1
|
Quintana JF, Field MC. Evolution, function and roles in drug sensitivity of trypanosome aquaglyceroporins. Parasitology 2021; 148:1137-1142. [PMID: 33602349 PMCID: PMC8311954 DOI: 10.1017/s0031182021000354] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/10/2021] [Accepted: 02/15/2021] [Indexed: 12/13/2022]
Abstract
Aquaglyceroporins (AQPs) are membrane proteins that function in osmoregulation and the uptake of low molecular weight solutes, in particular glycerol and urea. The AQP family is highly conserved, with two major subfamilies having arisen very early in prokaryote evolution and retained by eukaryotes. A complex evolutionary history indicates multiple lineage-specific expansions, losses and not uncommonly a complete loss. Consequently, the AQP family is highly evolvable and has been associated with significant events in life on Earth. In the African trypanosomes, a role for the AQP2 paralogue, in sensitivity to two chemotherapeutic agents, pentamidine and melarsoprol, is well established, albeit with the mechanisms for cell entry and resistance unclear until very recently. Here, we discuss AQP evolution, structure and mechanisms by which AQPs impact drug sensitivity, suggesting that AQP2 stability is highly sensitive to mutation while serving as the major uptake pathway for pentamidine.
Collapse
Affiliation(s)
- Juan F. Quintana
- Wellcome Centre for Integrative Parasitology (WCIP), Institute of Biodiversity, Animal Health and Comparative Medicine (IBAHCM), University of Glasgow, GlasgowG61 1QH, UK
| | - Mark C. Field
- School of Life Sciences, University of Dundee, DundeeDD1 5EH, UK
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 37005Ceske Budejovice, Czech Republic
| |
Collapse
|
2
|
Thuita JK, Wolf KK, Murilla GA, Bridges AS, Boykin DW, Mutuku JN, Liu Q, Jones SK, Gem CO, Ching S, Tidwell RR, Wang MZ, Paine MF, Brun R. Chemotherapy of second stage human African trypanosomiasis: comparison between the parenteral diamidine DB829 and its oral prodrug DB868 in vervet monkeys. PLoS Negl Trop Dis 2015; 9:e0003409. [PMID: 25654243 PMCID: PMC4318582 DOI: 10.1371/journal.pntd.0003409] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 11/12/2014] [Indexed: 11/18/2022] Open
Abstract
Human African trypanosomiasis (HAT, sleeping sickness) ranks among the most neglected tropical diseases based on limited availability of drugs that are safe and efficacious, particularly against the second stage (central nervous system [CNS]) of infection. In response to this largely unmet need for new treatments, the Consortium for Parasitic Drug Development developed novel parenteral diamidines and corresponding oral prodrugs that have shown cure of a murine model of second stage HAT. As a rationale for selection of one of these compounds for further development, the pharmacokinetics and efficacy of intramuscular (IM) active diamidine 2,5-bis(5-amidino-2-pyridyl)furan (DB829; CPD-0802) and oral prodrug2,5-bis[5-(N-methoxyamidino)-2-pyridyl]furan (DB868) were compared in the vervet monkey model of second stage HAT. Treatment was initiated 28 days post-infection of monkeys with T. b. rhodesiense KETRI 2537. Results showed that IM DB829 at 5 mg/kg/day for 5 consecutive days, 5 mg/kg/day every other day for 5 doses, or 2.5 mg/kg/day for 5 consecutive days cured all monkeys (5/5). Oral DB868 was less successful, with no cures (0/2) at 3 mg/kg/day for 10 days and cure rates of 1/4 at 10 mg/kg/day for 10 days and 20 mg/kg/day for 10 days; in total, only 2/10 monkeys were cured with DB868 dose regimens. The geometric mean plasma Cmax of IM DB829 at 5 mg/kg following the last of 5 doses was 25-fold greater than that after 10 daily oral doses of DB868 at 20 mg/kg. These data suggest that the active diamidine DB829, administered IM, should be considered for further development as a potential new treatment for second stage HAT. Treatment of human African trypanosomiasis (HAT, sleeping sickness) suffers from a shortage of medicines that are both effective, especially against the second (late) stage of the disease, and safe for patients. The development of new HAT medicines also has been significantly influenced by the perceived need for easily administered oral medicines to reduce the need for hospitalization of patients in resource-poor settings where HAT typically occurs. However, the clinical status of second stage patients is likely to dictate the need for their hospitalization, thus both oral and parenterally administered medicines would be utilised effectively. Therefore, in an effort to develop new medicines that meet efficacy and safety requirements, we evaluated a novel injectable diamidine 2,5-bis(5-amidino-2-pyridyl)furan (DB829; CPD-0802) and its oral prodrug formulation 2,5-bis[5-(N-methoxyamidino)-2-pyridyl]furan (DB868) in the vervet monkey model of second stage HAT. Treatment with either compound was initiated 28 days post-infection of monkeys with T. b. rhodesiense KETRI 2537. DB829 was dosed at 5 mg/kg/day for 5 consecutive days, 5 mg/kg/day every other day for 5 doses or 2.5 mg/kg/day for 5 consecutive days intramuscularly (IM) while DB868 was administered at 20, 10 or 3 mg/kg/day for 10 consecutive days orally. Clinical and parasitological monitoring was carried out for at least 300 days before the monkeys were declared cured. All IM DB829 and oral DB868 dose regimens were well tolerated. In addition, all monkeys (5/5) treated with IM DB829 were confirmed cured. In contrast, oral DB868 cured only 1/4 monkeys at either 10 or 20 mg/kg and did not cure any monkey when dosed at 3 mg/kg. These results indicate that IM DB829 is a suitable compound for further development as treatment for second stage HAT.
Collapse
Affiliation(s)
- John K. Thuita
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute (TRC-KARI), Kikuyu, Kenya
- * E-mail: ,
| | - Kristina K. Wolf
- University of North Carolina Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Grace A. Murilla
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute (TRC-KARI), Kikuyu, Kenya
| | - Arlene S. Bridges
- Department of Pathology and Laboratory Medicine, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - David W. Boykin
- Department of Chemistry, Georgia State University, Atlanta, Georgia, United States of America
| | - James N. Mutuku
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute (TRC-KARI), Kikuyu, Kenya
| | - Qiang Liu
- University of North Carolina Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Susan K. Jones
- Department of Pathology and Laboratory Medicine, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Charles O. Gem
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute (TRC-KARI), Kikuyu, Kenya
| | - Shelley Ching
- SVC Associates, Inc., Apex, North Carolina, United States of America
| | - Richard R. Tidwell
- Department of Pathology and Laboratory Medicine, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Michael Z. Wang
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, Kansas, United States of America
| | - Mary F. Paine
- University of North Carolina Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Reto Brun
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| |
Collapse
|
3
|
WRING STEPHEN, GAUKEL ERIC, NARE BAKELA, JACOBS ROBERT, BEAUDET BETH, BOWLING TANA, MERCER LUKE, BACCHI CYRUS, YARLETT NIGEL, RANDOLPH RYAN, PARHAM ROBIN, REWERTS CINDY, PLATNER JACOB, DON ROBERT. Pharmacokinetics and pharmacodynamics utilizing unbound target tissue exposure as part of a disposition-based rationale for lead optimization of benzoxaboroles in the treatment of Stage 2 Human African Trypanosomiasis. Parasitology 2014; 141:104-18. [PMID: 24007596 PMCID: PMC3884839 DOI: 10.1017/s003118201300098x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 05/21/2013] [Accepted: 05/24/2013] [Indexed: 11/06/2022]
Abstract
SUMMARY This review presents a progression strategy for the discovery of new anti-parasitic drugs that uses in vitro susceptibility, time-kill and reversibility measures to define the therapeutically relevant exposure required in target tissues of animal infection models. The strategy is exemplified by the discovery of SCYX-7158 as a potential oral treatment for stage 2 (CNS) Human African Trypanosomiasis (HAT). A critique of current treatments for stage 2 HAT is included to provide context for the challenges of achieving target tissue disposition and the need for establishing pharmacokinetic-pharmacodynamic (PK-PD) measures early in the discovery paradigm. The strategy comprises 3 stages. Initially, compounds demonstrating promising in vitro activity and selectivity for the target organism over mammalian cells are advanced to in vitro metabolic stability, barrier permeability and tissue binding assays to establish that they will likely achieve and maintain therapeutic concentrations during in-life efficacy studies. Secondly, in vitro time-kill and reversibility kinetics are employed to correlate exposure (based on unbound concentrations) with in vitro activity, and to identify pharmacodynamic measures that would best predict efficacy. Lastly, this information is used to design dosing regimens for pivotal pharmacokinetic-pharmacodyamic studies in animal infection models.
Collapse
Affiliation(s)
- STEPHEN WRING
- SCYNEXIS Inc., Research Triangle Park, North Carolina, USA
| | - ERIC GAUKEL
- SCYNEXIS Inc., Research Triangle Park, North Carolina, USA
| | - BAKELA NARE
- SCYNEXIS Inc., Research Triangle Park, North Carolina, USA
| | - ROBERT JACOBS
- SCYNEXIS Inc., Research Triangle Park, North Carolina, USA
| | - BETH BEAUDET
- SCYNEXIS Inc., Research Triangle Park, North Carolina, USA
| | - TANA BOWLING
- SCYNEXIS Inc., Research Triangle Park, North Carolina, USA
| | - LUKE MERCER
- SCYNEXIS Inc., Research Triangle Park, North Carolina, USA
| | - CYRUS BACCHI
- Haskins Laboratory, Pace University, New York, New York, USA
| | - NIGEL YARLETT
- Haskins Laboratory, Pace University, New York, New York, USA
| | - RYAN RANDOLPH
- SCYNEXIS Inc., Research Triangle Park, North Carolina, USA
| | - ROBIN PARHAM
- SCYNEXIS Inc., Research Triangle Park, North Carolina, USA
| | - CINDY REWERTS
- SCYNEXIS Inc., Research Triangle Park, North Carolina, USA
| | - JACOB PLATNER
- Anacor Pharmaceuticals, Inc., Palo Alto, California, USA
| | - ROBERT DON
- Drugs for Neglected Diseases Initiative, Geneva, Switzerland
| |
Collapse
|
4
|
Ajana I, Astier A, Gibaud S. Arsthinol nanosuspensions: pharmacokinetics and anti-leukaemic activity on NB4 promyelocytic leukaemia cells. J Pharm Pharmacol 2010. [DOI: 10.1211/jpp.61.10.0004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
Objectives
The organoarsenical arsthinol was used in the 1950s in the treatment of amoebiasis and yaws and was considered as ‘highly tolerated’. The aim of this work was to study its anti-leukaemic activity and to develop nanosuspensions of the drug, thereby limiting brain concentrations and the risk of encephalopathy.
Methods
Arsthinol nanosuspensions were produced by high-pressure homogenization. The anti-leukaemic activity was assessed on NB4 acute promyelocytic leukaemia cells (vs solutions of arsthinol, As2O3 and melarsoprol). In addition, a pharmacokinetics study was performed to compare the nanosuspensions and the solution of arsthinol.
Key findings
Arsthinol induced growth inhibition of NB4 cells at lower concentration (IC50 (concentration inhibiting growth by 50%) = 0.78 ± 0.08 μmol/l after 24 h) than As2O3 (IC50 = 1.60 ± 0.23 μmol/l after 24 h) or melarsoprol (IC50 = 1.44 ± 0.08 μmol/l after 24 h). When formulated as nanosuspension, arsthinol remained cytotoxic (IC50 = 1.33 ± 0.30 μmol/l after 24 h). This formulation also reduced the drug's access to the brain (Cmax = 0.03 μmol/g) whereas bone marrow concentrations remained very high (Cmax = 2 μmol/g).
Conclusions
Nanosuspensions of arsthinol could be proposed for further studies in the treatment of acute promyelocytic leukaemia.
Collapse
Affiliation(s)
- Imane Ajana
- EA 3452 ‘Cibles thérapeutiques formulation et expertise préclinique du médicament’, Nancy Université, Nancy, France
| | - Alain Astier
- EA 3452 ‘Cibles thérapeutiques formulation et expertise préclinique du médicament’, Nancy Université, Nancy, France
| | - Stéphane Gibaud
- EA 3452 ‘Cibles thérapeutiques formulation et expertise préclinique du médicament’, Nancy Université, Nancy, France
| |
Collapse
|
5
|
Efficacy of the novel diamidine compound 2,5-Bis(4-amidinophenyl)- furan-bis-O-Methlylamidoxime (Pafuramidine, DB289) against Trypanosoma brucei rhodesiense infection in vervet monkeys after oral administration. Antimicrob Agents Chemother 2008; 53:953-7. [PMID: 19064893 DOI: 10.1128/aac.00831-08] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Owing to the lack of oral drugs for human African trypanosomiasis, patients have to be hospitalized for 10 to 30 days to facilitate treatment with parenterally administered medicines. The efficacy of a novel orally administered prodrug, 2,5-bis(4-amidinophenyl)-furan-bis-O-methlylamidoxime (pafuramidine, DB289), was tested in the vervet monkey (Chlorocebus [Cercopithecus] aethiops) model of sleeping sickness. Five groups of three animals each were infected intravenously with 10(4) Trypanosoma brucei rhodesiense KETRI 2537 cells. On the seventh day postinfection (p.i.) in an early-stage infection, animals in groups 1, 2, and 3 were treated orally with pafuramidine at dose rates of 1, 3, or 10 mg/kg of body weight, respectively, for five consecutive days. The animals in groups 4 and 5 were treated with 10 mg/kg for 10 consecutive days starting on the 14th day p.i. (group 4) or on the 28th day p.i. (group 5), when these animals were in the late stage of the disease. In the groups treated in the early stage, 10 mg/kg of pafuramidine completely cured all three monkeys, whereas lower doses of 3 mg/kg and 1 mg/kg cured only one of three and zero of three monkeys, respectively. Treatment of late-stage infections resulted in cure rates of one of three (group 4) and zero of three (group 5) monkeys. These studies demonstrated that pafuramidine was orally active in monkeys with early-stage T. brucei rhodesiense infections at dose rates above 3 mg/kg for 5 days. It was also evident that the drug attained only minimal efficacy against late-stage infections, indicating the limited ability of the molecule to cross the blood-brain barrier. This study has shown that oral diamidines have potential for the treatment of early-stage sleeping sickness.
Collapse
|
6
|
Ward KW, Coon DJ, Magiera D, Bhadresa S, Nisbett E, Lawrence MS. Exploration of the African Green Monkey as a Preclinical Pharmacokinetic Model: Intravenous Pharmacokinetic Parameters. Drug Metab Dispos 2008; 36:715-20. [DOI: 10.1124/dmd.107.019315] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
7
|
Burri C, Nkunku S, Merolle A, Smith T, Blum J, Brun R. Efficacy of new, concise schedule for melarsoprol in treatment of sleeping sickness caused by Trypanosoma brucei gambiense: a randomised trial. Lancet 2000; 355:1419-25. [PMID: 10791526 DOI: 10.1016/s0140-6736(00)02141-3] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
BACKGROUND African trypanosomiasis is a fatal disease caused by protozoan parasites of the species Trypanosoma brucei. The disease has reached epidemic dimensions in various countries of central Africa. Treatment of the second stage is long and complicated, and is hampered by severe adverse reactions to the first-line drug, melarsoprol. Despite these problems, melarsoprol is likely to remain the drug of choice for the next decade. We therefore did a randomised trial comparing the standard treatment schedule with a new, concise regimen. METHODS The safety and efficacy of the new schedule were assessed in patients presenting to a hospital in Kwanza Norte, Angola with sleeping sickness. The control group followed the 26-day standard Angolan schedule of three series of four daily injections of melarsoprol at doses increasing from 1.2 to 3.6 mg/kg within each series, with a 7-day interval between series. The new treatment schedule comprised 10 daily injections of 2.2 mg/kg. Primary outcomes assessed were elimination of parasites, deaths attributed to treatment, and rate of encephalopathy. Analysis was by intention to treat. FINDINGS Of 767 patients with second-stage disease, 500 were enrolled: 250 were assigned the standard schedule, and 250 the new schedule. 40 patients on the standard schedule and 47 on the new schedule had adverse events which resulted in treatment disruption or withdrawal. 50 patients on the standard regimen deviated or withdrew from treatment, compared with two on the new regimen. Parasitological cure 24 h after treatment was 100% in both groups; there were six deaths (all due to encephalopathy) 30 days after treatment in each group. The number of patients with encephalopathic syndromes was also the same in each group (14). Skin reactions were more common with the new treatment, but all could be resolved by additional medication or withdrawal of treatment. INTERPRETATION Considering the economic and practical advantages of the new 10-day schedule over the standard 26-day treatment schedule, and the similarity of treatment outcome, the new schedule is a useful alternative to the present standard, especially in epidemic situations and in locations with limited resources.
Collapse
Affiliation(s)
- C Burri
- Swiss Tropical Institute, Basel.
| | | | | | | | | | | |
Collapse
|
8
|
Onyango JD, Burri C, Brun R. An automated biological assay to determine levels of the trypanocidal drug melarsoprol in biological fluids. Acta Trop 2000; 74:95-100. [PMID: 10643913 DOI: 10.1016/s0001-706x(99)00080-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
For the investigation of the pharmacokinetic properties of a drug, methods for sensitive and precise quantification are a prerequisite. Only few functional methods exist for the determination of the trypanocidal drug melarsoprol in biological fluids: A bioassay which requires microscopical evaluation and two HPLC methods, which require sample extraction and are difficult to automatize due to the drug's properties. We report the development of an automated biological assay, based on the fluorescent dye Alamar blue. To validate the assay for melarsoprol, 108 serum and 37 cerebrospinal fluid (CSF) samples were spiked with melarsoprol at concentrations of 17-92 ng/ml for CSF and 17 ng/ml-2.2 microg/ml for serum. The precision (repeatability) expressed as the interday average coefficient of variation was 9.9% for serum and 18.8% for CSF samples over the respective concentration range. The accuracy (measurement for the systematic error) of the test was 99.4% for serum and 96.4% for CSF. The assay's limit of quantitation with the use of the trypanosome stock STI 704 BABA was 4 ng/ml for both serum and CSF samples.
Collapse
|
9
|
Affiliation(s)
- J Keiser
- Swiss Tropical Institute, Department of Medical Parasitology and Infection Biology, Basel
| | | |
Collapse
|
10
|
Barrett SV, Barrett MP. Anti-sleeping sickness drugs and cancer chemotherapy. PARASITOLOGY TODAY (PERSONAL ED.) 2000; 16:7-9. [PMID: 10637579 DOI: 10.1016/s0169-4758(99)01560-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S V Barrett
- Department of Medical Oncology, University of Glasgow, UK.
| | | |
Collapse
|
11
|
Bronner U, Brun R, Doua F, Ericsson O, Burri C, Keiser J, Miézan TW, Boa YF, Rombo L, Gustafsson LL. Discrepancy in plasma melarsoprol concentrations between HPLC and bioassay methods in patients with T. gambiense sleeping sickness indicates that melarsoprol is metabolized. Trop Med Int Health 1998; 3:913-7. [PMID: 9855405 DOI: 10.1046/j.1365-3156.1998.00327.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE With the use of a specific high-performance liquid chromatography (HPLC) method and a bioassay which determines trypanocidal activity, concentrations of melarsoprol were assessed in plasma, urine and cerebrospinal fluid (CSF) from 8 patients with late-stage Trypanosoma gambiense sleeping sickness. The aim was to unravel to what extent the bioassay codetermines biologically active metabolites of melarsoprol. METHODS Subjects were given one dose of melarsoprol i.v. per day for 4 days (1.2, 2.4, 3.0-3.6, 3.0-3.6 mg per kg b.w., respectively). Plasma samples were obtained before the first melarsoprol injection, immediately after and at 1 h, 24 h and 5 days after the 4th injection. Urine was collected before melarsoprol therapy and at 24 h after the 4th injection. CSF samples were taken once before treatment and at 24 h after the 4th injection. RESULTS HPLC analyses showed that plasma concentrations immediately after the 4th injection varied from 2200 to 15,900 nmol/l; dropping to 0-1800 nmol/l at 1 h; and to undetectable levels at 24 h. In urine small amounts of melarsoprol were recovered. Melarsoprol could not be detected in CSF by HPLC. Immediately after injection, bioassay analyses showed plasma concentrations of the same magnitude as HPLC assays but at 1 h they were 4-65-fold higher than the levels assessed by HPLC. Even 24 h and 5 days after the 4th injection there was significant but decreasing activity. Urine levels were 40-260-fold higher than the measured HPLC concentrations, whereas there was low but detectable activity in CSF. CONCLUSION Results indicate that melarsoprol is rapidly eliminated from plasma. The significant trypanocidal activity determined by bioassay and simultaneous low or undetectable levels of melarsoprol assayed by HPLC indicate that the compound is transformed into metabolites with parasiticidal activity.
Collapse
Affiliation(s)
- U Bronner
- Division of Clinical Pharmacology, Karolinska Institute, Huddinge, Sweden.
| | | | | | | | | | | | | | | | | | | |
Collapse
|