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Jens Gottlieb

Publications and source records attributed to Jens Gottlieb.

6 recordsLinked to original sources
PubMed2006

Bridge to lung transplantation with the novel pumpless interventional lung assist device NovaLung.

BACKGROUND: Worsening of lung failure in patients awaiting a lung transplantation might lead to ventilation-refractory hypercapnia and respiratory acidosis. Most transplant centers consider pretransplantation extracorporeal membrane oxygenation as a contraindication for lung transplantation because of the poor outcome. We have, for the first time, applied the novel pumpless interventional lung assist NovaLung for bridge to lung transplantation in patients with severe ventilation-refractory hypercapnia. We report on our initial experience. METHODS: Between March 2003 and March 2005, 176 lung transplantations were performed, of which 60% were high-urgency lung transplantations. Twelve of the high-urgency recipients had severe ventilation-refractory hypercapnia and respiratory acidosis. These patients were connected to the novel pumpless interventional lung assist NovaLung for bridge to lung transplantation. RESULTS: The length of interventional lung assist NovaLung support was 15 +/- 8 days (4-32 days). PaO2, pH, and PaCO2 levels in arterial blood prior to interventional lung assist NovaLung implantation were 71 +/- 27 mm Hg, 7.121 +/- 0.1, and 128 +/- 42 mm Hg, respectively. Six hours after interventional lung assist NovaLung implantation, PaO2, pH, and PaCO2 levels had changed to 83 +/- 17 mm Hg (ns), 7.344 +/- 0.1 (P < .05), and 52 +/- 5 mm Hg (P < .05), respectively. Four patients died of multiorgan failure, 2 patients before and 2 after lung transplantation. Thus, 10 out of 12 patients were successfully bridged to lung transplantation, and 8 are still alive (1-year survival, 80%). CONCLUSIONS: This report suggests that interventional lung assist NovaLung implantation is an effective bridge to lung transplantation strategy in patients with ventilation-refractory hypercapnia.

Acidosis, Respiratory↗
PubMed2006

Long-term outcome after pulmonary retransplantation.

OBJECTIVE: Bronchiolitis obliterans syndrome has become the most limiting factor for long-term outcome after lung transplantation. Redo lung transplantation was performed for end-stage bronchiolitis obliterans syndrome. Long-term outcome was compared with that after primary lung transplantation as well as with other indications for retransplantation. METHODS: Of 614 lung transplantation procedures performed at our institution, 54 (8.5%) were redo transplants. These were stratified into different groups according to the indication for redo transplantation, including chronic graft failure/bronchiolitis obliterans syndrome, acute graft failure, and posttransplantation airway complications. Long-term survival was compared with that of the primary lung transplantation cohort, thereby respecting the need for pretransplant mechanical ventilatory support in a subanalysis. In addition, recurrence of bronchiolitis obliterans syndrome after redo lung transplantation was compared with the occurrence of bronchiolitis obliterans after primary transplantation. RESULTS: A 1-year survival of 50% was achieved after redo lung transplantation for acute graft failure and airway complications as well as after primary lung transplantation in patients with pretransplant ventilatory support. Retransplantation for bronchiolitis obliterans syndrome revealed superior 1- (78%) and 5-year (62%) survivals, which were not different from those of first-time lung transplant recipients. In addition, we found a similar incidence of bronchiolitis syndrome after retransplantation for BOS compared with its occurrence after primary lung transplantation. CONCLUSION: Redo lung transplantation for end-stage bronchiolitis obliterans syndrome leads to acceptable long-term outcome in selected patients. Future analyses of redo lung transplantation data should generally stratify bronchiolitis obliterans syndrome from other indications with higher mortality.

Adolescent↗
PubMed2005

Health-related quality of life in two hundred-eighty lung transplant recipients.

BACKGROUND: Health-related quality of life (HRQoL) has increasingly been accepted as a supplementary outcome measure for patients after lung transplantation (LTx). METHODS: Using a retrospective cross-sectional study design, 280 LTx recipients (3 months to 14 years after LTx) were asked to assess their HRQoL using a generic (Quality of Life Profile for Chronic Diseases) questionnaire, which was previously validated for this specific population. In addition, the questionnaire was also performed by 155 healthy participants. RESULTS: All sub-scale findings ranged from 2.40 to 3.08 (0 to 4) for all patients after LTx. A significantly reduced HRQoL was reported by the sub-cohort of patients living 5 to 6 years with the allograft for all sub-scales (p < 0.006), except for Social Functioning, and was associated with the incidence of bronchiolitis obliterans syndrome (BOS; p < 0.05). Cystic fibrosis patients (p < 0.05), single-lung transplant recipients (p < 0.05) and patients of older age (p < 0.05) showed significantly decreased physical ability ratings. Patients who remained free of infection and late acute rejection episodes scored themselves significantly higher with regard to their Relaxation Capabilities (p < 0.05 for rejection; p < 0.05 for infection) and Social Functioning (p < 0.01 for rejection; p < 0.05 for infection) vs patients who experienced infection or rejection episodes. Comparisons with a normative cohort showed similar HRQoL scales for LTx patients and the healthy population, except with regard to Social Functioning (p < 0.01). CONCLUSIONS: Self-ratings for HRQoL were high for all dimensions for the entire sample, and remained relatively similar even for medium- and long-term survivors. HRQoL was dependent on incidence of infections, rejections and the onset of BOS. Despite differences in life expectancy of LTx patients compared with the healthy population, HRQoL self-ratings were within similar ranges.

Adolescent↗
PubMed2005

Empirical analysis of locality, heritability and heuristic bias in evolutionary algorithms: a case study for the multidimensional knapsack problem.

Our main aim is to provide guidelines and practical help for the design of appropriate representations and operators for evolutionary algorithms (EAs). For this purpose, we propose techniques to obtain a better understanding of various effects in the interplay of the representation and the operators. We study six different representations and associated variation operators in the context of a steady-state evolutionary algorithm for the multidimensional knapsack problem. Four of them are indirect decoder-based techniques, and two are direct encodings combined with different initialization, repair, and local improvement strategies. The complex decoders and the local improvement and repair strategies make it practically impossible to completely analyze such EAs in a fully theoretical way. After comparing the general performance of the chosen EA variants for the multidimensional knapsack problem on two benchmark suites, we present a hands-on approach for empirically analyzing important aspects of initialization, mutation, and crossover in an isolated fashion. Static, inexpensive measurements based on randomly created solutions are performed in order to quantify and visualize specific properties with respect to heuristic bias, locality, and heritability. These tests shed light onto the complex behavior of such EAs and point out reasons for good or bad performance. In addition, the proposed measures are also examined during actual EA runs, which gives further insight into dynamic aspects of evolutionary search and verifies the validity of the isolated static measurements. All measurements are described in a general way, allowing for an easy adaption to other representations and problems.

Algorithms↗
PubMed2002

Evolutionary algorithms for the satisfiability problem.

Several evolutionary algorithms have been proposed for the satisfiability problem. We review the solution representations suggested in literature and choose the most promising one - the bit string representation - for further evaluation. An empirical comparison on commonly used benchmarks is presented for the most successful evolutionary algorithms and for WSAT, a prominent local search algorithm for the satisfiability problem. The key features of successful evolutionary algorithms are identified, thereby providing useful methodological guidelines for designing new heuristics. Our results indicate that evolutionary algorithms are competitive to WSAT.

Algorithms↗