Summary Background Haematoma expansion is a major cause of mortality in intracranial haemorrhage related to vitamin K antagonists (VKA-ICH). Normalisation of the international normalised ratio (INR) ...is recommended, but optimum haemostatic management is controversial. We assessed the safety and efficacy of fresh frozen plasma (FFP) versus prothrombin complex concentrate (PCC) in patients with VKA-ICH. Methods We did an investigator-initiated, multicentre, prospective, randomised, open-label, blinded-endpoint trial. Patients aged at least 18 years with VKA-ICH who presented within 12 h after symptom onset with an INR of at least 2·0 were randomly assigned (1:1) by numbered sealed envelopes to 20 mL/kg of intravenous FFP or 30 IU/kg of intravenous four-factor PCC within 1 h after initial cerebral CT scan. The primary endpoint was the proportion of patients with INR 1·2 or lower within 3 h of treatment initiation. Masking of treatment was not possible, but the primary analysis was observer masked. Analyses were done using a treated-as-randomised approach. This trial is registered with EudraCT, number 2008-005653-37, and ClinicalTrials.gov , number NCT00928915. Findings Between Aug 7, 2009, and Jan 9, 2015, 54 patients were randomly assigned (26 to FFP and 28 to PCC) and 50 received study drug (23 FFP and 27 PCC). The trial was terminated on Feb 6, 2015, after inclusion of 50 patients after a safety analysis because of safety concerns. Two (9%) of 23 patients in the FFP group versus 18 (67%) of 27 in the PCC group reached the primary endpoint (adjusted odds ratio 30·6, 95% CI 4·7–197·9; p=0·0003). 13 patients died: eight (35%) of 23 in the FFP group (five from haematoma expansion, all occurring within 48 h after symptom onset) and five (19%) of 27 in the PCC group (none from haematoma expansion), the first of which occurred on day 5 after start of treatment. Three thromboembolic events occurred within 3 days (one in the FFP group and two in the PCC group), and six after day 12 (one and five). 43 serious adverse events (20 in the FFP group and 23 in the PCC group) occurred in 26 patients. Six serious adverse events were judged to be FFP related (four cases of haematoma expansion, one anaphylactic reaction, and one ischaemic stroke) and two PCC related (ischaemic stroke and pulmonary embolism). Interpretation In patients with VKA-related intracranial hemorrhage, four-factor PCC might be superior to FFP with respect to normalising the INR, and faster INR normalisation seemed to be associated with smaller haematoma expansion. Although an effect of PCC on clinical outcomes remains to be shown, our data favour the use of PCC over FFP in intracranial haemorrhage related to VKA. Funding Octapharma.
Spreading depolarizations (SD) are waves of abrupt, near-complete breakdown of neuronal transmembrane ion gradients, are the largest possible pathophysiologic disruption of viable cerebral gray ...matter, and are a crucial mechanism of lesion development. Spreading depolarizations are increasingly recorded during multimodal neuromonitoring in neurocritical care as a causal biomarker providing a diagnostic summary measure of metabolic failure and excitotoxic injury. Focal ischemia causes spreading depolarization within minutes. Further spreading depolarizations arise for hours to days due to energy supply-demand mismatch in viable tissue. Spreading depolarizations exacerbate neuronal injury through prolonged ionic breakdown and spreading depolarization-related hypoperfusion (spreading ischemia). Local duration of the depolarization indicates local tissue energy status and risk of injury. Regional electrocorticographic monitoring affords even remote detection of injury because spreading depolarizations propagate widely from ischemic or metabolically stressed zones; characteristic patterns, including temporal clusters of spreading depolarizations and persistent depression of spontaneous cortical activity, can be recognized and quantified. Here, we describe the experimental basis for interpreting these patterns and illustrate their translation to human disease. We further provide consensus recommendations for electrocorticographic methods to record, classify, and score spreading depolarizations and associated spreading depressions. These methods offer distinct advantages over other neuromonitoring modalities and allow for future refinement through less invasive and more automated approaches.
The development of chemically modified mRNA holds great promise as a new class of biologic therapeutics. However, the intracellular delivery and endosomal escape of mRNA encapsulated in nanoparticles ...has not been systematically investigated. Here, we synthesized a diverse set of cationic polymers and lipids from a series of oligoalkylamines and subsequently characterized their mRNA delivery capability. Notably, a structure with an alternating alkyl chain length between amines showed the highest transfection efficiency, which was linked to a high buffering capacity in a narrow range of pH 6.2 to 6.5. Variation in only one methylene group resulted in enhanced mRNA delivery to both the murine liver as well as porcine lungs after systemic or aerosol administration, respectively. These findings reveal a novel fundamental structure–activity relationship for the delivery of mRNA that is independent of the class of mRNA carrier and define a promising new path of exploration in the field of mRNA therapeutics.
Oligoalkylamine‐based lipids and polymers were generated and screened for buffering capacity and mRNA delivery. Alternating ethylene/propylene/ethylene spacers in the tetramines improve transfection efficiency (see picture, middle) over ethylene‐only (left) or propylene‐only repeats (right). This trend is valid regardless of delivery platform (lipids or polymers), tested cell line, targeted tissue, or application route in vivo.
To investigate hemodynamic response pattern and spatiotemporal propagation of cortical spreading depolarization in the peri-infarct region of malignant hemispheric stroke.
In this prospective ...observational case study we used intraoperative laser speckle technology to measure cerebral blood flow in patients with malignant hemispheric stroke. Additionally, postoperative occurrence of cortical spreading depolarization was monitored using a subdural recording strip for electrocorticography and infarct progression was assessed by serial MRI.
In 7 of 20 patients, 19 blood flow changes typical of cortical spreading depolarizations occurred during a 20-minute period. Thirteen events were characterized by increase, 2 by biphasic response, and 4 by decrease of blood flow. Propagation velocity ranged from 1.7 to 9.2 mm/min and propagation area from 0.1 to 4.8 cm(2). Intrinsic optical signal alterations preceded and low-frequency vascular fluctuations were suppressed during the hemodynamic responses. A mean number of 56 ± 82 cortical spreading depolarizations per patient was recorded and a mean infarct progression of 30 ± 13 cm(3) was detected in 5 of 7 patients.
We visualize the spatiotemporal propagation of spreading depolarizations in the human cerebral cortex intraoperatively. In patients with focal ischemia, multiple cortical spreading depolarizations with either hyperemic or hypoemic flow responses occurred. Our data suggest that, in patients with focal ischemia, cortical spreading depolarizations are associated with both unfavorable and protective hemodynamic responses.
Aim of this study was the site-specific conjugation of an epidermal growth factor (EGF)-polyethylene glycol (PEG) chain by click chemistry onto a poly(amido amine) (PAMAM) dendron, as a key step ...toward defined multifunctional carriers for targeted gene delivery. For this purpose, at first propargyl amine cored PAMAM dendrons with ester ends were synthesized. The chain terminal ester groups were then modified by oligoamines with different secondary amino densities. The oligoamine-modified PAMAM dendrons were well biocompatible, as demonstrated in cytotoxicity assays. Among the different oligoamine-modified dendrons, PAMAM-pentaethylenehexamine (PEHA) dendron polyplexes displayed the best gene transfer ability. Conjugation of PAMAM-PEHA dendron with PEG spacer was conducted via click reaction, which was performed before amidation with PEHA. The resultant PEG-PAMAM-PEHA copolymer was then coupled with EGF ligand. pDNA transfections in HuH-7 hepatocellular carcinoma cells showed a 10-fold higher efficiency with the polyplexes containing conjugated EGF as compared to the ligand-free ones, demonstrating the concept of ligand targeting. Overall gene transfer efficiencies, however, were moderate, suggesting that additional measures for overcoming subsequent intracellular bottlenecks in delivery have to be taken.
Although our understanding of RNAi and our knowledge on designing and synthesizing active and safe siRNAs significantly increased during the past decade, targeted delivery remains the major ...limitation in the development of siRNA therapeutics. On one hand, practical considerations dictate robust chemistry reproducibly providing precise carrier molecules. On the other hand, the multistep delivery process requires dynamic multifunctional carriers of substantial complexity. We present a monodisperse and multifunctional carrier system, synthesized by solid phase supported chemistry, for siRNA delivery in vitro and in vivo. The sequence-defined assembly includes a precise cationic (oligoethanamino)amide core, terminated at the ends by two cysteines for bioreversible polyplex stabilization, at a defined central position attached to a monodisperse polyethylene glycol chain coupled to a terminal folic acid as cell targeting ligand. Complexation with an endosomolytic influenza peptide-siRNA conjugate results in nanosized functional polyplexes of 6 nm hydrodynamic diameter. The necessity of each functional substructure of the carrier system for a specific and efficient gene silencing was confirmed. The nanosized polyplexes showed stability in vivo, receptor-specific cell targeting, and silencing of the EG5 gene in receptor-positive tumors. The nanosized appearance of these particles can be precisely controlled by the oligomer design (from 5.8 to 8.8 nm diameter). A complete surface charge shielding together with the high stability result in good tolerability in vivo and the absence of accumulation in nontargeted tissues such as liver, lung, or spleen. Due to their small size, siRNA polyplexes are efficiently cleared by the kidney.
Objective
Delayed ischemic neurological deficit (DIND) contributes to poor outcome in subarachnoid hemorrhage (SAH) patients. Because there is continuing uncertainty as to whether proximal cerebral ...artery vasospasm is the only cause of DIND, other processes should be considered. A potential candidate is cortical spreading depolarization (CSD)‐induced hypoxia. We hypothesized that recurrent CSDs influence cortical oxygen availability.
Methods
Centers in the Cooperative Study of Brain Injury Depolarizations (COSBID) recruited 9 patients with severe SAH, who underwent open neurosurgery. We used simultaneous, colocalized recordings of electrocorticography and tissue oxygen pressure (ptiO2) in human cerebral cortex. We screened for delayed cortical infarcts by using sequential brain imaging and investigated cerebral vasospasm by angiography or time‐of‐flight magnetic resonance imaging.
Results
In a total recording time of 850 hours, 120 CSDs were found in 8 of 9 patients. Fifty‐five CSDs (∼46%) were found in only 2 of 9 patients, who later developed DIND. Eighty‐nine (∼75%) of all CSDs occurred between the 5th and 7th day after SAH, and 96 (80%) arose within temporal clusters of recurrent CSD. Clusters of CSD occurred simultaneously, with mainly biphasic CSD‐associated ptiO2 responses comprising a primary hypoxic and a secondary hyperoxic phase. The frequency of CSD correlated positively with the duration of the hypoxic phase and negatively with that of the hyperoxic phase. Hypoxic phases significantly increased stepwise within CSD clusters; particularly in DIND patients, biphasic ptiO2 responses changed to monophasic ptiO2 decreases within these clusters. Monophasic hypoxic ptiO2 responses to CSD were found predominantly in DIND patients.
Interpretation
We attribute these clinical ptiO2 findings mainly to changes in local blood flow in the cortical microcirculation but also to augmented metabolism. Besides classical contributors like proximal cerebral vasospasm, CSD clusters may reduce O2 supply and increase O2 consumption, and thereby promote DIND. ANN NEUROL 2010;67:607–617
Changes in lifestyle and environmental conditions give rise to an increasing prevalence of liver and lung fibrosis, and both have a poor prognosis. Promising results have been reported for ...recombinant angiotensin-converting enzyme 2 (ACE2) protein administration in experimental liver and lung fibrosis. However, the full potential of ACE2 may be achieved by localized translation of a membrane-anchored form. For this purpose, we advanced the latest RNA technology for liver- and lung-targeted ACE2 translation. We demonstrated in vitro that transfection with ACE2 chemically modified messenger RNA (cmRNA) leads to robust translation of fully matured, membrane-anchored ACE2 protein. In a second step, we designed eight modified ACE2 cmRNA sequences and identified a lead sequence for in vivo application. Finally, formulation of this ACE2 cmRNA in tailor-made lipidoid nanoparticles and in lipid nanoparticles led to liver- and lung-targeted translation of significant amounts of ACE2 protein, respectively. In summary, we provide evidence that RNA transcript therapy (RTT) is a promising approach for ACE2-based treatment of liver and lung fibrosis to be tested in fibrotic disease models.
Extracellular stability of electrostatically formed siRNA polyplexes is a significant concern in the delivery process. To overcome the risk of polyplex dissociation in the extracellular environment, ...siRNA was covalently incorporated into a pH- and redox-responsive polymer conjugate. The novel siRNA conjugate consists of polylysine (PLL) as RNA binding and protecting polycation, polyethylene glycol (PEG) as solubilizing and shielding polymer, the lytic peptide melittin masked by dimethylmaleic anhydride (DMMAn) removable at endosomal pH, and the siRNA attached at the 5′-end of the sense strand via a bioreducible disulfide bond. The purified siRNA conjugate was stable in the presence of the polyanion heparin at conditions where the analogous electrostatic siRNA polyplexes disassemble. Only the combination of heparin plus a reducing agent such as glutathione triggered the release of siRNA from the conjugate. High in vitro biocompatibility (absence of cytotoxicity or hemolytic activity at neutral pH) and efficient and sequence-specific gene silencing was found at ≥25 nM siRNA, comparable to the corresponding electrostatic polyplexes. In vivo toxicity studies of this formulation demonstrated that conjugates remain to be optimized for therapeutic application.
Mechanical Thrombectomy of M2-Occlusion Dorn, Franziska, MD; Lockau, Hannah, MD; Stetefeld, Henning, MD ...
Journal of stroke and cerebrovascular diseases,
07/2015, Letnik:
24, Številka:
7
Journal Article
Recenzirano
Background There is growing evidence for the efficacy of mechanical thrombectomy in acute stroke patients with large-vessel occlusions in the anterior circulation. Although distal occlusions of the ...middle cerebral artery (MCA) can cause severe clinical symptoms, endovascular therapy is not considered here as the first choice. The aim of our study was to prove the efficacy and safety of mechanical thrombectomy for distal occlusion types in the anterior circulation (M2-segment). Methods Stentretriever-based thrombectomy was performed in 119 patients with acute MCA occlusions between October 2011 and April 2013: 104 (87.4%) were M1- and 15 (12.6%) M2-occlusions. These groups were compared with regard to recanalization success, periprocedural complications, hemorrhage, and modified Rankin Scale (mRS) at 90 days. Results Thrombolysis in cerebral infarction 2b/3 reperfusion was more frequent in M2- than in M1-occlusions (93.3% versus 76.0%; P = .186). There was no significant difference in the mean National Institutes of Health Stroke Scale between the M1- and the M2-group both at admission and at discharge (16.18 ± 7.30 versus 13.73 ± 8.30, P = .235; 9.36 ± 8.60 versus 7.43 ± 9.84, P = .446). A good clinical outcome (mRS 0-2) at 3 months was more frequent in the M2-group (60% versus 43.3%; P = .273) and mortality was higher in the M1-group (21.2% versus 6.7%; P = .297). There were 3 periprocedural complications in the M1- and none in the M2-group. Conclusions Endovascular treatment of M2-occlusions in severely affected patients is not associated with a higher procedural risk or postprocedural hemorrhage. Compared with M1-occlusions, there was a greater chance for a good angiographic and clinical result in our case series. Therefore, stentretriever-based thrombectomy should also be considered for patients with severe symptoms because of an acute M2-occlusion.
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