The SOAR stroke score predicts hospital length of stay in acute stroke: an external validation study.

AIMS: The objective of this study is to externally validate the SOAR stroke score (Stroke subtype, Oxfordshire Community Stroke Project Classification, Age and prestroke modified Rankin score) in predicting hospital length of stay (LOS) following an admission for acute stroke. METHODS: We conducted a multi-centre observational study in eight National Health Service hospital trusts in the Anglia Stroke & Heart Clinical Network between September 2008 and April 2011. The usefulness of the SOAR stroke score in predicting hospital LOS in the acute settings was examined for all stroke and then stratified by discharge status (discharged alive or died during the admission). RESULTS: A total of 3596 patients (mean age 77 years) with first-ever or recurrent stroke (92% ischaemic) were included. Increasing LOS was observed with increasing SOAR stroke score (p < 0.001 for both mean and median) and the SOAR stroke score of 0 had the shortest mean LOS (12 ± 20 days) while the SOAR stroke score of 6 had the longest mean LOS (26 ± 28 days). Among patients who were discharged alive, increasing SOAR stroke score had a significantly higher mean and median LOS (p < 0.001 for both mean and median) and the LOS peaked among patients with score value of 6 [mean (SD) 35 ± 31 days, median (IQR) 23 (14-48) days]. For patients who died as in-patient, there was no significant difference in mean or median LOS with increasing SOAR stroke score (p = 0.68 and p = 0.79, respectively). CONCLUSION: This external validation study confirms the usefulness of the SOAR stroke score in predicting LOS in patients with acute stroke especially in those who are likely to survive to discharge. This provides a simple prognostic score useful for clinicians, patients and service providers.

Treatment of infantile haemangioma with captopril.

BACKGROUND: Infantile haemangioma (IH) has recently been reported as an aberrant proliferation and differentiation of a primitive mesoderm-derived haemogenic endothelium regulated by the renin-angiotensin system (RAS), leading us to propose angiotensin converting enzyme (ACE) as a potential therapeutic target. OBJECTIVES: To present initial results of our open-labelled observational clinical trial using captopril, an ACE inhibitor (ACEi), in the treatment of problematic proliferating IH. METHODS: After initial screening investigations, infants with problematic IH were admitted for initiation of captopril with a 0·1 mg kg(-1) test dose orally, followed by 0·15 8-hourly over 24 h. This was then followed by dose escalation to 0·3 mg kg(-1) 8-hourly for another 24 hours. The dosage was increased to 0·5 mg kg(-1) 8-hourly 1 week later, if a noticeable involution had not already occurred. The response of IH to captopril was documented clinically and photographically before and after treatment and any side-effect was recorded. RESULTS: Two boys and six girls aged 5-22 weeks (mean 12·9) with problematic IH were recruited with the lesions located in nasal tip (n = 1), cervicofacial (n = 3), periorbital (n = 1) and perineal (n = 2) areas, and shoulder (n = 1). Transient mild renal impairment occurred in one subject but resolved spontaneously. No other complication was observed. The IHs in all patients responded to captopril at a dosage of 1·5 mg kg(-1) daily which led to a dramatic response in three, moderate response in two, and slow response in three patients. Continued involution of IHs was observed during the follow-up period of 8-19 months (mean 15·8) in all subjects. Treatment was ceased at 14 months of age in seven patients with no rebound growth. In the remaining patient, rapid healing occurred with ongoing gradual reduction in the size and colour of a large ulcerated retroauricular lesion following 5·5 months of treatment. The lesion was excised to address its persistent distortion of the ear. CONCLUSIONS: The response of IH to an ACEi supports a critical role for the RAS in IH and represents a paradigm shift in the understanding and treatment of this enigmatic condition.

Primitive erythropoiesis in infantile haemangioma.

UNLABELLED: BACKGROUND; Infantile haemangioma (IH) is a tumour of the microvasculature composed predominantly of proliferating endothelial cells. It expresses markers associated with endothelial, haematopoietic and mesenchymal lineages. We have previously shown that the cells forming the capillary endothelium of proliferating IH express cell surface markers and transcriptions factors consistent with it being a haemogenic endothelium. OBJECTIVES: We wished to determine whether the expression of transcription factors associated with the erythroid lineage was of physiological relevance and sufficient for IH tissue cultured in vitro to undergo erythropoiesis. METHODS: Immunohistochemical staining of paraffin-embedded sections of proliferating IHs was undertaken and expression of the embryonically associated haemoglobin ζ (HBZ) chain and the erythropoietin receptor (EPO-R) was determined. Relative expression of mRNA encoding these proteins was determined by quantitative reverse transcription-polymerase chain reaction using snap-frozen biopsy samples. Differentiation towards erythrocytes was investigated using freshly resected tissue cultured as explants in Matrigel. RESULTS: The endothelium of the microvessels, but not the pericyte layer, was strongly immunoreactive for the EPO-R and the embryonically associated HBZ chain. Abundant expression of transcripts encoding these proteins was also detected, corroborating the immunohistochemical staining. When tissue was grown in culture the cells emanating from IH explants were able to generate enucleated erythrocytes in vitro. The erythrocytes were immunoreactive for the erythrocyte-specific marker glycophorin A. CONCLUSIONS: The microvessels in IH are a functional haemogenic endothelium that expresses the embryonically associated HBZ chain and is able to form erythrocytes in vitro. IH thus represents a possible extramedullary site for tumour-associated primitive erythropoiesis.

The relationship between motor deficit and primary motor cortex hemispheric activation balance after stroke: longitudinal fMRI study.

BACKGROUND: In the chronic stage of stroke, previous work has shown that the worse the hand motor deficit, the greater the shift of primary motor cortex (M(1)) activation towards the contralesional hemisphere (ie, unphysiological) balance. Whether the same relationship applies at earlier stages of recovery in serially studied patients is not known. METHODS: fMRI of fixed-rate auditory-cued affected index-thumb tapping was obtained at two time points (mean 36 and 147 days poststroke) in a cohort of nine patients with ischaemic stroke (age: 56+/-9 years; three women/six men; seven subcortical, one medullary and one cortical). On each fMRI day, the unaffected/affected ratio of maximal index tapping rate (IT-R) was obtained. To assess the M(1) hemispheric activation balance, the authors computed the classic Laterality Index (LI). The correlation between LI and IT-R was computed for each time point separately. RESULTS: The expected correlation between LI-M(1) and IT-R, that is, motor performance worse with more unphysiological LI, prevailed at both time points (Kendall p=0.008 and 0.058, respectively), with no statistically significant difference between the two regressions. The same analysis for the dorsal premotor cortex and the supplementary motor area showed no significant correlation at either time-point. CONCLUSION: These results from a small cohort of longitudinally assessed patients suggest that the relationship between M(1) laterality index and hand motor performance appears independent of time since onset of stroke. This in turn may suggest that attempting to restore the hemispheric balance by enhancing ipsilesional M(1) and/or constraining contralesional M(1) activity may have consistent efficacy throughout recovery.

Selective neuronal loss in rescued penumbra relates to initial hypoperfusion.

Selective neuronal loss (SNL) in the rescued penumbra could account for suboptimal clinical recovery despite effective early reperfusion. Previous studies of SNL used single-photon emission tomography (SPECT), did not account for potential volume loss secondary to collapse of the infarct cavity, and failed to show a relationship with initial hypoperfusion. Here, we obtained acute-stage computerized tomography (CT) perfusion and follow-up quantitative (11)C-flumazenil (FMZ)-PET to map SNL in the non-infarcted tissue and assess its relationship with acute-stage hypoperfusion. We prospectively recruited seven patients with evidence of (i) acute (<6 h) extensive middle cerebral artery territory ischaemia based on clinical deficit (National Institutes of Health stroke scale, NIHSS score range: 8-23) and CT Perfusion (CTp) findings and (ii) early recanalization (spontaneous or following thrombolysis) based on spectacular clinical recovery (DeltaNIHSS > or =6 at 24 h), good clinical outcome (NIHSS < or =5) and small final infarct (6/7 subcortical) on late-stage MRI. Ten age-matched controls were also studied. FMZ image analysis took into account potential post-stroke volume loss. Across patients, clusters of significantly reduced FMZ binding were more prevalent and extensive in the non-infarcted middle cerebral artery cortical areas than in the non-affected hemisphere (P = 0.028, Wilcoxon sign rank test). Voxel-based between-group comparisons revealed several large clusters of significantly reduced FMZ binding in the affected peri-insular, superior temporal and prefrontal cortices (FDR P < 0.05), as compared with no cluster on the unaffected side. Finally, comparing CTp and PET data revealed a significant negative correlation between FMZ binding and initial hypoperfusion. Applying correction for volume loss did not substantially alter the significance of these results. Although based on a small patient sample sometimes studied late after the index stroke, and as such preliminary, our results establish the presence and distribution of FMZ binding loss in ultimately non-infarcted brain areas after stroke. In addition, the data suggest that this binding loss is proportional to initial hypoperfusion, in keeping with the hypothesis that the rescued penumbra is affected by SNL. Although its clinical counterparts remain uncertain, it is tempting to speculate that peri-infarct SNL could represent a new therapeutic target.

How affected is oxygen metabolism in DWI lesions?: A combined acute stroke PET-MR study.

OBJECTIVE: To use back-to-back diffusion-weighted imaging (DWI) and PET to obtain quantitative measures of the cerebral metabolic rate of oxygen (CMRO(2)) within DWI lesions, and to assess the perfusion-metabolism coupling status by measuring the cerebral blood flow and the oxygen extraction fraction within DWI lesions. METHODS: Six prospectively recruited acute carotid-territory stroke patients completed the imaging protocol, which was commenced 7 to 21 hours from onset and combined DWI derived from state-of-the-art diffusion tensor imaging sequencing using a 3-T magnet and fully quantitative (15)O-PET. The PET variables were obtained in individual DWI lesions in each patient. RESULTS: Across patients, the CMRO(2) was reduced in the DWI lesion relative to mirror (mean reduction 39.5%; p = 0.028). Examining individual DWI lesions, however, revealed considerable variability in the extent of this CMRO(2) reduction. The flow-metabolism coupling pattern underlying the DWI lesion was also variable, including ongoing ischemia, mild oligemia, and partial or complete reperfusion. DISCUSSION: Diffusion-weighted imaging (DWI) lesions generally reflect substantial disruption of energy metabolism. However, the degree of metabolic disruption is variable, indicating DWI lesions may not always represent irreversibly damaged tissue. Finally, because DWI lesions can persist despite reperfusion, assessment of perfusion is necessary for interpretation of DWI changes in acute stroke.

Does healthy aging affect the hemispheric activation balance during paced index-to-thumb opposition task? An fMRI study.

Normal aging is generally associated with declining performance in cognitive and fine motor tasks. Previous functional imaging studies have been inconsistent regarding the effect of aging on primary motor cortex (M1) activation during finger movement, showing increased, unchanged or decreased activation contralaterally, and more consistently increased activation ipsilaterally. Furthermore, no study has addressed the effect of age on M1 hemispheric activation balance. We studied 18 optimally healthy right-handed subjects, age range 18-79 years (mean +/- SD: 47 +/- 17) using 3 T fMRI and right index finger-thumb tapping auditory-paced at 1.25 Hz. The weighted Laterality Index (wLI) for M1 was obtained according to Fernandez et al. (2001) [Fernandez, G., de Greiff, A., von Oertzen, J., Reuber, M., Lun, S., Klaver, P., et al. 2001. Language mapping in less than 15 min: real-time functional MRI during routine clinical investigation. Neuroimage 14 585-594], with some modifications. The wLI, as well as the total activation on each side, were assessed against age using non-parametric correlation. There was a highly significant negative correlation between age and wLI such that the older the subjects, the lower the wLI. Furthermore, there was a highly significant positive correlation between total activation for ipsilateral M1 and age, and a nearly significant trend for contralateral M1. This study documents that during execution of a simple paced motor task, the older the subject the less lateralized the M1 activation balance as a result of increasing amount of activation on both sides, more significantly so ipsilaterally. Thus, in aging, enhanced M1 recruitment bilaterally is required to produce the same motor performance, suggesting a compensatory process. These findings are in line with cognitive studies indicating a tendency for the aging brain to reduce its functional lateralization, perhaps from less efficient transcallosal connections.

Perfusion CT helps decision making for thrombolysis when there is no clear time of onset.

Current guidelines on thrombolysis post stroke with recombinant tissue plasminogen activator (rt-PA) exclude its use where time of onset is unknown, thus denying some patients potentially beneficial treatment. Contrast enhanced perfusion computed tomography (pCT) imaging can be used together with plain CT and information on clinical deficits to decide whether or not thrombolysis should be initiated even though the exact time of stroke onset is unknown. Based on the results of pCT and CT, rt-PA was administered to two patients with unknown time of stroke onset; one of the patients also underwent suction thrombectomy. Results in both cases were excellent.

Discordant temporal patterns of S100beta and cleaved tau protein elevation after head injury: a pilot study.

There is considerable interest in S100beta protein as a potential marker that can be used to quantify central nervous system injury. However, increasing appreciation that S100beta may be produced by non-neural tissue (specifically adipocytes), has led to a search for more specific markers of brain injury. Recent interests have focused on a cleaved form of tau protein (c tauP) which is elevated in CSF from patients suffering traumatic brain injury. We have investigated whether levels in peripheral blood are a satisfactory alternative to provide an accessible marker of CNS injury severity. We measured levels of S100beta and c tauP in arterial blood from 20 patients with severe head injury. When compared with normal values S100beta was elevated 10-fold in the first 24 hours and c tauP was elevated at all time points, but showed a reversal of the temporal trend observed with S100beta. Patients with a poor outcome (GOS 1-3) had significantly higher S100beta levels on day one. Plasma c tauP levels did not correlate with outcome following head injury.

Synthesis and application of circularizable ligation probes.

We describe a PCR-based approach for the synthesis of circularizable ligation probes (CLiPs). CLiPs are single-stranded probes that consist of target-specific ends separated by a noncomplementary "linker" sequence. When hybridized to a target, the CLiP forms a nicked circle that may be sealed by DNA ligase only if the 5' and 3' ends show perfect Watson-Crick base pairing, thus enabling the discrimination of single nucleotide polymorphisms. Primers incorporating target sequence at their 5' end and plasmid sequence at the 3' end were used in a PCR amplification. In addition, the antisense primer was 5' labeled with biotin, and the amplification was performed in the presence of fluorescently labeled dUTP. The resulting PCR product was captured with streptavidin-coated paramagnetic beads, and the top strand, which forms the CLiP, was alkali eluted. This PCR-based method has allowed the synthesis of CLiPs that are larger and more highly labeled than has previously been possible, with ligation efficiencies similar to those of the purest chemically synthesized padlock probes. Ligations performed in the presence of cognate or mismatched sequence were analyzed by denaturing PAGE using a fluorescent DNA sequencer. Genotyping using target immobilized to nylon membranes was also performed. The CLiPs were readily able to distinguish between mutant and wild-type alleles for the common genetic disorder, 21-hydroxylase deficiency. Additionally, CLiPs of different lengths were synthesized and compared.

Genotyping of CYP21, linked chromosome 6p markers, and a sex-specific gene in neonatal screening for congenital adrenal hyperplasia.

We investigated the feasibility and diagnostic utility of genotyping 9 CYP21 mutations, linked chromosome 6p markers, and a dimorphic X-Y marker from neonatal screening samples. Blood-impregnated filter papers (Guthrie cards) from 603 randomly chosen New Zealand neonates were genotyped blind to 17-hydroxyprogesterone (17-OHP) levels. Another 50 samples from Swiss and North American infants with correlative hormonal data were also genotyped. DNA was extracted, and gene-specific PCR was performed. CYP21 PCR products were subjected to ligase detection reaction, simultaneously analyzing 9 CYP21 mutations; PCR products of other genes were subjected to direct gel analysis. CYP21 genotyping indicated a heterozygote rate of 2.8% for classic mutations (excluding CYP21 deletions), and 2.0% for nonclassic mutations in New Zealanders. Ten full-term affected neonates showed a wide range of 17-OHP levels (15-1400 nmol/L). Sick or preterm infants or infants screened on the first day of life with high 17-OHP proved genetically unaffected. Genetic linkage disequilibrium was found between two CYP21 mutations and chromosome 6p markers. Guthrie cards can be used to accurately genotype CYP21 and other relevant markers, potentially enhancing the specificity and sensitivity of congenital adrenal hyperplasia screening. CYP21 heterozygote frequency for classic mutations is higher than expected based on genotype compared with that predicted by hormonal newborn screening.

Identification of non-amplifying CYP21 genes when using PCR-based diagnosis of 21-hydroxylase deficiency in congenital adrenal hyperplasia (CAH) affected pedigrees.

Steroid 21-hydroxylase deficiency is among the most common inborn errors of metabolism in man. Characterization of mutations in the 21-hydroxylase gene (CYP21) has permitted genetic diagnosis, facilitated by the polymerase chain reaction (PCR). The most common mutation is conversion of an A or C at nt656 to a G in the second intron causing aberrant splicing of mRNA. Homozygosity for nt656G is associated with profoundly deficient adrenal cortisol and aldosterone synthesis, secondary hypersecretion of adrenal androgens, and a severe form of congenital adrenal hyperplasia (CAH) characterized by ambiguous genitalia and/or sodium wasting in newborns. During the course of genetic analysis of CYP21 mutations in CAH families, we and others have noticed a number of relatives genotyped as nt656G homozygotes, yet showing no clinical signs of disease. A number of lines of evidence have led us to propose that the putative asymptomatic nt656G/G individuals are incorrectly typed due to dropout of one haplotype during PCR amplification of CYP21. For prenatal diagnosis, we recommend that microsatellite typing be used as a supplement to CYP21 genotyping in order to resolve ambiguities at nt656.

Detection of steroid 21-hydroxylase alleles using gene-specific PCR and a multiplexed ligation detection reaction.

Steroid 21-hydroxylase deficiency is the most common cause of congenital adrenal hyperplasia, an inherited inability to synthesize cortisol that occurs in 1 in 10,000-15,000 births. Affected females are born with ambiguous genitalia, a condition that can be ameliorated by administering dexamethasone to the mother for most of gestation. Prenatal diagnosis is required for accurate treatment of affected females as well as for genetic counseling purposes. Approximately 95% of mutations causing this disorder result from recombinations between the gene encoding the 21-hydroxylase enzyme (CYP21) and a linked, highly homologous pseudogene (CYP21P). Approximately 20% of these mutations are gene deletions, and the remainder are gene conversions that transfer any of nine deleterious mutations from the CYP21P pseudogene to CYP21. We describe a methodology for genetic diagnosis of 21-hydroxylase deficiency that utilizes gene-specific PCR amplification in conjunction with thermostable DNA ligase to discriminate single nucleotide variations in a multiplexed ligation detection assay. The assay has been designed to be used with either fluorescent or radioactive detection of ligation products by electrophoresis on denaturing acrylamide gels and is readily adaptable for use in other disease systems.

Primacy of dimensions in vibrotactile perception: an evaluation of early holistic models.

Early holistic models of perception presume that stimuli composed of interacting dimensions can be experienced initially as undifferentiated. This view, formalized through recourse to a Euclidean geometry of perceptual space, predicts that the orientation of axes used to create stimulus sets is unimportant to performance in speeded classification. We tested this idea by using the interacting vibrotactile dimensions of pitch and loudness. Despite perceivers' relatively poor experience with these dimensions, we showed that the orientation corresponding to pitch and loudness was unique in vibrotactile perceptual space; subjects classified stimuli more efficiently at this orientation than at other orientations. Certain holistic models also claim that when stimulus differences are small, perceivers can recognize change without distinguishing the kind of change. We tested this idea by using a signal detection analysis of unspeeded same-different decisions. We found that subjects' ability to notice the kind of change equaled their ability to notice the change alone. In view of these results, which indicate that pitch and loudness are primary in vibrotactile perception, we detail a new conception of dimensional interaction.

The interaction of methanol dehydrogenase and its electron acceptor, cytochrome cL in methylotrophic bacteria.

The interactions of methanol dehydrogenase (MDH, EC1.1.99.8) with its specific electron acceptor cytochrome cL has been investigated in Methylobacterium extorquens and Methylophilus methylotrophus. The MDHs of these two very different methylotrophs have the same alpha 2 beta 2 structure; the interaction of these MDHs with their specific electron acceptor, cytochrome cL, has been studied using a novel assay system. Electrostatic reactions are involved in 'docking' of the two proteins. EDTA inhibits the reaction by a process involving neither metal chelation nor the 'docking' process. Chemical modification studies showed that the two proteins interact by a 'docking' process involving interactions of lysyl residues on MDH and carboxyl residues on cytochrome cL. When 'zero length', two stage cross-linking was done (with proteins from both bacteria), the alpha-subunits of MDH cross-linked with cytochrome cL by way of lysyl groups on MDH and carboxyl groups on the cytochrome. Tuna mitochondrial cytochrome c provided a model for cytochrome cH which is the electron acceptor for cytochrome cL in the 'methanol oxidase' electron transport chain. Tuna cytochrome c was shown to form crosslinked products with carboxyl-modified cytochrome cL. MDH and tuna cytochrome c competed for the same domain on cytochrome cL. It was concluded that MDH reacts with cytochrome cL by an electrostatic reaction which involves carboxyl groups on cytochrome cL and amino groups on the alpha-subunit of MDH. The same domain on cytochrome cL is involved in subsequent 'docking' with its electron acceptor.

Characterization of a novel soluble c-type cytochrome in a moxD mutant of Methylobacterium extorquens AM1.

Methylobacterium extorquens AM1 contains a novel c-type cytochrome, called cytochrome c-553, previously thought to be a precursor of the electron acceptor (cytochrome cL) for methanol dehydrogenase. Its amino acid composition and serological characteristics show that it has no structural relationship to cytochrome cL. It usually comprises less than 5% of the total c-type cytochromes. In a moxD mutant, which contains neither methanol dehydrogenase nor cytochrome cL, it comprises 30% of the soluble cytochrome and it has been purified and characterized from that mutant. Cytochrome c-553 is large (Mr 23,000), acidic and monohaem, with a redox potential of 194 mV. It reacts rapidly and completely with CO but is not autoxidizable. It is not autoreducible, and it is not an electron acceptor from methanol dehydrogenase or methylamine dehydrogenase, nor an important electron donor to the oxidase. It is able to accept electrons from cytochrome cL and to donate electrons to cytochrome cH. It is present in the soluble fraction (presumably periplasmic) and membrane fraction of wild-type bacteria during growth on a wide range of growth substrates, but its function in these bacteria or in the moxD mutant has not been determined.