structure or function, tissue glues should show an acceptable microbial barrier function before being used in humans. This study proposes a novel in vitro method using Escherichia coli Lux and bioluminescence imaging technique to assess the microbial barrier function of tissue glues. Different volumes and concentrations of E. coli Lux were applied to precured or cured polyurethane-based tissue glue placed on agar plates. Plates were cultured for 1 h, 24 h, 48 h, and 72 h with bioluminescence signal measurement subsequently. Herein, protocol established a volume of 5 μL of a 1 : 100 dilution of E. coli Lux containing around 2 × 10 7  CFU/mL as optimal for testing polyurethane-based tissue glue. Measurement of OD600nm, determination of CFU/mL, and correlation with the bioluminescence measurement in p/s unit resulted in a good correlation between CFU/mL and p/s and demonstrated good reproducibility of our method. In addition, this in vitro method could show that the tested polyurethane-based tissue glue can provide a reasonable barrier against the microbial penetration and act as a bacterial barrier for up to 48 h with no penetration and up to 72 h with a low level of penetration through the material. Overall, we have established a novel, sensitive, and reproducible in vitro method using the bioluminescence imaging technique for testing the microbial barrier function of new tissue glues.


1960 ◽  
Vol 105 (3) ◽  
pp. 595-598 ◽  
Author(s):  
S. L. Steelman ◽  
R. Oslapas ◽  
R. D. Busch

1998 ◽  
Vol 128 (3) ◽  
pp. 651-660 ◽  
Author(s):  
Anna K. E. Åkerberg ◽  
Helena G. M. Liljeberg ◽  
Yvonne E. Granfeldt ◽  
Anders W. Drews ◽  
Inger M. E. Björck

2008 ◽  
Vol 71 (6) ◽  
pp. 1117-1118 ◽  
Author(s):  
Benjamin Choquenet ◽  
Céline Couteau ◽  
Eva Paparis ◽  
Laurence J. M. Coiffard

1956 ◽  
Vol 72 (5) ◽  
pp. 720-720 ◽  
Author(s):  
Z. Zolli ◽  
M. J. Gallian ◽  
G. S. Shea ◽  
K. E. Price

1991 ◽  
Vol 260 (1) ◽  
pp. F19-F26 ◽  
Author(s):  
M. C. Chobanian ◽  
C. M. Julin

To determine whether angiotensin II (ANG II) affects ammoniagenesis in renal proximal tubule, ammonia production was measured in suspensions of canine renal proximal tubule segments (PCT) incubated with L-glutamine and varying concentrations of ANG II. Ammonia production from PCT was significantly increased by 15.5 +/- 1.1% in the presence of ANG II (10(-6) M) at 2 h. Similarly, glucose production significantly increased by 10.0 +/- 0.9%. Half-maximal stimulation occurred at approximately 10(-9) M ANG II. Stimulation of ammonia production by ANG II was blocked in the presence of the ANG II antagonist, [Sar1-Ile8]ANG II (10(-6) M). Enhancement of ammonia production in PCT by ANG II occurred in acidotic and neutral media but not in alkalotic medium. When extracellular [Na+] = intracellular [Na+] ANG II significantly increased ammonia production in PCT. Absence of extracellular Ca2+ or addition of trifluoperazine or N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide (W-7) (Ca2(+)-calmodulin-dependent pathway inhibitors) blocked the action of ANG II to enhance ammonia production. We conclude that ANG II stimulates ammonia and glucose production in canine renal PCT via a receptor-mediated signal. The action of ANG II on ammoniagenesis may be mediated by a calcium-calmodulin-dependent pathway. Stimulation of ammoniagenesis in vitro under normal and acidotic conditions may reflect a role in vivo for ANG II in the regulation of renal acid-base metabolism.


2010 ◽  
Vol 299 (6) ◽  
pp. F1339-F1347 ◽  
Author(s):  
Karo Tanaka ◽  
Sara Terryn ◽  
Lars Geffers ◽  
Serge Garbay ◽  
Marco Pontoglio ◽  
...  

The Cl−/H+ exchanger ClC-5 is essential for the endocytic activity of the proximal tubule cells and the tubular clearance of proteins filtered in the glomeruli. The mechanisms that regulate the expression of ClC-5 in general and its specific expression in the proximal tubule are unknown. In this study, we investigated the hypothesis that the hepatocyte nuclear transcription factor HNF1α, which is predominantly expressed in proximal tubule segments, may directly regulate the expression of ClC-5. In situ hybridization demonstrated that the expression of Clcn5 overlaps with that of Hnf1α in the developing kidney as well as in absorptive epithelia, including the digestive tract and yolk sac. Multiple binding sites for HNF1 were mapped in the 5′-regulatory sequences of the mouse and human Clcn5/CLCN5 genes. The transactivation of the Clcn5/CLCN5 promoter by HNF1α was verified in vitro, and the binding of HNF1α to the Clcn5 promoter in vivo was confirmed by chromatin immunoprecipitation in mouse kidney. The expression of Clcn5 was reduced in the proximal tubule segments of HNF1α-null kidneys, and it was rescued upon transfection of HNF1α-null cells with wild-type but not with mutant HNF1α. These data demonstrate that HNF1α directly regulates the expression of ClC-5 in the renal proximal tubule and yield insights into the mechanisms governing epithelial differentiation and specialized transport activities in the kidney.


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