Endovascular treatment of wide-neck middle cerebral artery aneurysms with stents: a review of 16 cases

BACKGROUND AND PURPOSE

MCA aneurysms are common and often pose technical challenges to interventionalists. Intracranial stents are widely used in treating wide-neck aneurysms in other locations. To evaluate the feasibility, effectiveness, and safety of stent placement in MCA aneurysms, we performed this retrospective study.

MATERIALS AND METHODS

Between October 2003 and May 2009, 16 patients with 16 wide-neck MCA aneurysms were treated with stents at our institution. We retrospectively collected and analyzed the data for these patients, including demographics, morphologic features of the aneurysms, treatment results, and follow-up.

RESULTS

Seventeen stents, including 12 Neuroform, 4 LEO, and 1 Enterprise, were successfully deployed in this series. Of the 13 aneurysms treated with stent-assisted embolization, complete occlusion was achieved in 9 aneurysms; residual neck remained in 1, and residual aneurysm was present in 3. Contrast stasis in the aneurysm sac was observed in the other 3 aneurysms treated with stent alone. Procedure-related complication occurred in 1 patient, leading to no permanent effect. The mRS score at discharge was 0-2 in 14 patients and 3-6 in 2. The angiographic follow-up results of 9 patients (mean, 5.6 months) showed that all aneurysms remained stable or improved; there was no in-stent stenosis, recurrence, or retreatment. The clinical follow-up (mean, 20.1 months) demonstrated no neurologic deterioration or rebleeding.

CONCLUSIONS

Our preliminary experience demonstrates that stent placement for the treatment of selected wide-neck MCA aneurysms is feasible. However, its safety and efficacy should be further evaluated by larger case series and more adequate follow-up.

Azimuthal charged-particle correlations and possible local strong parity violation

Parity-odd domains, corresponding to nontrivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted to lead to charge separation of quarks along the system's orbital momentum axis. We investigate a three-particle azimuthal correlator which is a P even observable, but directly sensitive to the charge separation effect. We report measurements of charged hadrons near center-of-mass rapidity with this observable in Au + Au and Cu + Cu collisions at square root of s(NN) = 200 GeV using the STAR detector. A signal consistent with several expectations from the theory is detected. We discuss possible contributions from other effects that are not related to parity violation.

Four types of potassium currents in motor nerve terminals of snake

The experiments were performed on transversus abdominis muscle of Elaphe dione by subendothelial recording. The results indicate that in snake motor nerve endings there exist four types of K(+) channels, i.e. voltage-dependent fast and slow K(+) channels, Ca(2+)-activated K(+) channel and ATP-sensitive K(+) channel. (i) The typical wave form of snake terminal current was the double-peaked negativity in standard solution. The first peak was attributed to Na(+) influx (I(Na)) in nodes of Ranvier. The second one was blocked by 3,4-aminopyridine (3,4-DAP) or tetraethylammonium (TEA), which corresponded to fast K(+) outward current (I(k.f)) through the fast K(+) channels in terminal part. (ii) After I(K.F) as well as the slow K(+) current (I(K.S)) were blocked by 3, 4-DAP, the TEA-sensitive Ca(2 +)-dependent K(+) current (I(K(Ca))) passing through Ca(2 +)-activated K(+) channel was revealed, whose amplitude depended on [K(+)](o) and [ca(2+) ](o). It was blocked by Ba(2+), Cd(2+) or Co(2+). (iii) I(K.F) and I(K(Ca)) were blocked by TEA, while I(K. S) was retained. It was sensitive to 3,4-DAP, partially blocked by ethanol (200 mmol/L) or beta-bungarotoxin (2 micromol/L), and enhanced by low pH (6.4-6.7). This is the first report that certain current component of motor nerve terminal is sensitive to pH in the range of 6. 4-7. 5. (iv) That diazoxide (200 micromol/L) increased the second negative peak and the effect was eliminated after further addition of glibenclamide (50 micromol/L) was taken as evidence for the presence of ATP-sensitive K(+) current (I(K.ATP)) at snake nerve terminal.

Raman spectroscopic characteristics of microcosmic and photosensitive damage on space structure of liposomes sensitized by hypocrellin and its derivatives

Raman spect-pic characteristics of microcosmic and photosensitive damage on space structure of DP-PC liposomes sensitized by hypocrellin and its derivatives are obvious. The trans conformation decreased and the gauche conformation increased. The longitudinal order-parameter in chains and the lateral order-parameter between chains decreased in different degrees. The lateral packing became loose. Photodamage on the liposomes sensitized by 5-Br-hypocrellin B was stronger than that by hypocrellins A and B.

A, Hegde P, Cronin E, Kane M, Tavakoli B, Xu Y. Near Infrared Imaging Using US Localization To Assess Response to Neoadjuvant Chemotherapy

Background: Pilot data obtained from a novel ultrasound (US)-guided diffusive-wave optical tomography in the near infrared (NIR) spectrum showed that it is feasible to use this technique to monitor vascular changes within breast tumors during neoadjuvant chemotherapy. These changes correlated well to tumor pathologic response. The earlier study was performed at a single hospital with a smaller patient pool and the tumor vascular assessment was made at a period of two treatment cycles. The objectives of this study are: (i) to validate the initial findings with a larger patient pool, and (ii) to assess vascular changes at every treatment cycle and to correlate early vascular changes with the tumor pathological response.Materials and Methods: 13 patients who underwent neoadjuvant treatment were recruited from two hospitals from December 2007 to May 2009 and their tumor vascular content was assessed with a combined imager consisting of a commercially available US system coupled to a NIR imager (NIR/US). Patients were imaged before their treatment, at the end of every treatment cycle and before their definitive surgery. The co-registered US was used to localize the tumor and to guide the NIR imaging reconstruction, and the NIR imager was used to map the tumor vascular distribution which was assessed based on a percentage total hemoglobin (%tHb) concentration normalized to the pre-treatment level. Of the 13 patients, 12 patients had contrast enhanced MRI before treatment and prior to surgery. The NIR results were compared with MRI findings. At treatment completion, pathological assessment revealed three response groups: complete or near-complete responders (A), partial responders (B), and non-responders (C).Results: There were four complete or near-complete responders, five partial responders, and four non-responders. The mean %tHbs of groups of A, B and C at the treatment completion were 38%±7.0%, 57.3%±5.7%, and 91.0%±10.1%, respectively (differences statistically significant, p<0.05). At the end of cycle one, the %tHb of group A showed no noticeable difference than that of partial and non-responder groups, however, the %tHb at the end of cycle two or three of group A was significantly lower than that of partial and non-responder groups. Figure 1 shows an example of a complete responder imaged before the treatment and at the end of cycle two.All complete or near-complete responders showed rapid reduction in %tHb at the end of cycle two or three; while all non-responders showed no change or small change in %tHb throughout the treatment. On average, partial responders showed changes in between. Both NIR/US and MRI were equally effective in distinguishing different response groups in this study.Discussion: Our findings indicate that NIR can be used during neoadjuvant chemotherapy to repeatedly monitor tumor vascular changes. NIR/US may also assess early pathological response during treatment.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5016.

Treatment and outcome of intracranial hemorrhage after carotid artery stenting. A ten year single center experience

SUMMARY

Intracranial hemorrhage following carotid artery stenting (CAS) is a rare but potentially devastating complication. The present study reviewed intracranial hemorrhage cases from patients undergoing CAS in ten years to find the methods to rescue patients from this fatal complication. Patients with postoperative intracranial hemorrhage following CAS were retrospectively selected, and clinical features, treatments and outcomes were studied. Ten patients with intracranial hemorrhage were identified. The mean onset time of hemorrhage was 6.1-/+7.1h. Intracerebral hemorrhage occurred in eight patients and SAH in two patients. The patients were treated by stopping anti-platelet and anticoagulant for at least three days, and surgical drainage of the hematoma/ventricle drainage or conservative treatment. Six patients survived, two had left moderate paralysis, four had a good recovery at four week follow-up, and four patients died. No patients underwent thrombosis in stent after withdrawing of antiplatelet and anticoagulant. Intracranial hemorrhage after CAS occurs usually in a few hours and leads to catastrophic results. Once patients have intracranial hemorrhage, good neurocritical care may help to save them. Stopping antiplatelet and anticoagulant for at least three days may avoid thrombosis in the stenting site.

A common gain of function of p53 cancer mutants in inducing genetic instability

The critical tumor suppressor p53 is mutated in over half of all human cancers. The majority of p53 cancer mutations are missense mutations, which can be classified into contact mutations that directly disrupt the DNA-binding of p53 but have modest impact on p53 conformation and structural mutations that greatly disrupt p53 conformation. Many p53 cancer mutants, including the hot spot mutations (R175H, R248W and R273H), not only lose p53-dependent tumor-suppressor activities, but also acquire new oncogenic activities to promote cancer. Therefore, it is critical to elucidate the gain of oncogenic function of p53 cancer mutants. Using humanized p53-mutant knock-in mouse models, we have identified a gain of oncogenic function shared by the most common p53 contact mutants (R273H and R248W) and structural mutant (R175H). This gain of function inactivates Mre11/ATM-dependent DNA damage responses, leading to chromosomal translocation and defective G(2)/M checkpoint. Considering the critical roles of ATM in maintaining genetic stability and therapeutic responses to many cancer treatments, the identification of this common gain of function of p53 cancer mutants will have important implication on the drug resistance of a significant portion of human cancers that express either the contact or structural p53 cancer mutants.

Growth of long range forward-backward multiplicity correlations with centrality in Au + Au collisions at square root of sNN = 200 GeV

Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au + Au and p + p collisions at square root of s(NN) = 200 GeV. Strong short- and long-range correlations (LRC) are seen in central Au + Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short-range correlations are observed in peripheral Au + Au collisions. Both the dual parton model (DPM) and the color glass condensate (CGC) predict the existence of the long-range correlations. In the DPM, the fluctuation in the number of elementary (parton) inelastic collisions produces the LRC. In the CGC, longitudinal color flux tubes generate the LRC. The data are in qualitative agreement with the predictions of the DPM and indicate the presence of multiple parton interactions.

Glucose-6-phosphate dehydrogenase-deficient mice have increased renal oxidative stress and increased albuminuria

Glucose-6-phosphate dehydrogenase (G6PD) is the rate-limiting enzyme of the pentose phosphate pathway and the principal source of NADPH, a major cellular reductant, and is central to cell survival. Our previous work showed that diabetes and increased aldosterone are acquired forms of G6PD deficiency, leading to decreased G6PD activity and NADPH levels and damage to kidney tissue and endothelial cells. In this study, G6PD-deficient mice were studied to test the hypothesis that decreased G6PD activity per se can cause changes similar to those seen in the acquired conditions of G6PD deficiency. Results show that as compared with control mice, G6PD-deficient mice had increased oxidative stress, as manifested by decreased NADPH levels and decreased GSH levels, and increased markers of lipid peroxidation. G6PD-deficient mice had increased protein kinase C activity, increased nuclear factor-kappaB activity, and increased urinary albumin levels, all of which is similar to changes seen in diabetic mice. Changes persisted as the mice aged, as old G6PD-deficient mice (17-20 mo) had higher urine albumin levels and also had evidence for increased apoptosis in the renal cortex. These results show that decreased G6PD activity per se is sufficient to cause changes similar to those seen in diabetic mice.