Genomic analyses elucidate S-locus evolution in response to intra-specific losses of distyly in Primula vulgaris.

Distyly, a floral dimorphism that promotes outcrossing, is controlled by a hemizygous genomic region known as the S-locus. Disruptions of genes within the S-locus are responsible for the loss of distyly and the emergence of homostyly, a floral monomorphism that favors selfing. Using whole-genome resequencing data of distylous and homostylous individuals from populations of Primula vulgaris and leveraging high-quality reference genomes of Primula we tested, for the first time, predictions about the evolutionary consequences of transitions to selfing on S-genes. Our results reveal a previously undetected structural rearrangement in CYPᵀ associated with the shift to homostyly and confirm previously reported, homostyle-specific, loss-of-function mutations in the exons of the S-gene CYPᵀ. We also discovered that the promoter and intronic regions of CYPᵀ in distylous and homostylous individuals are conserved, suggesting that down-regulation of CYPᵀ via mutations in its promoter and intronic regions is not a cause of the shift to homostyly. Furthermore, we found that hemizygosity is associated with reduced genetic diversity in S-genes compared with their paralogs outside the S-locus. Additionally, the shift to homostyly lowers genetic diversity in both the S-genes and their paralogs, as expected in primarily selfing plants. Finally, we tested, for the first time, long-standing theoretical models of changes in S-locus genotypes during early stages of the transition to homostyly, supporting the assumption that two copies of the S-locus might reduce homostyle fitness.

Endovascular therapy outcome in isolated posterior cerebral artery occlusion strokes: A multicenter analysis of the Swiss Stroke Registry.

PURPOSE: There is little data on the safety and efficacy of endovascular treatment (EVT) in comparison with intravenous thrombolysis (IVT) in acute ischemic stroke due to isolated posterior cerebral artery occlusion (IPCAO). We aimed to investigate the functional and safety outcomes of stroke patients with acute IPCAO treated with EVT (with or without prior bridging IVT) compared to IVT alone. METHODS: We did a multicenter retrospective analysis of data from the Swiss Stroke Registry. The primary endpoint was overall functional outcome at 3 months in patients undergoing EVT alone or as part of bridging, compared with IVT alone (shift analysis). Safety endpoints were mortality and symptomatic intracranial hemorrhage. EVT and IVT patients were matched 1:1 using propensity scores. Differences in outcomes were examined using ordinal and logistic regression models. FINDINGS: Out of 17,968 patients, 268 met the inclusion criteria and 136 were matched by propensity scores. The overall functional outcome at 3 months was comparable between the two groups (EVT vs IVT as reference category: OR = 1.42 for higher mRS, 95% CI = 0.78-2.57, p = 0.254). The proportion of patients independent at 3 months was 63.2% in EVT and 72.1% in IVT (OR = 0.67, 95% CI = 0.32-1.37, p = 0.272). Symptomatic intracranial hemorrhages were overall rare and present only in the IVT group (IVT = 5.9% vs EVT = 0%). Mortality at 3 months was also similar between the two groups (IVT = 0% vs EVT = 1.5%). CONCLUSION: In this multicenter nested analysis, EVT and IVT in patients with acute ischemic stroke due to IPCAO were associated with similar overall good functional outcome and safety. Randomized studies are warranted.

Unified one-dimensional finite element for the analysis of hyperelastic soft materials and structures.

Based on the Carrera unified formulation (CUF) and first-invariant hyperelasticity, this work proposes a displacement-based high order one-dimensional (1 D) finite element model for the geometrical and physical nonlinear analysis of isotropic, slightly compressible soft material structures. Different strain energy functions are considered and they are decomposed in a volumetric and an isochoric part, the former acting as penalization of incompressibility. Given the material Jacobian tensor, the nonlinear governing equations are derived in a unified, total Lagrangian form by expanding the three-dimensional displacement field with arbitrary cross-section polynomials and using the virtual work principle. The exact analytical expressions of the elemental internal force vector and tangent matrix of the unified beam model are also provided. Several problems are addressed, including uniaxial tension, bending of a slender structure, compression of a three-dimensional block, and a thick pinched cylinder. The proposed model is compared with analytical solutions and literature results whenever possible. It is demonstrated that, although 1 D, the present CUF-based finite element can address simple to complex nonlinear hyperelastic phenomena, depending on the theory approximation order.

Initial experience with brachytherapy treatment adjuvant to surgical resection of keloid scars in the pediatric population. / Experiencia inicial del tratamiento braquiterápico en coadyuvancia a la resección quirúrgica de cicatrices queloideas en población pediátrica.

OBJECTIVES: The treatment of keloid scars is based on multiple lines of therapy, with varying levels of efficacy(1), and there is currently no single treatment that guarantees cure and prevents recurrence. In the pediatric population, the treatments used are not standardized, and there is insufficient evidence to support efficacy and complications. The objective of this study was to analyze the patients who required brachytherapy as an adjuvant to surgical resection in recurrent keloid scars. MATERIALS AND METHODS: A retrospective analysis of patients diagnosed with keloids and undergoing adjuvant brachytherapy in our institution was carried out, while assessing efficacy and implementation in our treatment protocol for keloid scarring. RESULTS: After various therapeutic lines, 4 patients aged 9-17 years old with recurrent keloid scars around the ear and eligible for adjuvant brachytherapy - administered after surgical resection, in two sessions - were studied and followed up for up to 18-21 months. CONCLUSIONS: Despite our limited experience in the use of adjuvant brachytherapy, the results obtained to date support its efficacy, as reported in the literature. We therefore consider its inclusion in the treatment of keloid scars that have recurred after other treatments to be appropriate.

OBJETIVOS: El tratamiento de las cicatrices queloideas se basa en múltiples líneas terapéuticas, con diferentes niveles de eficacia(1), sin existir actualmente un tratamiento que garantice su curación y prevenga su recurrencia. En la población pediátrica los tratamientos empleados no están estandarizados y no hay evidencia suficiente que avale su eficacia y sus complicaciones. Este trabajo tiene como objetivo analizar los pacientes que han precisado braquiterapia coadyuvante a la resección quirúrgica en cicatrices queloideas recidivantes. MATERIAL Y METODOS: Análisis retrospectivo de los pacientes diagnosticados en nuestro centro de cicatriz queloidea, en los que se realizó braquiterapia coadyuvante, valorando su eficacia y su implementación en nuestro protocolo de tratamiento de la cicatriz queloidea. RESULTADOS: Se estudiaron 4 pacientes entre 9-17 años con cicatrices queloideas a nivel auricular, recidivantes a varias líneas terapéuticas, que fueron candidatos para el uso de braquiterapia coadyuvante, administrada posterior a la resección quirúrgica, en dos sesiones, se realizó seguimiento hasta 18-21 meses. CONCLUSIONES: A pesar de nuestra limitada experiencia en el uso de la braquiterapia coadyuvante, los resultados obtenidos hasta la fecha avalan su eficacia, de acuerdo con lo publicado en la literatura. Consideramos adecuada su inclusión en el tratamiento de cicatrices queloideas recidivantes a otros tratamientos.

Neurosarcoidosis in acute inpatient rehabilitation: a case study.

INTRODUCTION: Sarcoidosis affects the nervous system in ~5-10% of cases. Common presentations for neurosarcoidosis can include facial nerve neuropathy, optic neuritis, meningitis, seizure muscle weakness, and paresthesia. Due to the complex treatment of neurosarcoidosis, few reports exist involving patients' recovery in an acute rehabilitation setting. CASE PRESENTATION: We describe a case of neurosarcoidosis affecting the cervical and thoracic spinal cord in an individual with known Chiari I malformation and associated syrinx decompression. DISCUSSION: We discuss the diagnosis and treatment of neurosarcoidosis and clinical implications of acute rehabilitation on functional recovery.

Techniques and results of palate fistula repair following palatoplasty: a 234-case multicenter study. / Técnicas y resultados de reparación de fístulas palatinas pospalatoplastia: estudio multicéntrico de 234 casos.

INTRODUCTION: Palate fistula is the most frequent complication following palatoplasty. The objectives of this study were: to describe the most widely used repair techniques; to study results and recurrence rate; to analyze potentially predictive recurrence variables; and to assess whether a specific technique is superior according to fistula size and location. MATERIALS AND METHODS: Retrospective study of patients undergoing palate fistula repair in 7 healthcare facilities from 2008 to 2018. All facilities had at least 20 new cases of cleft lift and palate annually (range: 20-80), with a fistula incidence of 14% (range: 1.5-20%). Minimum follow-up was 1 year. 8 variables were collected for statistical analysis purposes. RESULTS: 234 fistula patients underwent surgery. Most fistulas occurred in complete bilateral cleft lift and palate (Veau type IV). The most frequent location was the hard palate (Pittsburgh types IV and V (63.2%)), and fistulas were mostly large (42.1%) and medium (39.5%). The most frequent repair technique was re-palatoplasty (34.2%). Recurrence rate was 22%. The multivariate analysis demonstrated more recurrences in re-palatoplasty repaired type III fistulas in patients over 3 years old. CONCLUSION: A tendency towards using flap repair in large hard palate fistulas, re-palatoplasty in medium hard palate and soft and hard palate junction fistulas, and local flaps or re-palatoplasty in small fistulas at any location was observed. However, it could not be statistically demonstrated whether a specific repair technique was superior in different clinical situations.

INTRODUCCION: La fístula palatina es la complicación más frecuente tras una palatoplastia. Los objetivos de este estudio fueron: describir las técnicas de reparación más frecuentemente empleadas; estudiar los resultados y la tasa de recidiva; analizar posibles variables predictivas de recidiva y valorar la posible superioridad de una determinada técnica según el tamaño y la localización de la fístula. MATERIAL Y METODO: Estudio retrospectivo de pacientes operados de fístulas palatinas desde 2008 hasta 2018 en 7 centros. Todos operaban al menos 20 casos nuevos de fisuras labiopalatinas al año (rango 20-80) con una incidencia de fístulas de 14% (rango: 1,5-20%). El seguimiento mínimo fue de 1 año. Se recogieron 8 variables para el análisis estadístico. RESULTADOS: Se operaron 234 pacientes con fístulas. La mayoría ocurrieron en fisuras labiopalatinas bilateral completa (tipo IV de Veau). La localización más frecuente fue el paladar duro (tipos IV y V de Pittsburgh (63,2%) y la mayoría fueron grandes (42,1%) y medianas (39,5%). La técnica de reparación más frecuente fue la repalatoplastia (34,2%). La tasa de recidiva fue del 22%. El análisis multivariante mostró más recidivas en fístulas tipo III reparadas con repalatoplastia, en mayores de 3 años. CONCLUSION: Se observó una tendencia a utilizar más reparación con colgajo en fístulas grandes del paladar duro, repalatoplastia en fístulas medianas de paladar duro y de la unión, y colgajos locales o repalatoplastia en fístulas pequeñas en cualquier localización, pero no se pudo demostrar estadísticamente la superioridad de una técnica reparadora concreta en diferentes situaciones clínicas.

Static and free-vibration analyses of dental prosthesis and atherosclerotic human artery by refined finite element models.

Static and modal responses of representative biomechanical structures are investigated in this paper by employing higher-order theories of structures and finite element approximations. Refined models are implemented in the domain of the Carrera unified formulation (CUF), according to which low- to high-order kinematics can be postulated as arbitrary and, eventually, hierarchical expansions of the generalized displacement unknowns. By using CUF along with the principle of virtual work, the governing equations are expressed in terms of fundamental nuclei of finite element arrays. The fundamental nuclei are invariant of the theory approximation order and can be opportunely employed to implement variable kinematics theories of bio-structures. In this work, static and free-vibration analyses of an atherosclerotic plaque of a human artery and a dental prosthesis are discussed. The results from the proposed methodologies highlight a number of advantages of CUF models with respect to already established theories and commercial software tools. Namely, (i) CUF models can represent correctly the higher-order phenomena related to complex stress/strain field distributions and coupled mode shapes; (ii) bio-structures can be modeled in a component-wise sense by only employing the physical boundaries of the problem domain and without making any geometrical simplification. This latter aspect, in particular, can be currently accomplished only by using three-dimensional analysis, which may be computationally unbearable as complex bio-systems are considered.

[Pulmonary function assessment in juvenile idiopathic scoliosis managed with posterior instrumentation with a sublaminar hook system]. / Evaluación de la función pulmonar en escoliosis idiopática del adolescente manejado con instrumentación posterior con sistema de ganchos sublaminares.

INTRODUCTION: Scoliosis is a spine deformity diagnosed using Cobbs method when the AP X-ray view shows an angulation greater than 10º. Scoliosis exceeding 50º results in restrictive pulmonary alterations. Surgical management improves the angulation and the pulmonary restrictive process. The pre- and post-operative pulmonary function values were compared using spirometry. MATERIAL AND METHODS: 27 patients of both genders, ages 11-15 years, underwent corrective surgery using posterior instrumentation with sublaminar hooks, rods and posterolateral arthrodesis. Spirometry was done preoperatively and six months after the surgery. Patients without a postoperative spirometry and/or a postoperative episode of pulmonary infection were excluded. The pre- and postoperative Cobb index was calculated. Spirometry: lung function at forced vital capacity (FVC) and forced expiratory volume in one second (FEV1). Descriptive statistics, Student t test. RESULTS: Females, 78%; males, 22%; 13.7 ± 1.22 years. Cobb method 40 - 110º, preoperative angle 64.48 ± 17.79º and postoperative angle 30.44 ± 10.90º. There were no 0º values. Lung function: preoperative FVC for the values of the scoliosis curve (p 0.0001) and significant marginal FEV1 (p = 0. Baseline: 40.6-122.0%, mean: 76.3 ± 18.8%, postoperative: 40.75-112.6%, mean: 76.5 ± 16.8%. Preoperative FEV1: 39.8-111.59%, mean: 73.9 ± 16.8%, postoperative: 42.86-120.79%, mean: 69.7 ± 16.5. The difference was statistically significant, 0.064). CONCLUSIONS: The sublaminar hook system with a posterior approach provides improvement of the idiopathic scoliosis curve of adolescents assessed with the Cobb method. It stops the progression of lung function impairment, with a significant improvement in forced expiratory volume in one second.

La escoliosis es una deformidad de la columna vertebral; se diagnostica por el método de Cobb presentando una angulación mayor de 10º en proyección radiográfica anteroposterior. Produce alteraciones pulmonares de tipo restrictivo en angulaciones mayores a 50º. Su manejo puede ser quirúrgico, mejorando la angulación y el proceso restrictivo pulmonar. Se comparó la función pulmonar pre- y postquirúrgica con espirometría.

Evaluación de la función pulmonar en escoliosis idiopática del adolescente manejado con instrumentación posterior con sistema de ganchos sublaminares / Pulmonary function assessment in juvenile idiopathic scoliosis managed with posterior instrumentation with a sublaminar hook system

Resumen: Introducción: La escoliosis es una deformidad de la columna vertebral; se diagnostica por el método de Cobb presentando una angulación mayor de 10o en proyección radiográfica anteroposterior. Produce alteraciones pulmonares de tipo restrictivo en angulaciones mayores a 50o. Su manejo puede ser quirúrgico, mejorando la angulación y el proceso restrictivo pulmonar. Se comparó la función pulmonar pre- y postquirúrgica con espirometría. Material y métodos: 27 pacientes, cirugía correctiva mediante instrumentación posterior con ganchos sublaminares, barras y artrodesis posterolateral. Ambos géneros. 11-15 años. Espirometría prequirúrgica y postquirúrgica a los seis meses. Fueron excluidos quienes carecían de espirometría postquirúrgica y/o aquéllos con evento infeccioso pulmonar postquirúrgico. Índice de Cobb, pre- y postquirúrgico. Espirometría: función pulmonar, la capacidad vital forzada (VCF) y el volumen espiratorio forzado en un segundo (FEV1). Estadística descriptiva, t Student. Resultados: Femenino 78% y masculino 22%, 13.7 ± 1.22 años. Método de Cobb 40 a 110o; prequirúrgico, 64.48 ± 17.79o y postquirúrgico, 30.44 ± 10.90o. No hubo valor de 0o. Capacidad pulmonar: prequirúrgico VCF para los valores de la curva de escoliosis (p < 0.0001) y significativa marginal para FEV1 (p = 0; inicial 40.6-122.0%, media 76.3 ± 18.8%; postquirúrgico 40.75-112.6%, media 76.5 ± 16.8%. FEV1 prequirúrgico 39.83-111.59%, media 73.9 ± 16.8%; post­quirúrgico 42.86-120.79%, media de 69.7 ± 16.5. Diferencia estadísticamente significativa 0.064). Conclusiones: El sistema de ganchos sublaminares en abordaje posterior ofrece mejoría de la curva de la escoliosis idiopática del adolescente evaluada por método de Cobb, detiene el progreso del deterioro de la función pulmonar, con mejoría significativa para el volumen espiratorio forzado en un segundo.

Abstract: Introduction: Scoliosis is a spine deformity diagnosed using Cobb's method when the AP X-ray view shows an angulation greater than 10o. Scoliosis exceeding 50o results in restrictive pulmonary alterations. Surgical management improves the angulation and the pulmonary restrictive process. The pre- and post-operative pulmonary function values were compared using spirometry. Material and methods: 27 patients of both genders, ages 11-15 years, underwent corrective surgery using posterior instrumentation with sublaminar hooks, rods and posterolateral arthrodesis. Spirometry was done preoperatively and six months after the surgery. Patients without a postoperative spirometry and/or a postoperative episode of pulmonary infection were excluded. The pre- and postoperative Cobb index was calculated. Spirometry: lung function at forced vital capacity (FVC) and forced expiratory volume in one second (FEV1). Descriptive statistics, Student t test. Results: Females, 78%; males, 22%; 13.7 ± 1.22 years. Cobb method 40 - 110o, preoperative angle 64.48 ± 17.79o and postoperative angle 30.44 ± 10.90º. There were no 0o values. Lung function: preoperative FVC for the values of the scoliosis curve (p < 0.0001) and significant marginal FEV1 (p = 0. Baseline: 40.6-122.0%, mean: 76.3 ± 18.8%, postoperative: 40.75-112.6%, mean: 76.5 ± 16.8%. Preoperative FEV1: 39.8-111.59%, mean: 73.9 ± 16.8%, postoperative: 42.86-120.79%, mean: 69.7 ± 16.5. The difference was statistically significant, 0.064). Conclusions: The sublaminar hook system with a posterior approach provides improvement of the idiopathic scoliosis curve of adolescents assessed with the Cobb method. It stops the progression of lung function impairment, with a significant improvement in forced expiratory volume in one second.

Increased Nicotiana tabacum fitness through positive regulation of carotenoid, gibberellin and chlorophyll pathways promoted by Daucus carota lycopene ß-cyclase (Dclcyb1) expression.

Carotenoids, chlorophylls and gibberellins are derived from the common precursor geranylgeranyl diphosphate (GGPP). One of the enzymes in carotenoid biosynthesis is lycopene ß-cyclase (LCYB) that catalyzes the conversion of lycopene into ß-carotene. In carrot, Dclcyb1 is essential for carotenoid synthesis in the whole plant. Here we show that when expressed in tobacco, increments in total carotenoids, ß-carotene and chlorophyll levels occur. Furthermore, photosynthetic efficiency is enhanced in transgenic lines. Interestingly, and contrary to previous observations where overexpression of a carotenogenic gene resulted in the inhibition of the synthesis of gibberellins, we found raised levels of active GA4 and the concommitant increases in plant height, leaf size and whole plant biomass, as well as an early flowering phenotype. Moreover, a significant increase in the expression of the key carotenogenic genes, Ntpsy1, Ntpsy2 and Ntlcyb, as well as those involved in the synthesis of chlorophyll (Ntchl), gibberellin (Ntga20ox, Ntcps and Ntks) and isoprenoid precursors (Ntdxs2 and Ntggpps) was observed. These results indicate that the expression of Dclcyb1 induces a positive feedback affecting the expression of isoprenoid gene precursors and genes involved in carotenoid, gibberellin and chlorophyll pathways leading to an enhancement in fitness measured as biomass, photosynthetic efficiency and carotenoid/chlorophyll composition.

The application of antimicrobial photodynamic therapy (aPDT) in dentistry: a critical review.

In recent years there have been an increasing number of in vitro and in vivo studies that show positive results regarding antimicrobial photodynamic therapy (aPDT) used in dentistry. These include applications in periodontics, endodontics, and mucosal infections caused by bacteria present as biofilms. Antimicrobial photodynamic therapy is a therapy based on the combination of a non-toxic photosensitizer (PS) and appropriate wavelength visible light, which in the presence of oxygen is activated to produce reactive oxygen species (ROS). ROS induce a series of photochemical and biological events that cause irreversible damage leading to the death of microorganisms. Many light-absorbing dyes have been mentioned as potential PS for aPDT and different wavelengths have been tested. However, there is no consensus on a standard protocol yet. Thus, the goal of this review was to summarize the results of research on aPDT in dentistry using the PubMed database focusing on recent studies of the effectiveness aPDT in decreasing microorganisms and microbial biofilms, and also to describe aPDT effects, mechanisms of action and applications.

Gastroprotective potential of Buddleja scordioides Kunth Scrophulariaceae infusions; effects into the modulation of antioxidant enzymes and inflammation markers in an in vivo model.

ETHNOPHARMACOLOGICAL RELEVANCE: A common plant used to treat several gastric disorders is Buddleja scordioides Kunth, commonly known as salvilla. AIM OF THE STUDY: To detect inflammatory markers, in order to evaluate the gastroprotective potential of salvilla infusions, as this could have beneficial impact on the population exposed to gastric ulcers and colitis. MATERIALS AND METHODS: The present work attempted infusions were prepared with B. scordioides (1% w/w) lyophilized and stored. Total phenolic content and GC-MS analysis were performed. Wistar rats were divided into five groups (n=8), a negative vehicle control, an indomethacin group, and three experimental groups, named preventive, curative, and suppressive. All rats were sacrificed under deep ether anesthesia (6h) after the last oral administration of indomethacin/infusion. The rat stomachs were promptly excised, weighed, and chilled in ice-cold and 0.9% NaCl. Histological analysis, nitrites quantification and immunodetection assays were done. RESULTS: B. scordioides infusions markedly reduced the visible hemorrhagic lesions induced by indomethacin in rat stomachs, also showed down-regulation of COX2, IL-8 and TNFα and up-regulation of COX-1 with a moderate down-regulation of NFkB and lower amount of nitrites. However, this behavior was dependent on the treatment, showing most down-regulation of COX-2, TNFα and IL-8 in the curative treatment; more down-regulation of NF-kB in the preventive treatment; and more up-regulation of COX-1 for the suppressor and preventive treatments. CONCLUSION: The anti-inflammatory potential of B. scordioides infusions could be related with the presence of polyphenols as quercetin in the infusion and how this one is consumed.

Genetic differentiation of a primitive teleost, the African bonytongue Heterotis niloticus, among river basins and within a floodplain river system in Benin, West Africa.

Examination of eight microsatellite DNA loci revealed high levels of genetic differentiation among populations of the African bonytongue Heterotis niloticus from three river basins that constitute important fishing areas in Benin. Low levels of population genetic differentiation were detected within the Ouemé-Sô River floodplain system. These results have important implications for conservation and management of stocks supporting important inland fisheries in West Africa.

Histopathologic, immunohistochemical and ultrastructural features of a granular cell tumour in an Australian parakeet (Melopsittacus undulatus).

An adult male Australian parakeet (Melopsittacus undulatus) presented a firm nodular lesion in the lateral metacarpal region of the right wing. Microscopically, there were neoplastic cells, round and polyhedral in shape, with abundant, slightly eosinophilic granular cytoplasm; they were strongly periodic-acid Schiff-positive and resistant to diastase digestion. Some groups of neoplastic cells were immunopositive for smooth muscle actin and desmin. There was no immunopositivity for S-100 protein, CD68 and cytokeratin. Ultrastructurally, the neoplastic cells were round and polygonal in shape, and they were characterized by abundant cytoplasm with numerous homogeneous osmophilic bodies covered by an electron-dense membrane (lysosomes). The histopathologic, immunohistochemical and ultrastructural features of the neoplastic tissue are consistent with a granular cell tumour, which has been described in different animal species and anatomic locations; however, this seems to be an infrequent neoplasm in Australian parakeets. The immunopositivity of the neoplastic cells for smooth muscle actin and desmin, as well as slight positivity for muscle with Masson's trichrome, suggest that this is a tumour of myogenic origin.

Does perfusion computed tomography facilitate clinical decision making for thrombolysis in unselected acute patients with suspected ischaemic stroke?

BACKGROUND: Despite use in clinical practice and major positive trials of thrombolysis, non-contrast computed tomography (NCCT) is not sensitive for identifying penumbral tissue in acute stroke. This study evaluated how physiological imaging using CT perfusion (CTP) could add to the diagnostic utility of an NCCT and inform clinical decisions regarding thrombolysis. METHODS: Forty imaging datasets containing NCCT and CTP were retrospectively identified from a cohort of consecutive acute stroke patients. Two sets of observers (n = 6) and a neuroradiologist evaluated the images without knowledge of clinical symptoms. Inter-observer agreement was calculated using the κ statistic for identifying acute ischaemic change on NCCT: perfusion abnormalities (namely cerebral blood volume, cerebral blood flow and time to peak), and penumbral tissue on perfusion maps obtained by two image processing algorithms. RESULTS: Inter-rater agreement was moderate (κ = 0.54) for early ischaemic change on NCCT. Perfusion maps improved this to substantial for cerebral blood volume (κ = 0.67) and to almost perfect for time to peak (κ = 0.87) and cerebral blood flow (κ = 0.87). The agreement for qualitative assessment of penumbral tissue was substantial to perfect for images obtained using the two different perfusion algorithms. Overall, there was a high rate of decision to thrombolyse based on NCCT (81.25%). CTP strengthened the decision to thrombolyse based on NCCT in 38.3% of cases. It negatively influenced the decision in 14.6% of cases, this being significantly more common in experienced observers (p = 0.02). CONCLUSIONS: We demonstrate that the qualitative evaluation of CTP produces near perfect inter-observer agreement, regardless of the post-processing method used. CTP is a reliable, accessible and practical imaging modality that improves confidence in reaching the appropriate diagnosis. It is particularly useful for less experienced clinicians, to arrive at a physiologically informed treatment decision.

Cerebral arterial compliance in patients with internal carotid artery disease.

BACKGROUND: A decrease in arterial compliance of the internal carotid artery has been associated with an increased risk in ipsilateral ischaemic stroke. However, so far, no technique has been validated to monitor the compliance of intracerebral arteries (Ca) in patients with carotid artery disease. In this study, we sought to monitor Ca in patients with unilateral symptomatic disease and to determine its variations during changes in PaCO(2). METHODS: We studied 18 patients with unilateral symptomatic internal carotid artery stenosis >50% or occlusion. Patients underwent monitoring of arterial blood pressure (ABP) and middle cerebral artery cerebral blood flow velocities (CBFV) during baseline, hyperventilation and 5%CO(2) inhalation. Ca was calculated from pulsatile amplitudes of ABP and Cerebral arterial blood volume, extracted from the CBFV waveform using a new mathematical model. RESULTS: At baseline, the decrease in Ca on the diseased side was correlated with the degree of stenosis (r = -0.35; P = 0.01). During hypocapnia, Ca was lower compared to baseline on the normal side (P = 0.004) and on the diseased side (P = 0.04). Ca reactivity, reflecting the changes in Ca per changes in 1 mmHg PaCO(2), was lower on the diseased side between baseline and hypocapnia (3.4 vs. 2.6%; P = 0.04). During hypercapnia, no changes in Ca on the diseased (P = 0.8) nor on the normal sides (P = 0.2) were observed. CONCLUSIONS: The decrease in cerebral arterial compliance the side of stenosis/occlusion was correlated with the severity of the internal carotid artery disease. Further studies are needed to determine whether Ca may improve the prediction of ischaemic events in symptomatic and asymptomatic patients.

Metabolic syndrome and cerebral vasomotor reactivity.

BACKGROUND AND PURPOSE: Metabolic syndrome has been proposed as a risk factor for stroke and transient ischaemic attack. One pathophysiological mechanism could be impairment of endothelial function. Thus, we hypothesized that cerebral vasomotor reactivity would be decreased in patients with metabolic syndrome, compared to patients without metabolic syndrome. METHODS: In this retrospective analysis, 83 consecutive patients (aged 59.19 ± 15.98; 33 women) underwent Doppler examination for carotid artery disease including bi-hemispherical vasomotor reactivity assessment using transcranial Doppler monitoring. Vasomotor reactivity data were analyzed from the hemisphere with no or low-grade carotid stenosis (<40%). Cerebral vasomotor reactivity was calculated as percent increase in mean flow velocity per mmHg pCO(2) during 2 min of 5% CO(2) inhalation delivered by anesthesia mask (normal if ≥ 2%/mmHg). Univariate and multivariable linear regression models were used to determine factors, including metabolic syndrome, that were independently associated with pathologic vasomotor reactivity. RESULTS: After adjusting for the presence of contralateral carotid stenosis and ipsilateral stroke in the multivariable model, metabolic syndrome was independently associated with lower vasomotor reactivity values (2.27 ± 1.24% vs. 2.68 ± 1.37; ß = -0.258, P = 0.033). In this model, there was no association of cerebral vasomotor reactivity with age, gender, race, cardiac disease, current statin therapy, or small vessel disease. CONCLUSIONS: Our findings suggest that impaired cerebral vasomotor reactivity may be a mediator of stroke in patients with metabolic syndrome, a syndrome affecting a significant and growing proportion of the population. A prospective longitudinal study is warranted to study the cerebral haemodynamic effect of metabolic syndrome.