Safety and outcomes of routine endovascular thrombectomy in large artery occlusion recorded in the SITS Register: An observational study.

BACKGROUND AND OBJECTIVE: We aimed to evaluate the safety and outcomes of thrombectomy in anterior circulation acute ischaemic stroke recorded in the SITS-International Stroke Thrombectomy Register (SITS-ISTR) and compare them with pooled randomized controlled trials (RCTs) and two national registry studies. METHODS: We identified centres recording ≥10 consecutive patients in the SITS-ISTR with at least 70% of available modified Rankin Scale (mRS) at 3 months during 2014-2019. We defined large artery occlusion as intracranial internal carotid artery, first and second segment of middle cerebral artery and first segment of anterior cerebral artery. Outcome measures were functional independence (mRS score 0-2) and death at 3 months and symptomatic intracranial haemorrhage (SICH) per modified SITS-MOST. RESULTS: Results are presented in the following order: SITS-ISTR, RCTs, MR CLEAN Registry and German Stroke Registry (GSR). Median age was 73, 68, 71 and 75 years; baseline NIHSS score was 16, 17, 16 and 15; prior intravenous thrombolysis was 62%, 83%, 78% and 56%; onset to reperfusion time was 289, 285, 267 and 249 min; successful recanalization (mTICI score 2b or 3) was 86%, 71%, 59% and 83%; functional independence at 3 months was 45.5% (95% CI: 44-47), 46.0% (42-50), 38% (35-41) and 37% (35-41), respectively; death was 19.2% (19-21), 15.3% (12.7-18.4), 29.2% (27-32) and 28.6% (27-31); and SICH was 3.6% (3-4), 4.4% (3.0-6.4), 5.8% (4.7-7.1) and not available. CONCLUSION: Thrombectomy in routine clinical use registered in the SITS-ISTR showed safety and outcomes comparable to RCTs, and better functional outcomes and lower mortality than previous national registry studies.

The creation of an endovascular exit through the vessel wall using a minimally invasive working channel in order to reach all human organs.

Since the establishment of the Seldinger technique for secure entry to the vascular system, there has been a rapid evolution in imaging and catheters that has made the arteries and veins internal routes to any place in the body for interventions. It is curious that a general exit from the vasculature in a similar manner has not been proposed earlier. Possibly, the simplest reason is that accidental perforation of the vasculature by guide wire or catheter is a feared adverse event in endovascular intervention. Most places in the body can be reached by ultrasonography or computed tomography-guided intervention. Some organs such as the central nervous system, the heart and pancreas are harder to access and, in some organs, like the kidney, repeated percutaneous punctions to cover large areas is not suitable. We present a new general purpose micro-endovascular device creating a working channel to these 'hard to reach' organs by an inverted Seldinger technique. This review details this trans-vessel wall technique, which has been studied in pancreas for transplantation of insulin-producing cells, for injection of contrast agent to the heart and to the brain, bowels and kidney in rat, rabbit, swine and macaque monkeys with up to one year of follow-up without adverse events. Furthermore, the payloads that can be given through such a system are briefly discussed. Drugs, cells, gene vectors and other therapeutic substances may be injected directly to the tissue to increase efficacy and decrease risk of off-site adverse effects.

Superselective endovascular tissue access using trans-vessel wall technique: feasibility study for treatment applications in heart, pancreas and kidney in swine.

OBJECTIVES: With the emergence of targeted cell transplantation and gene therapy, there is a need for minimally invasive tissue access to facilitate delivery of therapeutic substrate. The objective of this study was to demonstrate the suitability of an endovascular device which is able to directly access tissue and deliver therapeutic agent to the heart, kidney and pancreas without need to seal the penetration site. METHODS: In vivo experiments were performed in 30 swine, including subgroups with follow-up to evaluate complications. The previously described trans-vessel wall (VW) device was modified to be sharper and not require tip detachment to seal the VW. Injections into targets in the heart (n = 13, 24-h follow-up n = 5, 72-h follow-up n = 3), kidney (n = 8, 14-day follow-up n = 3) and pancreas (n = 5) were performed. Some animals were used for multiple organ injections. Follow-up consisted of clinical monitoring, angiography and necropsy. Transvenous (in heart) and transarterial approaches (in heart, kidney and pancreas) were used. Injections were targeted towards the subepicardium, endomyocardium, pancreas head and tail, and kidney subcapsular space and cortex. RESULTS: Injections were successful in target organs, visualized by intraparenchymal contrast on fluoroscopy and by necropsy. No serious complications (defined as heart failure or persistent arrhythmia, haemorrhage requiring treatment or acute kidney injury) were encountered over a total of 157 injections. CONCLUSIONS: The trans-VW device can achieve superselective injections to the heart, pancreas and kidney for delivery of therapeutic substances without tip detachment. All parts of these organs including the subepicardium, pancreas tail and renal subcapsular space can be efficiently reached.

Randomized assessment of imatinib in patients with acute ischaemic stroke treated with intravenous thrombolysis.

BACKGROUND: Imatinib, a tyrosine kinase inhibitor, has been shown to restore blood-brain barrier integrity and reduce infarct size, haemorrhagic transformation and cerebral oedema in stroke models treated with tissue plasminogen activator. We evaluated the safety of imatinib, based on clinical and neuroradiological data, and its potential influence on neurological and functional outcomes. METHODS: A phase II randomized trial was performed in patients with acute ischaemic stroke treated with intravenous thrombolysis. A total of 60 patients were randomly assigned to four groups [3 (active): 1 (control)]; the active treatment groups received oral imatinib for 6 days at three dose levels (400, 600 and 800 mg). Primary outcome was any adverse event; secondary outcomes were haemorrhagic transformation, cerebral oedema, neurological severity on the National Institutes of Health Stroke Scale (NIHSS) at 7 days and at 3 months and functional outcomes on the modified Rankin scale (mRS). RESULTS: Four serious adverse events were reported, which resulted in three deaths (one in the control group and two in the 400-mg dose group; one patient in the latter group did not receive active treatment and the other received two doses). Nonserious adverse events were mostly mild, resulting in full recovery. Imatinib ameliorated neurological outcomes with an improvement of 0.6 NIHSS points per 100 mg imatinib (P = 0.02). For the 800-mg group, the mean unadjusted and adjusted NIHSS improvements were 4 (P = 0.037) and 5 points (P = 0.012), respectively, versus controls. Functional independence (mRS 0-2) increased by 18% versus controls (61 vs. 79; P = 0.296). CONCLUSION: This phase II study showed that imatinib is safe and tolerable and may reduce neurological disability in patients treated with intravenous thrombolysis after ischaemic stroke. A confirmatory randomized trial is currently underway.

Endovascular method for transplantation of insulin-producing cells to the pancreas parenchyma in swine.

Insulin-producing cells are transplanted by portal vein injection as an alternative to pancreas transplantation in both clinical and preclinical trials. Two of the main limitations of portal vein transplantation are the prompt activation of the innate immunity and concomitant loss of islets and a small but significant risk of portal vein thrombosis. Furthermore, to mimic physiological release, the insulin-producing cells should instead be located in the pancreas. The trans-vessel wall approach is an endovascular method for penetrating the vessel wall from the inside. In essence, a working channel is established to the parenchyma of organs that are difficult to access by percutaneous technique. In this experiment, we accessed the extra-vascular pancreatic parenchyma in swine by microendovascular technique and injected methylene blue, contrast fluids and insulin-producing cells without acute adverse events. Further, we evaluated the procedure itself by a 1-year angiographical follow-up, without adverse events. This study shows that the novel approach utilizing endovascular minimal invasiveness coupled to accurate trans-vessel wall placement of an injection in the pancreatic parenchyma with insulin-producing cells is possible. In clinical practice, the potential benefits compared to portal vein cell transplantation should significantly improve endocrine function of the graft and potentially reduce adverse events.

Treatment response assessment with (R)-[11CPAQ PET in the MMTV-PyMT mouse model of breast cancer.

BACKGROUND: The goal of the study was to assess the potential of the vascular endothelial growth factor receptor (VEGFR)-2-targeting carbon-11 labeled (R)-N-(4-bromo-2-fluorophenyl)-6-methoxy-7-((1-methyl-3-piperidinyl)methoxy)-4-quinazolineamine ((R)-[11C]PAQ) as a positron emission tomography (PET) imaging biomarker for evaluation of the efficacy of anticancer drugs in preclinical models. METHODS: MMTV-PyMT mice were treated with vehicle alone (VEH), murine anti-VEGFA antibody (B20-4.1.1), and paclitaxel (PTX) in combination or as single agents. The treatment response was measured with (R)-[11C]PAQ PET as standardized uptake value (SUV)mean, SUVmax relative changes at the baseline (day 0) and follow-up (day 4) time points, and magnetic resonance imaging (MRI)-derived PyMT mammary tumor volume (TV) changes. Expression of Ki67, VEGFR-2, and CD31 in tumor tissue was determined by immunohistochemistry (IHC). Non-parametric statistical tests were used to evaluate the relation between (R)-[11C]PAQ radiotracer uptake and therapy response biomarkers. RESULTS: The (R)-[11C]PAQ SUVmax in tumors was significantly reduced after 4 days in the B20-4.1.1/PTX combinational and B20-4.1.1 monotherapy groups (p < 0.0005 and p < 0.003, respectively). No significant change was observed in the PTX monotherapy group. There was a significant difference in the SUVmax change between the VEH group and B20-4.1.1/PTX combinational group, as well as between the VEH group and the B20-4.1.1 monotherapy group (p < 0.05). MRI revealed significant decreases in TV in the B20-4.1.1/PTX treatment group (p < 0.005) but not the other therapy groups. A positive trend was observed between the (R)-[11C]PAQ SUVmax change and TV reduction in the B20-4.1.1/PTX group. Statistical testing showed a significant difference in the blood vessel density between the B20-4.1.1/PTX combinational group and the VEH group (p < 0.05) but no significant difference in the Ki67 positive signal between treatment groups. CONCLUSIONS: The results of this study are promising. However, additional studies are necessary before (R)-[11C]PAQ can be approved as a predictive radiotracer for cancer therapy response.

Management of spontaneous haemorrhagic intracranial vertebrobasilar dissection: review of 21 consecutive cases.

INTRODUCTION: Haemorrhagic intracranial vertebrobasilar dissection is an uncommon cause of nontraumatic subarachnoid haemorrhage (SAH) and accounts for only 1-10% of non-traumatic SAH. Treatment in the acute phase is considered to be essential because of the high risk of rebleeding and the consequent unfavourable outcome. However, the location, the potential for involvement of eloquent vessels and the histopathological characteristics of the vessel wall make treatment demanding from both a technical and anatomical point of view. We report our experience in the management of this disease. PATIENTS AND TREATMENTS: From 1989 to June 2006, we managed 21 patients with spontaneous haemorrhagic dissection located in the intracranial vertebrobasilar system, 13 patients were treated using an endovascular approach, 1 by surgical clipping, and 7 were managed conservatively. RESULTS: Among the 13 patients treated endovascularly, 7 underwent proximal occlusion, 4 underwent parent artery embolization at the site of dissection, and 2 underwent endovascular trapping. Severe, treatment-related complications due to dislodgement of the thrombus during the procedure occurred in 1 patient, who then died from brainstem ischaemia. One patient died from severe pneumonia and one patient was left disabled from vasospastic ischaemia resulting from severe initial SAH. The remaining 10 patients had satisfactory outcomes: none rebled after treatment and when discharged they had Karnovsky scores of 80-100. Of the 7 conservatively treated patients, three died of rebleeding and four were discharged with Karnovsky scores of 50-100. One patient, who was treated surgically, was discharged with a Karnovsky of 90. CONCLUSION: The high rate of rebleeding and consequent mortality among the patients treated conservatively argues for treatment in the acute phase. Treatment should be guided by each patient's angiomorphology, clinical condition and the experience of the neurosurgical/neuroradiological team. Options include endovascular or surgical trapping of the dissection and proximal occlusion and embolisation of the parent artery at the site of the dissection.

Increase of insulin-like growth factor (IGF)-1, IGF binding protein-2 and -4 mRNAs following cerebral contusion.

The insulin-like growth factor (IGF) system has a role in repair following hypoxic-ischemic injury in many tissues including the brain. To study the involvement of the IGF system following head trauma, we used a rat contusion model, which produces a focal lesion of the cerebral cortex. Molecules in the IGF system were analyzed using in situ hybridization at different times following impact. We observed a dramatic up-regulation of insulin-like growth factor binding protein-2 (IGFBP-2) mRNA in cortical areas adjacent to the injury 24 h after impact, with a peak 10-fold increase engaging most of the ipsilateral cortex 2 and 3 days post-contusion. Seven days after the contusion, IGFBP-2 expression was only moderately up-regulated and again concentrated around the injury. IGFBP-4 mRNA levels increased 4-fold ipsilateral to the site of injury, with retained pattern of cortical expression. IGFBP-3, IGFBP-5 and IGFBP-6 mRNA all displayed distinct expression patterns in the brain but no significant changes were observed following injury. In contrast, IGF-1 mRNA levels were very low prior to contusion, but increased markedly at the site of injury with a peak at day 3. We were unable to detect any changes in the type 1 IGF-receptor or IGF-2 mRNA following contusion. The neuropeptide cholecystokinin (CCK) mRNA was clearly up-regulated following contusion, with an even distribution over the ipsilateral cortex. The expression pattern of molecules in the IGF system post-contusion differs in part to changes observed following hypoxic-ischemia or ischemia alone, perhaps reflecting different regulatory mechanisms depending on the type of injury.

Long-term intracerebral inflammatory response after experimental focal brain injury in rat.

Head injury is a risk factor for development of the sporadic form of Alzheimer's disease (AD) and chronic anti-inflammatory treatment reduces the prevalence of AD. This study was undertaken to test the hypothesis that inflammatory reactions persist in the long term. Rats were subjected to moderate focal brain injury. The brains were analyzed after 3 months by immunohistochemistry. Persistent major histocompatibility complex (MHC)-II up-regulation, mononuclear phagocytes, interleukin (IL)-1-beta and tumor necrosis factor (TNF)-alpha synthesis (p < 0.01) were detected in large areas of the ipsilateral hemisphere. The fact that a long-term inflammation is detectable following experimental brain injury corroborates the hypothesis that persistent post-traumatic inflammation is a possible factor in the causative chain of traumatically induced dementia.

MK-801 inhibits the cortical increase in IGF-1, IGFBP-2 and IGFBP-4 expression following trauma.

Cerebral contusions increase cortical expression of insulin-like growth factor 1 (IGF-1), IGF binding protein-2 (IGFBP-2) and IGFBP-4, mRNA levels increase at the contusion site (IGF-1, IGFBP-2 and -4) and along the ipsilateral cortex (IGFBP-2 and -4). Here we explore whether this upregulation is glutamate dependent. Rats were treated with the non-competitive N-methyl-D-aspartate (NMDA) antagonist MK-801 or the non-NMDA antagonist CNQX before and after trauma, and analysed using quantitative in situ hybridization. The induction of IGF-1 expression was completely blocked by MK-801 or CNQX. IGFBP-2 mRNA levels remained high at the contusion site in the presence of either drug, but the increase was blocked in the cortex temporal to the impact by MK-801. The increase in IGFBP-4 mRNA was blocked by MK-801 but not by CNQX.

Depolarization induces insulin-like growth factor binding protein-2 expression in vivo via NMDA receptor stimulation.

The effect of depolarization and N-methyl-D-aspartate (NMDA) receptor blockade on insulin-like growth factor-I (IGF-I), IGF binding protein-2 (IGFBP-2) and IGFBP-4 expression was analysed in vivo. Depolarization was induced in adult rat brains by applying 3 M KCl to the exposed cortex for 10 min. A subgroup of animals also received daily injections of MK-801. Four days after KCl exposure, the brains were analysed by in situ hybridization, immunohistochemistry and TUNEL. A significant upregulation of IGFBP-2 mRNA and protein was detected in astrocytes after KCl exposure This upregulation was reduced by MK-801 treatment. No alterations in IGF-I or IGFBP-4 mRNA levels were noted. We did not detect TUNEL positive cells, morphological signs of necrosis or apoptosis, or neuronal loss in the depolarized zone. Taken together, these findings indicate that upregulation of IGFBP-2 by depolarization is mediated by NMDA receptors, and, as no neuronal damage was detected, astrocytic NMDA receptors may be responsible for this upregulation.

Biphasic edema development after experimental brain contusion in rat.

The time course of edema development following experimental brain contusion was studied by measuring cortex specific gravity 1 and 12 h after the trauma, and thereafter once daily until 7 days after the trauma. A biphasic development of edema was observed; the specific gravity decreased to a minimum on day 2 (P < 0.001), increased to an almost normal level on day 4 and thereafter decreased again to a second minimum 6 days after the trauma (P < 0.01). Delayed edema formation has been recognized in clinical settings, but has not been described in experimental studies. This study, with a prolonged daily follow-up, clearly demonstrates that a secondary phase of edema is an experimentally reproducible entity. The model will enable study of the pathogenetic mechanisms.

Induction of astrocytic nestin expression by depolarization in rats.

Nestin is expressed in central nervous system (CNS) progenitor cells and its expression in mature cells represents transition to a less differentiated cellular state under cellular stress. This study was performed to corroborate the hypothesis that nestin synthesis is induced by depolarization and dependent on N-methyl-D-aspartate (NMDA)-receptor activation. Depolarization was induced with application of potassium chloride on the exposed rat cortex and nestin expression was evaluated by immunohistochemistry. Depolarization induced astrocytic nestin expression that was local, or evident in the entire ipsilateral cortex depending on the time of exposure. Nestin expression was NMDA-receptor-dependent since MK-801 treatment abolished the response. Understanding the mechanisms for nestin expression is important since this protein is expressed in reactive and less differentiated CNS cell states and also in neural stem cells. Insights into the control of nestin expression may also provide means for controlling differentiation of CNS cells either post-trauma/ischemia or in transplantation strategies.

Temporal profiles and cellular sources of three nitric oxide synthase isoforms in the brain after experimental contusion.

OBJECTIVE: Nitric oxide (NO) is a universal mediator of biological effects in the brain. It has been implicated in the pathophysiological processes of traumatic brain injury. Understanding its pathophysiological role in vivo requires an understanding of the cellular sources and tissue compartments of the differentially regulated NO synthase (NOS) isoforms. This study was undertaken to investigate the cellular sources and tissue compartments of NO produced after experimental brain contusions in rats, by analysis of the early expression of the three isoforms of NOS, i.e., the inducible, endothelial, and neuronal isoforms. METHODS: Focal brain contusions were produced in 24 rats using a weight-drop model. The animals were killed 6, 12, 24, 36, or 48 hours after trauma. Sections were analyzed by immunohistochemical and immunofluorescence analyses. Double staining assays were used to define which cells produced the different NOS isoforms. RESULTS: Increases in endothelial NOS-, inducible NOS (iNOS)-, and neuronal NOS-positive cells were detectable by 6 hours after trauma. Endothelial NOS and iNOS levels peaked at 6 and 12 hours, respectively. Expression of neuronal NOS initially increased to a peak at 12 hours but then decreased to a level lower than that in control samples at 36 hours. Endothelial NOS was expressed exclusively in endothelial cells, whereas iNOS was expressed in neutrophils and macrophages. Neuronal NOS was predominantly detected in neurons but was also unexpectedly detected in polymorphonuclear cells. CONCLUSION: In this model, the most striking finding regarding NO-producing enzymes was the expression of iNOS in polymorphonuclear cells and macrophages, cells that invade injured brain tissue. iNOS is thus implicated as a therapeutic target in contusional injuries. This pattern of NOS expression cannot be generalized to all types of brain injuries. The different compartments and cells that can produce NO are differentially regulated; therefore, compartmentalization can explain why NO is beneficial or detrimental, depending on the circumstances. A knowledge of different potential sites and sources of NO is required for any attempts to interfere with the pathophysiological properties of NO.

Intracerebral inflammation after human brain contusion.

OBJECTIVE: This study was undertaken to analyze the inflammatory components in contused human brain tissue to compare the findings with previous experimental data regarding the pathogenesis of brain contusions. METHODS: Contused brain tissue biopsies were obtained from 12 consecutive patients undergoing surgery for brain contusions 3 hours to 5 days after trauma. Inflammatory and immunological components were analyzed by immunohistochemistry. RESULTS: In patients undergoing surgery less than 24 hours after trauma, the inflammatory response was limited to vascular margination of polymorphonuclear cells. In patients undergoing surgery 3 to 5 days after trauma, however, a massive inflammatory response consisting of monocytes/macrophages, reactive microglia, polymorphonuclear cells, and CD4- and CD8-positive T lymphocytes was detected. Human lymphocyte antigen-DQ was expressed on reactive microglia and infiltrating leukocytes in the late patient group. In addition, CD1a, which is a marker for antigen-presenting dendritic cells, was detected in a subgroup of microglial cells. CONCLUSION: The results corroborated hypotheses derived from experimental data. In the early phase after contusional trauma, inflammation is mainly intravascular and dominated by polymorphonuclear cells. The inflammation was parenchymal in patients undergoing surgery 3 to 5 days after trauma. The brain swelling seemed to be biphasic, the delayed phase correlating with a parenchymal inflammation. The inflammatory cells may produce several potentially harmful effects, such as acute cellular degeneration; they may also lead to degenerative long-term effects.

Intracerebral administration of interleukin-1beta and induction of inflammation, apoptosis, and vasogenic edema.

OBJECT: The proinflammatory cytokines interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNFalpha) are produced intracerebrally in brain disorders such as trauma, ischemia, meningitis, and multiple sclerosis. This investigation was undertaken to analyze the effect of intracerebral administration of IL-1beta and TNFalpha on inflammatory response, cell death, and edema development. METHODS: Intracerebral microinjections of these cytokines were administered to rats. The animals were killed 24 or 72 hours after the injections, and their brains were analyzed by using deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) with digoxigenin-labeled deoxyuridine triphosphate, immunohistochemical studies, and brain-specific gravity measurement. The IL-1beta induced a transient inflammatory response (p < 0.001) and TUNEL staining (p < 0.001), indicating cell death, in intrinsic central nervous system (CNS) cells and infiltrating inflammatory cells. In 73.8+/-6.77% of the TUNEL-positive cells, small, fragmented nuclei were found. All TUNEL-positive cells expressed the proapoptotic gene Bax, and 69.6+/-4.6% of the TUNEL-positive cells expressed the antiapoptotic gene Bcl-2; the Bax expression was stronger than the Bcl-2 expression. Taken together, the data indicate that cell death occurred via the apoptotic pathway. The TNFalpha did not induce inflammation or DNA fragmentation within the analyzed time period. Both IL-1beta (p < 0.001) and TNFalpha (p < 0.01) caused vasogenic edema, as measured by specific gravity and albumin staining. The edematous effect of TNFalpha persisted 72 hours after injection (p < 0.01), whereas the IL-1beta-treated animals had normalized by that time. CONCLUSIONS: Intracerebral inflammation, death of intrinsic CNS cells, and vasogenic edema can be mediated by IL-1beta, and TNFalpha can cause vasogenic edema. Suppression of these cytokines in the clinical setting may improve outcome.

Delayed cytokine expression in rat brain following experimental contusion.

Proinflammatory cytokines mediate brain injury in experimental studies. This study was undertaken to analyze the production of proinflammatory cytokines in experimental contusion. A brain contusion causing delayed edema was mimicked experimentally in rats using a weight-drop model. Intracerebral expression of the cytokines interleukin (IL)-1 beta, tumor necrosis factor-alpha (TNF alpha), IL-6, and interferon-gamma (IFN gamma) was studied by in situ hybridization and immunohistochemistry. The animals were killed at 6 hours or 1, 2, 4, 6, 8, or 16 days postinjury. In the injured area, no messenger (m)RNA expression was seen during the first 2 days after the trauma. On Days 4 to 6 posttrauma, however, strong IL-1 beta, TNF alpha, and IL-6 mRNA expression was detected in mononuclear cells surrounding the contusion. Expression of IFN gamma was not detected. Immunohistochemical double labeling confirmed the in situ hybridization results and demonstrated that mononuclear phagocytes and astrocytes produced IL-1 beta and that mainly astrocytes produced TNF alpha. The findings showed, somewhat unexpectedly, a late peak of intracerebral cytokine production in the injured area and in the contralateral corpus callosum, allowing for both local and global effects on the brain. An unexpected difference in the cellular sources of TNF alpha and IL-1 beta was detected. The cytokine pattern differs from that seen in other central nervous system inflammatory diseases and trauma models, suggesting that the intracerebral immune response is not a uniform event. The dominance of late cytokine production indicates that many cytokine effects are late events in an experimental contusion: Different pathogenic mechanisms may thus be operative at different times after brain injury.

Chromatographic evaluation of structure selective and enantioselective retention of amines and acids on cellobiohydrolase I wild type and its mutant D214N.

The mechanisms of structure selective and enantioselective retentions of amines and acids on two chiral stationary phases based on wild type cellobiohydrolase I (CBH I) and its mutant D214N have been investigated. All the amino alcohols tested had an enantioselective site that overlaps with the catalytically active site of CBH I, whereas the enantioselectivity of prilocaine was not affected by the mutation. The hydroxyl group of the amino alcohols did not seem to be an important contributor to the total binding strength whereas a bromo substituent in the aromatic ring promotes a high enantioselectivity (alpha=7.05). Interestingly, the chiral recognition site of the acid warfarin overlaps with the binding site of the amino alcohols. Di-p-toluoyltartaric acid and dibenzoyltartaric acid were strongly retained probably due to electrostatic attraction, but no enantioselectivity was observed. The difference in retention characteristics for the amino alcohols on the two stationary phases was strongly pH-dependent. A change in elution order of different amino alcohols occurred when changing the pH from 5.0 to 7.0. The difference between the two phases was lower at low pH. The retention times could also be affected by ionic strength and by use of cellobiose as a mobile phase additive but no indication of ion-pair retention of the amines was observed, when adding hexanesulphonate as counter ion to the mobile phase. The temperature dependence of the retention of the enantiomers of propranolol at pH 7.0 on the mutant D214N was similar to what was earlier observed on the wild type CBH I at lower pH.

Superselective intra-arterial umbilical cord blood administration to BM in experimental animals.

Umbilical cord blood (UCB) as a source of hematopoietic stem cells for transplantation is limited by the low number of cells and delayed engraftment. UCB cells are infused i.v. for transplantation, although only a proportion of the cells reach the BM. We investigated whether UCB could be administered safely using superselective intra-arterial (i.a.) injection. We injected human UCB (5 × 10(6)) into the aorta in rats, into the iliac artery in mice and into the femoral nutrient artery (FNA) in rabbits. We used angiography, immunohistochemistry, intravital microscopy and qPCR to assess safety end points and the distribution of injected cells. All animals showed normal behavior. No evidence of organ infarction was noted. UCB injected into the FNA of rabbits did not change the flow rates, measured by angiography. By qPCR, we found significantly higher fold-change values in the injected BM compared with i.v. injection (P=0.0087). Using intravital microscopy we visualized the mouse capillary bed during i.a. injection without cellular congestion. In summary, we show that i.a. infusion of UCB is safe and reaches an eightfold increase in engraftment in the BM compared with i.v. infusion. These studies lay the foundation for clinical trials.

Vertebrobasilar Dissection with Pseudo-aneurysm or Subarachnoid Hemorrhage: Intracranial Stenting as the Only Treatment. A Report of Three Cases.

SUMMARY: Vertebrobasilar dissection may cause ischaemia or subarachnoid haemorrhage and can pose a significant treatment challenge. Endovascular treatment using stents alone has been described but there are few reports of its clinical application. We here report our experiences from three cases of vertebrobasilar dissection and pseudo-aneurysm or subarachnoid hemorrhage treated with stents alone.