Morphological classification of penetrating artery pontine infarcts and association with risk factors and prognosis: The SPS3 trial.

BACKGROUND: Pontine infarcts are common and often attributed to small vessel disease ("small deep infarcts") or basilar branch atherosclerosis ("wedge shaped"). A well-described morphological differentiation using magnetic resonance images has not been reported. Furthermore, whether risk factors and outcomes differ by morphology, or whether infarct morphology should guide secondary prevention strategy, is not well characterized. METHODS: All participants in the Secondary Prevention of Small Subcortical Strokes Study with magnetic resonance imaging -proven pontine infarcts were included. Infarcts were classified as well-circumscribed small deep (small deep infarct, i.e. lacunar), paramedian, atypical paramedian, or other based on diffusion-weighted imaging, T2/fluid-attenuated inversion recovery, and T1-magnetic resonance images. Inter-rater reliability was high (90% agreement, Cohen's kappa = 0.84). Clinical and radiologic features independently associated with small deep infarct versus paramedian infarcts were identified (multivariable logistic regression). Differences in stroke risk and death were assessed using Cox proportional hazards. RESULTS: Of the 3020 patients enrolled, 644 had pontine infarcts; 619 images were available: 302(49%) small deep infarct, 245 (40%) paramedian wedge, 35 (6%) atypical paramedian, and 37 (6%) other. Among vascular risk factors, only smoking (OR 2.1, 95% CI 1.3-3.3) was independently associated with small deep infarct versus paramedian infarcts; on neuroimaging, old lacunes on T1/fluid-attenuated inversion recovery (OR 1.8, 1.3-2.6) and intracranial stenosis (any location) ≥50% (OR 0.62, 0.41-0.96). Small deep infarct versus paramedian was not predictive of either recurrent stroke or death, and there was no interaction with assigned treatment. CONCLUSIONS: Pontine infarcts can be reliably classified based on morphology using clinical magnetic resonance images. Few risk factors differed between small deep infarct and paramedian infarcts with no differences in recurrent stroke or mortality. There was no difference in response to different antiplatelet or blood pressure treatment strategies between these two groups. REGISTRATION: http://www.clinicaltrials.gov/NCT00059306.

Summary of evidence-based guideline: periprocedural management of antithrombotic medications in patients with ischemic cerebrovascular disease: report of the Guideline Development Subcommittee of the American Academy of Neurology.

OBJECTIVE: To assess evidence regarding periprocedural management of antithrombotic drugs in patients with ischemic cerebrovascular disease. The complete guideline on which this summary is based is available as an online data supplement to this article. METHODS: Systematic literature review with practice recommendations. RESULTS AND RECOMMENDATIONS: Clinicians managing antithrombotic medications periprocedurally must weigh bleeding risks from drug continuation against thromboembolic risks from discontinuation. Stroke patients undergoing dental procedures should routinely continue aspirin (Level A). Stroke patients undergoing invasive ocular anesthesia, cataract surgery, dermatologic procedures, transrectal ultrasound-guided prostate biopsy, spinal/epidural procedures, and carpal tunnel surgery should probably continue aspirin (Level B). Some stroke patients undergoing vitreoretinal surgery, EMG, transbronchial lung biopsy, colonoscopic polypectomy, upper endoscopy and biopsy/sphincterotomy, and abdominal ultrasound-guided biopsies should possibly continue aspirin (Level C). Stroke patients requiring warfarin should routinely continue it when undergoing dental procedures (Level A) and probably continue it for dermatologic procedures (Level B). Some patients undergoing EMG, prostate procedures, inguinal herniorrhaphy, and endothermal ablation of the great saphenous vein should possibly continue warfarin (Level C). Whereas neurologists should counsel that warfarin probably does not increase clinically important bleeding with ocular anesthesia (Level B), other ophthalmologic studies lack the statistical precision to make recommendations (Level U). Neurologists should counsel that warfarin might increase bleeding with colonoscopic polypectomy (Level C). There is insufficient evidence to support or refute periprocedural heparin bridging therapy to reduce thromboembolic events in chronically anticoagulated patients (Level U). Neurologists should counsel that bridging therapy is probably associated with increased bleeding risks as compared with warfarin cessation (Level B). The risk difference as compared with continuing warfarin is unknown (Level U).

The STARD9/Kif16a kinesin associates with mitotic microtubules and regulates spindle pole assembly.

During cell division, cells form the microtubule-based mitotic spindle, a highly specialized and dynamic structure that mediates proper chromosome transmission to daughter cells. Cancer cells can show perturbed mitotic spindles and an approach in cancer treatment has been to trigger cell killing by targeting microtubule dynamics or spindle assembly. To identify and characterize proteins necessary for spindle assembly, and potential antimitotic targets, we performed a proteomic and genetic analysis of 592 mitotic microtubule copurifying proteins (MMCPs). Screening for regulators that affect both mitosis and apoptosis, we report the identification and characterization of STARD9, a kinesin-3 family member, which localizes to centrosomes and stabilizes the pericentriolar material (PCM). STARD9-depleted cells have fragmented PCM, form multipolar spindles, activate the spindle assembly checkpoint (SAC), arrest in mitosis, and undergo apoptosis. Interestingly, STARD9-depletion synergizes with the chemotherapeutic agent taxol to increase mitotic death, demonstrating that STARD9 is a mitotic kinesin and a potential antimitotic target.

TLR8-dependent TNF-(alpha) overexpression in Fanconi anemia group C cells.

Tumor necrosis factor alpha (TNF-alpha) production is abnormally high in Fanconi anemia (FA) cells and contributes to the hematopoietic defects seen in FA complementation group C-deficient (Fancc(-/-)) mice. Applying gene expression microarray and proteomic methods to studies on FANCC-deficient cells we found that genes encoding proteins directly involved in ubiquitinylation are overrepresented in the signature of FA bone marrow cells and that ubiquitinylation profiles of FA-C and complemented cells were substantially different. Finding that Toll-like receptor 8 (TLR8) was one of the proteins ubiquitinylated only in mutant cells, we confirmed that TLR8 (or a TLR8-associated protein) is ubiquitinylated in mutant FA-C cells and that TNF-alpha production in mutant cells depended upon TLR8 and the canonical downstream signaling intermediates interleukin 1 receptor-associated kinase (IRAK) and IkappaB kinase-alpha/beta. FANCC-deficient THP-1 cells and macrophages from Fancc(-/-) mice overexpressed TNF-alpha in response to TLR8 agonists but not other TLR agonists. Ectopically expressed FANCC point mutants were capable of fully complementing the mitomycin-C hypersensitivity phenotype of FA-C cells but did not suppress TNF-alpha overproduction. In conclusion, FANCC suppresses TNF-alpha production in mononuclear phagocytes by suppressing TLR8 activity and this particular function of FANCC is independent of its function in protecting the genome from cross-linking agents.

Comparison of two dosages of thymoglobulin used as a short-course for induction in kidney transplantation.

Thymoglobulin is used effectively as an induction agent in kidney transplantation, but the optimal dose is not well established. We evaluated the degree and durability of T-cell clearances with two different thymoglobulin regimens in adult kidney transplant recipients (KTR). Seven KTR received a 3-day thymoglobulin-based induction of 1.0 mg/kg/day while nine received 1.5 mg/kg/day, in addition to maintenance immunosuppression. Lymphocyte subsets were monitored for 6 months. Renal function, infections and malignancies were monitored for 24 months. T-cell subsets were significantly lower by day 30 with the thymoglobulin 1.5 mg/kg/day regimen when compared with the 1.0 mg/kg/day regimen; this trend was sustained at 6-month (CD3(+): 438 +/- 254 vs. 1001 +/- 532 cells/mm(3), P = 0.016). Renal function between the two groups was not significantly different at 6- and 24-months post-transplant. One case of BK Virus viremia in the 1.5 mg/kg/day thymoglobulin group was detected. No acute rejection episodes, cytomegalovirus infections, or malignancies were noted in either group. Thymoglobulin induction was efficacious in both groups, but with a significantly sustained T-cell clearance in the 1.5 mg/kg/day regimen. A more profound T-cell clearance within the first 6 months postinduction therapy may translate into a decreased risk of immunological injury and improved long-term outcome after kidney transplantation.

Novel use of the BD FACS SPA to automate custom monoclonal antibody panel preparations for immunophenotyping.

BACKGROUND: The effective and accurate diagnosis of hematologic malignancies relies on flow cytometric immunophenotyping. Selected combinations of monoclonal antibodies (mAbs) arranged in multicolor panels allow for the accurate definition of normal and abnormal hematologic cell populations. The most time-consuming and crucial step in the staining process involves dispensing combinations of multiple mAbs into their appropriate staining tubes. This step is prone to error, requires concentration and accuracy, and is dependent on technologist experience. The Becton Dickinson BioScience (BD) FACS Sample Prep Assistant (SPA) is touted as a breakthrough in automated in vitro diagnostic sample preparation. The SPA is designed to automate BD MultiTESk and BD TriTest lyse/no-wash assays. However, because most cases in our laboratory require tedious application of unique four-color mAb cocktails for leukemia and lymphoma testing, we wondered whether the SPA would be helpful in accurately dispensing these mixtures. METHODS: The mAb panels were prepared by the SPA in two separate timed runs and on separate days. Eleven specimens (nine from patients and two from normal volunteers) were split and stained with four-color cocktails created by the SPA or manually. The percentage of positive (%P) cells and mean fluorescent intensity for each mAb pair were determined. These values were plotted against each other and correlation values were calculated. To quantitate timesaving in the laboratory, two technologists prepared individually the same mAb panels and were timed. RESULTS: The correlation between the two methods was high; r(2) was 0.988 for 158 %P antigen pairs; no bias between the manual and robotic methods was detected with the Wilcoxon rank test. Bland-Altman analysis indicated no obvious relation between the difference and the mean of %P cells, suggesting that the SPA successfully dispensed antibodies for leukemia/lymphoma panels. The two methods may be interchangeable, although the limited sample size prohibits this conclusion from Bland-Altman statistics alone. In addition, one possible error was detected in the SPA-prepared panels. The SPA averaged 65 min/run, the experienced technologist 12.95 min/run, and the inexperienced technologist 54.9 min/run. CONCLUSIONS: SPA dispensing time was twice the average manual dispensing time; however, SPA use was completely automated and freed the technologist to perform other tasks. SPA use permitted preemptive preparation of mAb panels and thus streamlined processing; however, the cost of the assay and the amount of reagent waste increased. It is certain that software modifications by BD could decrease the SPA reagent dispense time and decrease the cost associated with reagent waste when the SPA is used in this novel fashion.

Differential expression of cell surface antigens on subsets of CD4+ and CD8+ T cells.

BACKGROUND: The assessment of relative antigen density on T cell subsets is a feature of antigen expression that is infrequently characterized. Defining phenotypic differences is a first step in understanding associated differences in function. Additionally, a better understanding of T cell heterogeneity may aid in clinical diagnoses. MATERIAL/METHODS: To further elucidate phenotypic differences of T cell subsets, and begin to determine what information relative antigen density contributes to immunology, we analyzed normal human peripheral blood T cells for a variety of immunophenotypic (CD2, CD3, CD4, CD5, CD7, CD8, CD45RA, CD45RO, TCR alpha beta) and light scatter characteristics using 6 color flow cytometry. T-cell leukemia specimens were also analyzed. RESULTS: Our data show that statistically significant immunophenotypic differences exist between subsets of human CD4 and CD8 T cells. Normal T cells express different levels of relative antigen density for some antigens compared to malignant T cells. CONCLUSIONS: Significant differences are seen in relative antigen density for several cell surface markers between CD4+ and CD8+ T cells. Neither donor source nor flow cytometric calibration account for these differences. The data are applied to specimens from patients with T-lineage acute lymphoblastic leukemia to show how antigen density can be used clinically in aiding to diagnose disease. The data presented here can be used to further investigate these cell populations for functional differences.

Cardioembolia cerebral: diagnostico y tratamiento / Cardiogenic brain embolism: diagnosis and treatment

Por lo general el diagnostico de cardioembolia se basa en la evidencia circunstancial. La ecocardiografia tiene un rendimiento de utilidad limitado y se debe reservar para pacientes jovenes o de edad avanzada con cardiopatia clinica. La profiliaxis primaria con anticoagulantes parecer estar indicada en pacientes con infarto agudo de la pared anterior del miocardio, enfermedad valvular reumatica o cardiomiopatia dilatada y, tal vez, para aquellos con fibrilacion auricular cronica no valvular. La profilaxis secundaria es recomendada para las mismas afecciones y, quiza, para el prolapso de la valvula mitral. El tratamiento anticoagulante es garantizable si despues de 24 horas de la embolia cerebral la tomografia computadorizada excluye un infarto grande