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2.
Sci Rep ; 13(1): 18386, 2023 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-37884548

RESUMO

Quantum mechanics increasingly penetrates modern technologies but, due to its non-deterministic nature seemingly contradicting our classical everyday world, our comprehension often stays elusive. Arguing along the correspondence principle, classical mechanics is often seen as a theory for large systems where quantum coherence is completely averaged out. Surprisingly, it is still possible to reconstruct the coherent dynamics of a quantum bit (qubit) by using a classical model system. This classical-to-quantum analogue is based on wave mechanics, which applies to both, the classical and the quantum world. In this spirit we investigate the dynamics of macroscopic physical pendula with a modulated coupling. As a proof of principle, we demonstrate full control of our one-to-one analogue to a qubit by realizing Rabi oscillations, Landau-Zener transitions and Landau-Zener-Stückelberg-Majorana interferometry. Our classical qubit demonstrator can help comprehending and developing useful quantum technologies.

3.
Commun Med (Lond) ; 2: 24, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35603294

RESUMO

Background: Pancreas surgery remains technically challenging and is associated with considerable morbidity and mortality. Identification of predictive risk factors for complications have led to a stratified surgical approach and postoperative management. The option of simultaneous islet autotransplantation (sIAT) allows for significant attenuation of long-term metabolic and overall complications and improvement of quality of life (QoL). The potential of sIAT to stratify a priori the indication for total pancreatectomy is yet not adequately evaluated. Methods: The aim of this analysis was to evaluate the potential of sIAT in patients undergoing total pancreatectomy to improve QoL, functional and overall outcome and therefore modify the surgical strategy towards earlier and extended indications. A center cohort of 24 patients undergoing pancreatectomy were simultaneously treated with IAT. Patients were retrospectively analyzed regarding in-hospital and overall mortality, postoperative complications, ICU stay, hospital stay, metabolic outcome, and QoL. Results: Here we present that all patients undergoing primary total pancreatectomy or surviving complicated two-stage pancreas resection and receiving sIAT show excellent metabolic outcome (33% insulin independence, 66% partial graft function; HbA1c 6,1 ± 1,0%) and significant benefit regarding QoL. Primary total pancreatectomy leads to significantly improved overall outcome and a significant reduction in ICU- and hospital stay compared to a two-stage completion pancreatectomy approach. Conclusions: The findings emphasize the importance of risk-stratified pancreas surgery. Feasibility of sIAT should govern the indication for primary total pancreatectomy particularly in high-risk patients. In rescue completion pancreatectomy sIAT should be performed whenever possible due to tremendous metabolic benefit and associated QoL.

4.
Langenbecks Arch Surg ; 407(5): 2085-2094, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35182180

RESUMO

PURPOSE: Chronic mesenteric ischemia (CMI) is a rare but life-threatening disease. This study reviewed outcomes in patients treated surgically for CMI by open treatment (OT) and endovascular treatment (ET), analyzing risk factors for endovascular failure. METHODS: Clinical data for 36 patients treated for CMI from 2007 to 2017 were retrospectively analyzed. The study's primary endpoint was symptom-free survival. The secondary endpoint was the primary technical success for endovascular and open surgical treatments. Risk factors for endovascular failure were identified by using univariate analysis. RESULTS: Patients were analyzed as treated: 21 patients (58.3%) in the ET and 15 (41.6%) in the OT group. Overall, 20 patients (56%) presented with abdominal angina, 9 (25%) with rest pain, and 7 (19%) without symptoms. An ET was initially attempted in 31 patients (86.1%). The conversion rate from ET to OT was 32.3%, which resulted in a primary technical success of 67.6% in ET and 100% in OT. Six patients from the ET group (19.3%) required surgical revision due to restenosis. One-year (OT 91.6% vs. ET 96.8%; n.s.) and three-year primary patency (OT 91.6% vs. ET 80.6%; n.s.) as well as 3-year symptom-free survival did not differ between the groups (OT 62.5% vs. ET 69.4%; n.s). Overall, in-hospital mortality was 2.8% (n = 1), which was not statistically different between the groups (OT 6% vs. ET 0%; n.s.). High-grade stenosis of the superior mesenteric artery tended to be associated with higher technical failure (P = 0.06). CONCLUSIONS: ET showed a comparable perioperative outcome with higher technical failure. OT was distinguished by excellent early and late technical success.


Assuntos
Procedimentos Endovasculares , Isquemia Mesentérica , Oclusão Vascular Mesentérica , Doença Crônica , Constrição Patológica , Humanos , Isquemia/etiologia , Isquemia Mesentérica/cirurgia , Oclusão Vascular Mesentérica/complicações , Oclusão Vascular Mesentérica/diagnóstico , Oclusão Vascular Mesentérica/cirurgia , Estudos Retrospectivos , Fatores de Risco , Stents/efeitos adversos , Fatores de Tempo , Resultado do Tratamento , Grau de Desobstrução Vascular
6.
Zentralbl Chir ; 146(5): 470-478, 2021 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-34666359

RESUMO

The classical approach of open repair (OR) for thoracic and thoracoabdominal aortic pathologies, including aneurysms and dissection, has been outnumbered by the use of fenestrated/branched (thoracic) endovascular aortic repair (f/b[T]EVAR) in recent years. Providing OR for complex cases in an aortic service requires a dedicated surgical setup and a huge body of expertise in this particular field.In order to reduce specific complications, such as perioperative mortality, kidney failure, spinal cord ischemia, stroke or bowel ischemia, it is necessary to apply cerebrospinal-spinal fluid drainage, point-of-care coagulation therapy, distal and retrograde aortic perfusion and sequential clamping. Despite the predominance of endovascular solutions, the specific OR expertise is still needed for specific indications, such as young patients, connective tissue disorder or aortic graft infections.Currently, the short and mid term results for f/b(T)EVAR outweigh those for OR, including the shorter hospital stay and less invasive procedures. However, OR provides better long-term results for overall mortality, re-intervention rates and secondary complications.In conclusion, in our opinion OR is a service that is still necessary for dedicated aortic centres, but will most likely become more frequent again in the years to come.


Assuntos
Aneurisma da Aorta Torácica , Implante de Prótese Vascular , Procedimentos Endovasculares , Aneurisma da Aorta Torácica/cirurgia , Humanos , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
7.
J Am Heart Assoc ; 10(17): e020231, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34420357

RESUMO

Background While numerous interventions effectively interfered with abdominal aortic aneurysm (AAA) formation/progression in preclinical models, none of the successes translated into clinical success. Hence, a systematic exploration of parallel and divergent processes in clinical AAA disease and its 2 primary models (the porcine pancreatic elastase and angiotensin-II infusion [AngII] murine model) was performed to identify mechanisms relevant for aneurysm disease. Methods and Results This study combines Movat staining and pathway analysis for histological and genomic comparisons between clinical disease and its models. The impact of a notable genomic signal for metabolic reprogramming was tested in a rescue trial (AngII model) evaluating the impact of 1-(4-pyridinyl)-3-(2-quinolinyl)-2-propen-1-one (PFK15)-mediated interference with main glycolytic switch PFKFB3. Histological evaluation characterized the AngII model as a dissection model that is accompanied by adventitial fibrosis. The porcine pancreatic elastase model showed a transient inflammatory response and aortic dilatation, followed by stabilization and fibrosis. Normalization of the genomic responses at day 14 confirmed the self-limiting nature of the porcine pancreatic elastase model. Clear parallel genomic responses with activated adaptive immune responses, and particularly strong signals for metabolic switching were observed in human AAA and the AngII model. Rescue intervention with the glycolysis inhibitor PFK15 in the AngII model showed that interference with the glycolytic switching quenches aneurysm formation. Conclusions Despite clear morphological contrasts, remarkable genomic parallels exist for clinical AAA disease and the AngII model. The metabolic response appears causatively involved in AAA progression and provides a novel therapeutic target. The clear transient genomic response classifies the porcine pancreatic elastase model as a disease initiation model.


Assuntos
Aneurisma da Aorta Abdominal , Angiotensina II , Animais , Aorta Abdominal/patologia , Aneurisma da Aorta Abdominal/induzido quimicamente , Aneurisma da Aorta Abdominal/genética , Aneurisma da Aorta Abdominal/patologia , Modelos Animais de Doenças , Fibrose , Genômica , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Elastase Pancreática , Suínos
8.
Ultrasound Med Biol ; 47(10): 2890-2902, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34325958

RESUMO

Ultrasound-guided intermediate cervical plexus blockade with perivascular infiltration of the carotid artery bifurcation perivacular block (PVB) is a reliable technique for regional anesthesia in carotid endarterectomy (CEA). We investigated the effect of the carotid bifurcation level (CBL) on PVB efficacy and safety in patients undergoing CEA. This prospective observational cohort study included 447 consecutive CEA patients who received PVB over a 6-y period. Vascular and neurologic puncture-related complications were recorded. The CBL was localized at the low level (C4 and C5 vertebra, low-level [LL] group) in 381 (85.2%) patients and at the high level (C2 and C3 vertebra, high-level [HL] group) in 66 (14.8%) patients. Local anesthetic supplementation by surgeons was necessary in 64 (14.3%) patients in the LL group and 38 (59.4%) patients in the HL group (p < 0.001) and was associated with a higher rate of central neurologic complications in the HL group (p = 0.031). Therefore, the efficacy of the PVB may be influenced by the CBL.


Assuntos
Bloqueio do Plexo Cervical , Endarterectomia das Carótidas , Artéria Carótida Interna , Plexo Cervical/diagnóstico por imagem , Humanos , Estudos Prospectivos , Ultrassonografia de Intervenção
9.
Leukemia ; 35(12): 3561-3567, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33976371

RESUMO

Humanized mouse models have become increasingly valuable tools to study human hematopoiesis and infectious diseases. However, human T-cell differentiation remains inefficient. We generated mice expressing human interleukin-7 (IL-7), a critical growth and survival factor for T cells, under the control of murine IL-7 regulatory elements. After transfer of human cord blood-derived hematopoietic stem and progenitor cells, transgenic mice on the NSGW41 background, termed NSGW41hIL7, showed elevated and prolonged human cellularity in the thymus while maintaining physiological ratios of thymocyte subsets. As a consequence, numbers of functional human T cells in the periphery were increased without evidence for pathological lymphoproliferation or aberrant expansion of effector or memory-like T cells. We conclude that the novel NSGW41hIL7 strain represents an optimized mouse model for humanization to better understand human T-cell differentiation in vivo and to generate a human immune system with a better approximation of human lymphocyte ratios.


Assuntos
Sangue Fetal/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Interleucina-7/metabolismo , Subpopulações de Linfócitos T/imunologia , Animais , Animais Geneticamente Modificados , Diferenciação Celular/fisiologia , Sangue Fetal/citologia , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/imunologia , Humanos , Interleucina-7/genética , Camundongos , Camundongos Transgênicos , Especificidade de Órgãos , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/metabolismo
10.
Langenbecks Arch Surg ; 406(3): 623-630, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33755764

RESUMO

PURPOSE: Visceral and renal artery aneurysms (VAA, RAA) are very rare pathologies. Both surgical and endovascular therapies are discussed as therapeutic options for ruptured and non-ruptured aneurysm repair; we describe our experience in the open and endovascular management of these entities. METHODS: Retrospective database analysis of 60 treated VAA and RAA in 59 patients between 1994 and 2020. Outcome data was descriptively analyzed. RESULTS: Thirty-seven aneurysms were surgically treated and 23 interventionally. In the total study cohort, we observed a mortality of 1.7% and a morbidity of 18.6%. One major complication occurred. The morbidity was higher after surgical repair in ruptured and non-ruptured cases. The mean aneurysm diameter was 30.5 ± 15.6 mm. Patients with hepatic or pancreaticoduodenal artery aneurysms presented more often in the stage of rupture, without differences in aneurysm size. The length of hospital stay after endovascular repair was significantly shorter compared to open surgical treatment (7.2 ± 6.9 days versus 11.8 ± 6.7 days, p = 0.014), but only in elective cases. Primary technical success was significantly better in patients that underwent surgical repair in an intention to treat analysis (100% versus 79.3%). The mean follow-up of the cohort was 53.5 months (range 3-207 months). CONCLUSION: Elective endovascular therapy and open surgery of VAA and RAA are safe procedures with a good periprocedural and long-term outcome. Surgical revascularization showed a better primary technical success but was associated with longer length of hospital stays.


Assuntos
Aneurisma , Implante de Prótese Vascular , Procedimentos Endovasculares , Aneurisma/diagnóstico por imagem , Aneurisma/cirurgia , Humanos , Artéria Renal/diagnóstico por imagem , Artéria Renal/cirurgia , Estudos Retrospectivos , Resultado do Tratamento , Vísceras/cirurgia
11.
Methods Mol Biol ; 2128: 115-134, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32180190

RESUMO

Safe and reliable large animal diabetes models are a key prerequisite for advanced preclinical studies on diabetes. Chemical induction is the standard model of diabetes in rodents but is often critiqued in higher animals due to reduced efficacy, relevant side effects, and inadequate mortality rate. In this chapter, we aim to describe both pharmacological and surgical approaches for reproducible and safe diabetes models in minipigs and primates. In addition, genetically modified pig models for diabetes research are described.


Assuntos
Criação de Animais Domésticos/métodos , Diabetes Mellitus Experimental/etiologia , Pancreatectomia/métodos , Anestesia/métodos , Animais , Animais Geneticamente Modificados , Glicemia/análise , Diabetes Mellitus Experimental/sangue , Insulina/administração & dosagem , Sistemas de Infusão de Insulina , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/metabolismo , Macaca mulatta , Monitorização Fisiológica/métodos , Organogênese , Pâncreas/embriologia , Pancreatectomia/efeitos adversos , Estreptozocina , Suínos , Porco Miniatura
12.
BMC Anesthesiol ; 19(1): 218, 2019 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-31771512

RESUMO

BACKGROUND: The ultrasound guided intermediate cervical plexus block with perivascular infiltration of the internal carotid artery (PVB) is a new technique for regional anesthesia in carotid endarterectomy (CEA). We conducted a pilot study investigating the effects of deep cervical block (DCB), intermediate cervical block alone (ICB) and PVB on perioperative complications in patients undergoing elective CEA. We hypothesized, that the ropivacaine plasma concentration is higher in patients receiving DCB compared to PVB and ICB. METHODS: In a randomized controlled pilot study thirty patients scheduled for elective CEA were randomly assigned into three groups: DCB receiving 20 mL ropivacaine 0.5% (n = 10), ICB receiving 20 mL ropivacaine 0.5% (n = 10) and PVB receiving 20 mL ropivacaine 0.5% and 10 mL ropivacaine 0,3% (n = 10). As primary outcome, plasma levels of ropivacaine were measured with high performance liquid chromatography before, 5, 10, 20, 60, and 180 min after the injection of ropivacaine. Secondary outcomes were vascular and neurological complications as well as patients' and surgeons' satisfaction. All analyses were performed on an intention-to-treat basis. Statistical significance was accepted at p < 0.05. RESULTS: No conversion to general anesthesia was necessary and we observed no signs of local anesthetic intoxication or accidental vascular puncture. Plasma concentration of ropivacaine was significantly higher in the DCB group compared to PVB and ICB (p < 0.001) and in the PVB group compared to ICB (p = 0.008). Surgeons' satisfaction was higher in the PVB group compared to ICB (p = 0.003) and patients' satisfaction was higher in the PVB group compared to ICB (p = 0.010) and DCB group (p = 0.029). Phrenic nerve paralysis was observed frequently in the DCB group (p < 0.05). None of these patients with hemi-diaphragmatic paralysis showed signs of respiratory distress. CONCLUSION: The ultrasound guided PVB is a safe and effective technique for CEA which is associated with lower plasma levels of local anesthetic than the standard DCB. Considering the low rate of complications in all types of regional anesthesia for CEA, larger randomized controlled trials are warranted to assess potential side effects among the blocks. TRIAL REGISTRATION: The trial was registered at German Clinical Trials Register (DRKS) on 04/05/2019 (DRKS00016705, retrospectively registered).


Assuntos
Anestésicos Locais/administração & dosagem , Bloqueio do Plexo Cervical/métodos , Endarterectomia das Carótidas/métodos , Ropivacaina/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Anestesia por Condução/métodos , Anestésicos Locais/farmacocinética , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Projetos Piloto , Ropivacaina/farmacocinética , Ultrassonografia de Intervenção
13.
PLoS One ; 14(3): e0213348, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30893334

RESUMO

Odontocetes have evolved a rich diversity of prey- and habitat-specific foraging strategies, which allows them to feed opportunistically on locally and temporally abundant prey. While habitat-specific foraging strategies have been documented for some odontocete species, this is less known for the harbour porpoise (Phocoena phocoena). We collected multiple years of acoustic data using echolocation click loggers to analyse porpoise occurrence and buzzing behaviour, indicating feeding, in the German Wadden Sea (North Sea). Seasonal, diel and tidal effects were studied using Generalised Estimating Equations (GEE-GAMs). Locally season, time of day and tidal time significantly influenced the probability of porpoise detections and detection of foraging sequences (buzzes). Hunting strategies, and therefore frequency of buzzes, were likely affected by prey distribution and large differences between POD locations indicated that porpoises used highly specific behaviour adapted to tide and time of day to efficiently feed on the available prey. Strong seasonal and spatial variation in diel and tidal effects underline the importance of long-term observations. Studies on porpoise behaviour are often based on short-term observations and might rather reflect a seasonal than a general pattern. The results of this study show clearly that significant changes in porpoise behaviour can be found in short and long-term observations. Here some features are based on short term determinants and others are stable over years and care should be taken about drawing general conclusions based on local patterns. Highly variable spatio-temporal patterns indicate a high flexibility of porpoises in a highly variable environment and address a challenge for complex conservation management plans.


Assuntos
Phocoena/fisiologia , Animais , Comportamento Animal , Ritmo Circadiano , Ecolocação , Ecossistema , Comportamento Alimentar , Mar do Norte , Phocoena/psicologia , Comportamento Predatório , Estações do Ano , Análise Espaço-Temporal , Ondas de Maré
14.
J Am Heart Assoc ; 6(12)2017 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-29191809

RESUMO

BACKGROUND: Clinical decision making in abdominal aortic aneurysms (AAA) relies completely on diameter. At this point, improved decision tools remain an unmet medical need. Our goal was to identify changes at the molecular level specifically leading up to AAA rupture. METHODS AND RESULTS: Aortic wall tissue specimens were collected during open elective (eAAA; n=31) or emergency repair of ruptured AAA (rAAA; n=17), and gene expression was investigated using microarrays. Identified candidate genes were validated with quantitative real-time polymerase chain reaction in an independent sample set (eAAA: n=46; rAAA: n=18). Two gene sets were identified, 1 set containing 5 genes linked to terminal progression, that is, positively associated with progression of larger AAA, and with rupture (HILPDA, ANGPTL4, LOX, SRPX2, FCGBP), and a second set containing 5 genes exclusively upregulated in rAAA (ADAMTS9, STC1, GFPT2, GAL3ST4, CCL4L1). Genes in both sets essentially associated with processes related to impaired tissue remodeling, such as angiogenesis and adipogenesis. In gene expression experiments we were able to show that upregulated gene expression for identified candidate genes is unique for AAA. Functionally, the selected upregulated factors converge at processes coordinated by the canonical HIF-1α signaling pathway and are highly expressed in fibroblasts but not inflammatory cells of the aneurysmatic wall. Histological quantification of angiogenesis and exploration of the HIF-1α network in rAAA versus eAAA shows enhanced microvessel density but also clear activation of the HIF-1α network in rAAA. CONCLUSIONS: Our study shows a specific molecular fingerprint for terminal AAA disease. These changes appear to converge at activation of HIF-1α signaling in mesenchymal cells. Aspects of this cascade might represent targets for rupture risk assessment.


Assuntos
Aorta Abdominal/metabolismo , Aneurisma da Aorta Abdominal/genética , Ruptura Aórtica/genética , Transcriptoma , Aorta Abdominal/patologia , Aorta Abdominal/cirurgia , Aneurisma da Aorta Abdominal/mortalidade , Aneurisma da Aorta Abdominal/patologia , Aneurisma da Aorta Abdominal/cirurgia , Ruptura Aórtica/mortalidade , Ruptura Aórtica/patologia , Ruptura Aórtica/cirurgia , Células Cultivadas , Fibroblastos/metabolismo , Fibroblastos/patologia , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes , Estudos de Associação Genética , Marcadores Genéticos , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Análise de Sequência com Séries de Oligonucleotídeos , Valor Preditivo dos Testes , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Risco , Transdução de Sinais
15.
Proc Natl Acad Sci U S A ; 114(44): 11745-11750, 2017 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-29078330

RESUMO

Transplantation of pancreatic islets for treating type 1 diabetes is restricted to patients with critical metabolic lability resulting from the need for immunosuppression and the shortage of donor organs. To overcome these barriers, we developed a strategy to macroencapsulate islets from different sources that allow their survival and function without immunosuppression. Here we report successful and safe transplantation of porcine islets with a bioartificial pancreas device in diabetic primates without any immune suppression. This strategy should lead to pioneering clinical trials with xenotransplantation for treatment of diabetes and, thereby, represents a previously unidentified approach to efficient cell replacement for a broad spectrum of endocrine disorders and other organ dysfunctions.


Assuntos
Diabetes Mellitus Experimental/cirurgia , Diabetes Mellitus Tipo 1/cirurgia , Diabetes Mellitus Tipo 1/terapia , Ilhotas Pancreáticas/cirurgia , Animais , Feminino , Terapia de Imunossupressão/métodos , Transplante das Ilhotas Pancreáticas/métodos , Primatas , Suínos , Transplante Heterólogo/métodos
16.
Xenotransplantation ; 24(1)2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28130838

RESUMO

BACKGROUND: The transplantation of porcine islets into man might soon become reality for patients with type 1 diabetes mellitus. Therefore, porcine islets of high quality and quantity, and a scalable isolation process with strict quality control will be an unconditional prerequisite to enable the best possible transplantation graft. In this study, we provide a comparative study evaluating islet isolation outcome and in vitro survival based upon donor age, organ preservation solution (OPS), and cold ischemia time (CIT). METHODS: Goettingen minipigs of younger age (1 year) and retired breeder animals (3.5 years) were studied. Pancreata were harvested according to the standards of human organ retrieval including in situ cold perfusion with either Custodiol® -HTK or Belzer® UW solution. Pancreatic tissue was characterized by quantification of apoptotic cells. Islet isolations were performed according to a modified Ricordi method, and isolation outcome was assessed by determining islet particle numbers (IP), islet equivalents (IEQ), and isolation factor (IF). Isolated islets were cultured for 24 and 48 h for the assessment of in vitro survival. RESULTS: Islet viability was significantly higher in Custodiol® -HTK preserved pancreas organs compared to Belzer® UW. Furthermore, organs harvested from retired breeder preserved in Custodiol® -HTK resulted in stable islet isolation yields even after prolonged CIT and showed superior survival rates of islets in vitro compared to the Belzer® UW group. Younger porcine donor organs resulted generally in lower islet yield and survival rates. CONCLUSIONS: In summary, Custodiol® -HTK solution should be preferred over Belzer® UW solution for the preservation of pancreata from porcine origin. Custodiol® -HTK allows for maintaining islet viability and promotes reproducible isolation outcome and survival even after longer CIT. The usage of retired breeder animals over young animals for islet isolation is highly advisable to yield high quality and quantity.


Assuntos
Isquemia Fria , Coleta de Tecidos e Órgãos , Animais , Isquemia Fria/métodos , Transplante das Ilhotas Pancreáticas/métodos , Soluções para Preservação de Órgãos , Pâncreas , Suínos , Porco Miniatura , Fatores de Tempo , Coleta de Tecidos e Órgãos/métodos , Transplante Heterólogo/métodos
17.
J Vasc Surg ; 64(2): 380-388.e1, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27763266

RESUMO

BACKGROUND: Peripheral arterial disease (PAD) is one of the most underestimated diseases because of its high prevalence and unfavorable prognosis. Many PAD patients without suitable autologous veins or options for endovascular treatment receive prosthetic above-knee femoropopliteal bypass (PAKB). Until now predictors of prosthetic bypass failure and of increased amputation risk remain indistinct. This study aimed to identify predictive factors associated with better bypass patency and limb salvage to achieve a more favorable outcome after PAKB reconstruction. METHODS: Pre-, intra-, and postoperative data of 244 PAKB procedures performed at a German university medical center were collected and analyzed using univariate and multivariate methods. To our knowledge this 12-year experience is the largest retrospective study to identify predictors for patency and limb salvage after PAKB reconstruction. RESULTS: Of the PAD patients 94% (229/244) were followed for an average of 34.9 months. Patient cohorts characteristics were: mean age, 66.1 years, 181 men (74%), claudication (64%), rest pain (16%), ischemic lesions (20%), arterial hypertension (92%), smoking (79%), hyperlipidemia (65%) and type 2 diabetes (43%). Cumulative primary 1- and 3-year graft patency rates were 60.8% and 50.7%, respectively, and cumulative 1- and 3-year limb salvage rates were 89.3% and 86.1%, respectively. One hundred seven bypasses (43.9%) failed, 26 patients (10.7%) required a major and seven patients (2.9%) required a minor amputation. Overall survival rates of PAD patients after 1- and 3-years were 94.4% and 82.9%, respectively. Subjective symptom improvement was found to be the most important prognostic follow-up factor for graft patency and limb salvage. Patients with recurrent symptoms in the follow-up had an increased risk of emerging bypass failure compared with patients with subjective symptom improvement (patency at 1 year: 40.8% vs 100% and at 3 years: 26% vs 100%; P < .001). No patient with subjective improvement in symptoms during follow-up underwent an amputation (limb salvage at 1 year: 100% vs 79% and at 3 years: 100% vs 72.8%; P < .001). Therefore, subjective symptom improvement should be the decisive criterion to determine follow-up intervals of PAD patients. In univariate analysis further significant factors associated with better graft patency and limb salvage rates were: claudication compared with critical ischemia, larger graft diameter (>6 mm), pre- and postoperative antiplatelet therapy, statin therapy independent from lipid values after PAKB revascularization, and an experienced vascular surgeon. CONCLUSIONS: In our study, we determined the subjective improvement in symptoms as the most important prognostic factor for bypass function and limb salvage after PAKB. Furthermore, disease stage of critical ischemia, graft diameter, preoperative aspirin use, and postoperative statin medication were independent predictive factors. Therefore, PAD patients should be treated with aspirin pre- and postoperatively as well as with a statin postoperatively. In case of PAKB reconstruction only prostheses with a large diameter (>6 mm) should be used and the procedure should be performed by an experienced surgeon. Considering these results with regard to the predictive factors for better graft patency and limb salvage rates a significant more favorable outcome during the follow-up and an increased 5-year patency rate for PAKB reconstructions can be expected.


Assuntos
Implante de Prótese Vascular , Claudicação Intermitente/cirurgia , Isquemia/cirurgia , Salvamento de Membro , Extremidade Inferior/irrigação sanguínea , Doença Arterial Periférica/cirurgia , Procedimentos de Cirurgia Plástica , Grau de Desobstrução Vascular , Centros Médicos Acadêmicos , Idoso , Amputação Cirúrgica , Implante de Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/mortalidade , Distribuição de Qui-Quadrado , Estado Terminal , Feminino , Alemanha , Oclusão de Enxerto Vascular/etiologia , Oclusão de Enxerto Vascular/fisiopatologia , Oclusão de Enxerto Vascular/cirurgia , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Claudicação Intermitente/diagnóstico por imagem , Claudicação Intermitente/mortalidade , Claudicação Intermitente/fisiopatologia , Isquemia/diagnóstico por imagem , Isquemia/mortalidade , Isquemia/fisiopatologia , Estimativa de Kaplan-Meier , Modelos Logísticos , Masculino , Análise Multivariada , Razão de Chances , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/mortalidade , Doença Arterial Periférica/fisiopatologia , Inibidores da Agregação Plaquetária/uso terapêutico , Modelos de Riscos Proporcionais , Fatores de Proteção , Procedimentos de Cirurgia Plástica/efeitos adversos , Procedimentos de Cirurgia Plástica/mortalidade , Recuperação de Função Fisiológica , Recidiva , Reoperação , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
18.
Xenotransplantation ; 23(5): 405-13, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27506420

RESUMO

BACKGROUND: Safe and reliable diabetes models are a key prerequisite for advanced preclinical studies on diabetes. Chemical induction is the standard model of diabetes in rodents and also widely used in large animal models of non-human primates and minipigs. However, uncertain efficacy, the potential of beta-cell regeneration, and relevant side effects are debatable aspects particularly in large animals. Therefore, we aimed to evaluate a surgical approach of total pancreatectomy combined with splenectomy for diabetes induction in an exploratory study in Goettingen minipigs. METHODS: Total pancreatectomy was performed in Goettingen minipigs (n = 4) under general anesthesia and endotracheal intubation. Prior to surgery, a central venous line was established for drug application and blood sampling. After median laparotomy, splenectomy was performed and the lobular pancreas was carefully dissected with particular attention to the duodenal vascular arcade. Close monitoring of blood glucose was initiated immediately after surgery by standard glucometer measurement or continuous glucose monitoring systems (CGMS). Exogenous insulin was given by multiple daily subcutaneous (s.c.) injections or via insulin pump systems (CSII). Complete endogenous insulin deficiency was confirmed by intravenous glucose tolerance test (ivGTT) and measurement of c-peptide. For establishing a suitable regimen for diabetes management, the animals were followed for 4-6 weeks. RESULTS: Following pancreatectomy and splenectomy, the animals showed a quick recovery from surgery and initial analgetic medication and volume substitution could be terminated within 24 h. A rapid increase in blood glucose was observed immediately following pancreatectomy necessitating insulin therapy. The induced exocrine insufficiency did not cause any clinical symptoms. Complete insulin deficiency could be confirmed in all animals by determination of negative c-peptide during glucose challenge. The two regimen of insulin treatment (multiple daily injections (MDI) and continuous subcutaneous insulin infusion (CSII)) were both feasible with respect to acceptable glycemic control whereas CSII was considerably advantageous in comfort and popularity for both animals and care takers. CONCLUSIONS: Surgical pancreatectomy in combination with splenectomy to facilitate access to the pancreas is a feasible model for efficient diabetes induction in minipigs. The procedure itself and postoperative animal care could be performed without complications in this exploratory study. Nevertheless, this approach requires well-equipped infrastructure, experienced and skilled surgeons and anesthesiologists and dedicated animal care takers. The impact of total pancreatectomy in combination with splenectomy on the digestive and immune system must be considered in the design and definition of end points of experimental diabetes and transplantation studies.


Assuntos
Diabetes Mellitus Experimental , Pancreatectomia , Esplenectomia , Animais , Glicemia/metabolismo , Feminino , Teste de Tolerância a Glucose/métodos , Sistemas de Infusão de Insulina , Células Secretoras de Insulina , Pancreatectomia/métodos , Esplenectomia/métodos , Suínos , Porco Miniatura , Transplante Heterólogo/métodos
19.
Xenotransplantation ; 23(4): 320-7, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27440468

RESUMO

BACKGROUND: Xenotransplantation using pig cells, tissues or organs may be associated with the transmission of porcine zoonotic micro-organisms. Hepatitis E virus (HEV), porcine cytomegalovirus (PCMV) and porcine endogenous retroviruses (PERVs) are potentially zoonotic micro-organisms which do not show clinical symptoms in pigs and which are due to the low expression level difficult to detect. Göttingen Minipigs (GöMP) are often used for biomedical investigations and they are well characterized concerning the presence of numerous bacteria, fungi, viruses and parasites and therefore may be used for islet cell transplantation. METHODS: Islet cells derived from three GöMP were transplanted into four healthy, non-diabetic cynomolgus monkeys using a macroencapsulation device. PCR, nested PCR, real-time PCR, real-time RT-PCR and Western blot analyses were used to estimate the presence of PERV, PCMV and HEV in the donors and recipients. RESULTS: Using sensitive detection methods, no HEV was found in the donor pigs and in the pig islet cell preparations. Antibodies against PERV, PCMV and HEV were not found in all cynomolgus monkeys with exception of one monkey showing an immune response against HEV. Using real-time PCR, no PCMV and HEV were found in the sera of all monkeys. CONCLUSION: Although the donor islet cells and the recipients were negative for HEV using PCR and Western blot analysis, in one recipient, antibodies against HEV were found, indicating infection in a single case. All recipients were negative for antibodies against PERV, and all were negative for PCMV, indicating absence of infection. As HEV was not detected in the donor pig before transplantation, a more complex and regular screening of the animals using highly sensitive methods is required to avoid virus transmission.


Assuntos
Ilhotas Pancreáticas/virologia , Macaca fascicularis/virologia , Porco Miniatura/virologia , Transplante Heterólogo , Animais , Vírus de DNA/genética , Retrovirus Endógenos , Vírus da Hepatite E , Transplante das Ilhotas Pancreáticas/métodos , Suínos , Transplante Heterólogo/métodos
20.
Adv Exp Med Biol ; 875: 547-54, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26611003

RESUMO

Within the European Defense Agency (EDA), the Protection of Marine Mammals (PoMM) project, a comprehensive common marine mammal database essential for risk mitigation tools, was established. The database, built on an extensive dataset collection with the focus on areas of operational interest for European navies, consists of annual and seasonal distribution and density maps, random and systematic sightings, an encyclopedia providing knowledge on the characteristics of 126 marine mammal species, data on marine mammal protection areas, and audio information including numerous examples of various vocalizations. Special investigations on marine mammal acoustics were carried out to improve the detection and classification capabilities.


Assuntos
Organismos Aquáticos/fisiologia , Conservação dos Recursos Naturais , Mamíferos/fisiologia , Acústica , Animais , Geografia , Estações do Ano , Baleias/fisiologia
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