Diagnostic and prognostic value of early MR Imaging vessel signs in hyperacute stroke patients imaged <3 hours and treated with recombinant tissue plasminogen activator

BACKGROUND AND PURPOSE: Analogous to the CT hyperattenuated vessel sign (HMCAS), MR imaging may show hypo- or hyperintense vessels in acute ischemic stroke (AIS) patients. We assessed the diagnostic and prognostic strength of early MR imaging vessel signs in AIS patients treated with intravenous thrombolysis (IVT) within 3 hours of the onset of symptoms. METHODS: We studied AIS patients both treated with IVT and stroke MR imaged within 3 hours of the onset of symptoms and at 2 hours and 24 hours after treatment. We assessed the presence or absence of early vessel signs (hyperintense fluid-attenuated inversion recovery sign [FLAIR HVS]; gradient-echo susceptibility vessel sign [GRE SVS]) compared with a combined MR angiography/perfusion-weighted imaging reference and their strength for predicting clinical outcome (favorable vs. poor, independent vs. dependent, or dead, death), recanalization (by clot composition and flow), and hemorrhage in uni- and multivariate analysis. RESULTS: Fifty-six patients (age range, 76 years +/- 13 years; median National Institutes of Health stroke scale score [NIHSSS], 11) met the inclusion criteria. Forty-four patients (78.6%) had a vessel occlusion at baseline; 22 of them (50%) recanalized. Nineteen patients (33.9%) suffered some form of intracranial hemorrhage (ICH), 24 patients (42.9%) had an independent outcome, 18 patients (32.1%) a favorable outcome, and 14 patients died. Compared with our combined reference for vessel status PWI/MRA, the sensitivities of CT HMCAS, FLAIR HVS, and GRE SVS were 40%, 66%, and 34%, respectively, and improved during the hours that followed. Localization was accurately reflected by FLAIR HVS but not by GRE SVS. Only NIHSSS and age were independent predictors for recanalization and all clinical outcomes in multiple logistic regression analysis. CONCLUSION: Although early vessel signs can be helpful in the diagnosis of intravascular disease, they do not independently predict recanalization, ICH, or any of the three clinical outcomes in a multivariate logistic regression model. Thrombus composition as reflected by signal intensity characteristics on GRE and FLAIR does not predict the therapeutic effect of IVT.     

Breastfeeding promotion and support services in local community health centers

This study had a two-fold goal. First, to document services relating to breastfeeding promotion and support in CLSCs and, second, to examine the links between the delivery of such services and certain organizational and environmental factors. The data were collected in 1999 by means of a self-administered questionnaire sent to all CLSCs in Quebec. The responses indicated that breastfeeding is most often systematically addressed at prenatal meetings and through integrated perinatal programs. CLSCs belonging to a multipurpose establishment are more apt to integrate the issue of breastfeeding into perinatal activities; in addition, many of them offer breastfeeding activities considered innovative, although the average for this kind of activities is fairly low (33%). In addition, CLSCs that collaborate more closely with community organizations and those that spend more on perinatal programs are the ones that most often offer "innovative" breastfeeding activities.     

Epstein-Barr virus (EBV) reactivation in allogeneic stem-cell transplantation: relationship between viral load, EBV-specific T-cell reconstitution and rituximab therapy

BACKGROUND: Monitoring of Epstein-Barr virus (EBV) reactivation after allogeneic hematopoietic stem-cell transplantation markedly improved with quantitative real-time polymerase chain reaction amplification of EBV DNA and visualization of EBV-specific CD8+ T cells with peptide-human leukocyte antigen (HLA) class I tetramers. We decided to combine these methods to evaluate posttransplant EBV reactivation and rituximab therapy. METHODS: We followed 56 patients treated with an HLA-genoidentical sibling (n=32), an HLA-matched unrelated donor (MUD, n=19), or an unrelated cord-blood transplant (n=5). EBV DNA was quantified in plasma and in peripheral blood mononuclear cells (PBMC). Patient CD8+ T cells were stained with a panel of eight tetramers. RESULTS: EBV DNA was detected in half of the patients, mainly in the MUD group (17/19). In 19 patients, viral DNA was detected only in the cellular compartment. All patients who controlled reactivation without rituximab and despite a viral load of greater than 500 genome equivalents (gEq)/150,000 PBMC mounted an EBV-specific CD8+ T-cell response in greater than 1.4% of CD3+CD8+ T cells. Plasmatic EBV genome was found in nine patients preceded by a high cellular viral load. Three of these patients controlled the reactivation before or without the introduction of rituximab, and they all developed a significant and increasing EBV-specific T-cell response. Patients with EBV-specific T cells at the onset of reactivation controlled viral reactivation without rituximab. CONCLUSION: This study emphasizes the benefit of an early and close monitoring of EBV reactivation and CD8+-specific immune responses to initiate rituximab only when necessary and before the immune response becomes overwhelmed by the viral burden.     

A molecular modeling study of the effect of surface chemistry on the adsorption of a fibronectin fragment spanning the 7-10th type III repeats

Although it is well documented that proteins adsorb onto biomaterial surfaces, relatively little is quantitatively understood about the effects of adsorption on protein orientation and conformation. Because this is the primary determining factor of protein bioactivity, the ability to accurately predict a protein's orientation and conformation following adsorption will be essential for the rational design of biomaterial surfaces to control biological responses. Force field-based computational chemistry methods provide an excellent means to theoretically address this issue, with the nontrivial requirement that the force field must be tailored to appropriately represent protein adsorption behavior. Accordingly, we have modified an existing force field (CHARMm) based on semiempirical quantum-mechanical peptide adsorption data to enable it to simulate protein adsorption behavior in an implicit aqueous environment. This modified force field was then applied to predict the adsorption behavior of the 7-10 type III repeats of fibronectin on functionalized surfaces. Predicted changes in adsorption energy and adsorption-induced conformation as a function of surface chemistry were found to correlate well with experimentally observed trends for these same systems. This work represents a first attempt towards the development of a molecular mechanics force field that is specifically parameterized to accurately simulate protein adsorption to biomaterial surfaces.     

Comparison of MRI and CT for detection of acute intracerebral hemorrhage

Context  Noncontrast computed tomography (CT) is the standard brain imaging study for the initial evaluation of patients with acute stroke symptoms. Multimodal magnetic resonance imaging (MRI) has been proposed as an alternative to CT in the emergency stroke setting. However, the accuracy of MRI relative to CT for the detection of hyperacute intracerebral hemorrhage has not been demonstrated. Objective  To compare the accuracy of MRI and CT for detection of acute intracerebral hemorrhage in patients presenting with acute focal stroke symptoms. Design, Setting, and Patients  A prospective, multicenter study was performed at 2 stroke centers (UCLA Medical Center and Suburban Hospital, Bethesda, Md), between October 2000 and February 2003. Patients presenting with focal stroke symptoms within 6 hours of onset underwent brain MRI followed by noncontrast CT. Main Outcome Measures  Acute intracerebral hemorrhage and any intracerebral hemorrhage diagnosed on gradient recalled echo (GRE) MRI and CT scans by a consensus of 4 blinded readers. Results  The study was stopped early, after 200 patients were enrolled, when it became apparent at the time of an unplanned interim analysis that MRI was detecting cases of hemorrhagic transformation not detected by CT. For the diagnosis of any hemorrhage, MRI was positive in 71 patients with CT positive in 29 (P<.001). For the diagnosis of acute hemorrhage, MRI and CT were equivalent (96% concordance). Acute hemorrhage was diagnosed in 25 patients on both MRI and CT. In 4 other patients, acute hemorrhage was present on MRI but not on the corresponding CT—each of these 4 cases was interpreted as hemorrhagic transformation of an ischemic infarct. In 3 patients, regions interpreted as acute hemorrhage on CT were interpreted as chronic hemorrhage on MRI. In 1 patient, subarachnoid hemorrhage was diagnosed on CT but not on MRI. In 49 patients, chronic hemorrhage, most often microbleeds, was visualized on MRI but not on CT. Conclusion  MRI may be as accurate as CT for the detection of acute hemorrhage in patients presenting with acute focal stroke symptoms and is more accurate than CT for the detection of chronic intracerebral hemorrhage.      

Theoretical analysis of adsorption thermodynamics for hydrophobic peptide residues on SAM surfaces of varying functionality

At a fundamental level, protein adsorption to a synthetic surface must be strongly influenced by the interaction between the peptide residues presented by the protein's surface (primary protein structure) and the functional groups presented by the synthetic surface. In this study, semi-empirical molecular modeling was used along with experimental wetting data to theoretically approach protein adsorption at this primary structural level. Changes in enthalpy, entropy, and Gibbs free energy were calculated as a function of residue-surface separation distance for the adsorption of individual hydrophobic peptide residues (valine, leucine, phenylalanine) on alkanethiol self-assembled monolayers on gold [Au-S(CH(2))(15)-X; X = CH(3), OH, NH(3)(+), COO(-)]. The results predict that the adsorption of each type of hydrophobic residue is energetically favorable and entropy dominated on a methyl-terminated hydrophobic surface, energetically unfavorable and enthalpy dominated on a hydroxyl-terminated neutral hydrophilic surface, and very slightly favorable to unfavorable and enthalpy dominated on charged surfaces. These theoretical results provide a basis for understanding some of the fundamental effects governing protein adsorption to synthetic surfaces. This level of understanding is needed for the proactive design of surfaces to control protein adsorption and subsequent cellular response for both implant and tissue engineering applications.     

Induction chemotherapy for breast carcinoma: predictive markers and relation with outcome

Induction chemotherapy provides an excellent model for evaluation of potential predictive factors. We studied expression of SBR grade, estrogen (ER) and progesterone (PR) receptors, HER2, Ki67 and P53 on core biopsies before and after chemotherapy in a series of 115 patients, who received anthracycline-based induction chemotherapy for primary breast cancer. HER2 overexpression independently predicted response to neoadjuvant anthracycline-based chemotherapy. Patients with HER2-positive status are 4.54 times more likely to have a pathological complete response than those with negative status (p<0.005). HER2, ER and PR status were stable during treatment. P53 and Ki67 significantly increased after treatment (p<0.005 and p<0.0005). SBR grade, proliferation markers, ER evaluated before and after treatment predicted disease-free survival (DFS) in univariate analysis.     

The preventive and health promotion services for infants,children and youth. What is problematic for clients of the CLSCs

OBJECTIVE: This article presents the results of a survey on preventive and health promotion (PHP) services provided by Quebec CLSCs for infants, children and youth. Two dimensions of services are examined: the diversity of PHP issues addressed and the type of clientele targeted by the CLSC team. METHODS: Questionnaire survey. RESULTS: Although identified a priori as public health priorities, many PHP issues remain less often addressed by CLSCs. This is particularly the case for activities aimed at children and youth as compared to infants. In addition, the data show that CLSC teams are less inclined to target specific clienteles; when they do so, it is more often in the context of services for infants. DISCUSSION: This study is important in that it constitutes one of the first efforts to systematically document PHP services for infants, children, and youth. In shedding new light on intervention sectors that need to be reinforced, these results should help managers and policymakers as they reflect on the role of PHP services in CLSCs within the context of health reform.     

Stewart-Treves syndrome following mastectomy for breast cancer: a case report

INTRODUCTION: Stewart-Treves syndrome has been defined by the eponymous authors as a lymphangiosarcoma in a setting of postmastectomy upper extremity lymphoedema. EXEGESIS: The clinical record of one patient with Stewart-Treves syndrome is analyzed. The primary angiosarcoma of the skin represented by a purple nodule occurred on a chronic lymphoedematous arm following radical mastectomy and axillary lymph node dissection for breast carcinoma performed 9 years earlier. Immunohistochemistry tests formally eliminated epithelial cutaneous metastasis and produced evidence in favour of conjunctive vascular tissue origin of the tumor. CONCLUSION: Conservative surgery for breast cancer, application of axillary sentinel node biopsy in the lymphatic staging and prevention of arm lymphoedema should reduce the incidence of this syndrome.