Rebleeding following aneurysmal subarachnoid hemorrhage before 'endovascular first' treatment: a retrospective case-control study of published scoring systems

BACKGROUND

Pre-treatment re-bleeding following aneurysmal subarachnoid hemorrhage (aSAH) affects up to 7.2% of patients even with ultra-early treatment within 24 hours. We retrospectively compared the utility of three published re-bleed prediction models and individual predictors between cases who re-bled matched to controls using size and parent vessel location from a cohort of patients treated in an ultra-early, 'endovascular first' manner.

METHODS

On retrospective analysis of our 9-year cohort of 707 patients suffering 710 episodes of aSAH, there were 53 episodes of pre-treatment re-bleeding (7.5%). Forty-seven cases who had a single culprit aneurysm were matched to 141 controls. Demographic, clinical and radiological data were extracted and predictive scores calculated. Univariate, multivariate, area under the receiver operator characteristic curve (AUROCC) and Kaplan-Meier (KM) survival curve analyses were performed.

RESULTS

The majority of patients (84%) were treated using endovascular techniques at a median 14.5 hours post-diagnosis. On AUROCC analysis the score of Liu et al. had minimal utility (C-statistic 0.553, 95% confidence interval (CI) 0.463 to 0.643) while the risk score of Oppong et al. (C-statistic 0.645 95% CI 0.558 to 0.732) and the ARISE-extended score of van Lieshout et al. (C-statistic 0.53 95% CI 0.562 to 0.744) had moderate utility. On multivariate modeling, the World Federation of Neurosurgical Societies (WFNS) grade was the most parsimonious predictor of re-bleeding (C-statistic 0.740, 95% CI 0.664 to 0.816).

CONCLUSIONS

For aSAH patients treated in an ultra-early timeframe matched on size and parent vessel location, WFNS grade was superior to three published models for re-bleed prediction. Future re-bleed prediction models should incorporate the WFNS grade.

Pre-treatment re-bleeding following aneurysmal subarachnoid hemorrhage: A systematic review of published prediction models with risk of bias and clinical applicability assessment

BACKGROUND

Pre-treatment rebleeding following aneurysmal subarachnoid hemorrhage (aSAH) increases the risk of death and a poor neurological outcome. Current guidelines recommend aneurysm treatment "as early as feasible after presentation, preferably within 24 h of onset" to mitigate this risk, a practice termed ultra-early treatment. However, ongoing debate regarding whether ultra-early treatment is independently associated with reduced re-bleeding risk, together with the recognition that re-bleeding occurs even in centres practicing ultra-early treatment due to the presence of other risk-factors has resulted in a renewed need for patient-specific re-bleed risk prediction. Here, we systematically review models which seek to provide patient specific predictions of pre-treatment rebleeding risk.

METHODS

Following registration on the International prospective register of systematic reviews (PROSPERO) CRD 42023421235; Ovid Medline (Pubmed), Embase and Googlescholar were searched for English language studies between 1st May 2002 and 1st June 2023 describing pre-treatment rebleed prediction models following aSAH in adults ≥18 years. Of 763 unique records, 17 full texts were scrutinised with 5 publications describing 4 models reviewed. We used the semi-automated template of Fernandez-Felix et al. incorporating the Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies (CHARMS) checklist and the Prediction model Risk Of Bias ASsessment Tool (PROBAST) for data extraction, risk of bias and clinical applicability assessment. To further standardize risk of bias and clinical applicability assessment, we also used the published explanatory notes for the PROBAST tool and compared the aneurysm treatment practices each prediction model's formulation cohort experienced to a prespecified benchmark representative of contemporary aneurysm treatment practices as outlined in recent evidence-based guidelines and published practice pattern reports from four developed countries.

RESULTS

Reported model discriminative performance varied between 0.77 and 0.939, however, no single model demonstrated a consistently low risk of bias and low concern for clinical applicability in all domains. Only the score of Darkwah Oppong et al. was formulated using a patient cohort in which the majority of patients were managed in accordance with contemporary, evidence-based aneurysm treatment practices defined by ultra-early and predominantly endovascular treatment. However, this model did not undergo calibration or clinical utility analysis and when applied to an external cohort, its discriminative performance was substantially lower that reported at formulation.

CONCLUSIONS

No existing prediction model can be recommended for clinical use in centers practicing contemporary, evidence-based aneurysm treatment. There is a pressing need for improved prediction models to estimate and minimize pre-treatment re-bleeding risk.

Balloon assisted Woven endobridge deployment (BAWD): A safety and efficacy study

BACKGROUND

Balloon-assisted deployment/remodelling is a proven adjunctive technique for coil embolization of intracranial aneurysms, and it may be a helpful adjunct in delivering the Woven EndoBridge (WEB) device.

OBJECTIVE

To evaluate the safety, efficacy and feasibility of balloon-assisted WEB deployment in both ruptured and unruptured intracranial aneurysms in both typical and atypical locations.

METHODS

Patients who underwent treatment of ruptured and unruptured intracranial aneurysms with the BAWD technique were retrospectively identified from a prospectively maintained database at two neurointerventional centres. Patient demographics, aneurysm characteristics, technical procedure details, clinical and imaging outcomes were reviewed.

RESULTS

Thirty-three aneurysms (23 women) were identified with a median age of 58 years. There were 15 (45.5%) ruptured aneurysms, 25 (64.3%) in the anterior circulation and 12 (36.4%) aneurysms having an atypical location for WEB treatment. The average aneurysm size was 6.8 mm (greatest dimension), 4.6 mm (height) and 4.5 mm (width), and 25 (75.8%) aneurysms had a wide neck morphology. One patient died (3.0%) secondary to a procedure-related complication, and there was no procedure-related permanent morbidity. Complete and adequate aneurysm occlusion on mid-term follow-up DSA was 85.2% and 92%, respectively.

CONCLUSION

Balloon-assisted WEB deployment appears to be a safe and effective technique that may increase the utility of the WEB device. Further prospective studies on BAWD should be considered.

Middle meningeal artery embolization for chronic subdural hematoma in a young patient with refractory thrombocytopenia secondary to leukemia: more evidence for a paradigm shift? Illustrative case

BACKGROUND

Chronic subdural hematoma (CSDH) is one of the most common neurosurgical presentations, with an increasing number now also presenting with concurrent thrombocytopenia. Although middle meningeal artery (MMA) embolization has been considered in elderly patients with high comorbidities, it may permit treatment of CSDH in patients who are at high risk for recurrence or deemed unsuitable for surgical management due to thrombocytopenia.

OBSERVATIONS

A 35-year-old man who had severe thrombocytopenia due to blast cell crisis with chronic myeloid leukemia developed an atraumatic CSDH. The patient developed severe headaches in the hospital while being treated for febrile neutropenia. He remained neurologically intact. MMA embolization was undertaken due to the morbidity and mortality risks associated with surgery and the high risk of recurrence due to severe thrombocytopenia. At 2 months post-procedure the patient was asymptomatic and there was almost complete resolution of the hematoma.

LESSONS

Thrombocytopenia in the presence of a CSDH is becoming increasingly common. This case highlights the particular role of MMA embolization in patients with severe thrombocytopenia where surgery carries high morbidity and increased mortality.

High-precision measurement of the W boson mass with the CDF II detector

The mass of the W boson, a mediator of the weak force between elementary particles, is tightly constrained by the symmetries of the standard model of particle physics. The Higgs boson was the last missing component of the model. After observation of the Higgs boson, a measurement of the W boson mass provides a stringent test of the model. We measure the W boson mass, M_W, using data corresponding to 8.8 inverse femtobarns of integrated luminosity collected in proton-antiproton collisions at a 1.96 tera-electron volt center-of-mass energy with the CDF II detector at the Fermilab Tevatron collider. A sample of approximately 4 million W boson candidates is used to obtain [Formula: see text], the precision of which exceeds that of all previous measurements combined (stat, statistical uncertainty; syst, systematic uncertainty; MeV, mega-electron volts; c, speed of light in a vacuum). This measurement is in significant tension with the standard model expectation.

Injection laryngoplasty during transoral laser microsurgery for early glottic cancer: a randomized controlled trial

BACKGROUND

Transoral laser microsurgery is widely used for treating T1/T2 glottic cancers. Hyaluronic acid (HA) is commonly used in vocal cord augmentation. We investigated the impact of intra-operative injection laryngoplasty on voice outcomes in early glottic cancer.

METHODS

Twenty patients were randomized to the treatment group receiving HA injection to the vocal cord contralateral to the lesion; or the control group, receiving no injection. Patients had a Voice Handicap Index-10 (VHI-10) questionnaire and a Maximum Phonation Time (MPT) measurement preoperatively and at 3, 12 and 24 months post-operatively. Mean change in VHI-10 and MPT, compared to baseline and between time points, were compared. Survival estimates were calculated.

RESULTS

Mean VHI-10 scores improved over time amongst all patients. There were no changes in mean VHI-10 from pre-operative values to 3, 12 or 24 months post-operatively. There were no significant differences when comparing various timepoints between groups. There were no significant changes in MPT amongst the groups, or the time-points compared. Two-year overall survival was 91.7%; disease free survival was 80.9%; no difference in recurrence free survival was seen between the groups.

CONCLUSION

Subjective voice scores improved over time in both groups; there were no improvements in VHI-10 or MPT scores in the injection group, over control, at any time points. We saw no significant impact for intra-operative HA injection laryngoplasty on subjective or objective voice outcomes following surgery for early glottic cancers.

Peri-adolescent exposure to (meth)amphetamine in animal models

Experimentation with psychoactive drugs is often initiated in the peri-adolescent period, but knowledge of differences in the outcomes of peri-adolescent- vs adult-initiated exposure is incomplete. We consider the existing animal research in this area for (meth)amphetamines. Established for a number of phenotypes, is lower sensitivity of peri-adolescents than adults to acute effects of (meth)amphetamines, including neurotoxic effects of binge-level exposure. More variable are data for long-term consequences of peri-adolescent exposure on motivational and cognitive traits. Moreover, investigations often exclude an adult-initiated exposure group critical for answering questions about outcomes unique to peri-adolescent initiation. Despite this, it is clear from the animal research that (meth)amphetamine exposure during the peri-adolescent period, whether self- or other-administered, impacts brain motivational circuitry and cognitive function, and alters adult sensitivity to other drugs and natural rewards. Such consequences occurring in humans have the potential to predispose toward unfortunate and potentially disastrous family, social and livelihood outcomes.

Mechanical thrombectomy is efficacious in patients with pre-stroke moderate disability

INTRODUCTION

Patients with ischaemic stroke due to large vessel occlusion (LVO) can be treated successfully with mechanical thrombectomy (MT) and/or intravenous thrombolysis. In the landmark trials, MT was only performed for those with no functional disability prior to stroke (mRS 0-2). There are limited data available regarding clinical outcomes for patients with pre-stroke moderate disability (mRS ≥ 3). The aims of this study were to analyse the clinical outcomes and financial implications in regard to accommodation costs of performing MT in patients with pre-stroke mRS = 3.

METHODS

An observational cohort study was performed of 802 patients with anterior circulation LVO ischaemic stroke who underwent MT between October 2016 and January 2020 at three tertiary hospitals. Patient demographics, premorbid mRS, stroke and interventional data, 90-day mRS and accommodation situation were recorded.

RESULTS

Eighty-two patients with anterior circulation LVO ischaemic stroke were pre-stroke mRS 3. 38% had a good clinical outcome, as defined by mRS 3 at 90 days. Mortality rate was 38%. The majority of patients presented from home (83%) and greater than one third of those returned home during the 90 days post treatment. 81% of patients had no increase in accommodation cost at 90 days.

CONCLUSION

Patients with pre-stroke moderate disability may benefit from MT if they are appropriately selected. This may result in fewer patients requiring nursing home placement and less financial burden on the public health system, indicating significant savings are possible.

Maternal antioxidant treatment prevents the adverse effects of prenatal stress on the offspring's brain and behavior

Maternal exposure to stress during pregnancy is associated with an increased risk of psychiatric disorders in the offspring in later life. The mechanisms through which the effects of maternal stress are transmitted to the fetus are unclear, however the placenta, as the interface between mother and fetus, is likely to play a key role. Using a rat model, we investigated a role for placental oxidative stress in conveying the effects of maternal social stress to the fetus and the potential for treatment using a nanoparticle-bound antioxidant to prevent adverse outcomes in the offspring.

Maternal psychosocial stress increased circulating corticosterone in the mother, but not in the fetuses. Maternal stress also induced oxidative stress in the placenta, but not in the fetal brain. Blocking oxidative stress using an antioxidant prevented the prenatal stress-induced anxiety phenotype in the male offspring, and prevented sex-specific neurobiological changes, specifically a reduction in dendrite lengths in the hippocampus, as well as reductions in the number of parvalbumin-positive neurons and GABA receptor subunits in the hippocampus and basolateral amygdala of the male offspring. Importantly, many of these effects were mimicked in neuronal cultures by application of placental-conditioned medium or fetal plasma from stressed pregnancies, indicating molecules released from the placenta may mediate the effects of prenatal stress on the fetal brain. Indeed, both placenta-conditioned medium and fetal plasma contained differentially abundant microRNAs following maternal stress, and their predicted targets were enriched for genes relevant to nervous system development and psychiatric disorders.

The results highlight placental oxidative stress as a key mediator in transmitting the maternal social stress effects on the offspring's brain and behavior, and offer a potential intervention to prevent stress-induced fetal programming of affective disorders.

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Social stress in pregnancy induces oxidative stress but is prevented by antioxidant.

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Prenatal stress induces behavioural, neuroanatomical and neurochemical changes.

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Maternal antioxidant treatment prevents stress-induced effects in the offspring.

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Maternal stress alters the balance of microRNAs secreted from the placenta.

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Placental oxidative stress mediates maternal social stress effects on the offspring.

Non-genetic factors that influence methamphetamine intake in a genetic model of differential methamphetamine consumption

RATIONALE

Genetic and non-genetic factors influence substance use disorders. Our previous work in genetic mouse models focused on genetic factors that influence methamphetamine (MA) intake. The current research examined several non-genetic factors for their potential influence on this trait.

OBJECTIVES

We examined the impact on MA intake of several non-genetic factors, including MA access schedule, prior forced MA exposure, concomitant ethanol (EtOH) access, and gamma-aminobutyric acid type B (GABA_B) receptor activation. Selectively bred MA high drinking (MAHDR) and low drinking (MALDR) mice participated in this research.

RESULTS

MAHDR, but not MALDR, mice increased MA intake when given intermittent access, compared with continuous access, with a water choice under both schedules. MA intake was not altered by previous exposure to forced MA consumption. Male MAHDR mice given simultaneous access to MA, EtOH, and an EtOH+MA mixture exhibited a strong preference for MA over EtOH and EtOH+MA; MA intake was not affected by EtOH in female MAHDR mice. When independent MAHDR groups were given access to MA, EtOH, or EtOH+MA vs. water in each case, MA intake was reduced in the water vs. EtOH+MA group, compared with the water vs. MA group. The GABA_B receptor agonist R(+)-baclofen (BAC) not only reduced MA intake but also reduced water intake and locomotor activity in MAHDR mice. There was a residual effect of BAC, such that MA intake was increased after termination of BAC treatment.

CONCLUSIONS

These findings demonstrate that voluntary MA intake in MAHDR mice is influenced by non-genetic factors related to MA access schedule and co-morbid EtOH exposure.

Demonstration of Muon-Beam Transverse Phase-Space Compression

We demonstrate efficient transverse compression of a 12.5  MeV/c muon beam stopped in a helium gas target featuring a vertical density gradient and crossed electric and magnetic fields. The muon stop distribution extending vertically over 14 mm was reduced to a 0.25 mm size (rms) within 3.5  μs. The simulation including cross sections for low-energy μ^{+}-He elastic and charge exchange (μ^{+}↔ muonium) collisions describes the measurements well. By combining the transverse compression stage with a previously demonstrated longitudinal compression stage, we can improve the phase space density of a μ^{+} beam by a factor of 10^{10} with 10^{-3} efficiency.

First line transradial access for posterior circulation stroke intervention; initial 12-month experience at a high volume thrombectomy center

BACKGROUND

The Neurointerventional Surgery Standards and Guidelines Committee has advocated the use of transradial access in the setting of posterior circulation stroke intervention, however there is a paucity of published data on this approach. The purpose of this study is to present 12-months of prospectively collected data from a high volume thrombectomy center following the adoption of a first line transradial approach for posterior circulation stroke intervention.

METHODS

A range of data on patient characteristics, procedural metrics, complications and outcomes was prospectively collected between August 2018 - August 2019 following the adoption of first line transradial access for posterior circulation stroke intervention at a high volume thrombectomy center.

RESULTS

Transradial access was successful in 22/23 cases (96%), median arteriotomy to reperfusion time was 24 min (IQR 18-40), good angiographic outcome (mTICI 2b-3) was achieved in all cases and good clinical outcome (mRs 0-2) was achieved in 61% of cases. No intracranial or radial artery access site complications occurred.

CONCLUSION

The fast procedure times, excellent outcomes and low complication rates achieved in this prospective 12-month study indicate that transradial access is a viable first line strategy in posterior circulation stroke intervention.

Chondromalacia of the cranial medial femoral condyle; its occurrence and association with clinical outcome in a population of adult horses with stifle lameness

BACKGROUND

Chondromalacia of the cranial medial femoral condyle (CMFC) is a potential cause of stifle lameness in adult horses. However, there is scant published evidence of either its occurrence or its clinical significance.

OBJECTIVES

To document the occurrence of CMFC seen during diagnostic arthroscopy in adult horses with stifle lameness and to investigate its prognostic significance.

STUDY DESIGN

Retrospective cohort study.

METHODS

The records were reviewed of all horses with unilateral or bilateral lameness localised to the stifle that underwent diagnostic arthroscopy of the cranial medial femorotibial joint at a UK equine hospital. The surgical findings were noted from each. Case outcomes were determined by unstructured telephone discussions with owners. A satisfactory outcome was defined as a horse that was in ridden work without ongoing anti-inflammatory medication. Multivariable logistic regression was used to create a model with an outcome time point at 12-month post-operatively.

RESULTS

One hundred and four horses were included in the study. CMFC was found in 79. In 25 CMFC was the only finding, 54 horses had CMFC plus other pathology and 25 had other pathology, but no CMFC. At 12 months, horses with CMFC were 9.9 (95% CI 2.2-45.0, P<0.01) times more likely to have an unsatisfactory outcome than horses without CMFC.

MAIN LIMITATIONS

The study relied on retrospective analysis of clinical notes and archived arthroscopy videos. Assessment of outcome was determined by unstructured telephone interview and therefore there is potential for reporting errors to exist.

CONCLUSIONS

CMFC is a common arthroscopic finding in horses with stifle lameness and is significantly associated with an increased likelihood of the horse not being in ridden work at long-term follow-up.

Pathological margins and advanced cutaneous squamous cell carcinoma of the head and neck

Objective

The recommended treatment for cutaneous squamous cell cancer (CuSCC) of the head and neck is Mohs surgical excision or wide local excision. Excision is recommended to a gross surgical margin of 4–6 mm however this is based on limited evidence and specify a goal histologic margin. The objective of this study was therefore to examine the reported histological margin distance following WLE of advanced CuSCC and its association with recurrence and survival.

Study design

Retrospective database review.

Setting

All patients included received treatment at UC Davis Department of Otolaryngology-Head and Neck Surgery and/or Radiation Oncology in Sacramento, California.

Subjects and methods

The patients included were treated for advanced CuSCC with primary surgery with or without adjuvant therapy. Kaplan Meier survival curves with log rank analysis were then performed to compare 5-year recurrence free survival, and disease-specific survival for patients with different margin distances.

Results

Total number of subjects was 92. The overall 5-year DSS and RFS was 68.8 and 51.0% respectively. When the pathological margin distance was ≥5 mm, 5-year disease specific survival was improved when compared to margin distance less than 5 mm (94.7 vs 60.7 p = 0.034).

Conclusion

The findings of this study suggest that a histologic margin of at least 5 mm may increase survival in advanced head and neck CuSCC patients.

Pipeline shield with single antiplatelet therapy in aneurysmal subarachnoid haemorrhage: multicentre experience

Background

The Pipeline Embolisation Device with Shield technology (PED-Shield) is suggested to have reduced thrombogenicity. This reduced thrombogenicity may make it possible to use safely in the acute treatment of aneurysmal subarachnoid haemorrhage (aSAH) on single antiplatelet therapy (SAPT).

Objective

To evaluate the safety and efficacy of the off-label use of PED-Shield with SAPT for the acute treatment of aSAH.

Methods

Patients who underwent acute treatment of ruptured intracranial aneurysms with the PED-Shield with SAPT were retrospectively identified from prospectively maintained databases at three Australian neurointerventional centres. Patient demographics, aneurysm characteristics, clinical and imaging outcomes were reviewed.

Results

Fourteen patients were identified (12 women), median age 64 (IQR 21.5) years. Aneurysm morphology was saccular in seven, fusiform in five, and blister in two. Aneurysms arose from the anterior circulation in eight patients (57.1%). Six (42.9%) patients were poor grade (World Federation of Neurological Societies grade ≥IV) SAH. Median time to treatment was 1 (IQR 0.5) day. Complete or near complete aneurysm occlusion (Raymond-Roy <3) was achieved in 12 (85.7%) patients at the end of early-acute follow-up (median day 7 after SAH). Permanent, treatment-related morbidity occurred in one (7.1%) patient and one (7.1%) treatment-related death occurred. The use of a postoperative heparin infusion (n=5) was associated with a higher rate of all complications (80.0% vs 11.1%, p=0.023) and symptomatic complications (60% vs 0.0%, p=0.028). No symptomatic ischaemic or haemorrhagic complications were observed in the patients who did not receive a post-operative heparin infusion. Nine (64.3%) patients were functionally independent on discharge from the treatment centre.

Conclusion

The PED-Shield may be safe to use in the acute treatment of ruptured intracranial aneurysms with SAPT. Further investigation with a formal treatment registry is needed.

Search for the Exotic Meson X(5568) with the Collider Detector at Fermilab

A search for the exotic meson X(5568) decaying into the B_{s}^{0}π^{±} final state is performed using data corresponding to 9.6  fb^{-1} from pp[over ¯] collisions at sqrt[s]=1960  GeV recorded by the Collider Detector at Fermilab. No evidence for this state is found and an upper limit of 6.7% at the 95% confidence level is set on the fraction of B_{s}^{0} produced through the X(5568)→B_{s}^{0}π^{±} process.

Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron

The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of sqrt[s]=1.96  TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is A_{FB}^{tt[over ¯]}=0.128±0.025. The combined inclusive and differential asymmetries are consistent with recent standard model predictions.

Embolization for the treatment of intractable epistaxis: 12 month outcomes in a two centre case series

OBJECTIVE

Embolization is a treatment option for intractable epistaxis; however, concerns regarding tissue necrosis, stroke and blindness persist in the literature.

METHODS

A retrospective review of patients from September 2010 to January 2016 treated with embolization for epistaxis was performed. No patient was excluded. Follow-up was 12 months and no patient was lost.

RESULTS

62 embolizations on 59 patients occurred. 21 cases were taking anticoagulants, P2Y12 inhibiting agents or had a systemic coagulopathy. Embolized territories typically involved bilateral distal internal maxillary arteries with unilateral or bilateral facial arteries with polyvinyl alcohol particles. 60 cases had procedural general anaesthesia. There were no major complications. Six died of unrelated causes. Of the surviving 53 patients, excluding the 3 patients with hereditary haemorrhagic telangiectasia, 5 had recurrent epistaxis post-embolization. Four were taking P2Y12 inhibiting and/or anticoagulants, none of which required surgery, prolonged packing or repeat embolization. This group had a propensity to recur compared with cases taking aspirin only or no antiplatelet/anticoagulant (77.8 vs 97.1%, p = 0.04). The fifth underwent repeat embolization after previously only having ipsilateral distal internal maxillary and facial arteries treated.

CONCLUSION

Embolization for epistaxis is safe and effective. Of those who had recurrent epistaxis post embolization, most were taking P2Y12 inhibition and/or anticoagulation. We prefer bilateral distal internal maxillary artery and unilateral facial artery embolization under general anaesthesia for optimal safety and efficacy. Advances in knowledge: Embolization with this technique seems to facilitate superior outcomes without complications despite the large proportion of patients taking anticoagulating or P2Y12 inhibiting agents.

Outcomes of Endovascular Thrombectomy with and without Thrombolysis for Acute Large Artery Ischaemic Stroke at a Tertiary Stroke Centre

BACKGROUND AND PURPOSE

Endovascular thrombectomy (EVT) improves the functional outcome when added to best medical therapy, including alteplase, in patients with acute ischaemic stroke secondary to large vessel occlusion (LVO) in the anterior circulation. However, the evidence for EVT in alteplase-ineligible patients is less compelling. It is also uncertain whether alteplase is necessary in patients with successful recanalization by EVT, as the treatment effect of EVT may be so powerful that bridging alteplase may not add to efficacy and may compromise safety by increasing bleeding risks. We aimed to survey the proportion of patients suitable for EVT who are alteplase-ineligible and to compare the safety and effectiveness of standard care of acute large artery ischaemic stroke by EVT plus thrombolysis with that of EVT alone in a tertiary hospital clinical stroke service.

METHODS

We performed a retrospective analysis of acute ischaemic stroke patients treated with EVT at our centre between October 2013 and April 2016, based on a registry with prospective and consecutive patient collection. Individual patient records were retrieved for review. Significant early neurological improvement was defined as a NIHSS score of 0-1, or a decrease from baseline of ≤8, at 24 h after stroke onset.

RESULTS

Fifty patients with acute ischaemic stroke secondary to LVO in the anterior circulation received EVT in this period, of whom 21 (42%) received concurrent alteplase and 29 (58%) EVT alone. The 2 groups had similar baseline characteristics and similar outcomes. Significant neurological improvement at 24 h occurred in 47.6% of the patients with EVT and bridging alteplase and in 51.7% of the patients with EVT alone (p = 0.774). Mortality during acute hospitalization was 20% for the bridging alteplase group versus 7.1% for EVT alone (p = 0.184). Intracranial haemorrhage rates were 14.3% for bridging alteplase versus 20.7% for EVT alone (p = 0.716). Local complications, groin haematoma (23.8 vs. 10.3%) and groin pseudoaneurysms (4.8 vs. 0%) (p = 0.170), were not significantly different.

CONCLUSION

Our study highlights the relatively large proportion of patients suitable for EVT who have a contraindication to alteplase and raises the hypothesis that adding alteplase to successful EVT may not be necessary to optimize functional outcome. The results are consistent with observational data from other endovascular centres and support a randomised controlled trial of EVT versus EVT with bridging alteplase.

Breast nodularity and ulceration: diffuse dermal angiomatosis a corticosteroid responsive disease

Diffuse dermal angiomatosis of the breast (DDAB) is an uncommon ulcerative angiomatosis, which occurs in middle aged women with large pendulous breasts, a history of cigarette smoking, and risk factors for atherosclerosis. Based on its rarity, no well-defined therapeutic regimen has been elucidated. We report a case of DDAB in a woman with no history of smoking or radiographic evidence of occluded vasculature who presented with ulceration and pain-associated breast nodularity. She had a complete reproducible response to oral corticosteroids.

Mechanical thrombectomy for anterior circulation stroke: 5-year experience in a statewide service with differences in pretreatment time metrics across two hospitals sites

OBJECTIVE

To audit our institutional mechanical thrombectomy (MT) outcomes for acute anterior circulation stroke and examine the influence of workflow time metrics on patient outcomes.

METHODS

A database of 100 MT cases was maintained throughout May 2010-February 2015 as part of a statewide service provided across two tertiary hospitals (H1 and H2). Patient demographics, stroke and procedural details, blinded angiographic outcomes, and 90-day modified Rankin Scale (mRS) scores were recorded. The following time points in stroke treatment were recorded: stroke onset, hospital presentation, CT imaging, arteriotomy, and recanalization. Statistical analysis of outcomes, predictors of outcome, and differences between the hospitals was carried out.

RESULTS

Thrombolysis in Cerebral Infarction (TICI) 2b/3 reperfusion was 79%. Forty-nine per cent of patients had good clinical outcomes (mRS 0-2). In a subgroup analysis of 76 patients with premorbid mRS 0-1 and first CT performed ≤4.5 h after stroke onset, 60% had good clinical outcomes. Patient and disease characteristics were matched between the two hospitals. H1 had shorter times between hospital presentation and CT (32 vs 55 min, p=0.01), CT and arteriotomy (33 vs 69 min, p=0.00), and stroke onset and recanalization (198 vs 260 min, p=0.00). These time metrics independently predicted good clinical outcome. Median days spent at home in the first 90 days was greater at H1 (61 vs 8, p=0.04) than at H2. A greater proportion of patients treated at H1 were independent (mRS 0-2) at 90 days (54% vs 42%); however, this was not statistically significant (p=0.22).

CONCLUSIONS

Outcomes similar to randomized controlled trials are attainable in 'real-world' settings. Workflow time metrics were independent predictors of clinical outcome, and differed between the two hospitals owing to site-specific organizational differences.

Identification of Treatment Targets in a Genetic Mouse Model of Voluntary Methamphetamine Drinking

Methamphetamine has powerful stimulant and euphoric effects that are experienced as rewarding and encourage use. Methamphetamine addiction is associated with debilitating illnesses, destroyed relationships, child neglect, violence, and crime; but after many years of research, broadly effective medications have not been identified. Individual differences that may impact not only risk for developing a methamphetamine use disorder but also affect treatment response have not been fully considered. Human studies have identified candidate genes that may be relevant, but lack of control over drug history, the common use or coabuse of multiple addictive drugs, and restrictions on the types of data that can be collected in humans are barriers to progress. To overcome some of these issues, a genetic animal model comprised of lines of mice selectively bred for high and low voluntary methamphetamine intake was developed to identify risk and protective alleles for methamphetamine consumption, and identify therapeutic targets. The mu opioid receptor gene was supported as a target for genes within a top-ranked transcription factor network associated with level of methamphetamine intake. In addition, mice that consume high levels of methamphetamine were found to possess a nonfunctional form of the trace amine-associated receptor 1 (TAAR1). The Taar1 gene is within a mouse chromosome 10 quantitative trait locus for methamphetamine consumption, and TAAR1 function determines sensitivity to aversive effects of methamphetamine that may curb intake. The genes, gene interaction partners, and protein products identified in this genetic mouse model represent treatment target candidates for methamphetamine addiction.

Tevatron Combination of Single-Top-Quark Cross Sections and Determination of the Magnitude of the Cabibbo-Kobayashi-Maskawa Matrix Element V_{tb}

We present the final combination of CDF and D0 measurements of cross sections for single-top-quark production in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb^{-1} per experiment. The t-channel cross section is measured to be σ_{t}=2.25_{-0.31}^{+0.29} pb. We also present the combinations of the two-dimensional measurements of the s- vs t-channel cross section. In addition, we give the combination of the s+t channel cross section measurement resulting in σ_{s+t}=3.30_{-0.40}^{+0.52} pb, without assuming the standard model value for the ratio σ_{s}/σ_{t}. The resulting value of the magnitude of the top-to-bottom quark coupling is |V_{tb}|=1.02_{-0.05}^{+0.06}, corresponding to |V_{tb}|>0.92 at the 95% C.L.

Preclinical evidence implicating corticotropin-releasing factor signaling in ethanol consumption and neuroadaptation

The results of many studies support the influence of the corticotropin-releasing factor (CRF) system on ethanol (EtOH) consumption and EtOH-induced neuroadaptations that are critical in the addiction process. This review summarizes the preclinical data in this area after first providing an overview of the components of the CRF system. This complex system involves hypothalamic and extra-hypothalamic mechanisms that play a role in the central and peripheral consequences of stressors, including EtOH and other drugs of abuse. In addition, several endogenous ligands and targets make up this system and show differences in their involvement in EtOH drinking and in the effects of chronic or repeated EtOH treatment. In general, genetic and pharmacological approaches paint a consistent picture of the importance of CRF signaling via type 1 CRF receptors (CRF(1)) in EtOH-induced neuroadaptations that result in higher levels of intake, encourage alcohol seeking during abstinence and alter EtOH sensitivity. Furthermore, genetic findings in rodents, non-human primates and humans have provided some evidence of associations of genetic polymorphisms in CRF-related genes with EtOH drinking, although additional data are needed. These results suggest that CRF(1) antagonists have potential as pharmacotherapeutics for alcohol use disorders. However, given the broad and important role of these receptors in adaptation to environmental and other challenges, full antagonist effects may be too profound and consideration should be given to treatments with modulatory effects.

Search for Resonances Decaying to Top and Bottom Quarks with the CDF Experiment

We report on a search for charged massive resonances decaying to top (t) and bottom (b) quarks in the full data set of proton-antiproton collisions at a center-of-mass energy of √[s]=1.96  TeV collected by the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.5  fb(-1). No significant excess above the standard model background prediction is observed. We set 95% Bayesian credibility mass-dependent upper limits on the heavy charged-particle production cross section times branching ratio to tb. Using a standard model extension with a W'→tb and left-right-symmetric couplings as a benchmark model, we constrain the W' mass and couplings in the 300-900  GeV/c(2) range. The limits presented here are the most stringent for a charged resonance with mass in the range 300-600  GeV/c(2) decaying to top and bottom quarks.

Long-Term Follow-Up Results following Elective Treatment of Unruptured Intracranial Aneurysms with the Pipeline Embolization Device

BACKGROUND AND PURPOSE

Numerous reports of treatment of wide-neck aneurysms by flow diverters have been published; however, long-term outcomes remain uncertain. This article reports the imaging results of unruptured aneurysms treated electively with the Pipeline Embolization Device for up to 56 months and clinical results for up to 61 months.

MATERIALS AND METHODS

One hundred nineteen aneurysms in 98 patients from 3 centers admitted between August 2009 and June 2011 were followed at 6-month, 1-year, and 2+-year postprocedural timeframes. Analyses on the effects of incorporated vessels, previous stent placement, aneurysm size, and morphology on aneurysm occlusion were performed.

RESULTS

The 1- and 2+-year imaging follow-ups were performed, on average, 13 and 28 months postprocedure. At 2+-year follow-up, clinical data were 100% complete and imaging data were complete for 103/116 aneurysms (88.8%) with a 93.2% occlusion rate. From 0 to 6 months, TIA, minor stroke, and major stroke rates were 4.2%, 3.4%, and 0.8% respectively. After 6 months, 1 patient had a TIA of uncertain cause, with an overall Pipeline Embolization Device-related mortality rate of 0.8%. An incorporated vessel was significant for a delay in occlusion (P = .009) and nonocclusion at 6 months and 1 year, with a delayed mean time of occlusion from 9.1 months (95% CI, 7.1-11.1 months) to 16.7 months (95% CI, 11.4-22.0 months). Other factors were nonsignificant.

CONCLUSIONS

The Pipeline Embolization Device demonstrates continued very high closure rates at 2+ years, with few delayed clinical adverse sequelae. The presence of an incorporated vessel in the wall of the aneurysm causes a delay in occlusion that approaches sidewall closure rates by 2 years.

Tevatron constraints on models of the Higgs boson with exotic spin and parity using decays to bottom-antibottom quark pairs

Combined constraints from the CDF and D0 Collaborations on models of the Higgs boson with exotic spin J and parity P are presented and compared with results obtained assuming the standard model value JP=0+. Both collaborations analyzed approximately 10  fb(-) of proton-antiproton collisions with a center-of-mass energy of 1.96 TeV collected at the Fermilab Tevatron. Two models predicting exotic Higgs bosons with JP=0- and JP=2+ are tested. The kinematic properties of exotic Higgs boson production in association with a vector boson differ from those predicted for the standard model Higgs boson. Upper limits at the 95% credibility level on the production rates of the exotic Higgs bosons, expressed as fractions of the standard model Higgs boson production rate, are set at 0.36 for both the JP=0- hypothesis and the JP=2+ hypothesis. If the production rate times the branching ratio to a bottom-antibottom pair is the same as that predicted for the standard model Higgs boson, then the exotic bosons are excluded with significances of 5.0 standard deviations and 4.9 standard deviations for the JP=0- and JP=2+ hypotheses, respectively.

Constraints on models of the Higgs boson with exotic spin and parity using decays to bottom-antibottom quarks in the full CDF data set

A search for particles with the same mass and couplings as those of the standard model Higgs boson but different spin and parity quantum numbers is presented. We test two specific alternative Higgs boson hypotheses: a pseudoscalar Higgs boson with spin-parity J^{P}=0^{-} and a gravitonlike Higgs boson with J^{P}=2^{+}, assuming for both a mass of 125  GeV/c^{2}. We search for these exotic states produced in association with a vector boson and decaying into a bottom-antibottom quark pair. The vector boson is reconstructed through its decay into an electron or muon pair, or an electron or muon and a neutrino, or it is inferred from an imbalance in total transverse momentum. We use expected kinematic differences between events containing exotic Higgs bosons and those containing standard model Higgs bosons. The data were collected by the CDF experiment at the Tevatron proton-antiproton collider, operating at a center-of-mass energy of sqrt[s]=1.96  TeV, and correspond to an integrated luminosity of 9.45  fb^{-1}. We exclude deviations from the predictions of the standard model with a Higgs boson of mass 125  GeV/c^{2} at the level of 5 standard deviations, assuming signal strengths for exotic boson production equal to the prediction for the standard model Higgs boson, and set upper limits of approximately 30% relative to the standard model rate on the possible rate of production of each exotic state.

Measurement of the single top quark production cross section and |Vtb| in events with one charged lepton, large missing transverse energy, and jets at CDF

We report a measurement of single top quark production in proton-antiproton collisions at a center-of-mass energy of sqrt[s]=1.96  TeV using a data set corresponding to 7.5  fb(-1) of integrated luminosity collected by the Collider Detector at Fermilab. We select events consistent with the single top quark decay process t→Wb→ℓνb by requiring the presence of an electron or muon, a large imbalance of transverse momentum indicating the presence of a neutrino, and two or three jets including at least one originating from a bottom quark. An artificial neural network is used to discriminate the signal from backgrounds. We measure a single top quark production cross section of 3.04(-0.53)(+0.57)  pb and set a lower limit on the magnitude of the coupling between the top quark and bottom quark |Vtb|>0.78 at the 95% credibility level.

Measurements of direct CP-violating asymmetries in charmless decays of bottom baryons

We report final measurements of direct CP-violating asymmetries in charmless decays of neutral bottom hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using the complete √s=1.96  TeV proton-antiproton collisions data set, corresponding to 9.3  fb⁻¹ of integrated luminosity, we measure A(Λ(b)⁰→pπ⁻)=+0.06±0.07(stat)±0.03(syst) and A(Λ(b)⁰→pK⁻)=-0.10±0.08(stat)±0.04(syst), compatible with no asymmetry. In addition we measure the CP-violating asymmetries in B(s)⁰→K⁻π⁺ and B⁰→K⁺π⁻ decays to be A(B(s)⁰→K⁻π⁺)=+0.22±0.07(stat)±0.02(syst) and A(B⁰→K⁺π⁻)=-0.083±0.013(stat)±0.004(syst), respectively, which are significantly different from zero and consistent with current world averages.

Measurement of the inclusive leptonic asymmetry in top-quark pairs that decay to two charged leptons at CDF

We measure the inclusive forward-backward asymmetry of the charged-lepton pseudorapidities from top-quark pairs produced in proton-antiproton collisions and decaying to final states that contain two charged leptons (electrons or muons). The data are collected with the Collider Detector at Fermilab and correspond to an integrated luminosity of 9.1 fb(-1). We measure the leptonic forward-backward asymmetry, A(FB)(ℓ), to be 0.072 ± 0.060 and the leptonic pair forward-backward asymmetry, A(FB)(ℓℓ), to be 0.076 ± 0.082. The measured values can be compared with the standard model predictions of A(FB)(ℓ) = 0.038 ± 0.003 and A(FB)(ℓℓ) = 0.048 ± 0.004, respectively. Additionally, we combine the A(FB)(ℓ) result with a previous determination from a final state with a single lepton and hadronic jets and obtain A(FB)(ℓ) = 0.090(-0.026)(+0.028).

An RCT to compare a bio-cellulose wound dressing with a non-adherent dressing in VLUs

OBJECTIVE

To compare the efficacy of a bio-cellulose dressing (BWD) versus a non-adherent wound contact layer in venous leg ulcer (VLU) outpatients.

METHOD

In a prospective, randomised, controlled multicentre study, 48 VLU patients were randomised to receive compression bandages and either standard care (non-adherent dressing; n=23) or a BWD (Suprasorb X; n=25). VLUs were evaluated for debridement efficacy, time to 75-100% granulation and ≥ 50% re-epithelialisation, reduction of ulcer size and patient-reported ulcer pain, comparing the status at day 0 and weekly, over a 12-week study treatment period.

RESULTS

Thirty-three patients (n=18 BWD and n=15 control dressing) were included in the analysis. Autolytic debridement was significantly faster in the BWD group, with an 84% removal of yellow tissue compared with 26% in the control group, over the 12-week period (p < 0.0001). A median of 25 days were required to achieve 75-100% granulation in the BWD group vs 36 days for controls. A median of 36 days was taken to achieve ≥ 50% re-epithelialisation in the BWD group vs 50 days for controls. Patient-reported ulcer pain reduced significantly faster in the BWD group (p < 0.05), by week 7, 100% of patients reported no pain, compared with 63% of controls.

CONCLUSION

Autolytic debridement was faster and more effective in the BWD group compared with standard care, as was pain reduction. Although the time to healing was shorter with the BWD vs standard care, the difference was not statistically significant.

DECLARATION OF INTEREST

This study was supported by Xylos Corporation. The study product was called X-Cell at the time, and is now available as Suprasorb X (Lohmann & Rauscher). Each principal investigator (Alvarez, Phillips, Menzoian, Etris-Brown) and respective clinical centre received funding for the conduct of the study. Each site executed a clinical study agreement independently with the sponsor. The sponsors had no role in the design and conduct of the study, in the collection, analysis, or interpretation of data, or in the preparation of the manuscript, review, or approval of the manuscript. None of the authors received administrative, technical or material support for the conduct of this study. The authors have no relevant financial interest in this article.

Evidence for s-channel single-top-quark production in events with one charged lepton and two jets at CDF

We report evidence for s-channel single-top-quark production in proton-antiproton collisions at center-of-mass energy sqrt[s] = 1.96 TeV using a data set that corresponds to an integrated luminosity of 9.4 fb(-1) collected by the Collider Detector at Fermilab. We select events consistent with the s-channel process including two jets and one leptonically decaying W boson. The observed significance is 3.8 standard deviations with respect to the background-only prediction. Assuming a top-quark mass of 172.5 GeV/c(2), we measure the s-channel cross section to be 1.41(-0.42)(+0.44) pb.

Search for s-channel single-top-quark production in events with missing energy plus jets in pp collisions at sqrt[s] = 1.96 TeV

The first search for single-top-quark production from the exchange of an s-channel virtual W boson using events with an imbalance in the total transverse energy, b-tagged jets, and no identified leptons is presented. Assuming the electroweak production of top quarks of mass 172.5 GeV/c(2) in the s channel, a cross section of 1.12(-0.57)(+0.61) (stat+syst) pb with a significance of 1.9 standard deviations is measured. This measurement is combined with the result obtained from events with an imbalance in total transverse momentum, b-tagged jets, and exactly one identified lepton, yielding a cross section of 1.36(-0.32)(+0.37) (stat+syst) pb, with a significance of 4.2 standard deviations.

Observation of s-channel production of single top quarks at the Tevatron

We report the first observation of single-top-quark production in the s channel through the combination of the CDF and D0 measurements of the cross section in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb(-1) per experiment. The measured cross section is σ(s) = 1.29(-0.24)(+0.26) pb. The probability of observing a statistical fluctuation of the background to a cross section of the observed size or larger is 1.8 × 10(-10), corresponding to a significance of 6.3 standard deviations for the presence of an s-channel contribution to the production of single-top quarks.

Measurement of B(t→Wb)/B(t→Wq) in top-quark-pair decays using dilepton events and the full CDF Run II data set

We present a measurement of the ratio of the top-quark branching fractions R=B(t→Wb)/B(t→Wq), where q represents any quark flavor, in events with two charged leptons, imbalance in total transverse energy, and at least two jets. The measurement uses proton-antiproton collision data at center-of-mass energy 1.96 TeV, corresponding to an integrated luminosity of 8.7  fb^{-1} collected with the Collider Detector at Fermilab during Run II of the Tevatron. We measure R to be 0.87±0.07, and extract the magnitude of the top-bottom quark coupling to be |V_{tb}|=0.93±0.04, assuming three generations of quarks. Under these assumptions, a lower limit of |V_{tb}|>0.85(0.87) at 95% (90%) credibility level is set.

Differences in the reinstatement of ethanol seeking with ganaxolone and gaboxadol

The endogenous neuroactive steroid allopregnanolone (ALLO) has previously been shown to induce reinstatement of ethanol seeking in rodents. ALLO is a positive allosteric modulator at both synaptic and extrasynaptic GABAA receptors. The contribution of each class of GABAA receptors in mediating reinstatement of ethanol seeking is unknown. The first aim of the present study was to determine whether ganaxolone (GAN), a longer-acting synthetic analog of ALLO, also promotes reinstatement of ethanol seeking. The second aim was to examine whether preferentially activating extrasynaptic GABAA receptors with the selective agonist gaboxadol (THIP) was sufficient to reinstate responding for ethanol in mice. Male C57BL/6J mice were trained to lever press for access to a 10% ethanol (v/v) solution (10E), using a sucrose-fading procedure. Following extinction of the lever-pressing behavior, systemic THIP (0, 4 and 6mg/kg) and GAN (0, 10, and 15mg/kg) were tested for their ability to reinstate ethanol-appropriate responding in the absence of 10E access. GAN significantly increased lever pressing on the previously active lever, while THIP did not alter lever-pressing behavior. The results of this study suggest that direct activation of extrasynaptic GABAA receptors at the GABA site is not sufficient to induce ethanol seeking in the reinstatement procedure. Future studies are necessary to elucidate the mechanisms and brain areas by which differences in the pharmacological activity of GAN and THIP at the GABAA receptor contribute to the dissimilarity in their effect on the reinstatement of ethanol seeking. Nonetheless, based on the increased use of these drugs in clinical trials across multiple disease states, the effects of GAN or THIP on alcohol seeking may be an important consideration if these drugs are to be used clinically in a population with a co-occurring alcohol use disorder.

First search for exotic Z Boson decays into photons and neutral pions in hadron collisions

A search for forbidden and exotic Z boson decays in the diphoton mass spectrum is presented for the first time in hadron collisions, based on data corresponding to 10.0 fb(-1) of integrated luminosity from proton-antiproton collisions at √s = 1.96 TeV collected by the CDF experiment. No evidence of signal is observed, and 95% credibility level Bayesian upper limits are set on the branching ratios of decays of the Z boson to a photon and neutral pion (which is detected as a photon), a pair of photons, and a pair of neutral pions. The observed branching ratio limits are 2.01 × 10(-5) for Z → π(0)γ, 1.46 × 10(-5) for Z → γγ, and 1.52 × 10(-5) for Z → π(0)π(0). The Z → π(0)γ and Z → γγ limits improve the most stringent results from other experiments by factors of 2.6 and 3.6, respectively. The Z → π(0)π(0) branching ratio limit is the first experimental result on this decay.

Progress in a replicated selection for elevated blood ethanol concentrations in HDID mice

Drinking in the dark (DID) is a limited access ethanol-drinking phenotype in mice. High Drinking in the Dark (HDID-1) mice have been bred for 27 selected generations (S27) for elevated blood ethanol concentrations (BECs) after a 4-h period of access to 20% ethanol. A second replicate line (HDID-2) was started later from the same founder population and is currently in S20. An initial report of response to selection in HDID-1 was published after S11. This article reports genetic and behavioral characteristics of both lines in comparison with the HS controls. Heritability is low in both replicates (h(2)  = 0.09) but the lines have shown 4-5 fold increases in BEC since S0; 80% of HDID-1 and 60% of HDID-2 mice reach BECs greater than 1.0 mg/ml. Several hours after a DID test, HDID mice show mild signs of withdrawal. Although not considered during selection, intake of ethanol (g/kg) during the DID test increased by approximately 80% in HDID-1 and 60% in HDID-2. Common genetic influences were more important than environmental influences in determining the similarity between BEC and intake for HDID mice. Analysis of the partitioning of intake showed that 60% of intake is concentrated in the last 2 h of the 4 h session. However, this has not changed during selection. Hourly BECs during the DID test reach peak levels after 3 or 4 h of drinking. HDID mice do not differ from HS mice in their rate of elimination of an acute dose of alcohol.

Observation of D⁰-D¯⁰ mixing using the CDF II detector

We measure the time dependence of the ratio of decay rates for D0→K(+)π(-) to the Cabibbo-favored decay D(0)→K(-)π(+). The charge conjugate decays are included. A signal of 3.3×10(4) D(*+)→π(+)D(0), D(0)→K(+)π(-) decays is obtained with D0 proper decay times between 0.75 and 10 mean D0 lifetimes. The data were recorded with the CDF II detector at the Fermilab Tevatron and correspond to an integrated luminosity of 9.6  fb(-1) for pp¯ collisions at √s=1.96  TeV. Assuming CP conservation, we search for D0-D¯0 mixing and measure the mixing parameters to be R(D)=(3.51±0.35)×10(-3), y'=(4.3±4.3)×10(-3), and x'2=(0.08±0.18)×10(-3). We report Bayesian probability intervals in the x'2-y' plane and find that the significance of excluding the no-mixing hypothesis is equivalent to 6.1 Gaussian standard deviations, providing the second observation of D0-D¯0 mixing from a single experiment.

Morphine intake and the effects of naltrexone and buprenorphine on the acquisition of methamphetamine intake

Some common genetic factors appear to influence risk for drug dependence across multiple drugs of abuse. In previous research, mice that were selectively bred for higher amounts of methamphetamine consumption, using a two-bottle choice methamphetamine drinking procedure, were found to be less sensitive to the locomotor stimulant effects of morphine and of the more selective μ-opioid receptor agonist fentanyl, compared to mice that were bred for low methamphetamine consumption. This suggested that μ-opioid receptor-mediated pathways may influence genetic risk for methamphetamine consumption. We hypothesized that these differences in opioid sensitivity would impact opioid intake in the methamphetamine drinking lines and that drugs with μ-opioid receptor activity would impact methamphetamine intake. Consumption of morphine was examined in 2, two-bottle choice studies, one that compared morphine to quinine consumption and another that used a saccharin fading procedure. Next, naltrexone (0, 0.5, 1, 2, 5, 10 and 20 mg/kg), a μ-opioid receptor antagonist, and buprenorphine (0, 1, 2 or 4 mg/kg), a μ-opioid receptor partial agonist, were each examined for their effects on the acquisition of methamphetamine consumption. Low methamphetamine drinking mice consumed more morphine compared to high methamphetamine drinking mice. Naltrexone did not alter methamphetamine consumption in either selected line; however, buprenorphine reduced methamphetamine intake in the high methamphetamine drinking line. These data show that greater sensitivity to opioids is associated with greater opioid intake and warrant further investigation of drugs with μ-opioid receptor-specific agonist activity in genetically determined differences in methamphetamine consumption.

Direct measurement of the total decay width of the top quark

We present a measurement of the total decay width of the top quark using events with top-antitop quark pair candidates reconstructed in the final state with one charged lepton and four or more hadronic jets. We use the full Tevatron run II data set of sqrt[s]=1.96  TeV proton-antiproton collisions recorded by the CDF II detector. The top quark mass and the mass of the hadronically decaying W boson are reconstructed for each event and compared with distributions derived from simulated signal and background samples to extract the top quark width (Γtop) and the energy scale of the calorimeter jets with in situ calibration. For a top quark mass Mtop=172.5  GeV/c2, we find 1.10<Γtop<4.05  GeV at 68% confidence level, which is in agreement with the standard model expectation of 1.3 GeV and is the most precise direct measurement of the top quark width to date.

Measurement of the differential cross section dσ/d(cosθ(t)) for Top-Quark Pair Production in pp Collisions at sqrt[s] = 1.96 TeV

We report a measurement of the differential cross section dσ/d(cosθ(t)) for top-quark pair production as a function of the top-quark production angle in proton-antiproton collisions at sqrt[s] = 1.96 TeV. This measurement is performed using data collected with the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.4 fb(-1). We employ the Legendre polynomials to characterize the shape of the differential cross section at the parton level. The observed Legendre coefficients are in good agreement with the prediction of the next-to-leading-order standard-model calculation, with the exception of an excess linear-term coefficient a(1) = 0.40 ± 0.12, compared to the standard-model prediction of a(1)=0.15(-0.03)(+0.07).

Measurement of the cross section for direct-photon production in association with a heavy quark in pp[over ¯] collisions at sqrt[s]=1.96 TeV

We report on a measurement of the cross section for direct-photon production in association with a heavy quark using the full data set of sqrt[s]=1.96  TeV proton-antiproton collisions corresponding to 9.1  fb-1 of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron. The measurements are performed as a function of the photon transverse momentum, covering a photon transverse momentum between 30 and 300 GeV, photon rapidities |yγ|<1.0, a heavy-quark-jet transverse momentum pTjet>20  GeV, and jet rapidities |yjet|<1.5. The results are compared with several theoretical predictions.

Search for pair production of strongly interacting particles decaying to pairs of jets in pp collisions at √s=1.96 TeV

We present a search for the pair production of a narrow nonstandard-model strongly interacting particle that decays to a pair of quarks or gluons, leading to a final state with four hadronic jets. We consider both nonresonant production via an intermediate gluon as well as resonant production via a distinct nonstandard-model intermediate strongly interacting particle. We use data collected by the CDF experiment in proton-antiproton collisions at √[s]=1.96 TeV corresponding to an integrated luminosity of 6.6 fb(-1). We find the data to be consistent with nonresonant production. We report limits on σ(pp[over ¯]→jjjj) as a function of the masses of the hypothetical intermediate particles. Upper limits on the production cross sections for nonstandard-model particles in several resonant and nonresonant processes are also derived.

Normalizing dopamine D2 receptor-mediated responses in D2 null mutant mice by virus-mediated receptor restoration: comparing D2L and D2S

D2 receptor null mutant (Drd2(-/-)) mice have altered responses to the rewarding and locomotor effects of psychostimulant drugs, which is evidence of a necessary role for D2 receptors in these behaviors. Furthermore, work with mice that constitutively express only the D2 receptor short form (D2S), as a result of genetic deletion of the long form (D2L), provides the basis for a current model in which D2L is thought to be the postsynaptic D2 receptor on medium spiny neurons in the basal forebrain, and D2S the autoreceptor that regulates the activity of dopamine neurons and dopamine synthesis and release. Because constitutive genetic deletion of the D2 or D2L receptor may cause compensatory changes that influence functional outcomes, our approach is to identify aspects of the abnormal phenotype of a Drd2(-/-) mouse that can be normalized by virus-mediated D2 receptor expression. Drd2(-/-) mice are deficient in basal and methamphetamine-induced locomotor activation and lack D2 receptor agonist-induced activation of G protein-regulated inward rectifying potassium channels (GIRKs) in dopaminergic neurons. Here we show that virus-mediated expression of D2L in the nucleus accumbens significantly restored methamphetamine-induced locomotor activation, but not basal locomotor activity, compared to mice receiving the control virus. It also restored the effect of methamphetamine to decrease time spent in the center of the activity chamber in female but not male Drd2(-/-) mice. Furthermore, the effect of expression of D2S was indistinguishable from D2L. Similarly, virus-mediated expression of either D2S or D2L in substantia nigra neurons restored D2 agonist-induced activation of GIRKs. In this acute expression system, the alternatively spliced forms of the D2 receptor appear to be equally capable of acting as postsynaptic receptors and autoreceptors.

Search for supersymmetry with like-sign lepton-tau events at CDF

We present a search for chargino-neutralino associated production using like electric charge dilepton events collected by the CDF II detector at the Fermilab Tevatron in proton-antiproton collisions at sqrt[s] = 1.96 TeV. One lepton is identified as the hadronic decay of a tau lepton, while the other is an electron or muon. In data corresponding to 6.0 fb(-1) of integrated luminosity, we obtain good agreement with standard model predictions and set limits on the chargino-neutralino production cross section for simplified gravity- and gauge-mediated models. As an example, assuming that the chargino and neutralino decays to taus dominate, in the simplified gauge-mediated model we exclude cross sections greater than 300 fb at 95% credibility level for chargino and neutralino masses of 225 GeV/c(2). This analysis is the first to extend the LHC searches for electroweak supersymmetric production of gauginos to high tanβ and slepton next-to-lightest supersymmetric particle scenarios.