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1.
Alzheimers Dement ; 20(6): 4351-4365, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38666355

RESUMEN

INTRODUCTION: Amyloid beta and tau pathology are the hallmarks of sporadic Alzheimer's disease (AD) and autosomal dominant AD (ADAD). However, Lewy body pathology (LBP) is found in ≈ 50% of AD and ADAD brains. METHODS: Using an α-synuclein seed amplification assay (SAA) in cerebrospinal fluid (CSF) from asymptomatic (n = 26) and symptomatic (n = 27) ADAD mutation carriers, including 12 with known neuropathology, we investigated the timing of occurrence and prevalence of SAA positive reactivity in ADAD in vivo. RESULTS: No asymptomatic participant and only 11% (3/27) of the symptomatic patients tested SAA positive. Neuropathology revealed LBP in 10/12 cases, primarily affecting the amygdala or the olfactory areas. In the latter group, only the individual with diffuse LBP reaching the neocortex showed α-synuclein seeding activity in CSF in vivo. DISCUSSION: Results suggest that in ADAD LBP occurs later than AD pathology and often as amygdala- or olfactory-predominant LBP, for which CSF α-synuclein SAA has low sensitivity. HIGHLIGHTS: Cerebrospinal fluid (CSF) real-time quaking-induced conversion (RT-QuIC) detects misfolded α-synuclein in ≈ 10% of symptomatic autosomal dominant Alzheimer's disease (ADAD) patients. CSF RT-QuIC does not detect α-synuclein seeding activity in asymptomatic mutation carriers. Lewy body pathology (LBP) in ADAD mainly occurs as olfactory only or amygdala-predominant variants. LBP develops late in the disease course in ADAD. CSF α-synuclein RT-QuIC has low sensitivity for focal, low-burden LBP.


Asunto(s)
Enfermedad de Alzheimer , Cuerpos de Lewy , alfa-Sinucleína , Humanos , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/líquido cefalorraquídeo , alfa-Sinucleína/líquido cefalorraquídeo , alfa-Sinucleína/genética , Femenino , Masculino , Persona de Mediana Edad , Cuerpos de Lewy/patología , Anciano , Mutación , Encéfalo/patología , Péptidos beta-Amiloides/líquido cefalorraquídeo , Péptidos beta-Amiloides/metabolismo , Progresión de la Enfermedad
2.
J Environ Manage ; 352: 119960, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38198838

RESUMEN

Nutrient recovery from wastewater treatment plants (WWTPs) for hydroponic cultivation holds promise for closing the nutrient loop and meeting rising food demands. However, most studies focus on solid products for soil-based agriculture, thus raising questions about their suitability for hydroponics. In this study, we address these questions by performing the first in-depth assessment of the extent to which state-of-the-art nutrient recovery processes can generate useful products for hydroponic application. Our results indicate that less than 11.5% of the required nutrients for crops grown hydroponically can currently be recovered. Potassium nitrate (KNO3), calcium nitrate (Ca(NO3)2), and magnesium sulfate (MgSO4), constituting over 75% of the total nutrient demand for hydroponics, cannot be recovered in appropriate form due to their high solubility, hindering their separated recovery from wastewater. To overcome this challenge, we outline a novel nutrient recovery approach that emphasizes the generation of multi-nutrient concentrates specifically designed to meet the requirements of hydroponic cultivation. Based on a theoretical assessment of nutrient and contaminant flows in a typical municipal WWTP, utilizing a steady-state model, we estimated that this novel approach could potentially supply up to 56% of the nutrient requirements of hydroponic systems. Finally, we outline fundamental design requirements for nutrient recovery systems based on this new approach. Achieving these nutrient recovery potentials could be technically feasible through a combination of activated sludge processes for nitrification, membrane-based desalination processes, and selective removal of interfering NaCl. However, given the limited investigation into such treatment trains, further research is essential to explore viable system designs for effective nutrient recovery for hydroponics.


Asunto(s)
Aguas Residuales , Purificación del Agua , Hidroponía , Fertilizantes , Nutrientes , Purificación del Agua/métodos
3.
BMC Neurol ; 23(1): 308, 2023 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-37608315

RESUMEN

BACKGROUND: Persisting coma is a common complication in (neuro)intensive care in neurological disease such as acute ischemic stroke, intracerebral hemorrhage or subarachnoid hemorrhage. Amantadine acts as a nicotinic receptor antagonist, dopamine receptor agonist and non-competitive N-Methyl-D-aspartate receptor antagonist. Amantadine is a long-known drug, originally approved for treatment of influenza A and Parkinson`s Disease. It has been proven effective in improving vigilance after traumatic brain injury. The underlying mechanisms remain largely unknown, albeit anti-glutamatergic and dopaminergic effects might be most relevant. With limited evidence of amantadine efficacy in non-traumatic pathologies, the aim of our study is to assess the effects of amantadine for neuroenhancement in non-traumatic neurointensive patients with persisting coma. METHODS: An investigator-initiated, monocenter, phase IIb proof of concept open-label pilot study will be carried out. Based on the Simon design, 43 adult (neuro)intensive care patients who meet the clinical criteria of persisting coma not otherwise explained and < 8 points on the Glasgow Coma Scale (GCS) will be recruited. Amantadine will be administered intravenously for five days at a dosage of 100 mg bid. The primary endpoint is an improvement of at least 3 points on the GCS. If participants present as non-responders (increase < 3 points or decrease on the GCS) within the first 48 h, the dosage will be doubled from day three to five. Secondary objectives aim to demonstrate that amantadine improves vigilance via alternative scales. Furthermore, the incidence of adverse events will be investigated and electroencephalography (EEG) will be recorded at baseline and end of treatment. DISCUSSION: The results of our study will help to systematically assess the clinical utility of amantadine for treatment of persisting coma in non-traumatic brain injury. We expect that, in the face of only moderate treatment risk, a relevant number of patients will benefit from amantadine medication by improved vigilance (GCS increase of at least 3 points) finally leading to a better rehabilitation potential and improved functional neurological outcome. Further, the EEG data will allow evaluation of brain network states in relation to vigilance and potentially outcome prediction in this study cohort. TRIAL REGISTRATION: NCT05479032.


Asunto(s)
Lesiones Traumáticas del Encéfalo , Lesiones Encefálicas , Accidente Cerebrovascular Isquémico , Adulto , Humanos , Amantadina/uso terapéutico , Ensayos Clínicos Fase II como Asunto , Coma , Proyectos Piloto , Estudios Prospectivos , Prueba de Estudio Conceptual
4.
Cell Mol Life Sci ; 79(3): 185, 2022 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-35279766

RESUMEN

Golgi membrane proteins such as glycosyltransferases and other glycan-modifying enzymes are key to glycosylation of proteins and lipids. Secretion of soluble Golgi enzymes that are released from their membrane anchor by endoprotease activity is a wide-spread yet largely unexplored phenomenon. The intramembrane protease SPPL3 can specifically cleave select Golgi enzymes, enabling their secretion and concomitantly altering global cellular glycosylation, yet the entire range of Golgi enzymes cleaved by SPPL3 under physiological conditions remains to be defined. Here, we established isogenic SPPL3-deficient HEK293 and HeLa cell lines and applied N-terminomics to identify substrates cleaved by SPPL3 and released into cell culture supernatants. With high confidence, our study identifies more than 20 substrates of SPPL3, including entirely novel substrates. Notably, our N-terminome analyses provide a comprehensive list of SPPL3 cleavage sites demonstrating that SPPL3-mediated shedding of Golgi enzymes occurs through intramembrane proteolysis. Through the use of chimeric glycosyltransferase constructs we show that transmembrane domains can determine cleavage by SPPL3. Using our cleavage site data, we surveyed public proteome data and found that SPPL3 cleavage products are present in human blood. We also generated HEK293 knock-in cells expressing the active site mutant D271A from the endogenous SPPL3 locus. Immunoblot analyses revealed that secretion of select novel substrates such as the key mucin-type O-glycosylation enzyme GALNT2 is dependent on endogenous SPPL3 protease activity. In sum, our study expands the spectrum of known physiological substrates of SPPL3 corroborating its significant role in Golgi enzyme turnover and secretion as well as in the regulation of global glycosylation pathways.


Asunto(s)
Ácido Aspártico Endopeptidasas/metabolismo , Aparato de Golgi/metabolismo , N-Acetilgalactosaminiltransferasas/metabolismo , Proteolisis , Proteoma/análisis , Ácido Aspártico Endopeptidasas/deficiencia , Ácido Aspártico Endopeptidasas/genética , Dominio Catalítico/genética , Edición Génica , Células HEK293 , Células HeLa , Humanos , Mutagénesis Sitio-Dirigida , N-Acetilgalactosaminiltransferasas/genética , Proteómica/métodos , ARN Guía de Kinetoplastida/metabolismo , Especificidad por Sustrato , Polipéptido N-Acetilgalactosaminiltransferasa
5.
Alzheimers Dement ; 19(2): 632-645, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-35609137

RESUMEN

INTRODUCTION: As knowledge about neurological examination findings in autosomal dominant Alzheimer disease (ADAD) is incomplete, we aimed to determine the frequency and significance of neurological examination findings in ADAD. METHODS: Frequencies of neurological examination findings were compared between symptomatic mutation carriers and non mutation carriers from the Dominantly Inherited Alzheimer Network (DIAN) to define AD neurological examination findings. AD neurological examination findings were analyzed regarding frequency, association with and predictive value regarding cognitive decline, and association with brain atrophy in symptomatic mutation carriers. RESULTS: AD neurological examination findings included abnormal deep tendon reflexes, gait disturbance, pathological cranial nerve examination findings, tremor, abnormal finger to nose and heel to shin testing, and compromised motor strength. The frequency of AD neurological examination findings was 65.1%. Cross-sectionally, mutation carriers with AD neurological examination findings showed a more than two-fold faster cognitive decline and had greater parieto-temporal atrophy, including hippocampal atrophy. Longitudinally, AD neurological examination findings predicted a significantly greater decline over time. DISCUSSION: ADAD features a distinct pattern of neurological examination findings that is useful to estimate prognosis and may inform clinical care and therapeutic trial designs.


Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Humanos , Enfermedad de Alzheimer/patología , Disfunción Cognitiva/genética , Examen Neurológico
6.
Br J Surg ; 109(9): 839-845, 2022 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-35707932

RESUMEN

BACKGROUND: Incisional hernia remains a frequent problem after midline laparotomy. This study compared a short stitch to standard loop closure using an ultra-long-term absorbent elastic suture material. METHODS: A prospective, multicentre, parallel-group, double-blind, randomized, controlled superiority trial was designed for the elective setting. Adult patients were randomly assigned by computer-generated sequence to fascial closure using a short stitch (5 to 8 mm every 5 mm, USP 2-0, single thread HR 26 mm needle) or long stitch technique (10 mm every 10 mm, USP 1, double loop, HR 48 mm needle) with a poly-4-hydroxybutyrate-based suture material (Monomax®). Incisional hernia assessed by ultrasound 1 year after surgery was the primary outcome. RESULTS: The trial randomized 425 patients to short (n = 215) or long stitch technique (n = 210) of whom 414 (97.4 per cent) completed 1 year of follow-up. In the short stitch group, the fascia was closed with more stitches (46 (12 s.d.) versus 25 (7 s.d.); P < 0.001) and higher suture-to-wound length ratio (5.3 (2.2 s.d.) versus 4.0 (1.3 s.d.); P < 0.001). At 1 year, seven of 210 (3.3 per cent) patients in the short and 13 of 204 (6.4 per cent) patients in the long stitch group developed incisional hernia (odds ratio 1.97, 95 per cent confidence interval 0.77 to 5.05; P = 0.173). CONCLUSION: The 1-year incisional hernia development was relatively low with clinical but not statistical difference between short and long stitches. Registration number: NCT01965249 (http://www.clinicaltrials.gov).


Asunto(s)
Técnicas de Cierre de Herida Abdominal , Hernia Incisional , Adulto , Humanos , Hernia Incisional/cirugía , Laparotomía/métodos , Estudios Prospectivos , Técnicas de Sutura , Suturas
7.
Eur J Epidemiol ; 37(8): 849-870, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35904671

RESUMEN

The German government initiated the Network University Medicine (NUM) in early 2020 to improve national research activities on the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic. To this end, 36 German Academic Medical Centers started to collaborate on 13 projects, with the largest being the National Pandemic Cohort Network (NAPKON). The NAPKON's goal is creating the most comprehensive Coronavirus Disease 2019 (COVID-19) cohort in Germany. Within NAPKON, adult and pediatric patients are observed in three complementary cohort platforms (Cross-Sectoral, High-Resolution and Population-Based) from the initial infection until up to three years of follow-up. Study procedures comprise comprehensive clinical and imaging diagnostics, quality-of-life assessment, patient-reported outcomes and biosampling. The three cohort platforms build on four infrastructure core units (Interaction, Biosampling, Epidemiology, and Integration) and collaborations with NUM projects. Key components of the data capture, regulatory, and data privacy are based on the German Centre for Cardiovascular Research. By April 01, 2022, 34 university and 40 non-university hospitals have enrolled 5298 patients with local data quality reviews performed on 4727 (89%). 47% were female, the median age was 52 (IQR 36-62-) and 50 pediatric cases were included. 44% of patients were hospitalized, 15% admitted to an intensive care unit, and 12% of patients deceased while enrolled. 8845 visits with biosampling in 4349 patients were conducted by April 03, 2022. In this overview article, we summarize NAPKON's design, relevant milestones including first study population characteristics, and outline the potential of NAPKON for German and international research activities.Trial registration https://clinicaltrials.gov/ct2/show/NCT04768998 . https://clinicaltrials.gov/ct2/show/NCT04747366 . https://clinicaltrials.gov/ct2/show/NCT04679584.


Asunto(s)
COVID-19 , Pandemias , Adulto , COVID-19/epidemiología , Niño , Ensayos Clínicos como Asunto , Femenino , Humanos , Unidades de Cuidados Intensivos , Masculino , Persona de Mediana Edad , Proyectos de Investigación , SARS-CoV-2
8.
Sensors (Basel) ; 22(20)2022 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-36298274

RESUMEN

In recent years, it has become increasingly popular to solve inverse problems of various tomography methods with deep learning techniques. Here, a deep residual neural network (ResNet) is introduced to reconstruct the conductivity distribution of a biomedical, voluminous body in magnetic induction tomography (MIT). MIT is a relatively new, contactless and noninvasive tomography method. However, the ill-conditioned inverse problem of MIT is challenging to solve, especially for voluminous bodies with conductivities in the range of biological tissue. The proposed ResNet can reconstruct up to two cuboid perturbation objects with conductivities of 0.0 and 1.0 S/m in the whole voluminous body, even in the difficult-to-detect centre. The dataset used for training and testing contained simulated signals of cuboid perturbation objects with randomised lengths and positions. Furthermore, special care went into avoiding the inverse crime while creating the dataset. The calculated metrics showed good results over the test dataset, with an average correlation coefficient of 0.87 and mean squared error of 0.001. Robustness was tested on three special test cases containing unknown shapes, conductivities and a real measurement that showed error results well within the margin of the metrics of the test dataset. This indicates that a good approximation of the inverse function in MIT for up to two perturbation objects was achieved and the inverse crime was avoided.


Asunto(s)
Procesamiento de Imagen Asistido por Computador , Tomografía , Procesamiento de Imagen Asistido por Computador/métodos , Tomografía/métodos , Magnetismo , Conductividad Eléctrica , Redes Neurales de la Computación
9.
Nat Mater ; 18(2): 149-155, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30643236

RESUMEN

Molecular doping is a crucial tool for controlling the charge-carrier concentration in organic semiconductors. Each dopant molecule is commonly thought to give rise to only one polaron, leading to a maximum of one donor:acceptor charge-transfer complex and hence an ionization efficiency of 100%. However, this theoretical limit is rarely achieved because of incomplete charge transfer and the presence of unreacted dopant. Here, we establish that common p-dopants can in fact accept two electrons per molecule from conjugated polymers with a low ionization energy. Each dopant molecule participates in two charge-transfer events, leading to the formation of dopant dianions and an ionization efficiency of up to 200%. Furthermore, we show that the resulting integer charge-transfer complex can dissociate with an efficiency of up to 170%. The concept of double doping introduced here may allow the dopant fraction required to optimize charge conduction to be halved.

10.
Surg Endosc ; 31(11): 4717-4724, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28424908

RESUMEN

INTRODUCTION: Negative pressure wound therapy (NPWT) is widely used in the treatment of open abdomen (OA). The use of dynamic fascial sutures (DFS) increases the rate of successful delayed closure by reducing fascial lateralization. We recently published a prospective controlled trial including 87 patients undergoing abdominal surgery for secondary peritonitis between 2007 and 2012. Patients were treated with NPWT and DFS for approximation of fascial edges. The present study represents a follow-up assessment of these patients 5-9 years after OA treatment with NPWT and DFS. METHODS: The 39 patients still alive were included in the recent study according to the protocol of our last study in 2013. All patients received a questionnaire regarding long-term complications after OA treatment between 2007 and 2012. Mean follow-up was 5-9 years. Analyzed parameters included pain, the presence of incisional hernia, and subsequent surgical interventions. Results were analyzed quantitatively. RESULTS: One patient had deceased since the last publication in 2013, and hence 38 patients were included in the current study. The median age was 60.9 (25.2-86.1) years, and 17 (44.7%) were females. Overall 56.3% of the original 87 patients had died during the long-term follow-up period. 21 patients (55.3%) answered the questionnaire. Six (28.6%) declared that they suffered from pain in the previous operating field, five (23.8%) at rest, and three (14.3%) during exercise. In five patients (23.8%), pain lasted for more than 3 months. One patient (4.8%) still requires analgesic treatment. Among the 21 patients, seven (33.3%) were found to have incisional hernias. Three hernias (42.9%) were treated by surgery. CONCLUSION: Incisional hernia rates after OA treatment remain high, but are accompanied by little pain. The ideal technique of fascial closure after NPWT should be investigated in further research.


Asunto(s)
Técnicas de Cierre de Herida Abdominal/efectos adversos , Terapia de Presión Negativa para Heridas/métodos , Peritonitis/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Fascia , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Terapia de Presión Negativa para Heridas/efectos adversos , Peritonitis/etiología , Complicaciones Posoperatorias/epidemiología , Estudios Prospectivos , Mallas Quirúrgicas , Encuestas y Cuestionarios , Suturas/efectos adversos
11.
Proc Natl Acad Sci U S A ; 111(19): 6952-7, 2014 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-24778233

RESUMEN

Clinical trials of therapeutic angiogenesis by vascular endothelial growth factor (VEGF) gene delivery failed to show efficacy. Major challenges include the need to precisely control in vivo distribution of growth factor dose and duration of expression. Recombinant VEGF protein delivery could overcome these issues, but rapid in vivo clearance prevents the stabilization of induced angiogenesis. Here, we developed an optimized fibrin platform for controlled delivery of recombinant VEGF, to robustly induce normal, stable, and functional angiogenesis. Murine VEGF164 was fused to a sequence derived from α2-plasmin inhibitor (α2-PI1-8) that is a substrate for the coagulation factor fXIIIa, to allow its covalent cross-linking into fibrin hydrogels and release only by enzymatic cleavage. An α2-PI1-8-fused variant of the fibrinolysis inhibitor aprotinin was used to control the hydrogel degradation rate, which determines both the duration and effective dose of factor release. An optimized aprotinin-α2-PI1-8 concentration ensured ideal degradation over 4 wk. Under these conditions, fibrin-α2-PI1-8-VEGF164 allowed exquisitely dose-dependent angiogenesis: concentrations ≥25 µg/mL caused widespread aberrant vascular structures, but a 500-fold concentration range (0.01-5.0 µg/mL) induced exclusively normal, mature, nonleaky, and perfused capillaries, which were stable after 3 mo. Optimized delivery of fibrin-α2-PI1-8-VEGF164 was therapeutically effective both in ischemic hind limb and wound-healing models, significantly improving angiogenesis, tissue perfusion, and healing rate. In conclusion, this optimized platform ensured (i) controlled and highly tunable delivery of VEGF protein in ischemic tissue and (ii) stable and functional angiogenesis without introducing genetic material and with a limited and controllable duration of treatment. These findings suggest a strategy to improve safety and efficacy of therapeutic angiogenesis.


Asunto(s)
Fibrina/farmacocinética , Técnicas de Transferencia de Gen , Isquemia/terapia , Neovascularización Fisiológica/fisiología , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/farmacocinética , Animales , Femenino , Geles/farmacocinética , Terapia Genética/métodos , Miembro Posterior , Células Endoteliales de la Vena Umbilical Humana , Humanos , Ratones , Ratones Endogámicos , Ratones SCID , Músculo Esquelético/irrigación sanguínea , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacocinética , Factor A de Crecimiento Endotelial Vascular/metabolismo
12.
Am J Hum Biol ; 27(6): 862-6, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25994239

RESUMEN

OBJECTIVES: The pupillographic sleepiness test (PST) measures the amplitude of the fluctuations of pupil size in the dark, which reflects the level of central nervous system activation and thus alertness. The aim of this study was to assess the short-term reproducibility and variability of the results obtained with the PST in normal healthy subjects. METHODS: The PST was measured at 9.00, 11:00, and 13:00 h on three consecutive days in 13 young adults. Subjective sleepiness was assessed with the Stanford Sleepiness Scale (SSS) and with a Visual Analogue Scale (VAS). The intra-class correlation (ICC), a measure of reproducibility and the intra- and inter-individual variability, was calculated. RESULTS: ANOVA analysis of the data revealed no significant differences in the PST measurements for testing day. Time of day and subject did however significantly affect the results with an ICC 73.1%. For the SSS and VAS, the ICC was 38.8% and 45.9%, respectively. The intra- and inter-individual variability in PST results did not differ considerably between time and days. CONCLUSIONS: We conclude that recordings of the PST have a good reproducibility and low intra- and inter-individual variability compared to subjective scales of sleepiness or the Multiple Sleep Latency Test. The PST is thus a viable method to measure daytime sleepiness objectively.


Asunto(s)
Luz , Pupila/fisiología , Sueño/fisiología , Adulto , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados
13.
Angew Chem Int Ed Engl ; 54(29): 8506-10, 2015 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-26033573

RESUMEN

Organic conducting polymers are promising electrode materials for printable organic electronics. One of the most studied conducting polymers is PEDOT: PSS, which is sufficiently conductive and transparent, but which shows some drawbacks, such as hygroscopicity and acidity. A new approach to stabilize PEDOT in aqueous dispersions involves the replacement of PSS with a basic polyanion based on a polystyrene backbone with (trifluoromethylsulfonyl)imide (TSFI) side groups. The PEDOT: PSTFSIK dispersions were obtained by oxidative polymerization of EDOT in an aqueous PSTFSIK solution and were characterized with regard to their composition, morphology, doping, rheological behavior, and optoelectronic performance. The PEDOT: PSTFSIK dispersions showed excellent printability and good optoelectronic performance (238 Ohm sq(-1) at 91% transmittance, σ>260 S cm(-1)) and were successfully integrated as flexible electrodes in OLED and OPV devices.

14.
Biomacromolecules ; 15(7): 2440-8, 2014 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-24805163

RESUMEN

Aiming at controlled modification of liposomal surface structures, we describe a postpreparational approach for surface derivatization of a new type of multifunctional, sterically stabilized liposomes. Application of dual centrifugation (DC) resulted in high encapsulation efficiencies above 50% at very small batch sizes with a total volume of 150 µL, which were conductive to fast and efficient optimization of variegated surface modification reactions. Cholesterol-polymer amphiphiles, including complex hyperbranched polyether structures bearing 1-4 terminal alkynes, were used in DC formulations to provide steric stabilization. The alkyne moieties were explored as anchors for the conjugation of small molecules to the liposomal surface via click chemistry, binding 350-450 fluorophores per liposome as examples for surface active molecules. Using Förster resonance energy transfer (FRET) spectroscopy, the conjugation reaction as well as the uptake of FRET-labeled liposomes by RBE4 cells was monitored, and the distribution of the fluorescent lipids among cellular structures and membranes could be studied. Thus, the combination of clickable hyperbranched amphiphiles and dual centrifugation provides access to well-defined liposomal formulations with a variety of surface moieties.


Asunto(s)
Doxorrubicina/análogos & derivados , Polímeros/farmacología , Alquinos/química , Animales , Encéfalo/citología , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Línea Celular , Química Clic , Doxorrubicina/química , Doxorrubicina/farmacología , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Transferencia Resonante de Energía de Fluorescencia , Liposomas , Microscopía Confocal , Polietilenglicoles/química , Polietilenglicoles/farmacología , Polímeros/química , Ratas
15.
Surg Endosc ; 28(3): 735-40, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24149855

RESUMEN

INTRODUCTION: The aim of this prospective controlled trial was the definition of the optimal timepoint for delayed closure after negative pressure wound therapy (NPWT) in the treatment of the open abdomen (OA) in septic patients after abdominal surgery. The delayed closure of the abdominal wall after abdominal NPWT treatment is often problematic due to the lateralization of the fascial edge leading to unfavorably high tensile forces of the adapting sutures in the midline. We present the results of an innovative combination of NPWT with a new fascial-approximation technique using dynamic fascial sutures (DFS) and delayed closure of the abdominal wall. METHODS: Eighty-seven patients subjected to OA therapy following surgery for secondary peritonitis were treated with NPWT and DFS. In all patients, a running suture of elastic vessel loops was used to approximate fascial edges. This procedure was continued for the duration of NPWT until final closure of the abdomen with running suture in 55 patients (63.2 %) and interrupted suture technique in eight patients (9.2 %). An anterior component separation was performed in seven patients. RESULTS: Delayed closure was achieved in 68 patients (78.2 %) after 12.6 days [mean (SD) 25.1 (2-204)] days and 4.3 re-operations [mean (SD) 6.0 (1-43)]. Fifteen (17.2 %) superficial and two (2.3 %) deep wound infections occurred. In three (3.4 %) cases, entero-atmospheric fistulas had to be treated. We recorded no technique-specific complications. Four (5.9 %) incisional hernia were detected in a mean follow-up of 40.5 months (16-65). Mortality rate was 55.2 %. CONCLUSION: Using a new technique combining NPWT and DFS in the treatment of the OA, the delayed closure of the fascial edges by running suture can be achieved and the number of re-operations can be kept low. The technique was safe and led to a low incidence of incisional hernias. Extensive abdominal wall reconstruction was seldom required.


Asunto(s)
Técnicas de Cierre de Herida Abdominal , Fasciotomía , Laparotomía/efectos adversos , Terapia de Presión Negativa para Heridas/métodos , Sepsis/etiología , Infección de la Herida Quirúrgica/terapia , Técnicas de Sutura , Abdomen/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Austria/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Peritonitis/cirugía , Estudios Prospectivos , Reoperación , Infección de la Herida Quirúrgica/complicaciones , Infección de la Herida Quirúrgica/mortalidad , Tasa de Supervivencia/tendencias , Factores de Tiempo , Resultado del Tratamiento
16.
Lasers Surg Med ; 46(10): 773-80, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25363448

RESUMEN

BACKGROUND AND OBJECTIVE: Low-level light therapy (LLLT) has been revealed as a potential means to improve wound healing. So far, most studies are being performed with irradiation in the red to near-infrared spectra. Recently, we showed that blue light (470 nm) can significantly influence biological systems such as nitric oxide (NO) metabolism and is able to release NO from nitrosyl-hemoglobin or mitochondrial protein complexes. Therefore, the aim of this study was to evaluate and compare the therapeutic value of blue or red light emitting diodes (LEDs) on wound healing in an ischemia disturbed rodent flap model. STUDY DESIGN/MATERIALS AND METHODS: An abdominal flap was rendered ischemic by ligation of one epigastric bundle and subjected to LED illumination with a wavelength of 470 nm (blue, n = 8) or 629 nm (red, n = 8) each at 50 mW/cm(2) and compared to a non-treated control group (n = 8). Illumination was performed for 10 minutes on five consecutive days. RESULTS: LED therapy with both wavelengths significantly increased angiogenesis in the sub-epidermal layer and intramuscularly (panniculus carnosus muscle) which was associated with significantly improved tissue perfusion 7 days after the ischemic insult. Accordingly, tissue necrosis was significantly reduced and shrinkage significantly less pronounced in the LED-treated groups of both wavelengths. CONCLUSIONS: LED treatment of ischemia challenged tissue improved early wound healing by enhancing angiogenesis irrespective of the wavelength thus delineating this noninvasive means as a potential, cost effective tool in complicated wounds.


Asunto(s)
Isquemia/radioterapia , Neovascularización Fisiológica/efectos de la radiación , Fototerapia/instrumentación , Colgajos Quirúrgicos/irrigación sanguínea , Cicatrización de Heridas/efectos de la radiación , Abdomen , Animales , Modelos Animales de Enfermedad , Isquemia/etiología , Isquemia/patología , Ligadura , Masculino , Ratas , Ratas Sprague-Dawley
17.
Int Orthop ; 38(12): 2607-13, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25192687

RESUMEN

PURPOSE: Treatment of large-segmental bone defects still is a challenge in clinical routine. Application of gene-activated matrices (GAMs) based on fibrin, bone morphogenic protein (BMP) 2/7 plasmids and nonviral transfection reagents (cationic polymers) could be an innovative treatment strategy to overcome this problem. The aim of this study was to determine the therapeutic efficacy of fibrin GAMs with or without additional transfection reagents for BMP2 and 7 plasmid codelivery in a femur nonunion rat model. METHODS: In this experimental study, a critical-sized femoral defect was created in 27 rats. At four weeks after the surgery, animals were separated into four groups and underwent a second operation. Fibrin clots containing BMP2/7 plasmids with and without cationic polymer were implanted into the femoral defect. Fibrin clots containing recombinant human (rh) BMP2 served as positive and clots without supplement as negative controls. RESULTS: At eight weeks, animals that received GAMs containing the cationic polymer and BMP2/7 plasmids showed decreased bone volume compared with animals treated with GAMs and BMP2/7 only. Application of BMP2/7 plasmids in fibrin GAMs without cationic polymer led to variable results. Animals that received rhBMP2 protein showed increased bone volume, and osseous unions were achieved in two of six animals. CONCLUSIONS: Cationic polymers decrease therapeutic efficiency of fibrin GAM-based BMP2/7 plasmid codelivery in bone regeneration. Nonviral gene transfer of BMP2/7 plasmids needs alternative promoters (e.g. by sonoporation, electroporation) to produce beneficial clinical effects.


Asunto(s)
Terapia Genética/métodos , Osteogénesis/genética , Ingeniería de Tejidos/métodos , Animales , Proteína Morfogenética Ósea 2 , Proteínas Morfogenéticas Óseas , Regeneración Ósea/efectos de los fármacos , Regeneración Ósea/genética , Modelos Animales de Enfermedad , Fibrina/fisiología , Técnicas de Transferencia de Gen , Masculino , Plásmidos , Ratas Sprague-Dawley , Proteínas Recombinantes , Factor de Crecimiento Transformador beta
18.
Methods Mol Biol ; 2785: 3-14, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38427184

RESUMEN

As our knowledge about the biology of Alzheimer's disease (AD) expands and we recognize the significance of early intervention for effective treatment, there is a shift in focus toward detecting the disease at an early stage. AD is characterized by the accumulation of misfolded amyloid-ß (Aß) and phosphorylated tau proteins in the brain, leading to the formation of senile plaques and neurofibrillary tangles. While a definitive diagnosis of AD can only be confirmed through autopsy by examining these pathological features, there are now reliable methods available for diagnosing the disease in living individuals. These methods involve analyzing cerebrospinal fluid and using positron emission tomography to accurately assess the presence of Aß and tau proteins. While these diagnostic markers have shown high accuracy in memory-clinic populations, they do have limitations such as the requirement for invasive lumbar puncture or exposure to ionizing radiation. Additionally, they are not easily accessible outside of specialized healthcare settings. Blood-based biomarkers of the core pathological features of AD are being developed, showing promise for less invasive, scalable identification of AD cases in the community. The advantages for the healthcare systems of this development are obvious, but the diagnostic performance of blood-based biomarkers in broader, non-selected populations outside of retrospective analyses and research cohorts still requires further investigation, including the combination with more effective neuropsychological assessments such as digital cognitive test solutions.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Enfermedad de Alzheimer/líquido cefalorraquídeo , Proteínas tau/líquido cefalorraquídeo , Estudios Retrospectivos , Péptidos beta-Amiloides/líquido cefalorraquídeo , Biomarcadores/líquido cefalorraquídeo
19.
Biomedicines ; 11(4)2023 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-37189661

RESUMEN

Chronic wounds remain a serious clinical problem with insufficient therapeutic approaches. In this study we investigated the dose dependency of rhVEGF165 in fibrin sealant in both ischemic and non-ischemic excision wounds using our recently developed impaired-wound healing model. An abdominal flap was harvested from the rat with unilateral ligation of the epigastric bundle and consequent unilateral flap ischemia. Two excisional wounds were set in the ischemic and non-ischemic area. Wounds were treated with three different rhVEGF165 doses (10, 50 and 100 ng) mixed with fibrin or fibrin alone. Control animals received no therapy. Laser Doppler imaging (LDI) and immunohistochemistry were performed to verify ischemia and angiogenesis. Wound size was monitored with computed planimetric analysis. LDI revealed insufficient tissue perfusion in all groups. Planimetric analysis showed slower wound healing in the ischemic area in all groups. Wound healing was fastest with fibrin treatment-irrespective of tissue vitality. Lower dose VEGF (10 and 50 ng) led to faster wound healing compared to high-dose VEGF. Immunohistochemistry showed the highest vessel numbers in low-dose VEGF groups. In our previously established model, different rhVEGF165 treatments led to dose-dependent differences in angiogenesis and wound healing, but the fastest wound closure was achieved with fibrin matrix alone.

20.
Lancet Neurol ; 22(9): 787-799, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37459876

RESUMEN

BACKGROUND: Patients with ischaemic stroke are at risk of recurrent stroke. In this study, we aimed to compare the effect of a structured ambulatory post-stroke care programme versus usual care on recurrent vascular events and death and control of cardiovascular risk factors. METHODS: We did a prospective, open-label, cluster-randomised controlled trial (SANO) at stroke centres in regions of Germany. A cluster was defined as a region in which acute stroke care is provided by a participating stroke centre. Patients were eligible for participation if they were aged 18 years or older, had no severe disabilities before the index stroke (modified Rankin scale 0-1), had at least one modifiable cardiovascular risk factor, and presented within 14 days of symptom onset of their first ischaemic stroke. The participating regions were randomly assigned (1:1) to the intervention and control group (usual care) by the statistician using block randomisation (block sizes of six), stratified by rural and urban regions. In intervention regions, a cross-sectoral multidisciplinary network was established to provide a 1-year organisational and patient-centred intervention. Due to the type of intervention, masking of participants and study physicians was not possible. Endpoint adjudication was performed by an independent endpoint adjudication committee who were masked to cluster allocation. The primary endpoint was a composite of recurrent stroke, myocardial infarction, and all-cause death within 12 months after baseline assessment, assessed in the modified intention-to-treat (mITT) population, which included all patients who did not withdraw consent and completed the primary endpoint assessment at 12 months. This study was registered with the German Clinical Trials Register, DRKS00015322. FINDINGS: Between Jan 1, 2019 and Dec 22, 2020, 36 clusters were assessed for eligibility, of which 30 were randomly assigned to the intervention group (n=15 clusters) or control group (n=15 clusters). No clusters dropped out of the study. 1203 (86%) of 1396 enrolled patients in the intervention group and 1283 (92%) of 1395 enrolled patients in the control group were included in the mITT population. The primary endpoint was confirmed in 64 (5·3%) of 1203 patients in the intervention group and 80 (6·2%) of 1283 patients in the control group (unadjusted odds ratio [OR] 0·80 [95% CI 0·49-1·30]; adjusted OR [aOR] 0·95 [95% CI 0·54-1·67]). All-cause deaths occurred in 31 (2·4%) of 1203 patients in the intervention group and 12 (1·0%) of 1283 patients in the control group. The incidence of serious adverse events was higher in the intervention group (266 [23·1%] of 1151) than the control group (106 [9·2%] of 1152). Falls (134 [11·4%] of 1203 patients in the intervention group; 39 [3·3%] of 1152 patients in the control group), hypertensive crisis (55 [4·7%]; 34 [2·8%]), and diagnosis of depression (51 [4·3%]; 13 [1·1%]) were the most frequent adverse events in both groups. No differences were identified in the rate of readmission to hospital between groups. INTERPRETATION: No differences were identified between patients with ischaemic stroke in the intervention group and control group with regard to the incidence of vascular events 1 year after baseline assessment, despite positive effects with regard to the control of some cardiovascular risk factors. Longer-term effects and other potentially favourable effects on stroke-related sequelae and quality of life require further evaluation. FUNDING: Innovation Fund of the Federal Joint Committee.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Accidente Cerebrovascular/tratamiento farmacológico , Isquemia Encefálica/epidemiología , Isquemia Encefálica/terapia , Isquemia Encefálica/complicaciones , Pacientes Ambulatorios , Cuidados Posteriores , Calidad de Vida , Estudios Prospectivos , Accidente Cerebrovascular Isquémico/complicaciones , Infarto Cerebral , Resultado del Tratamiento
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