Extracellular ATP regulates transcervical permeability by modulating two distinct paracellular pathways

1997 ◽  
Vol 272 (5) ◽  
pp. C1602-C1610 ◽  
Author(s):  
G. I. Gorodeski ◽  
J. Goldfarb
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Extracellular Atp ◽  
Acetoxymethyl Ester ◽  
Experimental Conditions ◽  
Mucus Production ◽  
Atp Regulation ◽  
Junctional Resistance ◽  
Kinetics Of

Extracellular ATP stimulates a biphasic change in transepithelial electrical resistance (RTE) across cultures of human cervical epithelial cells: an acute decrease (phase I), followed by a delayed increase in resistance (phase II). The objective of this study was to determine the contributions of changes in the lateral intercellular space resistance (RLIS) and the tight junctional resistance (RTJ) to the changes in RTE. Phase I and phase II effects were uncoupled by treatment with 1,2-bis(2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid (BAPTA)-acetoxymethyl ester, which blocks the ATP-induced increases in cytosolic Ca2+ and abolishes phase I. BAPTA-loaded cells differed from control cells in that 1) phase I began when ATP was added, in contrast to a delay of 1.5-3.5 min in phase II, 2) phase I decreases in RLIS followed a simple exponential pattern, in contrast to the complex kinetics of phase II, and 3) the magnitude of phase II varied between 20 and 100% for increases of RTJ in day 2-6 cultures; the phase I decrease of 50% in RLIS was unrelated to different experimental conditions. These results indicate that phase I and phase II are induced simultaneously and independently by ATP, and they contribute to the total changes in RTE. We conclude that ATP regulation of RLIS and RTJ may be important mechanisms of modulating cervical mucus production in vivo.

Biphasic regulation of paracellular permeability in human cervical cells by two distinct nucleotide receptors

1995 ◽  
Vol 268 (5) ◽  
pp. C1215-C1226 ◽  
Author(s):  
G. I. Gorodeski ◽  
U. Hopfer ◽  
B. J. De Santis ◽  
R. L. Eckert ◽  
E. A. Rorke ◽  
...  
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Intracellular Signaling ◽  
Electrical Conductance ◽  
Cytosolic Calcium ◽  
Paracellular Permeability ◽  
Nucleotide Receptors ◽  
Mucus Production ◽  
Cervical Cells

The effects of extracellular ATP (ATPe) were characterized in human cervical cells grown on filters. ATPe changed the transepithelial conductance (GT) in a biphasic manner with an initial acute increase of 13 +/- 3% (phase I), lasting approximately 2 min, followed by a sustained decrease of 49 +/- 17% (phase II). ATPe also effected decreases of permeabilities to pyranine and to sucrose, which correspond to the phase II decrease in GT. Both phase I and II effects appear to be mediated by apical nucleotide receptors. However, the phase I effect differed from the phase II effect as follows: 1) a higher 50% effective concentration for ATPe, 22 vs. 3 microM; 2) different nucleotide specificity; 3) lack of influence of pretreatment with pertussis toxin; 4) independence from time in culture after seeding; and 5) involvement of cytosolic calcium, rather than diacylglycerol, as intracellular messenger. These differences suggest the presence of two different types of nucleotide receptors that use different intracellular signaling systems and have opposite effects on the paracellular permeability and electrical conductance. These results suggest that ATPe could regulate cervical mucus production in vivo by regulating the paracellular permeability. Depending on the specific receptors present, ATPe could either increase or decrease mucus production.

scholarly journals Phase I/II and Phase II Studies of Targeted Gene Delivery In Vivo: Intravenous Rexin-G for Chemotherapy-resistant Sarcoma and Osteosarcoma

2009 ◽  
Vol 17 (9) ◽  
pp. 1651-1657 ◽  
Author(s):  
Sant P Chawla ◽  
Victoria S Chua ◽  
Lita Fernandez ◽  
Doris Quon ◽  
Andreh Saralou ◽  
...  
Keyword(s):  
Gene Delivery ◽  
Phase I ◽  
Phase Ii ◽  
Targeted Gene Delivery ◽  
Phase Ii Studies

Effects of Ofloxacin Administration on the Reliability of Urine Glucose Testing

1996 ◽  
Vol 30 (5) ◽  
pp. 469-472
Author(s):  
Tsong-Mei Tsai ◽  
Brian F Shea ◽  
Paul F Souney ◽  
Fred G Volinsky ◽  
Joseph M Scavone ◽  
...  
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Tertiary Care ◽  
Urine Samples ◽  
Care Hospital ◽  
Open Label ◽  
Urine Glucose ◽  
Glucose Testing

OBJECTIVE: TO study the effects of ofloxacin on the reliability of urine glucose testing. DESIGN: Open-label, nonrandomized. SETTING: A university-affiliated tertiary care hospital, ambulatory clinic. PARTICIPANTS: Ten healthy volunteers (8 men and 2 women) aged 22-39 years. MAIN OUTCOME MEASURES: Phase I (in vitro) involved the addition of selected amounts of ofloxacin to a set of standard 50-mL urine samples prepared to simulate glycosuria. Phase II (in vivo) involved the oral administration of ofloxacin 400 mg to 10 subjects. Urine was collected: (1) immediately predose, (2) pooled 0–4 hours postdose, and (3) pooled 4–8 hours postdose. Known glucose concentrations were then added to these samples. Clinitest and Diastix tests were performed on all samples. The accuracy of these tests in determining glucose concentrations was compared among urine samples taken before and after ofloxacin dosing. RESULTS: None of the ofloxacin concentrations in phase I (0,25,50, 100, 200,400, and 800 μg/mL) influenced these testing methods at the urine glucose concentrations of 0.0%, 0.5%, 1%, and 2%. Likewise, the accuracy of these two tests was unaffected by ofloxacin administration in phase II. CONCLUSIONS: In single-dose administration, ofloxacin does not interfere with Clinitest or Diastix for determining urine glucose concentrations. Supported by a grant from the RW Johnson Pharmaceutical Research Institute. Presented in abstract form at the American College of Clinical Pharmacy 1994 Winter Practice and Research Forum, February 6–9, 1994, San Diego. CA.

Different mechanisms in the attachment of cells to native and denatured collagen

1979 ◽  
Vol 38 (1) ◽  
pp. 267-281
Author(s):  
S.L. Schor ◽  
J. Court
Keyword(s):  
Cell Attachment ◽  
Experimental Conditions ◽  
Cell Matrix ◽  
Matrix Interactions ◽  
Independent Mechanism ◽  
Cell Matrix Interactions ◽  
Serum Dependent ◽  
Kinetics Of ◽  
Dependent Mechanism

The attachment of cells to collagen has been reported previously to require the presence of serum and the particular serum protein involved in this process, variously known as CIG, CAP or fibronectin, has been isolated. This conclusion that cell attachment to collagen requires serum (or more precisely, fibronectin) is based on experiments measuring the kinetics of cell attachment to films of collagen. We have measured the kinetics of attachment of HeLa and attachment to films of collagen-containing substrata under a variety of experimental conditions and present evidence that the serum-dependent mechanism of cell attachment described by others is actually only the case for films of denatured collagen, while cell attachment to native collagen fibres occurs by a different, serum-independent, mechanism. The possible relevance of these findings to cell-matrix interactions in vivo is discussed.

scholarly journals Ochratoxin A-Induced Hepatotoxicity through Phase I and Phase II Reactions Regulated by AhR in Liver Cells

Toxins ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 377 ◽  
Author(s):  
Hye Soo Shin ◽  
Hyun Jung Lee ◽  
Min Cheol Pyo ◽  
Dojin Ryu ◽  
Kwang-Won Lee
Keyword(s):  
Oxidative Stress ◽  
Phase I ◽  
Ochratoxin A ◽  
Phase Ii ◽  
Glutathione Depletion ◽  
Related Factor ◽  
Aryl Hydrocarbon ◽  
Similar Mode ◽  
Phase I And Ii

Ochratoxin A (OTA) is a widespread mycotoxin produced by several species of the genera Aspergillus and Penicillium. OTA exists in a variety of foods, including rice, oats, and coffee and is hepatotoxic, with a similar mode of action as aflatoxin B1. The precise mechanism of cytotoxicity is not yet known, but oxidative damage is suspected to contribute to its cytotoxic effects. In this study, human hepatocyte HepG2 cells were treated with various concentrations of OTA (5–500 nM) for 48 h. OTA triggered oxidative stress as demonstrated by glutathione depletion and increased reactive oxygen species, malondialdehyde level, and nitric oxide production. Apoptosis was observed with 500 nM OTA treatment. OTA increased both the mRNA and protein expression of phase I and II enzymes. The same results were observed in an in vivo study using ICR mice. Furthermore, the relationship between phase I and II enzymes was demonstrated by the knockdown of the aryl hydrocarbon receptor (AhR) and NF-E2-related factor 2 (Nrf2) with siRNA. Taken together, our results show that OTA induces oxidative stress through the phase I reaction regulated by AhR and induces apoptosis, and that the phase II reaction is activated by Nrf2 in the presence of oxidative stress.

Predictions of the In Vivo Clearance of Drugs from Rate of Loss Using Human Liver Microsomes for Phase I and Phase II Biotransformations

2006 ◽  
Vol 23 (4) ◽  
pp. 654-662 ◽  
Author(s):  
Michael A. Mohutsky ◽  
Jenny Y. Chien ◽  
Barbara J. Ring ◽  
Steven A. Wrighton
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Human Liver ◽  
Liver Microsomes ◽  
Human Liver Microsomes

Gas Chromatographic Determination of Poly chlorinated Biphenyls (as Aroclor 1254) in Serum: Collaborative Study

1989 ◽  
Vol 72 (4) ◽  
pp. 649-659
Author(s):  
Virlyn W Burse ◽  
Margaret P Korver ◽  
Larry L Needham ◽  
Chester R Lapeza ◽  
Elizabeth L Chester R ◽  
...  
Keyword(s):  
Phase I ◽  
Silica Gel ◽  
Phase Ii ◽  
Collaborative Study ◽  
Chlorinated Hydrocarbons ◽  
Aroclor 1254 ◽  
Relative Standard

Abstract A gas chromatographic-electron capture detection method for determining the concentration of polychlorinated biphenyls (PCBs) as Aroclor 1254 (AR 1254) in serum was evaluated through a 2-phase collaborative study. In Phase I, each collaborator's lot of Woelm silica gel (70-150 mesh) was evaluated for elution and recovery of AR 1254, which had been added in vitro at 25 ng/mL to a serum extract. In Phase II, each collaborator analyzed a series of bovine serum samples that contained the following: (1) in vitro-spiked AR 1254; (2) in vivo AR 1254 and 8 in vitro-spiked chlorinated hydrocarbons; (3) in vivo AR 1254 only; (4) 8 in vitro-spiked chlorinated hydrocarbons only; and (5) neither AR 1254 nor chlorinated hydrocarbons above the detection limit of the method. In Phase I, the average recovery of AR 1254 from silica gel for the 6 collaborators was 87.9 ± 15.44% (mean ± 1 SD; N = 18; range = 52.3-105.8%). In Phase II, the analysis of in vitro spikes of AR 1254 in serum at 8.58,16.8, 41.8, and 84.3 ppb gave mean (X) interlaboratory recoveries of 89.0, 83.3, 79.4, and 76.9%, respectively, with within-laboratory (repeatability) relative standard deviations (RSDr) of 18.8, 20.5, 10.2, and 14.1%, respectively, and among-laboratory (reproducibility) relative standard deviations (RSDR) of 21.5, 21.1, 14.6, and 20.8%, respectively. The determination of in vivo AR 1254 in samples containing approximately 10, 25, 50, and 100 ng/mL of AR 1254 resulted in interlaboratory means of 10,22,39, and 79 ng/mL, respectively, with RSDr = 6.7,9.7,6.4, and 5.8%, respectively, and RSDR = 20.6,16.0, 10.9, and 10.3%, respectively. The precision of the method for incurred AR 1254 showed a maximum RSDr of less than 10% and a maximum RSDR of less than 21% for a concentration range of 10-100 ng/mL. The accuracy of the method as demonstrated by the mean recovery of in vitro-spiked AR 1254 over a concentration range of 8.58-84.3 ng/mL was 82.2%. The method has been approved interim official first action.

Novel organic arsenic molecule darinaparsin: Development of IV and oral forms

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 8501-8501 ◽  
Author(s):  
I. Lossos ◽  
M. D. Craig ◽  
M. S. Tallman ◽  
R. V. Boccia ◽  
P. R. Conkling ◽  
...  
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Phase Ii Study ◽  
Complete Response ◽  
Median Number ◽  
Two Phase ◽  
Phase I Studies ◽  
Advanced Malignancies

8501 Background: Darinaparsin (ZIO-101) is a novel organic arsenical active against diverse cancers in vitro, and in vivo. Darinaparsin i.v. activity in lymphoma is being evaluated in a phase II study. Darinaparsin is orally bioavailable; the oral form is being investigated in two phase I studies in patients with advanced malignancies. Methods: Phase II trial is being conducted in patients diagnosed with advanced lymphomas who had ≥ 1 prior therapy. Patients receive 300 mg/m2/day of darinaparsin i.v. for 5 consecutive days every 28 days. Efficacy and safety are evaluated by standard criteria. Phase I oral dose escalation studies are being conducted in patients with advanced malignancies and explore safety, MTD, DLTs and preliminary efficacy of continuous and intermittent dosing schedules. Starting continuous dose is 100 mg BID for 3 weeks with 1 week rest, starting intermittent dose is 300 mg twice weekly for 3 weeks followed by 1 week rest. Results: The phase II study has accrued 28 lymphoma patients (21 non-Hodgkin's, 7 Hodgkin's); median age at baseline 61 years, ECOG ≤2, median number of prior therapies 3. Seventeen subjects have received at least 2 cycles of darinaparsin and are evaluable for efficacy. Of these, 1 subject (PTCL) has achieved a complete response, 3 - partial responses (2 marginal zone, 1 Hodgkin's), and 4 stable disease (2 PTCL, 1 DLBCL, 1 Hodgkin's). A total of 63 cycles of darinaparsin have been administered to subjects with lymphoma. No Gr. 3 or higher drug-related AEs were reported. Two SAEs were considered possibly drug-related (fall; neutropenic fever). Phase I studies accrued 35 patients; median age at baseline 58 years, ECOG ≤2, median number of prior therapies 3. Predominant tumor types include: colorectal (17), pancreatic (3), NHL (3). Current darinaparsin dose levels: continuous 200 mg BID, 2× weekly 900 mg. Of 18 patients evaluable for efficacy, 10 demonstrate SD ≥ 3 cycles. Oral darinaparsin bioavailability is 58%. Drug-related AEs include nausea/vomiting, fatigue, decreased appetite/anorexia. Conclusions: Darinaparsin is active in heavily pretreated patients with advanced lymphoma and has been very well tolerated. Oral darinaparsin is also well tolerated, and shows early activity. [Table: see text]

Updated phase I results of a phase I/II trial of BNC105P with everolimus in patients with metastatic renal cell carcinoma (mRCC).

2013 ◽  
Vol 31 (6_suppl) ◽  
pp. 397-397
Author(s):  
Thomas E. Hutson ◽  
Long H. Dang ◽  
Richard C. Lauer ◽  
Alexander Starodub ◽  
Ralph J. Hauke ◽  
...  
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Cellular Response ◽  
Kinase Inhibitors ◽  
Single Agent ◽  
Sequential Approach ◽  
Randomized Phase Ii ◽  
Disease Stabilization ◽  
Grade 3

397 Background: BNC105P is an inhibitor of tubulin polymerization. In vivo exposure to BNC105P leads to selective damage of tumor vasculature in both primary and metastatic lesions, causing disruption of blood flow to tumors, hypoxia and associated tumor necrosis. BNC105P also has a direct anti-proliferative action on cancer cells. Up regulation of the mTOR pathway has been identified as a cellular response to hypoxic stress. The combined use of BNC105P with an agent active against mTOR may improve clinical outcome in patients with progressive mRCC who are refractory to VEGFR-directed tyrosine kinase inhibitors (TKI). Methods: A phase I/II study in mRCC patients who have received 1-2 prior TKIs was undertaken. The phase I component enrolled 12 subjects at 4 dose levels of BNC105P (4.2, 8.4, 12.6, 16 mg/m2; IV infusion Days 1 and 8, 21-day repeating cycle). Everolimus was administered concurrently (10 mg p.o.). PK analysis was performed during cycle 1. Results: Updated results from the completed phase I component confirm the BNC105P/everolimus combination was well tolerated. No DLTs (drug-related, during cycle 1) were observed in any of the phase I subjects. Toxicities on study deemed to be drug-related (either single agent or combination) included single grade 3 events of anemia and pericardial effusion. Grade 2 events (more than 1 occurrence) of fatigue, anemia, and oral mucositis were also observed. 8 of the 12 phase I subjects achieved disease stabilization (7 of these subjects had a minimum time on therapy of 18 weeks, 6 cycles). Across all subjects a median of 6 cycles (range: 1-21) was administered, with removal from study predominantly due to disease progression. PK analysis confirmed no drug-drug interaction. The randomized phase II component of the study continues and will compare everolimus given concomitantly with BNC105P to a sequential approach (everolimus followed by BNC105P). Conclusions: BNC105P (16 mg/m2) can be combined with full dose everolimus and is being evaluated in a randomized phase II study. Clinical trial information: NCT01034631.

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