bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Antigenically Important Residues in Human Influenza A Virus in Terms of B-Cell Epitopes
Authors: Lees William D. , Moss David S. , Shepherd Adrian J. 
Published: June 2011

ABSTRACT
In this paper we undertake an analysis of the antigenicity of influenza A virus hemagglutinin. We developed a novel computational approach to the identification of antigenically active regions and showed that the amino acid substitutions between successive predominant seasonal strains form clusters that are consistent, in terms of both their location and their size, with the properties of B-cell epitopes in general and with those epitopes that have been identified experimentally in influenza A virus hemagglutinin to date. Such an interpretation provides a biologically plausible framework for an understanding of the location of antigenically important substitutions that is more specific than the canonical “antigenic site” model and provides an effective basis for deriving models that predict antigenic escape in the H3N2 subtype. Our results support recent indications that antibodies binding to the “stalk” region of hemagglutinin are found in the human population and exert evolutionary pressure on the virus. Our computational approach provides a possible method for identifying antigenic escape through evolution in this region, which in some cases will not be identified by the hemagglutinin inhibition assay.
Roles of the Fusion and Hemagglutinin-Neuraminidase Proteins in Replication, Tropism, and Pathogenicity of Avian Paramyxoviruses
Authors: Kim Shin-Hee , Subbiah Madhuri , Samuel Arthur S. , Collins Peter L. , Samal Siba K. 
Published: June 2011

ABSTRACT

Virulent and moderately virulent strains of Newcastle disease virus (NDV), representing avian paramyxovirus serotype 1 (APMV-1), cause respiratory and neurological disease in chickens and other species of birds. In contrast, APMV-2 is avirulent in chickens. We investigated the role of the fusion (F) and hemagglutinin-neuraminidase (HN) envelope glycoproteins in these contrasting phenotypes by designing chimeric viruses in which the F and HN glycoproteins or their ectodomains were exchanged individually or together between the moderately virulent, neurotropic NDV strain Beaudette C (BC) and the avirulent APMV-2 strain Yucaipa. When we attempted to exchange the complete F and HN glycoproteins individually and together between the two viruses, the only construct that could be recovered was recombinant APMV-2 strain Yucaipa (rAPMV-2), containing the NDV F glycoprotein in place of its own. This substitution of NDV F into APMV-2 was sufficient to confer the neurotropic, neuroinvasive, and neurovirulent phenotypes, in spite of all being at reduced levels compared to what was seen for NDV-BC. When the ectodomains of F and HN were exchanged individually and together, two constructs could be recovered: NDV, containing both the F and HN ectodomains of APMV-2; and APMV-2, containing both ectodomains of NDV. This supported the idea that homologous cytoplasmic tails and matched F and HN ectodomains are important for virus replication. Analysis of these viruses for replication
in vitro
, syncytium formation, mean embryo death time, intracerebral pathogenicity index, and replication and tropism in 1-day-old chicks and 2-week-old chickens showed that the two contrasting phenotypes of NDV and APMV-2 could largely be transferred between the two backbones by transfer of homotypic F and HN ectodomains. Further analysis provided evidence that the homologous stalk domain of NDV HN is essential for virus replication, while the globular head domain of NDV HN could be replaced with that of APMV-2 with only a minimal attenuating effect. These results demonstrate that the F and HN ectodomains together determine the cell fusion, tropism, and virulence phenotypes of NDV and APMV-2 and that the regions of HN that are critical to replication and the species-specific phenotypes include the cytoplasmic tail and stalk domain but not the globular head domain.
Disruption of Nuclear Organization during the Initial Phase of African Swine Fever Virus Infection
Authors: Ballester Maria , Rodríguez-Cariño Carolina , Pérez Mónica , Gallardo Carmina , Rodríguez Javier M. , Salas María L. , Rodriguez Fernando 
Published: June 2011

ABSTRACT
African swine fever virus (ASFV), the causative agent of one of the most devastating swine diseases, has been considered exclusively cytoplasmic, even though some authors have shown evidence of an early stage of nuclear replication. In the present study, an increment of lamin A/C phosphorylation was observed in ASFV-infected cells as early as 4 h postinfection, followed by the disassembling of the lamina network close to the sites where the viral genome starts its replication. At later time points, this and other nuclear envelope markers were found in the cytoplasm of the infected cells. The effect of the infection on the cell nucleus was much more severe than previously expected, since a redistribution of other nuclear proteins, such as RNA polymerase II, the splicing speckle SC-35 marker, and the B-23 nucleolar marker, was observed from 4 h postinfection. All this evidence, together with the redistribution, dephosphorylation, and subsequent degradation of RNA polymerase II after ASFV infection, suggests the existence of sophisticated mechanisms to regulate the nuclear machinery during viral infection.
Reassortment between Seasonal H1N1 and Pandemic (H1N1) 2009 Influenza Viruses Is Restricted by Limited Compatibility among Polymerase Subunits
Authors: Octaviani Cássio Pontes , Goto Hideo , Kawaoka Yoshihiro 
Published: June 2011

ABSTRACT
Reassortment is important for influenza virus evolution and the generation of novel viruses with pandemic potential; however, the factors influencing reassortment are still poorly understood. Here, using reverse genetics and a replicon assay, we demonstrated that a mixed polymerase complex containing a pandemic (H1N1) 2009 influenza virus PB2 on a seasonal H1N1 virus background has reduced polymerase activity, leading to impaired virus viability. Adaptation of viruses containing the mixed polymerase complex resulted in compensatory mutations in PB1. Taken together, our results identify the cooperation between PB2 and PB1 as an important restricting factor for reassortment of influenza viruses.
Is There a Role for Acupuncture in the Symptom Management of Patients Receiving Palliative Care for Cancer? A Pilot Study of 20 Patients Comparing Acupuncture with Nurse-Led Supportive Care
Authors: Lim Jan T W , Wong Erin T , Aung Steven K H 
Published: June 2011

Purpose A pilot study to document changes in symptoms after acupuncture or nurse-led supportive care in patients with incurable cancer. Methods Patients receiving palliative care with estimated survival of at least 3 months were screened with the Edmonton Symptom Assessment System (ESAS). Patients (n=20) with significant symptoms were randomised to receive weekly acupuncture or nurse-led supportive care for 4 weeks. ESAS scores were obtained before and after each treatment, and weekly for 6 weeks after treatment by telephone. Results 42 of 170 patients screened were eligible. 20 gave consent for recruitment. The compliance rate was 90% for acupuncture and 80% for nurse-led supportive care. Total symptom scores were reduced by an average of 22% after each acupuncture visit and by 14% after each supportive care visit. Compared with baseline, ESAS scores at the end of the follow-up period were reduced by 19% for the acupuncture arm and 26% for nurse-led supportive care. Conclusion Patients appear to benefit from incorporating acupuncture in the treatment of advanced incurable cancer. Acupuncture was well tolerated with no significant or unexpected side effects. Acupuncture had an immediate effect on all symptoms, whereas nurse-led supportive care had a larger impact 6 weeks after the final session. Both interventions appear helpful to this population and warrant further study.
Indoor air pollution (PM2.5) due to secondhand smoke in selected hospitality and entertainment venues of Karachi, Pakistan
Authors: Nafees Asaad Ahmed , Taj Tahir , Kadir Muhammad Masood , Fatmi Zafar , Lee Kiyoung , Sathiakumar Nalini 
Published: June 2011

ObjectiveTo determine particulate matter smaller than 2.5 μm (PM2.5) levels at various hospitality and entertainment venues of Karachi, Pakistan.MethodsThis was a descriptive cross-sectional study conducted at various locations in Karachi, during July 2009. Sampling was performed at 20 enclosed public places, including hospitality (restaurants and cafés) and entertainment (snooker/billiard clubs and gaming zones) venues. PM2.5levels were measured using an aerosol monitor.ResultsAll entertainment venues had higher indoor PM2.5levels as compared to the immediate outdoors. The indoor PM2.5levels ranged from 25 to 390 μg/m3and the outdoor PM2.5levels ranged from 18 to 96 μg/m3. The overall mean indoor PM2.5level was 138.8 μg/m3(±112.8). Among the four types of venues, the highest mean indoor PM2.5level was reported from snooker/billiard clubs: 264.7 μg/m3(±85.4) and the lowest from restaurants: 66.4 μg/m3(±57.6) while the indoor/outdoor ratio ranged from 0.97 to 10.2, highest being at the snooker/billiard clubs. The smoking density ranged from 0.21 to 0.57, highest being at gaming zones. The indoor PM2.5concentration and smoking density were not significantly correlated (Spearman's correlation coefficient=0.113; p=0.636).ConclusionsThis study demonstrates unacceptably high levels of PM2.5exposure associated with secondhand smoke (SHS) at various entertainment venues of Karachi even after 8 years since the promulgation of smoke-free ordinance (2002) in Pakistan; however, better compliance may be evident at hospitality venues. The results of this study call for effective implementation and enforcement of smoke-free environment at public places in the country.
Tolerance of low cerebral intracellular pH in rats during hyperbaric hypercapnia.
Authors: Xu Y , Cohen Y , Litt L , Chang L H , James T L 
Published: June 2011

Brain acidosis from cerebral ischemia is characterized by average intracellular pH levels of approximately 5.8-6.2, which appear in turn to worsen cellular injury. We report that the brain is not injured when hypercapnia is used to reduce intracellular pH to about 6.2 during adequate oxygenation. A hyperbaric chamber is needed to achieve intracellular pH values so low because inspired CO2 tensions must be increased to approximately 1 atm.
Using in vivo phosphorus-31 and proton nuclear magnetic resonance spectroscopy, we measured brain intracellular pH and lactate concentration of rats inside a nonmagnetic polycarbonate chamber at a barometric pressure of 1,500 mm Hg. Intubated rats were ventilated with a 50% O2/50% CO2 gas mixture for specific times. All six rats ventilated for 15 minutes with CO2 tensions of approximately 750 mm Hg woke up without neurological impairment, despite a decrease in intracellular pH to about 6.2. Higher CO2 tensions and longer exposures resulted in cardiovascular collapse and sudden death, followed by the postmortem appearance of brain lactate.
Brain intracellular pH values near 6.2 can be induced briefly in vivo in ventilated rats without injury under hyperbaric hypercapnic conditions. If attempts are made to lower brain pH in vivo even further by increasing PCO2 beyond 750 mm Hg, mean arterial blood pressure and cerebral blood flow decrease to values incompatible with life.
Selection process for surgeons in the Asymptomatic Carotid Atherosclerosis Study.
Authors: Moore W S , Vescera C L , Robertson J T , Baker W H , Howard V J , Toole J F 
Published: June 2011

The Asymptomatic Carotid Atherosclerosis Study is a prospective, multicenter, randomized clinical trial of carotid endarterectomy for the treatment of asymptomatic hemodynamically significant stenosis. This report describes the selection process for participating surgeons in the trial.
The Surgical Management Committee established guidelines for minimal annual experience and maximum neurological morbidity and mortality for surgeons to qualify to participate in the study. For approval, a surgeon must perform at least 12 carotid endarterectomies per year. Based on a review of the surgeon's last 50 consecutive endarterectomies, the combined neurological morbidity and mortality rate must be no greater than 5% for all indications and no greater than 3% for endarterectomies performed on asymptomatic patients.
One hundred sixty-four surgeons from 48 centers applied for approval: 117 were approved, 17 were rejected, and 30 were not reviewed. The 117 approved surgeons submitted a total of 5,641 endarterectomies with a combined mortality and neurological morbidity rate of 2.3% for the variety of indications for operation.
This overall experience with carotid endarterectomy is one of the largest series reported to date. The data from approved surgeons are well within the range of acceptable neurological morbidity and mortality rates recommended by the Stroke Council of the American Heart Association, which attests to the overall quality of the surgeons participating in the study.
Cerebral vasculitis associated with cocaine abuse.
Authors: Fredericks R K , Lefkowitz D S , Challa V R , Troost B T 
Published: June 2011

Earlier reports of cocaine-associated cerebral vasculitis have been based primarily on angiographic findings without pathological verification.
We present a case of acute encephalopathy following intravenous and intranasal administration of cocaine. Brain biopsy revealed vascular changes involving primarily small arteries. Findings included lymphocytic infiltration, endothelial thickening, and deposition of proteinaceous amorphous material within and around vessel walls.
These abnormalities are consistent with pathological features of arteritis previously reported in association with amphetamine and multiple-drug abuse. Vasospasm-induced changes are an alternative explanation for the vascular picture seen in this case. The patient made modest improvement with high-dose intravenous steroids.
Changes in middle cerebral artery blood velocity in uremic patients after hemodialysis.
Authors: Postiglione A , Faccenda F , Gallotta G , Rubba P , Federico S 
Published: June 2011

Strokes are a frequent complication in uremic patients on dialysis. We wanted to evaluate the effect of this treatment on cerebral hemodynamic parameters, particularly those of patients with carotid stenosis, who are at higher risk for atherothrombotic ischemic events.
We used transcranial Doppler ultrasonography to evaluate blood velocity of the middle cerebral artery in 18 uremic patients before and after hemodialysis. Carotid stenosis was evaluated by echo-Doppler investigation. Six patients were also studied before and after recombinant human erythropoietin treatment.
Dialysis treatment decreased mean blood velocity in all patients (p less than 0.001). Eight of 18 patients (44%) with mild (16-50%), moderate (51-80%), or severe (greater than 80%) carotid stenosis had lower velocity than patients with normal carotid arteries (p less than 0.01), and they experienced a further decrease to even lower levels after hemodialysis (p less than 0.05). In patients treated with recombinant human erythropoietin, hematocrit increased from 28 +/- 8% to 37 +/- 5% (p less than 0.001), and blood velocity had a further decrease by 11%. All changes were associated with modifications toward normality of pH, PaCO2, and hematocrit.
Transcranial Doppler ultrasonography represents a useful method for monitoring cerebral circulation of uremic patients, especially of those at possible risk for ischemia.
Impact of unruptured intracranial aneurysms on public health in the United States.
Authors: Wiebers D O , Torner J C , Meissner I 
Published: June 2011

Unruptured intracranial aneurysms constitute a significant public health problem that has not been quantified. The purpose of this study is to document the magnitude of this problem in the United States.
National Hospital Discharge Survey data from 1979, 1984, and 1989 served as the basis for calculating patient numbers and frequency distributions. Cost estimates included the direct costs of hospitalization and surgery for those who had surgery, disability and lost income from morbidity, and lost income from mortality.
The estimated lifetime cost (including hospitalization, surgery, morbidity, and mortality) for annual cases of patients hospitalized with unruptured intracranial aneurysms in the United States is $522,500,000 compared with $1,755,600,000 for patients with aneurysmal subarachnoid hemorrhage.
These data underscore the need to better understand unruptured intracranial aneurysm as a risk factor for subarachnoid hemorrhage, to define other subarachnoid hemorrhage risk factors, and to optimize the management of patients with these conditions.
Effect of lidocaine on somatosensory evoked response and cerebral blood flow after canine cerebral air embolism.
Authors: Dutka A J , Mink R , McDermott J , Clark J B , Hallenbeck J M 
Published: June 2011

Victims of air embolism often recover rapidly on hyperbaric treatment then deteriorate again, even if hyperbaric treatment is continued. In previous animal experiments, lidocaine has been shown to improve recovery of somatosensory evoked response amplitude after air embolism. However, animals in these experiments rarely deteriorated. We have shown that the induction of air embolism and transient hypertension in canines produces deterioration despite hyperbaric treatment, and we decided to test the effect of lidocaine on somatosensory evoked potential recovery and cerebral blood flow in this model.
Dogs were treated with repeated doses of lidocaine or equivalent volumes of saline during hyperbaric therapy after internal carotid air embolism and transient hypertension. The investigators were unaware of treatment group assignment during the experiments. The amplitude of the median nerve somatosensory evoked potential and cerebral blood flow measured with carbon-14-labeled iodoantipyrine autoradiography were used to assess effect of therapy.
Lidocaine-treated dogs recovered 60 +/- 10% (mean +/- 95% confidence limits) of the baseline somatosensory evoked potential amplitude 220 minutes after air embolism; saline-treated dogs recovered 32 +/- 10% (a significant difference at p less than 0.01). Lidocaine-treated dogs also had higher cerebral blood flow values than saline-treated dogs 220 minutes after air embolism.
Lidocaine ameliorated the delayed deterioration of evoked potential associated with air embolism and hypertension in this canine model. The improved cerebral blood flow may be a mechanism of action of lidocaine or an associated effect of improved neuronal survival.
Early time course of N-acetylaspartate, creatine and phosphocreatine, and compounds containing choline in the brain after acute stroke. A proton magnetic resonance spectroscopy study.
Authors: Gideon P , Henriksen O , Sperling B , Christiansen P , Olsen T S , Jørgensen H S , Arlien-Søborg P 
Published: June 2011

The early time course after acute stroke of cerebral N-acetylaspartate, creatine and phosphocreatine, and compounds containing choline was studied in vivo by means of localized water-suppressed proton magnetic resonance spectroscopy.
Eight patients with acute stroke were studied serially in the acute phase, 1 week after, and 2-4 weeks after the onset of clinical symptoms. Ten healthy volunteers served as controls. A stimulated echo (STEAM) sequence was used for measurement of the brain metabolites in a volume of interest located within the infarcted area as visualized by magnetic resonance imaging. For quantification, the unsaturated water signal was used as the internal standard. Regional cerebral blood flow in the infarcted area was measured relative to a symmetrically located unaffected area by means of single-photon emission computed tomographic scanning, using 99mTc-labeled d,l-hexamethylenepropyleneamine oxime as the flow tracer.
Relative regional cerebral blood flow was considerably reduced in the infarcted area in the acute phase. After 1 week, hyperemia was seen in all but one patient. The N-acetylaspartate content was significantly reduced, with the loss appearing to occur between 6 and 24 hours after the stroke incident. The reduction in N-acetylaspartate content was greater in the central part than in the peripheral part of the infarcted area. Creatine and phosphocreatine were also reduced in the infarcted area, whereas no significant change was seen in the choline content.
Assuming that N-acetylaspartate content reflects neuronal survival or loss, our results may suggest that treatment procedures with restoration of blood flow to severely ischemic areas should be initiated within the first 6 hours after stroke onset.
Imaging of the intracranial vertebrobasilar system using color-coded ultrasound.
Authors: Kaps M , Seidel G , Bauer T , Behrmann B 
Published: June 2011

Anatomic variety and difficult accessibility of the vertebrobasilar arteries pose considerable problems to conventional ultrasound. We evaluated the diagnostic potential of transcranial color-coded sonography in the distal part of this system.
We insonated the intracranial section of the vertebrobasilar arteries through the foramen magnum window in 24 healthy individuals using a Doppler color flow imaging system in connection with a 2.5-MHz sector transducer. Magnetic resonance images in special inclination planes were performed and compared with the color-coded duplex images in five cases.
The B-mode image of the craniocervical junction and the intracranial parenchymal structures in addition to the color-coded blood flow allowed an unambiguous identification of the vertebrobasilar arteries (vertebral artery, 96%; basilar artery, 79%; and posterior inferior cerebellar artery, 50%). Blood flow velocities were measured considering the insonation angles: vertebral arteries, 50/24 cm/sec (30 degrees); basilar artery, 59/28 cm/sec (4 degrees); and posterior inferior cerebellar artery, 56/30 cm/sec (20 degrees) [peak systolic/end diastolic blood flow velocity (mean angle correction)].
Transcranial color-coded sonography enables accurate identification and differentiation of the intracranial vertebrobasilar arteries and improves accuracy of Doppler measurements. It may prove useful for evaluation of tortuosity and for hemodynamic studies in this vascular territory.
Risks and benefits of shunting in carotid endarterectomy. The International Transcranial Doppler Collaborators.
Authors: Halsey J H 
Published: June 2011

Controversy continues about the pathogenesis of perioperative stroke in carotid endarterectomy and the use of shunting. The purpose of this study was to determine, using transcranial Doppler ultrasonography, the severity of ischemia during clamping of the carotid artery as a basis for analysis of complications in patients operated on with and without shunting.
In a retrospective study, 11 centers contributed 1,495 carotid endarterectomies monitored with transcranial Doppler. The cases were divided into groups with severe, mild, and no ischemia, and each group was subdivided according to shunt use. The perioperative rate of severe stroke attributable to intraoperative ischemia, in addition to total perioperative stroke, was determined for each subgroup.
Severe ischemia occurred in 7.2% of our cases but cleared spontaneously in about half of these. In those with persisting ischemia the rate of severe stroke was very high, while shunting protected against stroke in such cases. If ischemia did not occur, the stroke rate was higher with shunting, although not so high as in unshunted cases with severe ischemia. Slightly more than one third of the severe strokes were due to postoperative cerebral hemorrhage or carotid thrombosis, unrelated to clamp-induced ischemia or shunting.
Carotid endarterectomy complications might be reduced by selectively shunting only for severe persisting ischemia. Monitoring of cerebral ischemia would be essential to selective shunting.