1
|
Di Gennaro G, Chamitava L, Pertile P, Ambrosi E, Mosci D, Fila A, Alemayohu MA, Cazzoletti L, Tardivo S, Zanolin ME. A stepped-wedge randomised controlled trial to assess efficacy and cost-effectiveness of a care-bundle to prevent falls in older hospitalised patients. Age Ageing 2024; 53:afad244. [PMID: 38251740 PMCID: PMC10801830 DOI: 10.1093/ageing/afad244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Indexed: 01/23/2024] Open
Abstract
BACKGROUND Patient accidental falls in a hospital environment are a serious problem for patient safety, and for the additional costs due to associated medical interventions. OBJECTIVE The endpoints of this study were the assessment of the fall incidence in the hospital before and after the implementation of a multidisciplinary care-bundle, along with a cost-effectiveness evaluation. DESIGN A stepped-wedge trial was conducted between April 2015 and December 2016 in Bologna University Hospital. METHODS Incidence rates (IRs) of falls in both the control and intervention periods were calculated. A multilevel mixed-effects generalised linear model with logit link function, adjusted for age, sex, cluster cross-over timing and patients' clinical severity was used to estimate odds ratios (OR) of fall risk of patients of the intervention group respect to the controls.Intervention costs associated with the introduction of the care-bundle intervention were spread between patients per cluster-period-group of exposure. Incremental cost-effectiveness ratio was evaluated using total costs in the intervention and control groups. RESULTS IRs of falls in control and intervention periods were respectively 3.15 and 2.58 for 1,000 bed-days. After adjustment, the subjects receiving the intervention had a statistically significant reduced risk of falling with respect to those who did not (OR = 0.71, 95% confidence interval: 0.60-0.84). According to the cost-effectiveness analysis, the incremental cost per fall prevented was €873.92 considering all costs, and €1644.45 excluding costs related falls. CONCLUSIONS Care-bundle had a protective effect on patients, with a statistically significant reduction of the fall risk. This type of intervention appears cost-effective compared to routine practices.
Collapse
Affiliation(s)
- Gianfranco Di Gennaro
- Department of Health Sciences, University of Catanzaro "Magna Græcia", Catanzaro, Italy
| | - Liliya Chamitava
- Department of Diagnostics and Public Health, University of Verona, Verona, Italy
| | - Paolo Pertile
- Department of Economics, University of Verona, Verona, Italy
| | - Elisa Ambrosi
- Department of Diagnostics and Public Health, University of Verona, Verona, Italy
| | - Daniela Mosci
- Hospital Hygiene and Prevention, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Alice Fila
- Department of Diagnostics and Public Health, University of Verona, Verona, Italy
| | | | - Lucia Cazzoletti
- Department of Diagnostics and Public Health, University of Verona, Verona, Italy
| | - Stefano Tardivo
- Department of Diagnostics and Public Health, University of Verona, Verona, Italy
| | | |
Collapse
|
2
|
Gamba S, Magazzini L, Pertile P. R&D and market size: Who benefits from orphan drug legislation? J Health Econ 2021; 80:102522. [PMID: 34530381 DOI: 10.1016/j.jhealeco.2021.102522] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 08/01/2021] [Accepted: 08/21/2021] [Indexed: 06/13/2023]
Abstract
Since the early 80s, incentives have been introduced to stimulate R&D for rare diseases. We develop a theoretical model to study the impact of push and pull incentives on the intensive and extensive margin of optimal R&D investments. The model describes the mechanisms by which the type of incentives provided may favor R&D for orphan diseases with comparatively high prevalence. In our empirical analysis, we merge data on orphan drug designations by the Food and Drug Administration with Orphanet data on disease characteristics. In line with the theoretical results, we find evidence supporting the idea that the incentives adopted may have contributed substantially to widening the gap between more and less rare diseases classified as orphan. Our theoretical and empirical findings together suggest that, if providing some therapeutic option to patients with very rare diseases is a priority, a revision of the current system of incentives should be considered.
Collapse
Affiliation(s)
- Simona Gamba
- Department of Economics, Management and Quantitative Methods, Università degli Studi di Milano, Milan, Italy.
| | - Laura Magazzini
- Department of Economics, University of Verona, Via Cantarane 24, Verona, 37129, Italy; Institute of Economics and EMbeDS Economics and Management in the era of Data Science, Sant'Anna School of Advanced Studies, Pisa, Italy.
| | - Paolo Pertile
- Department of Economics, University of Verona, Via Cantarane 24, Verona, 37129, Italy.
| |
Collapse
|
3
|
Levaggi R, Pertile P. A reply to "Who would benefit from average value-based pricing?". Health Econ 2021; 30:2284-2286. [PMID: 34245084 DOI: 10.1002/hec.4392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Affiliation(s)
- Rosella Levaggi
- Department of Economics and Management, University of Brescia, Brescia, Italy
| | - Paolo Pertile
- Department of Economics, University of Verona, Verona, Italy
| |
Collapse
|
4
|
Forster M, Brealey S, Chick S, Keding A, Corbacho B, Alban A, Pertile P, Rangan A. Cost-effective clinical trial design: Application of a Bayesian sequential model to the ProFHER pragmatic trial. Clin Trials 2021; 18:647-656. [PMID: 34407641 PMCID: PMC8592107 DOI: 10.1177/17407745211032909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background/Aims: There is growing interest in the use of adaptive designs to improve the efficiency of clinical trials. We apply a Bayesian decision-theoretic model of a sequential experiment using cost and outcome data from the ProFHER pragmatic trial. We assess the model’s potential for delivering value-based research. Methods: Using parameter values estimated from the ProFHER pragmatic trial, including the costs of carrying out the trial, we establish when the trial could have stopped, had the model’s value-based stopping rule been used. We use a bootstrap analysis and simulation study to assess a range of operating characteristics, which we compare with a fixed sample size design which does not allow for early stopping. Results: We estimate that application of the model could have stopped the ProFHER trial early, reducing the sample size by about 14%, saving about 5% of the research budget and resulting in a technology recommendation which was the same as that of the trial. The bootstrap analysis suggests that the expected sample size would have been 38% lower, saving around 13% of the research budget, with a probability of 0.92 of making the same technology recommendation decision. It also shows a large degree of variability in the trial’s sample size. Conclusions: Benefits to trial cost stewardship may be achieved by monitoring trial data as they accumulate and using a stopping rule which balances the benefit of obtaining more information through continued recruitment with the cost of obtaining that information. We present recommendations for further research investigating the application of value-based sequential designs.
Collapse
Affiliation(s)
- Martin Forster
- Department of Statistical Sciences 'Paolo Fortunati', University of Bologna, Bologna, Italy.,Department of Economics and Related Studies, University of York, York, UK
| | - Stephen Brealey
- York Trials Unit, Department of Health Sciences, University of York, York, UK
| | - Stephen Chick
- Technology & Operations Management Area, INSEAD, Fontainebleau, France
| | - Ada Keding
- York Trials Unit, Department of Health Sciences, University of York, York, UK
| | - Belen Corbacho
- York Trials Unit, Department of Health Sciences, University of York, York, UK
| | - Andres Alban
- Technology & Operations Management Area, INSEAD, Fontainebleau, France
| | - Paolo Pertile
- Department of Economics, University of Verona, Verona, Italy
| | - Amar Rangan
- Department of Health Sciences, University of York, York, UK.,Faculty of Medical Sciences & NDORMS, University of Oxford, Oxford, UK.,James Cook University Hospital, Middlesbrough, UK
| |
Collapse
|
5
|
Gamba S, Pertile P, Vogler S. The impact of managed entry agreements on pharmaceutical prices. Health Econ 2020; 29 Suppl 1:47-62. [PMID: 32628324 DOI: 10.1002/hec.4112] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 04/30/2020] [Accepted: 05/04/2020] [Indexed: 06/11/2023]
Abstract
Managed entry agreements (MEAs) have been used for several years, with the aim of curbing the growth of pharmaceutical expenditure and enhancing patient access to innovation. Yet, much remains to be understood about their economic implications. This paper studies the impact of MEAs on list prices, that is, prices before the deduction of any discount. Using a theoretical model, we show that, under most price setting regimes, the introduction of an MEA leads to a higher list price. This is confirmed by our empirical analysis of a sample of 156 medicines in six countries, providing a conservative estimate of the increase in price due to the MEA of 5.9%. A relevant policy implication is that payers may overestimate the financial gains that can be achieved through this tool.
Collapse
Affiliation(s)
- Simona Gamba
- Department of Economics and Finance, Università Cattolica del Sacro Cuore, Milan, Italy
| | - Paolo Pertile
- Department of Economics, University of Verona, Verona, Italy
| | - Sabine Vogler
- Pharmacoeconomics Department, Gesundheit Österreich GmbH, Austrian National Public Health Institute, Vienna, Austria
| |
Collapse
|
6
|
Levaggi R, Pertile P. Which valued-based price when patients are heterogeneous? Health Econ 2020; 29:923-935. [PMID: 32537816 DOI: 10.1002/hec.4033] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 03/09/2020] [Accepted: 04/22/2020] [Indexed: 06/11/2023]
Abstract
We use a simple model to study the static and dynamic efficiency of alternative regulation regimes for the reimbursement of medical innovations when responses to a new treatment (effectiveness) are heterogeneous across the eligible population. When the rational behavior of profit-maximizing firms is taken into account, only average value-based prices can ensure both static and dynamic efficiency, but they imply higher expenditure and lower consumer surplus. Ignoring dynamic efficiency, if patients' responses are sufficiently homogeneous, marginal value-based prices may dominate from the payer's perspective. We also present a refinement of average value-based prices that could reverse this result. Overall, the cost of ensuring static and dynamic efficiency is increasing in the degree of heterogeneity. A real-world example is used to illustrate these results.
Collapse
Affiliation(s)
- Rosella Levaggi
- Department of Economics and Management, University of Brescia, Brescia, Italy
| | - Paolo Pertile
- Department of Economics, University of Verona, Verona, Italy
| |
Collapse
|
7
|
Levaggi R, Pertile P. Value-Based Pricing Alternatives for Personalised Drugs: Implications of Asymmetric Information and Competition. Appl Health Econ Health Policy 2020; 18:357-362. [PMID: 31788763 DOI: 10.1007/s40258-019-00541-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The market for new drugs is changing: personalised drugs will increase the heterogeneity in patients' responses and, possibly, costs. In this context, price regulation will play an increasingly important role. In this article, we argue that personalised medicine opens new scenarios in the relationship between value-based prices, regulation and industry listing strategies. Our focus is on the role of asymmetry of information and competition. We show that, if the firm has more information than the payer on the heterogeneity in patients' responses and it adopts a profit-maximising listing strategy, the outcome may be independent of the choice of the type of value-based price. In this case, the information advantage that the manufacturer has prevents the payer from using marginal value-based prices to extract part of the surplus. However, in a dynamic setting where competition by a new entrant is possible, the choice of the type of value-based price may matter. We suggest that more research should be devoted to the dynamic analysis of price regulation for personalised medicines.
Collapse
Affiliation(s)
- Rosella Levaggi
- Department of Economics and Management, University of Brescia, Via San Faustino 74b, 25122, Brescia, Italy.
| | - Paolo Pertile
- Department of Economics, University of Verona, Verona, Italy
| |
Collapse
|
8
|
Levaggi R, Pertile P. Authors' Reply to Garattini and Freemantle: "Value-Based Pricing Alternatives for Personalised Drugs: Implications of Asymmetric Information and Competition". Appl Health Econ Health Policy 2020; 18:455-456. [PMID: 32016831 DOI: 10.1007/s40258-020-00557-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- Rosella Levaggi
- Department of Economics and Management, University of Brescia, Via San Faustino 74b, 25122, Brescia, Italy.
| | - Paolo Pertile
- Department of Economics, University of Verona, Via Cantarane, 24, 37129, Verona, Italy
| |
Collapse
|
9
|
Biscardo CA, Bucciol A, Pertile P. Job sick leave: Detecting opportunistic behavior. Health Econ 2019; 28:373-386. [PMID: 30562844 DOI: 10.1002/hec.3850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Revised: 09/26/2018] [Accepted: 10/23/2018] [Indexed: 06/09/2023]
Abstract
We utilize a large administrative dataset of sickness leave in Italy (a) to investigate whether private firms are more effective than the public insurer in choosing who to monitor and (b) to study the correlation between potentially opportunistic behavior and the observable characteristics of the employee. We find that private employers are more likely to select into monitoring employees who are fit for work despite being on sick leave, if the public insurer is not supported by any data-driven tool. However, the use of a scoring mechanism, based on past records, allows the public insurer to be as effective as the employer. This result suggests that the application of machine learning to appropriate databases may improve the targeting of public monitoring to detect opportunistic behavior. Concerning the association between observable characteristics and potentially opportunistic behavior, we find that males, employees younger than 50, those on short leaves, or without a history of illness are more likely to be found fit for work.
Collapse
Affiliation(s)
| | | | - Paolo Pertile
- Department of Economics, University of Verona, Verona, Italy
| |
Collapse
|
10
|
Pasello G, Vicario G, Gori S, Zustovich F, Bonetti A, Rosetti F, Favaretto A, Oniga F, Bria E, Toso S, Boccalon M, Oliani C, Palazzolo G, Frega S, Basso M, Pertile P, Bortolami A, Verrienti R, Scanni R, Conte P. Compliance to diagnostic and therapeutic pathways and innovative drug recommendations in advanced non-small cell lung cancer: preliminary results from the MOST study. Ann Oncol 2017. [DOI: 10.1093/annonc/mdx426.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
11
|
Chick S, Forster M, Pertile P. A Bayesian decision theoretic model of sequential experimentation with delayed response. J R Stat Soc Series B Stat Methodol 2017. [DOI: 10.1111/rssb.12225] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
12
|
Jobjörnsson S, Forster M, Pertile P, Burman CF. Late-stage pharmaceutical R&D and pricing policies under two-stage regulation. J Health Econ 2016; 50:298-311. [PMID: 27776744 DOI: 10.1016/j.jhealeco.2016.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 04/12/2016] [Accepted: 06/01/2016] [Indexed: 06/06/2023]
Abstract
We present a model combining the two regulatory stages relevant to the approval of a new health technology: the authorisation of its commercialisation and the insurer's decision about whether to reimburse its cost. We show that the degree of uncertainty concerning the true value of the insurer's maximum willingness to pay for a unit increase in effectiveness has a non-monotonic impact on the optimal price of the innovation, the firm's expected profit and the optimal sample size of the clinical trial. A key result is that there exists a range of values of the uncertainty parameter over which a reduction in uncertainty benefits the firm, the insurer and patients. We consider how different policy parameters may be used as incentive mechanisms, and the incentives to invest in R&D for marginal projects such as those targeting rare diseases. The model is calibrated using data on a new treatment for cystic fibrosis.
Collapse
Affiliation(s)
- Sebastian Jobjörnsson
- Department of Mathematical Sciences, Chalmers University of Technology and University of Gothenburg, SE-412 96, Gothenburg, Sweden
| | - Martin Forster
- Department of Economics and Related Studies, University of York, Heslington, York YO10 5DD, UK
| | - Paolo Pertile
- Department of Economics, University of Verona, 37129 Verona, Italy.
| | - Carl-Fredrik Burman
- Department of Mathematical Sciences, Chalmers University of Technology and University of Gothenburg, SE-412 96, Gothenburg, Sweden; Advanced Analytics Centre, AstraZeneca R&D, SE-431 83 Mölndal, Sweden
| |
Collapse
|
13
|
Pertile P, Poli A, Dominioni L, Rotolo N, Nardecchia E, Castiglioni M, Paolucci M, Mantovani W, Imperatori A. Is chest X-ray screening for lung cancer in smokers cost-effective? Evidence from a population-based study in Italy. Cost Eff Resour Alloc 2015; 13:15. [PMID: 26366122 PMCID: PMC4567810 DOI: 10.1186/s12962-015-0041-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Accepted: 09/04/2015] [Indexed: 12/18/2022] Open
Abstract
Background After implementation of the PREDICA annual chest X-ray (CXR) screening program in smokers in the general practice setting of Varese-Italy a significant reduction in lung cancer-specific mortality (18 %) was observed. The objective of this study covering July 1997 through December 2006 was to estimate the cost-effectiveness of this intervention. Methods We examined detailed information on lung cancer (LC) cases that occurred among smokers invited to be screened in the PREDICA study (Invitation-to-screening Group, n = 5815 subjects) to estimate costs and quality-adjusted life-years (QALYs) from LC diagnosis until death. The control group consisted of 156 screening-eligible smokers from the same area, uninvited and unscreened, who developed LC and were treated by usual care. We calculated the incremental net monetary benefit (INMB) by comparing LC management in screening participants (n = 1244 subjects) and in the Invitation-to-screening group versus control group. Results The average number of QALYs since LC diagnosis was 1.7, 1.49 and 1.07, respectively, in screening participants, the invitation-to-screening group, and the control group. The average total cost (screening + management) per LC case was higher in screening participants (€17,516) and the Invitation-to-screening Group (€16,167) than in the control group (€15,503). Assuming a maximum willingness to pay of €30,000/QALY, we found that the intervention was cost-effective with high probability: 79 % for screening participation (screening participants vs. control group) and 95 % for invitation-to-screening (invitation-to-screening group vs. control group). Conclusions Based on the PREDICA study, annual CXR screening of high-risk smokers in a general practice setting has high probability of being cost-effective with a maximum willingness to pay of €30,000/QALY.
Collapse
Affiliation(s)
- Paolo Pertile
- Department of Economics, University of Verona, Via dell'Artigliere 19, 37129 Verona, Italy
| | - Albino Poli
- Department of Public Health and Community Medicine, University of Verona, Verona, Italy
| | - Lorenzo Dominioni
- Center for Thoracic Surgery, University of Insubria, Ospedale di Circolo, Varese, Italy
| | - Nicola Rotolo
- Center for Thoracic Surgery, University of Insubria, Ospedale di Circolo, Varese, Italy
| | - Elisa Nardecchia
- Center for Thoracic Surgery, University of Insubria, Ospedale di Circolo, Varese, Italy
| | - Massimo Castiglioni
- Center for Thoracic Surgery, University of Insubria, Ospedale di Circolo, Varese, Italy
| | - Massimo Paolucci
- Department of Radiology, Ospedale S. Antonio Abate, Gallarate, Italy
| | - William Mantovani
- Department of Public Health and Community Medicine, University of Verona, Verona, Italy ; Department of Prevention, Public Health Trust, Trento, Italy
| | - Andrea Imperatori
- Center for Thoracic Surgery, University of Insubria, Ospedale di Circolo, Varese, Italy
| |
Collapse
|
14
|
Pomari E, Valle LD, Pertile P, Colombo L, Thornton MJ. Intracrine sex steroid synthesis and signaling in human epidermal keratinocytes and dermal fibroblasts. FASEB J 2014; 29:508-24. [DOI: 10.1096/fj.14-251363] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Elena Pomari
- Centre for Skin SciencesSchool of Life Sciences University of BradfordBradfordUnited Kingdom
- Comparative Endocrinology LaboratoryDepartment of BiologyUniversity of PadovaPaduaItaly
| | - Luisa Dalla Valle
- Comparative Endocrinology LaboratoryDepartment of BiologyUniversity of PadovaPaduaItaly
| | | | - Lorenzo Colombo
- Comparative Endocrinology LaboratoryDepartment of BiologyUniversity of PadovaPaduaItaly
| | - M. Julie Thornton
- Centre for Skin SciencesSchool of Life Sciences University of BradfordBradfordUnited Kingdom
| |
Collapse
|
15
|
Forster M, Pertile P. Optimal decision rules for HTA under uncertainty: a wider, dynamic perspective. Health Econ 2013; 22:1507-1514. [PMID: 23225192 DOI: 10.1002/hec.2893] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 10/24/2012] [Accepted: 11/11/2012] [Indexed: 06/01/2023]
Abstract
We present a two-period framework, which combines real option and decision-theoretic approaches to health technology assessment under uncertainty. By viewing adoption, treatment and research decisions as a single economic project, we illustrate how their key dimensions affect optimal rules. We consider the results in relation to the existing literature and argue that developments in this direction could contribute substantially to efficiency gains in resource allocation.
Collapse
|
16
|
Tessitore N, Bedogna V, Poli A, Lipari G, Pertile P, Baggio E, Contro A, Criscenti P, Mansueto G, Lupo A. Should current criteria for detecting and repairing arteriovenous fistula stenosis be reconsidered? Interim analysis of a randomized controlled trial. Nephrol Dial Transplant 2013; 29:179-87. [PMID: 24166470 DOI: 10.1093/ndt/gft421] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND The vascular access guidelines recommend that arteriovenous fistulas (AVFs) with access dysfunction and an access blood flow (Qa) <300-500 mL/min be referred for stenosis imaging and treatment. Significant (>50%) stenosis, however, may be detected in a well-functioning AVF with a Qa > 500 mL/min, too, but whether it is worth correcting or not remains to be seen. METHODS In October 2006, we began an open randomized controlled trial enrolling patients with an AVF with subclinical stenosis and Qa > 500 mL/min, to see how elective stenosis repair [treatment group (TX)] influenced access failure (thrombosis or impending thrombosis requiring access revision), or loss and the related cost compared with stenosis correction according to the guidelines, i.e. after the onset of access dysfunction or a Qa < 400 mL/min [control group (C)]. An interim analysis was performed in July 2012, by which time the trial had enrolled 58 patients (30 C and 28 TX). RESULTS TX led to a relative risk of 0.47 [95% confidence interval (CI): 0.17-1.15] for access failure (P = 0.090), 0.37 [95% CI: 0.12-0.97] for thrombosis (P = 0.033) and 0.36 [95% CI: 0.09-0.99] for access loss (P = 0.041). In the setting of our study (in which all surgery was performed as in patient procedure) no significant differences in costs emerged between the two strategies. The mean incremental cost-effectiveness ratio for TX was €282 or €321 to avoid one episode of thrombosis or access loss, respectively. CONCLUSIONS Our interim analysis showed that elective repair of subclinical stenosis in AVFs with Qa > 500 mL/min cost-effectively reduces the risk of thrombosis and access loss in comparison with the approach of the Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines, raising the question of whether the currently recommended criteria for assessing and treating stenosis should be reconsidered.
Collapse
Affiliation(s)
- Nicola Tessitore
- Department of Medicine, Renal Unit, University Hospital, Verona, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Forster M, Pertile P. Public Health Interventions: Evaluating the Economic Evaluations. J Public Health Res 2013; 2:e21. [PMID: 25170492 PMCID: PMC4147730 DOI: 10.4081/jphr.2013.e21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 10/10/2013] [Indexed: 11/23/2022] Open
Affiliation(s)
- Martin Forster
- Department of Economics and Related Studies, University of York, UK
| | | |
Collapse
|
18
|
Levaggi R, Moretto M, Pertile P. Static and dynamic efficiency of irreversible health care investments under alternative payment rules. J Health Econ 2012; 31:169-179. [PMID: 22019114 DOI: 10.1016/j.jhealeco.2011.09.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 08/25/2011] [Accepted: 09/25/2011] [Indexed: 05/31/2023]
Abstract
The paper studies the incentive for providers to invest in new health care technologies under alternative payment systems, when the patients' benefits are uncertain. If the reimbursement by the purchaser includes both a variable (per patient) and a lump-sum component, efficiency can be ensured both in the timing of adoption (dynamic) and the intensity of use of the technology (static). If the second instrument is unavailable, a trade-off may emerge between static and dynamic efficiency. In this context, we also discuss how the regulator could use control of the level of uncertainty faced by the provider as an instrument to mitigate the trade-off between static and dynamic efficiency. Finally, we calibrate the model to study a specific technology and estimate the cost of a regulatory failure.
Collapse
Affiliation(s)
- R Levaggi
- Dip. di Scienze Economiche, University of Brescia, Italy
| | | | | |
Collapse
|
19
|
Pertile P. An extension of the real option approach to the evaluation of health care technologies: the case of positron emission tomography. ACTA ACUST UNITED AC 2009; 9:317-32. [PMID: 19152067 DOI: 10.1007/s10754-008-9053-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Accepted: 12/30/2008] [Indexed: 11/25/2022]
Abstract
This paper aims to incorporate option values into the economic evaluation of positron emission tomography (PET). The installation of this equipment requires a substantial capital outlay, while uncertainty, especially regarding the possibility of new applications, is relevant, because the evidence available is still insufficient. Treating the number of examinations to provide as a stochastic variable, the cost-effectiveness analysis is extended to include the value of flexibility both with respect to the timing of investment and to the size of the project. The threshold values of the stochastic variable that ensure the cost-effectiveness of a PET scan according to this approach are obtained as a function of the value of the incremental effectiveness.
Collapse
Affiliation(s)
- Paolo Pertile
- Department of Law and Economics, University of Verona, Via dell'Artigliere 19, 37129, Verona, Italy.
| |
Collapse
|
20
|
Havlickova B, Bíró T, Mescalchin A, Tschirschmann M, Mollenkopf H, Bettermann A, Pertile P, Lauster R, Bodó E, Paus R. A human folliculoid microsphere assay for exploring epithelial- mesenchymal interactions in the human hair follicle. J Invest Dermatol 2008; 129:972-83. [PMID: 18923448 DOI: 10.1038/jid.2008.315] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The search for more effective drugs for the management of common hair growth disorders remains a top priority, both for clinical dermatology and industry. In this pilot study, we report a pragmatic organotypic assay for basic and applied hair research. The patented technique produces microdroplets, which generate human folliculoid microspheres (HFMs), consisting of human dermal papilla fibroblasts and outer root sheath keratinocytes within an extracellular matrix that simulates elements of the hair follicle mesenchyme. Studying a number of different markers (for example, proliferation, apoptosis, cytokeratin-6, versican), we show that these HFMs, cultured under well-defined conditions, retain several essential epithelial-mesenchymal interactions characteristic for human scalp hair follicle. Selected, recognized hair growth-modulatory agents modulate these parameters in a manner that suggests that HFMs allow the standardized preclinical assessment of test agents on relevant human hair growth markers under substantially simplified in vitro conditions that approximate the in vivo situation. Furthermore, we show by immunohistochemistry, reverse transcriptase-PCR, and DNA microarray techniques that HFMs also offer a useful discovery tool for the identification of target genes and their products for candidate hair drugs. HFM thus represent an instructive modern experimental and screening tool for basic and applied hair research in the human system.
Collapse
Affiliation(s)
- Blanka Havlickova
- Department of Dermatology, Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Bodó E, Bíró T, Telek A, Czifra G, Griger Z, Tóth IB, Lázár J, Meschalchin A, Ito T, Bettermann A, Pertile P, Kovács L, Paus R. A ‘hot’ new twist to hair biology - involvement of vanilloid receptor-1 signaling in human hair growth control. Exp Dermatol 2008. [DOI: 10.1111/j.0906-6705.2004.212bd.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
22
|
Adly MA, Assaf HA, Pertile P, Hussein MR, Paus R. Expression patterns of the glial cell line–derived neurotrophic factor, neurturin, their cognate receptors GFRα-1, GFRα-2, and a common signal transduction element c-Ret in the human skin hair follicles. J Am Acad Dermatol 2008; 58:238-50. [DOI: 10.1016/j.jaad.2007.10.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Revised: 09/11/2007] [Accepted: 10/09/2007] [Indexed: 01/03/2023]
|
23
|
Abstract
The trimethylated amino acid l-carnitine plays a key role in the intramitochondrial transport of fatty acids for beta-oxidation and thus serves important functions in energy metabolism. Here, we have tested the hypothesis that l-carnitine, a frequently employed dietary supplement, may also stimulate hair growth by increasing energy supply to the massively proliferating and energy-consuming anagen hair matrix. Hair follicles (HFs) in the anagen VI stage of the hair cycle were cultured in the presence of 0.5-50 microm of l-carnitine-l-tartrate (CT) for 9 days. At day 9, HFs treated with 5 microm or 0.5 microm of CT showed a moderate, but significant stimulation of hair shaft elongation compared with vehicle-treated controls (P < 0.05). Also, CT prolonged the duration of anagen VI, down regulated apoptosis (as measured by TUNEL assay) and up regulated proliferation (as measured by Ki67 immunohistology) of hair matrix keratinocytes (P < 0.5). By immunohistology, intrafollicular immunoreactivity for TGFbeta2, a key catagen-promoting growth factor, in the dermal papilla and TGF-beta II receptor protein in the outer root sheath and dermal papilla was down regulated. As shown by caspase activity assay, caspase 3 and 7, which are known to initiate apoptosis, are down regulated at day 2 and day 4 after treatment of HFs with CT compared with vehicle-treated control indicating that CT has an immediate protective effect on HFs to undergo programmed cell death. Our findings suggest that l-carnitine stimulates human scalp hair growth by up regulation of proliferation and down regulation of apoptosis in follicular keratinocytes in vitro. They further encourage one to explore topical and nutraceutical administration of l-carnitine as a well-tolerated, relatively safe adjuvant treatment in the management of androgenetic alopecia and other forms of hair loss.
Collapse
Affiliation(s)
- Kerstin Foitzik
- Department of Dermatology, University Hospital Hamburg-Eppendorf, University of Hamburg, Hamburg, Germany.
| | | | | | | | | |
Collapse
|
24
|
Peters EMJ, Hansen MG, Overall RW, Nakamura M, Pertile P, Klapp BF, Arck PC, Paus R. Control of Human Hair Growth by Neurotrophins: Brain-Derived Neurotrophic Factor Inhibits Hair Shaft Elongation, Induces Catagen, and Stimulates Follicular Transforming Growth Factor β2 Expression. J Invest Dermatol 2005; 124:675-85. [PMID: 15816823 DOI: 10.1111/j.0022-202x.2005.23648.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Neurotrophins are important modulators of epithelial-mesenchymal interactions. Previously, we had shown that brain-derived neurotrophic factor (BDNF) and its high-affinity receptor tyrosine kinase B (TrkB) are prominently involved in the control of murine hair follicle cycling. We now show that BDNF and TrkB are also expressed in the human hair follicle in a manner that is both hair cycle dependent and suggestive of epithelial-mesenchymal cross-talk between BDNF-secreting dermal papilla fibroblasts of anagen hair follicles and subpopulations of TrkB+ hair follicle keratinocytes. As functional evidence for an involvement of BDNF/TrkB in human hair growth control, we show in organ-cultured human anagen hair follicles that 50 ng per mL BDNF significantly inhibit hair shaft elongation, induce premature catagen development, and inhibit keratinocyte proliferation. Quantitative real-time rtPCR analysis demonstrates upregulation of the potent catagen inducer, transforming growth factor beta2 (TGFbeta2) by BDNF, whereas catagen induction by BDNF was partially reversible through co-administration of TGFbeta-neutralizing antibody. This suggests that TrkB-mediated signaling promotes the switch between anagen and catagen at least in part via upregulation of TGFbeta2. Thus, human scalp hair follicles are both a source and target of bioregulation by BDNF, which invites to target TrkB-mediated signaling for therapeutic hair growth modulation.
Collapse
Affiliation(s)
- Eva M J Peters
- Department of Internal Medicine, Biomedical Research Center, University Medicine Charité, Campus Virchow Hospital, Berlin, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Mancini R, Piccolo E, Mariggio' S, Filippi BM, Iurisci C, Pertile P, Berrie CP, Corda D. Reorganization of actin cytoskeleton by the phosphoinositide metabolite glycerophosphoinositol 4-phosphate. Mol Biol Cell 2003; 14:503-15. [PMID: 12589050 PMCID: PMC149988 DOI: 10.1091/mbc.e02-04-0179] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Glycerophosphoinositol 4-phosphate (GroPIns-4P) is a biologically active, water-soluble phospholipase A metabolite derived from phosphatidylinositol 4-phosphate, whose cellular concentrations have been reported to increase in Ras-transformed cells. It is therefore important to understand its biological activities. Herein, we have examined whether GroPIns-4P can regulate the organization of the actin cytoskeleton, because this could be a Ras-related function involved in cell motility and metastatic invasion. We find that in serum-starved Swiss 3T3 cells, exogenously added GroPIns-4P rapidly and potently induces the formation of membrane ruffles, and, later, the formation of stress fibers. These actin structures can be regulated by the small GTPases Cdc42, Rac, and Rho. To analyze the mechanism of action of GroPIns-4P, we selectively inactivated each of these GTPases. GroPIns-4P requires active Rac and Rho, but not Cdc42, for ruffle and stress fiber formation, respectively. Moreover, GroPIns-4P induces a rapid translocation of the green fluorescent protein-tagged Rac into ruffles, and increases the fraction of GTP-bound Rac, in intact cells. The activation of Rac by GroPIns-4P was near maximal and long-lasting. Interestingly, this feature seems to be critical in the induction of actin ruffles by GroPIns-4P.
Collapse
Affiliation(s)
- Raffaella Mancini
- Department of Cell Biology and Oncology, Istituto di Ricerche Farmacologiche Mario Negri, Consorzio Mario Negri Sud, 66030 Santa Maria Imbaro, Chieti, Italy
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Godi A, Pertile P, Meyers R, Marra P, Di Tullio G, Iurisci C, Luini A, Corda D, De Matteis MA. ARF mediates recruitment of PtdIns-4-OH kinase-beta and stimulates synthesis of PtdIns(4,5)P2 on the Golgi complex. Nat Cell Biol 1999; 1:280-7. [PMID: 10559940 DOI: 10.1038/12993] [Citation(s) in RCA: 438] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The small GTPase ADP-ribosylation factor (ARF) regulates the structure and function of the Golgi complex through mechanisms that are understood only in part, and which include an ability to control the assembly of coat complexes and phospholipase D (PLD). Here we describe a new property of ARF, the ability to recruit phosphatidylinositol-4-OH kinase-beta and a still unidentified phosphatidylinositol-4-phosphate-5-OH kinase to the Golgi complex, resulting in a potent stimulation of synthesis of phosphatidylinositol-4-phosphate and phosphatidylinositol-4,5-bisphosphate; this ability is independent of its activities on coat proteins and PLD. Phosphatidylinositol-4-OH kinase-beta is required for the structural integrity of the Golgi complex: transfection of a dominant-negative mutant of the kinase markedly alters the organization of the organelle.
Collapse
Affiliation(s)
- A Godi
- Department of Cell Biology and Oncology, Istituto di Ricerche Farmacologiche Mario Negri, Santa Maria Imbaro, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Godi A, Santone I, Pertile P, Marra P, Di Tullio G, Luini A, Corda D, De Matteis MA. ADP-ribosylation factor regulates spectrin skeleton assembly on the Golgi complex by stimulating phosphatidylinositol 4,5-bisphosphate synthesis. Biochem Soc Trans 1999; 27:638-42. [PMID: 10917657 DOI: 10.1042/bst0270638] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- A Godi
- Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Santa Maria Imbaro, Chieti, Italy
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Godi A, Santone I, Pertile P, Devarajan P, Stabach PR, Morrow JS, Di Tullio G, Polishchuk R, Petrucci TC, Luini A, De Matteis MA. ADP ribosylation factor regulates spectrin binding to the Golgi complex. Proc Natl Acad Sci U S A 1998; 95:8607-12. [PMID: 9671725 PMCID: PMC21123 DOI: 10.1073/pnas.95.15.8607] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Homologues of two major components of the well-characterized erythrocyte plasma-membrane-skeleton, spectrin (a not-yet-cloned isoform, betaI Sigma* spectrin) and ankyrin (AnkG119 and an approximately 195-kDa ankyrin), associate with the Golgi complex. ADP ribosylation factor (ARF) is a small G protein that controls the architecture and dynamics of the Golgi by mechanisms that remain incompletely understood. We find that activated ARF stimulates the in vitro association of betaI Sigma* spectrin with a Golgi fraction, that the Golgi-associated betaI Sigma* spectrin contains epitopes characteristic of the betaI Sigma2 spectrin pleckstrin homology (PH) domain known to bind phosphatidylinositol 4,5-bisphosphate (PtdInsP2), and that ARF recruits betaI Sigma* spectrin by inducing increased PtdInsP2 levels in the Golgi. The stimulation of spectrin binding by ARF is independent of its ability to stimulate phospholipase D or to recruit coat proteins (COP)-I and can be blocked by agents that sequester PtdInsP2. We postulate that a PH domain within betaI Sigma* Golgi spectrin binds PtdInsP2 and acts as a regulated docking site for spectrin on the Golgi. Agents that block the binding of spectrin to the Golgi, either by blocking the PH domain interaction or a constitutive Golgi binding site within spectrin's membrane association domain I, inhibit the transport of vesicular stomatitis virus G protein from endoplasmic reticulum to the medial compartment of the Golgi complex. Collectively, these results suggest that the Golgi-spectrin skeleton plays a central role in regulating the structure and function of this organelle.
Collapse
Affiliation(s)
- A Godi
- Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Santa Maria Imbaro (Chieti), Italy 66030
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Pertile P, Baldi A, De Luca A, Bagella L, Virgilio L, Pisano MM, Giordano A. Molecular cloning, expression, and developmental characterization of the murine retinoblastoma-related gene Rb2/p130. Cell Growth Differ 1995; 6:1659-64. [PMID: 9019172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The product of the retinoblastoma-related human gene Rb2/p130 is highly homologous with the product of the retinoblastoma tumor suppressor gene (pRb) and Rb-related p107. this homology is shared mainly in the pocket domain, a region that seems to play a key role in the functions of these proteins. Here we report the molecular cloning and initial characterization of the cDNA encoding the murine homologue of the human Rb2/p130 gene product. The 4.8-kb cDNA encodes a protein of 1125 amino acids that shows 90% indentity to that of the human protein. The Rb2/p130 mRNA is found to be expressed in all of the adult mouse tissues examined, with the highest level being detected in kidney and skeletal muscle. For the protein characterization, we used a polyclonal antibody raised against the COOH terminus of the human Rb2/p130 protein that also recognizes the mouse protein. In developing mouse embryos, the Rb2/p130 protein is expressed as early as day 10 of gestation and reached a peak of expression around day 13 of gestation, implying a developmental regulation of the Rb2/p130 gene in murine ontogeny.
Collapse
Affiliation(s)
- P Pertile
- Department of Microbiology/Immunology, Jefferson Cancer Institute, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
| | | | | | | | | | | | | |
Collapse
|
30
|
Abstract
CD4 serves as a cell-cell adhesion molecule, with specific affinity for class II MHC molecules, and as a receptor for the human immunodeficiency virus type 1 (HIV-1) viral coat protein. Phosphoinositide (PI)-3-kinase and 1-phosphatidylinositol (PtdIns)-4-kinase activities were previously found to associate with the CD4:p56lck complex, but the protein responsible for PtdIns 4-kinase activity was not identified. Here we demonstrate that the 53 kDa type 2 PtdIns 4-kinase associates with CD4 using a monoclonal antibody specific for this enzyme. We also show that an increase in PtdIns 4-kinase activity is due to recruitment of the type 2 PtdIns 4-kinase protein to the CD4:p56lck complex after cross-linking with anti-CD4.
Collapse
Affiliation(s)
- P Pertile
- Department of Medicine, Beth Israel Hospital, Boston, MA, USA
| | | |
Collapse
|
31
|
Pertile P, Liscovitch M, Chalifa V, Cantley LC. Phosphatidylinositol 4,5-bisphosphate synthesis is required for activation of phospholipase D in U937 cells. J Biol Chem 1995; 270:5130-5. [PMID: 7890622 DOI: 10.1074/jbc.270.10.5130] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Phospholipase D (PLD) has been implicated in signal transduction and membrane traffic. We have previously shown that phosphatidylinositol 4,5-bisphosphate (PtdIns-4,5-P2) stimulates in vitro partially purified brain membrane PLD activity, defining a novel function of PtdIns-4,5-P2 as a PLD cofactor. In the present study we extend these observations to permeabilized U937 cells. In these cells, the activation of PLD by guanosine 5'-3-O-(thio)triphosphate (GTP gamma S) is greatly potentiated by MgATP. We have utilized this experimental system to test the hypothesis that MgATP potentiates PLD activation by G proteins because it is required for PtdIns-4,5-P2 synthesis by phosphoinositide kinases. As expected, MgATP was absolutely required for maintaining elevated phosphatidylinositol 4-phosphate (PtdIns-4-P) and PtdIns-4,5-P2 levels in the permeabilized cells. In the presence of MgATP, GTP gamma S further elevated the levels of the phosphoinositides. The importance of PtdIns-4,5-P2 for PLD activation was examined by utilizing a specific inhibitory antibody directed against phosphatidylinositol 4-kinase (PtdIns 4-kinase), the enzyme responsible for the first step in the synthesis of PtdIns-4,5-P2. Anti-PtdIns 4-kinase completely inhibited PtdIns 4-kinase activity in vitro and reduced by 75-80% PtdIns-4-P and PtdIns-4,5-P2 levels in the permeabilized cells. In parallel, the anti-PtdIns 4-kinase fully inhibited the activation of PLD by GTP gamma S and caused a 60% inhibition of PLD activation by the phorbol ester 12-O-tetradecanoylphorbol-13-acetate, indicating that elevated PtdIns-4,5-P2 levels are required for PLD activation. This conclusion is supported by the fact that neomycin, a high affinity ligand of PtdIns-4,5-P2, also blocked PLD activation. Furthermore, the activity of PLD in U937 cell lysate was stimulated by PtdIns-4,5-P2 in a dose-dependent manner. The current results indicate that PtdIns-4,5-P2 synthesis is required for PLD activation in permeabilized U937 cells and strongly support the proposed function of PtdIns-4,5-P2 as a cofactor for PLD. In addition, the results further establish PtdIns-4,5-P2 as a key component in the generation of second messengers via multiple pathways including phosphoinositide-phospholipase C, phosphoinositide 3-kinase and PLD.
Collapse
Affiliation(s)
- P Pertile
- Division of Signal Transduction, Beth Israel Hospital, Boston, Massachusetts
| | | | | | | |
Collapse
|
32
|
Liscovitch M, Chalifa V, Pertile P, Chen CS, Cantley LC. Novel function of phosphatidylinositol 4,5-bisphosphate as a cofactor for brain membrane phospholipase D. J Biol Chem 1994; 269:21403-6. [PMID: 8063770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The activation of phospholipase D (PLD) is a receptor-mediated event that has been implicated in signal transduction and membrane traffic in eukaryotic cells. Little is known about the biochemical and molecular properties of signal-activated PLDs, and none has been isolated. Here we report that phosphatidylinositol 4,5-bisphosphate (PIP2) potently stimulates brain membrane PLD activity in vitro in a highly specific manner. PIP2 increases 10-fold the maximal activity of a partially purified PLD with an EC50 of < 0.5 mol %. Other acidic phospholipids, including phosphatidylinositol 4-phosphate, phosphatidylinositol, phosphatidylserine, and phosphatidic acid, are completely or nearly ineffective. Neomycin, a high affinity ligand of PIP2, inhibits membrane-bound PLD but has no effect on the activity of a detergent-solubilized or partially purified enzyme. The addition of PIP2 restores the sensitivity of partially purified PLD to neomycin inhibition, indicating that neomycin blocks membrane PLD activity by binding to endogenous PIP2. These results define a novel function of PIP2 as a cofactor for brain membrane PLD and suggest that PIP2 synthesis and hydrolysis could be important determinants in regulating PLD action in signal transduction and membrane transport.
Collapse
Affiliation(s)
- M Liscovitch
- Department of Hormone Research, Weizmann Institute of Science, Rehovot, Israel
| | | | | | | | | |
Collapse
|
33
|
Abstract
We observed that peripheral T cells activated in vivo or in vitro by superantigens are susceptible to cell death when their antigen receptor is cross-linked with the appropriate anti-alpha beta TCR mAb. TCR ligation by mAbs specifically drove the T cell clonal deletion in both CD4+ and CD8+ cell subsets. An IL-2/IL-2R interaction seems to be a critical step in predisposing superantigen activated cells to death; in fact, in vivo IL-2R blockade reversed T cell deletion in superantigen plus anti-alpha beta TCR mAb treated mice. TCR ligation by mAbs also produced cell death of the relevant targets in in vitro IL-2 activated T cells. Surprisingly, no T cell deletion was demonstrable in IL-2 activated cells following staphylococcal enterotoxin B--TCR interaction, ruling out the possibility that superantigen in itself can induce cell death. Thus, while superantigen activation opens the cell death program, a subsequent TCR--antigen (self) interaction appears necessary to produce clonal deletion in mature T lymphocytes.
Collapse
Affiliation(s)
- G Biasi
- Institute of Experimental Pathology, Ancona, Italy
| | | | | | | | | |
Collapse
|
34
|
Affiliation(s)
- G Biasi
- Institute of Experimental Pathology, University of Ancona, Italy
| | | | | | | |
Collapse
|
35
|
Facchinetti A, Panozzo M, Pertile P, Tessarollo L, Biasi G. In vivo and in vitro death of mature T cells induced by separate signals to CD4 and alpha beta TCR. Immunobiology 1992; 185:380-9. [PMID: 1452211 DOI: 10.1016/s0171-2985(11)80654-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
To investigate whether a clonal deletion mechanism is responsible for the mature T cell tolerance that may be induced in vivo by TCR signal to anti-CD4 (H129.19 mAb) coated cells, we analyzed the T cell repertoire in anti-CD4 mAb treated BALB/c mice by flow cytometry following TCR signals through anti-alpha beta TCR mAb or SEB superantigen. Lymph nodes showed a strong reduction in the CD4+/CD8+ cell ratio, and a selective clonal loss of CD4+ V beta 8+ cells 4d following anti-alpha beta TCR or SEB injection, respectively. Following lymph node cell activation in a short-term in vitro assay with SEB or anti-V beta 8 mAb, a selective elimination of CD4+ V beta 8+ cells was again detected, and DNA fragmentation analysis disclosed a cell death by apoptosis. These findings suggest that TCR triggering transduces an apoptotic signal into CD4+ mAb saturated cells that in turn leads to specific holes in the mature T cell repertoire.
Collapse
|