Correction to: Treatment of adults with intracranial hemorrhage on apixaban or rivaroxaban with prothrombin complex concentrate products

Journal of Thrombosis and Thrombolysis - In the original publication of the article, unfortunately the given name and family name of the author’s in the author group were inadvertently...     

Signalling pathways induced by protease-activated receptors and integrins in T cells

Recent characterization of the thrombin receptor indicates that it plays a role in T-cell signalling pathways. However, little is known regarding the signalling events following stimulation of additional members of the protease-activated receptor (PAR) family, i.e. PAR2 and PAR3. Most of the postligand cascades are largely unknown. Here, we illustrate that in Jurkat T-leukaemic cells, activation of PAR1, PAR2 and PAR3 induce tyrosine phosphorylation of Vav1. This response was impaired in Jurkat T cells deficient in p56lck (JCaM1.6). Activation of PARs also led to an increase in tyrosine phosphorylation of ZAP-70 and SLP-76, two key proteins in T-cell receptor (TCR) signalling. We also demonstrated that p56lck is meaningful for integrin signalling. Thus, JCaM1.6 cells exhibited a marked reduction in their adherence to fibronectin-coated plates, as compared to the level of adherence of Jurkat T cells. While the phosphorylation of Vav1 in T cells is augmented following adhesion, no additional increase was noted following treatment of the adhered cells with PARs. Altogether, we have identified key components in the postligand-signalling cascade of PARs and integrins. Furthermore, we have identified Lck as a critical and possibly upstream component of PAR-induced Vav1 phosphorylation, as well as integrin activation, in Jurkat T cells.     

Effect of caffeine on cerebral blood flow response to somatosensory stimulation.

Despite caffeine's wide consumption and well-documented psychoactive effects, little is known regarding the effects of caffeine on neurovascular coupling. In the present study, we evaluated the effects of caffeine, an adenosine receptor antagonist, on intracerebral arterioles in vitro and subsequently, on the pial circulation in vivo during cortical activation induced by contralateral sciatic nerve stimulation (SNS). In our in vitro studies, we utilized isolated intracerebral arterioles to determine the effects of caffeine (10 or 50 micromol/L) on adenosine-induced vasodilatation. At the lower concentration, caffeine was without effect, but at the higher concentration, caffeine produced significant attenuation. In our in vivo studies, we determined the cerebrospinal fluid (CSF) caffeine concentrations at 15, 30, and 60 mins after intravenous administration of 5, 10 and 40 mg/kg. At the latter two concentrations, CSF levels exceeded 10 micromol/L. We then evaluated the pial arteriolar response during cortical activation caused by contralateral SNS after administering caffeine intravenously (0, 5, 10, 20 30, and 40 mg/kg). The pial circulation was observed through a closed cranial window in chloralose-anesthetized Sprague-Dawley rats. The contralateral sciatic nerve was isolated, positioned on silver electrodes and stimulated for 20 secs (0.20 V, 0.5 ms, and 5 Hz). Arteriolar diameter was quantified using an automated video dimension analyzer. Contralateral SNS resulted in a 23.8% +/-3.9% increase in pial arteriolar diameter in the hindlimb sensory cortex under control conditions. Intravenous administration of caffeine at the lowest dose studied (5 mg/kg) had no effect on either resting arteriolar diameter or SNS-induced vasodilatation. However, at higher doses (10, 20, 30, and 40 mg/kg, intravenously), caffeine significantly (P < 0.05; n = 6) attenuated both resting diameter and cerebral blood flow (CBF) responses to somatosensory stimulation. Intravenous administration of theophylline (10, 20, and 40 mg/kg), another adenosine receptor antagonist, also significantly reduced SNS-induced vasodilatation in a dose-dependent manner. Hypercarbic vasodilatation was unaffected by either caffeine or theophylline. The results of the present study show that caffeine significantly reduces cerebrovascular responses to both adenosine and to somatosensory stimulation and supports a role of adenosine in the regulation of CBF during functional neuronal activity.     

Enhanced synaptic integration of adult-born neurons in the olfactory bulb of lactating mothers

One of the most dramatic events during the life of adult mammals is the transition into motherhood. This transition is accompanied by specific maternal behaviors, displayed by the mother, that ensure the survival and the well-being of her offspring. The execution of these behaviors is most likely accompanied by plastic changes in specific neuronal circuits, but these are still poorly defined. In this work, we studied the mammalian olfactory bulb (OB), which has been shown to be an essential brain region for maternal behaviors in mice. In the OB, we focused on adult-born neurons, which are continuously incorporated into the circuit during adulthood, thus providing a potential substrate for heightened plasticity after parturition. We analyzed the dynamics and morphological characteristics of adult-born granule cells (abGCs), innervating the OB of primiparous lactating mothers, shortly after parturition as well as in naive females. In vivo time-lapse imaging of abGCs revealed that dendritic spines were significantly more stable in lactating mothers compared with naive virgins. In contrast, spine stability of resident GCs remained unchanged after parturition. In addition, while spine size distribution of abGCs was approximately similar between mothers and naive virgins, the spine density of abGCs was lower in lactating mothers and the density of their presynaptic components was higher. These structural features are indicative of enhanced integration of adult-born neurons into the bulbar circuitry of lactating mothers. This enhanced integration may serve as a cellular mechanism, supporting changes in olfactory coding of new mothers during their first days following parturition.     

Use of a combination of class III and class Ic antiarrhythmic agents in patients with electrical storm

STUDY OBJECTIVE: To determine the efficacy of the combination of class III and class Ic antiarrhythmic agents in suppressing an electrical storm in patients with and without a transvenous implantable cardioverter-defibrillator (ICD). DESIGN: Retrospective medical record review. SETTING: Arrhythmia service of an academic medical center in Zerifin, Israel. PATIENTS: Ten patients who experienced an electrical storm that was not effectively treated with amiodarone or sotalol monotherapy between December 15, 1999, and June 13, 2007. MEASUREMENTS AND MAIN RESULTS: The medical records of 152 patients who received an ICD during the study period were reviewed. Twenty patients experienced an electrical storm, an arrhythmia defined as more than two episodes of hemodynamically unstable ventricular tachycardia during a 24- hour period. Ten of the 20 patients responded favorably to amiodarone or sotalol monotherapy (class III antiarrhythmics), but in 10 patients, the combination of a class III and a class Ic antiarrhythmic agent was needed to effectively eliminate the electrical storm. Of the 10 patients who required both agents, two (20%) developed an electrical storm before implantation of their ICD. In another patient who had ongoing ischemia, ventricular tachycardia recurred, but the drug combination decreased the number of ventricular arrhythmia episodes. One patient with dilated cardiomyopathy had one recurrence of ventricular tachycardia, which was terminated with antitachycardia pacing. Three patients died during a mean +/- SD follow-up of 8.7 +/- 9.9 months. CONCLUSION: Electrical storm can be acutely treated with the combination of a class III and a class Ic antiarrhythmic agent when a class III agent alone is insufficient and when radiofrequency ablation is not an option. Patients receiving this drug combination can be discharged from the hospital only if they have an ICD.     

The haematopoietic specific signal transducer Vav1 is expressed in a subset of human neuroblastomas

Vav1 is a signal transducer protein expressed exclusively in the haematopoietic system, where it plays a pivotal role in growth factor-induced differentiation and proliferation. Vav1 couples tyrosine kinase signals with the activation of the Rho/Rac GTPases, leading to cell differentiation and/or proliferation. Vav1 was originally detected as an oncogene, but its involvement in human malignancies has not been reported thus far. We report here that Vav1 is expressed in a neuroblastoma cell line, SK-N-MC. Molecular analysis indicated that there are no gross rearrangements or mutations in the Vav1 gene in SK-N-MC cells. Vav1 protein from SK-N-MC cells was similar to wild-type Vav1 in apparent molecular weight, phosphorylation state, and ability to associate with active EGFR. We also analysed the expression of Vav1 in 42 specimens of human neuroblastoma. Vav1 was expressed in the majority of these tumours. Our results suggest that Vav1 may play a role in the neoplastic process in a subset of neuroblastomas.     

Woringer–Kolopp (Pagetoid Reticulosis) disease successful response to bexarotene gel

Woringer–Kolopp (WK) is a rare subtype of cutaneous T‐cell lymphoma (CTCL) with limited treatment options. Bexarotene gel is a topical retinoid used in the treatment of CTCL. This report describes three female patients (mean age 66 years) with WK disease who had an effective treatment response to bexarotene 1% gel. This treatment could provide a safe alternative to other current treatment modalities which have higher risks of potential adverse effects and lack of access to other conventional treatments such as light therapy.     

A review of DRESS-associated myocarditis

DRESS (drug rash with eosinophilia and systemic symptoms), also known as drug-induced hypersensitivity syndrome, is a severe, systemic drug reaction most commonly associated with aromatic anticonvulsants and sulfonamides. Patients typically present with fever, facial edema, cervical lymphadenopathy and a morbilliform eruption, which may progress to erythroderma. Hematologic abnormalities are a hallmark of the condition, including eosinophilia and atypical lymphocytosis. Visceral organ involvement typically manifests as hepatic dysfunction but may include lymphadenopathy, nephritis, interstitial pneumonitis, and myocarditis. Five to ten percent of patients with DRESS die from systemic complications, making timely recognition and treatment essential to prevent life-threatening manifestations. Myocarditis is a fatal and under-recognized manifestation of DRESS, which may occur long after the initial diagnosis. We review the literature of previously reported cases of DRESS and myocardial involvement, highlighting the presenting symptoms associated with cardiac involvement, treatments used, and the outcome for each patient. In addition, we offer an algorithm for early diagnosis, treatment, and subsequent monitoring of these patients.