White matter thresholds for ischemic penumbra and infarct core in patients with acute stroke: CT perfusion study.

Purpose: To prospectively determine the parameters derived at admission computed tomographic (CT) perfusion imaging admission that best differentiate ischemic white matter that recovers from that which infarcts, with the latter retrospectively defined at a CT examination performed without contrast material (unenhanced CT) 5-7 days after the event.

Materials And Methods: Ethics committee approval and informed consent were obtained. Thirty patients with stroke underwent unenhanced CT, CT angiography, and CT perfusion studies at admission.

When to expect negative diffusion-weighted images in stroke and transient ischemic attack.

Background And Purpose: The frequency of DWI negative cerebral ischemia and clinical factors associated with such a circumstance is not well understood.

Methods: We performed MRI including diffusion-weighted imaging (DWI) in patients with stroke and transient ischemic attack (TIA) within 24 hours of symptom onset and again at 30 days.

Results: Of 401 patients, 103 (25.

Activin signals via SMAD2/3 between germ and somatic cells in the human fetal ovary and regulates kit ligand expression.

Ovarian germ cell survival is dependent upon the formation of primordial follicles, which occurs during fetal life in the human. Activin contributes to germ cell proliferation and survival at this time. SMADs2 and 3 are central elements in the activin signalling pathway and thus indicate sites of activin action.

Conserved and divergent patterns of expression of DAZL, VASA and OCT4 in the germ cells of the human fetal ovary and testis.

Background: Germ cells arise from a small group of cells that express markers of pluripotency including OCT4. In humans formation of gonadal compartments (cords in testis, nests in ovary) takes place during the 1st trimester (6-8 weeks gestation). In the 2nd trimester germ cells can enter meiotic prophase in females whereas in males this does not occur until puberty.

Environmental toxicant-induced germ cell apoptosis in the human fetal testis.

Background: Disorders of the male reproductive system are increasing in prevalence. The term testicular dysgenesis syndrome emphasizes the importance of developmental influences on the aetiology of conditions including cryptorchidism, testicular germ cell cancer and reduced spermatogenesis. Men whose mothers smoked during pregnancy have lower sperm production.

Dramatic MRI improvement with refractory neurosarcoidosis treated with infliximab.

Background: Neurosarcoidosis is often a devastating, refractory condition without definite pharmacotherapies beyond corticosteroids.

Aim: To describe a case of steroid-refractory neurosarcoidosis with a marked clinical and radiological response to infliximab.

Methods: We describe the case of a young female patient with biopsy-proven neurosarcoidosis leading to gait failure.

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

Background And Purpose: Early ischemic changes on noncontrast CT in acute stroke include both hypoattenuation and brain swelling, which may have different pathophysiological significance.

Methods: 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).

Diffusion-weighted imaging-negative patients with transient ischemic attack are at risk of recurrent transient events.

Background And Purpose: Among patients presenting with a transient ischemic attack (TIA), some clinical features predispose to recurrent TIA, whereas others predispose to subsequent strokes. We assessed the implication of negative diffusion-weighted imaging on a baseline MRI in predicting subsequent TIA.

Methods: We prospectively studied patients presenting in the emergency department within 12 hours of a TIA (motor or speech).

Incidence of radiocontrast nephropathy in patients undergoing acute stroke computed tomography angiography.

Background And Purpose: Minimal research has evaluated the renal safety of emergent computed tomography angiography (CTA) procedures, consecutive contrast medium application, and the long-term outcome in acute stroke patients. We investigated the incidence of contrast-induced renal impairment in these populations.

Methods: We retrospectively reviewed patients with acute stroke syndrome who received a CTA of the brain with or without the neck within 24 hours from onset of symptoms.

Effects of monobutyl and di(n-butyl) phthalate in vitro on steroidogenesis and Leydig cell aggregation in fetal testis explants from the rat: comparison with effects in vivo in the fetal rat and neonatal marmoset and in vitro in the human.

Background: Certain phthalates can impair Leydig cell distribution and steroidogenesis in the fetal rat in utero, but it is unknown whether similar effects might occur in the human.

Objectives: Our aim in this study was to investigate the effects of di(n-butyl) phthalate (DBP), or its metabolite monobutyl phthalate (MBP), on testosterone production and Leydig cell aggregation (LCA) in fetal testis explants from the rat and human, and to compare the results with in vivo findings for DBP-exposed rats. We also wanted to determine if DBP/MBP affects testosterone production in vivo in the neonatal male marmoset.

Systematic review of associations between the presence of acute ischemic lesions on diffusion-weighted imaging and clinical predictors of early stroke risk after transient ischemic attack.

Background And Purpose: Early risk of stroke after a transient ischemic attack can be reliably predicted with risk scores based on clinical features of the patient and of the ischemic event, but it is unclear how these features correlate with findings on brain imaging.

Methods: We performed a systematic review of the literature and identified all previous studies which reported patient characteristics and the nature of transient ischemic attack symptoms in relation to appearances on diffusion-weighted imaging (DWI). We then performed a meta-analysis of the associations between the components of the risk scores and positive DWI.

Acute ischemic lesions of varying ages predict risk of ischemic events in stroke/TIA patients.

Background: Multiple ischemic lesions identified by diffusion-weighted imaging (DWI) have been shown to predict high risk of future ischemic events. However, the importance of lesion age has not been factored into this risk. Our goal was to evaluate whether the presence of ischemic lesions of varying ages identified by DWI and apparent diffusion coefficient (ADC) suggests a higher risk of future ischemic events.

Gonadotrope and thyrotrope development in the human and mouse anterior pituitary gland.

Genes and orthologous intrinsic and extrinsic factors critical for embryonic pituitary gonadotrope and thyrotrope cell differentiation have been identified mainly in rodents, but data on the human are very limited. In human fetal pituitaries examined between 14 and 19 weeks of gestation using immunofluorescent confocal microscopy, we found that most fetal gonadotropes expressed alpha-GSU, LHbeta, and FSHbeta gonadotropin subunits while almost no cells expressed alpha-GSU and LHbeta alone. Gonadotropes expressing alpha-GSU and FSHbeta only were detected in both male and female pituitaries, increasing in proportion to total gonadotropes in both males and females from 14 (approximately 4.

Identification of penumbra and infarct in acute ischemic stroke using computed tomography perfusion-derived blood flow and blood volume measurements.

Background And Purpose: We investigated whether computed tomography (CT) perfusion-derived cerebral blood flow (CBF) and cerebral blood volume (CBV) could be used to differentiate between penumbra and infarcted gray matter in a limited, exploratory sample of acute stroke patients.

Methods: Thirty patients underwent a noncontrast CT (NCCT), CT angiography (CTA), and CT perfusion (CTP) scan within 7 hours of stroke onset, NCCT and CTA at 24 hours, and NCCT at 5 to 7 days. Twenty-five patients met the criteria for inclusion and were subsequently divided into 2 groups: those with recanalization at 24 hours (n=16) and those without (n=9).

Differential expression of the Bhmp39 major outer membrane proteins of Brachyspira hyodysenteriae.

The enteric, anaerobic spirochete Brachyspira hyodysenteriae is the causative agent of swine dysentery, a severe mucohemorrhagic diarrheal disease of pigs that has economic significance in every major pork-producing country. Recent investigation into potential vaccine candidates has focused on the outer membrane proteins of B. hyodysenteriae.

MR angiography compared to conventional selective angiography in acute stroke.

Background And Purpose: Accuracy of intracranial magnetic resonance angiography (MRA) and reliability of interpretation are not well established compared to conventional selective catheter angiography. The purpose of this study was to determine the accuracy of MRA in evaluation of intracranial vessels in acute stroke and transient ischemic attack (TIA) patients

Methods: Twenty-nine patients (seven females, 22 males; median age 53) with acute stroke or TIA were enrolled into the study. All patients underwent both MRA using a 3 T clinical magnet and conventional angiography within 48 hours.

Extent of early ischemic changes on computed tomography (CT) before thrombolysis: prognostic value of the Alberta Stroke Program Early CT Score in ECASS II.

Background And Purpose: The significance of early ischemic changes (EICs) on computed tomography (CT) to triage patients for thrombolysis has been controversial. The Alberta Stroke Program Early CT Score (ASPECTS) semiquantitatively assesses EICs within the middle cerebral artery territory using a10-point grading system. We hypothesized that dichotomized ASPECTS predicts response to intravenous thrombolysis and incidence of secondary hemorrhage within 6 hours of stroke onset.

Cerebral microhemorrhages predict new disabling or fatal strokes in patients with acute ischemic stroke or transient ischemic attack.

Background And Purpose: Cerebral microhemorrhages (MHs) are common among patients presenting with acute ischemic stroke and may predict both subsequent ischemic and hemorrhagic strokes.

Methods: We prospectively studied patients with and without MHs presenting within 12 hours of their ischemic stroke or transient ischemic attack (TIA). A magnetic resonance (MR) scan was performed within 24 hours of symptom(s) onset.

Perfusion MRI abnormalities in speech or motor transient ischemic attack patients.

Background And Purpose: Transient ischemic attack (TIA) patients may deteriorate rapidly. MRI is being increasingly used to assess such patients. One possible mechanism of neurological worsening is the presence of perfusion abnormalities.

Alberta Stroke Program Early CT Score in acute stroke triage.

In the setting of acute stroke evaluation, CT is accessible, versatile, available, inexpensive, and, most importantly, fast. Its use extends beyond that of identifying intracranial hemorrhage. We have emphasized the importance of clinical assessment, supported by a systematic approach to unenhanced CT interpretation using the Alberta Stroke Program Early CT Score for determining the extent of early ischemic change.

Silent ischemia in minor stroke and TIA patients identified on MR imaging.

Background: In a general population of patients with stroke, the rate of new MRI lesions at 1 week was much higher than expected. With patients with minor stroke and TIA having a higher risk of recurrent clinical events, the authors examined whether patients with minor stroke and TIA also had a high rate of asymptomatic lesions on repeat MRI scanning.

Methods: Patients with minor stroke and TIA presenting within 12 hours of symptom onset with a NIH Stroke Scale score less than six, who had a baseline MRI and a 1-month follow-up, were enrolled in this study.

"Clinical-CT mismatch" and the response to systemic thrombolytic therapy in acute ischemic stroke.

Background And Purpose: Mismatch between clinical deficits and imaging lesions in acute stroke has been proposed as a method of identifying patients who have hypoperfused but still have viable brain, and may be especially apt to respond to reperfusion therapy. We explored this hypothesis using a combined database including 4 major clinical trials of intravenous (IV) thrombolytic therapy.

Methods: To determine what the radiological correlates of a "matched" functional deficit are, we calculated the relationship between the ASPECT score of the 24-hour (follow-up) CT scan and the 24-hour National Institutes of Health Stroke Scale (NIHSS) score on the subsample with ASPECT scores performed at this time (n=820).

Triaging transient ischemic attack and minor stroke patients using acute magnetic resonance imaging.

We examined whether the presence of diffusion-weighted imaging (DWI) lesions and vessel occlusion on acute brain magnetic resonance images of minor stroke and transient ischemic attack patients predicted the occurrence of subsequent stroke and functional outcome. 120 transient ischemic attack or minor stroke (National Institutes of Health Stroke Scale < or = 3) patients were prospectively enrolled. All were examined within 12 hours and had a magnetic resonance scan within 24 hours.