Can the ischemic penumbra be identified on noncontrast CT of acute stroke?

<p><b>Background and Purpose:</b> Early ischemic changes on noncontrast CT in acute stroke include both hypoattenuation and brain swelling, which may have different pathophysiological significance.</p> <p><b>Methods:</b> Noncontrast CT and CT perfusion brain scans from patients with suspected acute stroke <6 hours after onset were reviewed. Five raters independently scored noncontrast CTs blind to clinical data using the Alberta Stroke Program Early CT Score (ASPECTS). Each ASPECTS region was scored as hypodense or swollen. A separate reviewer measured time to peak and cerebral blood volume in each ASPECTS region on CT perfusion. Time to peak and cerebral blood volume were compared for each region categorized as normal, hypodense, or isodense and swollen.</p> <p><b>Results:</b> Scans of 32 subjects a median 155 minutes after onset yielded 228 regions with both CT perfusion and noncontrast CT data. Isodense swelling was associated with significantly higher cerebral blood volume (P=0.016) and with penumbral perfusion (posttest:pretest likelihood ratio 1.44 [95% CI: 0.68 to 2.90]), whereas hypodensity was associated with more severe time to peak delay and with core perfusion (likelihood ratio 3.47 [95% CI: 1.87 to 6.34]). Neither isodense swelling nor hypodensity was sensitive for prediction of perfusion pattern, but appearances were highly specific (87.2% and 91.0% for penumbra and core, respectively). Intrarater agreement was good or excellent, but interrater agreement for both hypodensity and swelling was poor.</p> <p><b>Conclusions:</b> Regions exhibiting hypoattenuation are likely to represent the infarct core, whereas regions that are isodense and swollen have increased cerebral blood volume and are more likely to signify penumbral perfusion. Although noncontrast CT is not sensitive for detection of core and penumbra, appearances are specific. Some information on tissue viability can therefore be obtained from noncontrast CT.</p&gt

Characterising and Testing Deep UV LEDs for Use in Space Applications

Deep ultraviolet (DUV) light sources are used to neutralise isolated test masses in highly sensitive space-based gravitational experiments. An example is the LISA Pathfinder charge management system, which uses low-pressure mercury lamps. A future gravitational-wave observatory such as eLISA will use UV light-emitting diodes (UV LEDs), which offer numerous advantages over traditional discharge lamps. Such devices have limited space heritage but are are now available from a number of commercial suppliers. Here we report on a test campaign that was carried out to quantify the general properties of three types of commercially available UV LEDs and demonstrate their suitability for use in space. Testing included general electrical and UV output measurements, spectral stability, pulsed performance, temperature dependence as well as thermal vacuum, radiation and vibration survivability

Evolution and diversity of secretome genes in the apicomplexan parasite Theileria annulata

<b>BACKGROUND</b>: Little is known about how apicomplexan parasites have evolved to infect different host species and cell types. Theileria annulata and Theileria parva invade and transform bovine leukocytes but each species favours a different host cell lineage. Parasite-encoded proteins secreted from the intracellular macroschizont stage within the leukocyte represent a critical interface between host and pathogen systems. Genome sequencing has revealed that several Theileria-specific gene families encoding secreted proteins are positively selected at the inter-species level, indicating diversification between the species. We extend this analysis to the intra-species level, focusing on allelic diversity of two major secretome families. These families represent a well-characterised group of genes implicated in control of the host cell phenotype and a gene family of unknown function. To gain further insight into their evolution and function, this study investigates whether representative genes of these two families are diversifying or constrained within the T. annulata population. <b>RESULTS</b>: Strong evidence is provided that the sub-telomerically encoded SVSP family and the host-nucleus targeted TashAT family have evolved under contrasting pressures within natural T. annulata populations. SVSP genes were found to possess atypical codon usage and be evolving neutrally, with high levels of nucleotide substitutions and multiple indels. No evidence of geographical sub-structuring of allelic sequences was found. In contrast, TashAT family genes, implicated in control of host cell gene expression, are strongly conserved at the protein level and geographically sub-structured allelic sequences were identified among Tunisian and Turkish isolates. Although different copy numbers of DNA binding motifs were identified in alleles of TashAT proteins, motif periodicity was strongly maintained, implying conserved functional activity of these sites. <b>CONCLUSIONS</b>: This analysis provides evidence that two distinct secretome genes families have evolved under contrasting selective pressures. The data supports current hypotheses regarding the biological role of TashAT family proteins in the management of host cell phenotype that may have evolved to allow adaptation of T. annulata to a specific host cell lineage. We provide new evidence of extensive allelic diversity in representative members of the enigmatic SVSP gene family, which supports a putative role for the encoded products in subversion of the host immune response

Unabbreviation

Readers of this journal are probably formidable players of most of the commercially-available word games, and always on the look-out for something new. If so, they might be interested in a game, called Unabbreviation for lack of anything catchier, which a few of us have been playing on occasion for a few years. The game is for two or more players, and is suitable for home or travel

Early recurrent ischemic stroke complicating intravenous thrombolysis for stroke: incidence and association with atrial fibrillation

<p><b>Background and Purpose:</b> Mechanisms of early neurologic deterioration after treatment with intravenous, recombinant, tissue-type plasminogen activator (IV rt-PA) include symptomatic intracerebral hemorrhage (SICH) and early recurrent ischemic stroke. We observed a number of cases of acute deterioration due to recurrent ischemic events.</p> <p><b>Methods:</b> We undertook a single-center, retrospective analysis of consecutive acute stroke patients treated with IV rt-PA between January 2006 and December 2008 to define the incidence of early neurologic deterioration (>= 4-point drop on the National Institutes of Health Stroke Scale within 72 hours) and its mechanism. Deterioration was attributed to SICH when associated with a PH1 or PH2 hemorrhage on postdeterioration computed tomography scans, to recurrent ischemic stroke when there was clinical and radiologic evidence of a new territorial infarction or new vessel occlusion, and otherwise to evolution of the incident stroke.</p> <p><b>Results:</b> Of 228 consecutive IV rt-PA-treated patients, 34 (15%) developed early neurologic deterioration, 18 (8%) secondary to incident strokes 10 (4.4%) due to SICH, and 6 (2.6%) due to early recurrent ischemic events, which were significantly associated with atrial fibrillation (present in 5 of 6 patients; 4 paroxysmal, 1 permanent). In 4 patients, sudden clinical deterioration developed during or shortly after IV rt-PA infusion, and in 2, deterioration developed 3 days later. All died 2 days to 2 weeks later. The single case without atrial fibrillation had a recurrent, contralateral, middle cerebral artery stroke during IV rt-PA infusion and multiple high-signal emboli detected by transcranial Doppler. Early recurrent ischemic stroke accounted for 5 of 12 (42%) cases of early neurologic deterioration in patients with atrial fibrillation.</p> <p><b>Conclusion:</b> In this single-center series, the incidence of early recurrent ischemic stroke after IV rt-PA was 2.6% and was associated with previous atrial fibrillation.</p&gt

Contributions to the biology of the panga Pterogymnus laniarus (Pisces : Sparidae): age, growth and reproduction

All the fish used in this investigation were caught by commercial side trawlers along the eastern Cape coast of South Africa. Age and growth of P. laniarius was determined from otoliths collected monthly from April 1974 to September 1975. The validity of annuli was proved by monthly edge examination of the otoliths. There is no difference in growth between the sexes. The Von Bertalanffy equation Lt = 48,1 (l-e-0,10(e + 0.22)) was found to describe the growth of the panga in length. Some fish become sexually mature at a total length of 26 cm. Fifty percent maturity is attained at a length of 28 cm, between the ages of 4 and 5 years. All fish are sexually mature at a total length of 32 cm, at an age of 6 years. The spawning season of the panga extends from mid-September to May

Contemporary splinting practice in the UK for adults with neurological dysfunction: A cross-sectional survey

This article is made available through the Brunel Open Access Publishing Fund.Aim: To explore the contemporary splinting practice of UK occupational therapists and physiotherapists for adults with neurological dysfunction. Method: Cross-sectional online survey of members of the Association of Chartered Physiotherapists in Neurology and College of Occupational Therapists Specialist Section Neurological Practice. Results: Four hundred and twenty therapists completed the survey. Contracture management is the most common rationale for therapists splinting adults with neurological dysfunction. Other shared therapeutic goals of splinting include maintaining muscle and joint alignment, spasticity management, function, pain management and control of oedema. Considerable clinical uncertainty was uncovered in practice particularly around wearing regimens of splints. Most therapists have access to locally-derived splinting guidelines, which may contribute to this diversity of practice. Conclusions: This study provides a unique insight into aspects of contemporary splinting practice among UK therapists, who belong to a specialist neurological professional network and work in a number of different health-care settings with adults who have a neurological condition. Study findings show a wide variation in splinting practice, thereby indicating a potential need for national guidance to assist therapists in this area of clinical uncertainty. Further research is required to establish best practice parameters for splinting in neurological rehabilitation

Portal vein thrombosis after laparoscopic splenectomy: an ongoing clinical challenge.

ObjectivesPortal vein thrombosis (PVT) following open splenectomy is a potentially lethal complication with an incidence of up to 6%. The objective of this report is to describe our management of a recent laparoscopic case, discuss current therapies, and consider antiplatelet therapy for prophylaxis.MethodsMedical records, laboratory studies, and imaging studies pertaining to a recent case of a laparoscopic splenectomy were examined. Current literature related to this topic was reviewed.ResultsA 16-year-old girl underwent laparoscopic splenectomy for idiopathic thrombocytopenic purpura. Her preoperative platelet count was 96K. She was discharged on postoperative day 1 after an uneventful operation including division of the splenic hilum with an endoscopic linear stapler. On postoperative day 20, she presented with a 5-day history of epigastric pain, nausea, and low-grade fevers without peritoneal signs. Her white blood cell count was 17.3; her platelets were 476K. Computed tomography demonstrated thrombosis of the splenic, superior mesenteric, and portal veins propagating into the liver. Heparinization was begun followed by an unsuccessful attempt at pharmacologic and mechanical thrombolysis by interventional radiology. Over the next 5 days, her pain resolved, she tolerated a full diet, was converted to oral anticoagulation and sent home. Follow-up radiographic studies demonstrated the development of venous collaterals and cavernous transformation of the portal vein.DiscussionNo standard therapy for PVT exists; several approaches have been described. These include systemic anticoagulation, systemic or regional medical thrombolysis, mechanical thrombolysis, and surgical thrombectomy. Unanswered questions exist about the most effective acute therapy, duration of anticoagulation, and the potential efficacy of routine prophylaxis with perioperative antiplatelet agents. PVT following splenectomy occurs with both the open and laparoscopic approach

Psychological factors in retrograde amnesia: self-deception and a broken heart

We explored potential contributing psychological factors in a patient (‘XF’) with focal retrograde amnesia, within the framework proposed by Kopelman (2000). In particular, we investigated the psychological trait of self-enhancement. We constructed a self-report questionnaire measure of self-enhancement and compared XF’s score on this measure with the scores of 61 control participants. XF was found to have a significantly greater level of self-enhancement than the entire control group, and also than a smaller sample of age- and sex-matched controls. We propose that heightened self-enhancement may reflect a premorbid tendency that potentially predisposes individuals to develop retrograde amnesia

Biharmonic Riemannian submersions from 3-manifolds

An important theorem about biharmonic submanifolds proved independently by Chen-Ishikawa [CI] and Jiang [Ji] states that an isometric immersion of a surface into 3-dimensional Euclidean space is biharmonic if and only if it is harmonic (i.e, minimal). In a later paper [CMO2], Cadeo-Monttaldo-Oniciuc shown that the theorem remains true if the target Euclidean space is replaced by a 3-dimensional hyperbolic space form. In this paper, we prove the dual results for Riemannian submersions, i.e., a Riemannian submersion from a 3-dimensional space form of non-positive curvature into a surface is biharmonic if and only if it is harmonic