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Axel J Rosengart

Publications and source records attributed to Axel J Rosengart.

6 recordsLinked to original sources
PubMed2006

A novel human detoxification system based on nanoscale bioengineering and magnetic separation techniques.

We describe the conceptual approach, theoretical background and preliminary experimental data of a proposed platform technology for specific and rapid decorporation of blood-borne toxins from humans. The technology is designed for future emergent in-field or in-hospital detoxification of large numbers of biohazard-exposed victims; for example, after radiological attacks. The proposed systems is based on nanoscale technology employing biocompatible, superparamagnetic nanospheres, which are functionalized with target-specific antitoxin receptors, and freely circulate within the human blood stream after simple intravenous injection. Sequestration of the blood-borne toxins onto the nanosphere receptors generates circulating nanosphere-toxin complexes within a short time interval; mathematical modeling indicates prevailing of unbound nanosphere receptors over target toxin concentrations at most therapeutic injection dosages. After a toxin-specific time interval nanosphere-toxin complexes are generated within the blood stream and, after simple arterial or venous access, the blood is subsequently circulated via a small catheter through a portable high gradient magnetic separator device. In this device, the magnetic toxin complexes are retained by a high gradient magnetic field and the detoxified blood is then returned back to the blood circulation (extracorporeal circulation). Our preliminary in vitro experiments demonstrate >95% first pass capture efficiency of magnetic spheres within a prototype high gradient magnetic separation device. Further, based on the synthesis of novel hydrophobic magnetite nanophases with high magnetization ( approximately 55 emu/g), the first biodegradable magnetic nanospheres at a size range of approximately 280 nm and functionalized with PEG-maleimide surface groups for specific antibody attachment are described here. In future applications, we envision this technology to be suitable for emergent, in-field usage for acutely biohazard exposed victims as both the injectable toxin-binding magnetic spheres and the separator device are made to be portable, light-weight, zero-power, and self- or helper-employed. Details of the technology are presented and the state-of-knowledge and research is discussed.

Biocompatible Materials↗
PubMed2006

Return of vision after transarterial coiling of a carotid cavernous sinus fistula: case report.

BACKGROUND: Carotid cavernous sinus fistulae are abnormal communications between the carotid circulation and cavernous sinus that may arise spontaneously or develop after craniocerebral trauma. They may present with a constellation of signs and symptoms characteristic of raised cavernous sinus pressure, including orbital or retro-orbital pain, pulsatile proptosis, chemosis, ocular or cranial bruit, deterioration of visual acuity, or ophthalmoplegia. Visual loss is likely the result of multiple insults to the visual system, including reversal of venous drainage from the fistula, arterial flow into the superior ophthalmic vein, increased intraocular venous pressure, venous stasis retinopathy, and eventually ischemic optic neuropathy [Brodsky MC, Hoyt WF, Halbach VV, et al. Recovery from total monocular blindness after balloon embolization of carotid-cavernous fistula. Am J Ophthalmol 1987;104:86-87; Sanders MD, Hoyt WF. Hypoxic ocular sequelae of carotid-cavernous fistulae: study of the causes of visual failure before and after neurosurgical treatment in a series of 25 cases. Br J Ophthalmol 1969;53:82-97]. CASE DESCRIPTION: With few exceptions, the literature is replete with evidence of persistent blindness despite successful treatment of the CCF [Albuquerque FC, Heinz GW, McDougall CG. Reversal of blindness after transvenous embolization of a carotid-cavernous fistula: case report. Neurosurgery 2003;52:233-237; Brodsky MC, Hoyt WF, Halbach VV, et al. Recovery from total monocular blindness after balloon embolization of carotid-cavernous fistula. Am J Ophthalmol 1987;104:86-87; Weinstein JM, Rufenacht DA, Partington CR, et al. Delayed visual loss due to trauma of the internal carotid artery. Arch Neurol. 1991;48:490-497]. Here, we report a patient who experienced recovery of vision after endovascular obliteration of the offending CCF. DISCUSSION: To our knowledge, this is the second reported case of recovery of visual function in a patient presenting with loss of light perception after treatment of a direct CCF.

Blindness↗
PubMed2005

Identification and treatment of cervical and oromandibular dystonia in acutely brain-injured patients.

INTRODUCTION: Primary cervical and oromandibular dystonia (CD and OMD, respectively) are well-recognized movement disorders, often treated with botulinum toxin (BTx). In contrast, dystonia related to acute brain injuries is not well delineated. Our objective was to define in neurocritically ill patients the clinical characteristics of CD and OMD and to investigate the safety of BTx. METHODS: All acutely brain-injured patients admitted to a neurocritical care unit over a 10-month period were prospectively screened for CD and OMD. Clinical characteristics, etiology of brain injury, and pattern of dystonia were analyzed. Patients with clinically significant CD and OMD were treated with BTx and followed for 12 weeks. RESULTS: Of 165 patients screened, 33 had new-onset CD or OMD. Of 21 patients enrolled, 14 had CD, 5 had OMD, and 2 had both. The pattern of brain injury included 13 cerebral hemorrhages, 6 ischemic strokes, 1 status epilepticus, and 1 unclear etiology. Improvement after BTx was seen in four of seven patients with CD and two of four with OMD; no adverse effects occurred. Spontaneous improvement was recorded in 7 of 11 nontreated patients with CD or OMD. CONCLUSIONS: Acute secondary CD or OMD, associated with a variety of causes, was identified in 20% of acutely brain-injured patients. The temporal profile of dystonia onset and resolution in these patients was variable. Treatment with BTx in the neurocritical care setting seems to be safe. Future, larger scale randomized studies should evaluate the effectiveness of BTx treatment in this patient population.

Adult↗
PubMed2005

Racial differences in demographics, acute complications, and outcomes in patients with subarachnoid hemorrhage: a large patient series.

OBJECT: Few studies have focused on the impact of racial differences in demographics, clinical characteristics, acute complications, and outcomes of patients with aneurysmal subarachnoid hemorrhage (SAH). The purpose of this study was to examine this issue. METHODS: The authors evaluated prospectively collected data on 1711 adult patients with aneurysmal SAH who were entered into two randomized, double-blind, placebo-controlled trials conducted at neurosurgical centers in North America between 1991 and 1997. Admission characteristics, treatment modalities, in-hospital complications, and 3-month outcomes assessed by application of the Glasgow Outcome Scale were compared using the chi-square test, a t-test, the Wilcoxon rank-sum test, and multiple logistic regressions based on a significance level of 0.05 in 241 African-American, 1342 Caucasian, and 128 other racial minority patients. Caucasian patients were significantly older than patients of other races (p < 0.0001). African-American patients more frequently had a history of hypertension (p < 0.0001) and an elevated blood pressure at the time of admission (p < 0.0001). African-Americans and other racial minorities were more likely to have internal carotid artery aneurysms and Caucasians were more likely to have posterior circulation aneurysms (p = 0.0002). Rates of in-hospital complications were not significantly different except that pulmonary edema occurred more commonly in Caucasians (p = 0.036). After an adjustment was made for significant admission characteristics, the 3-month outcome was not significantly different among the races. CONCLUSIONS: Race was not found to be a prognostic factor for outcome after aneurysmal SAH. The higher SAH mortality rate previously observed in African-American patients is likely a result of a higher incidence of SAH in this group. These findings highlight the importance of primary prevention programs aimed at modifying risk factors for SAH.

Adult↗
PubMed2004

Early vasospasm on admission angiography in patients with aneurysmal subarachnoid hemorrhage is a predictor for in-hospital complications and poor outcome.

BACKGROUND AND PURPOSE: Early vasospasm (EVSP), defined here as arterial narrowing seen on diagnostic angiography within the first 48 hours of aneurysmal rupture, is a rarely reported and poorly defined phenomenon in patients with subarachnoid hemorrhage (SAH). The purpose of this study was to characterize EVSP in a large database of such patients. METHODS: We analyzed the relationship of EVSP to clinical characteristics, in-hospital complications, and outcome at 3 months among 3478 patients entered into 4 prospective, randomized, double-blind, placebo-controlled trials of tirilazad conducted in neurosurgical centers around the world between 1991 and 1997. RESULTS: Three hundred thirty-nine (10%) of 3478 patients had EVSP. EVSP was significantly more likely in patients with poor neurological grade on admission, history of SAH, intracerebral hematoma, larger aneurysm, thick SAH on cranial computed tomography, and intraventricular hemorrhage. EVSP was not associated with delayed cerebral vasospasm. After adjustment for differences in admission characteristics, EVSP was associated with cerebral infarction (adjusted odds ratios [OR]=1.51; 95% CI, 1.18 to 1.94; P=0.001), neurological worsening (OR=1.41; 95% CI, 1.10 to 1.81; P=0.007), and unfavorable outcome (OR=1.51; 95% CI, 1.15 to 2.00; P=0.003). In addition, there was a trend for patients with increasingly severe EVSP to have unfavorable outcome (OR=1.84 for mild and OR=2.66 for moderate/severe EVSP). CONCLUSIONS: EVSP was seen in 10% of SAH patients and was predictive of cerebral infarction and neurological worsening as well as unfavorable outcome at 3 months. EVSP was not associated with late vasospasm. EVSP may be as important as delayed vasospasm in predicting complications and long-term morbidity in SAH patients.

Adult↗