ECG-synchronized cardiac MR imaging: method and evaluation

An electrocardiographic (ECG) sensing and gating device compatible with a 0.35-tesla (T) magnetic resonance (MR) imager has been developed and used to produce 802 MR images of the heart in 30 patients. The instrument consists of an isolated acquisition module, an electrically floating preamplifier, and a monitor gating module. Two spin-echo images were acquired for each of five, 0.7-cm thick, transaxial sections from the base to the apex of the heart during each ECG-synchronized imaging run. Image quality was assessed in a blind study by two investigators, on a scale from 0 to 3, as diagnostic [2-3] or nondiagnostic [0-1]. There was agreement in 91.4% of their assessments of diagnostic images (68.1% of the images studied). Resolution of heart anatomy on the MR images was adversely affected by prolonged spin-echo time delay, imaging in late diastole, image acquisition at the cardiac apex, irregular triggering, and artifacts. The synchronization of gradient pulses to the ECG at 0.35 T appears safe for patients, permits diagnostic resolution of images, allows image acquisition at distinct points during the cardiac cycle, and enables monitoring of patients during imaging.     

一氧化氮的脊髓作用对局麻药耐药反应的影响

目的 探讨一氧化氮（NO）在脊髓的作用与局麻药外围神经阻滞耐药的关系。方法 ①鼠随机分为3组，组1腹腔和蛛网膜下腔注射生理盐水（NS），组2接受NS腹腔和5个剂量之一的L－NAME蛛网膜下腔给药，组3接受5个测量之一的L－NAME腹腔和NS蛛网膜下腔注射。L－NAME剂量是1，10，100，1000，10000nmol(n=9)；②蛛网膜下腔注射NS，L－NAME或D－NMAE 1000nmol(n=9).③蛛网膜下腔注射NS，精氨酸25μmol跟 随L－NAME1000nmol或NS（n=9)。随后用3％氯普鲁卡因0．3ml依次3次阻滞鼠坐骨神经，用热板、触觉复位、单足跳和肌力测试记录阻滞时间。结果 L－NAME蛛网膜下腔和腹腔给药阻止局麻药耐药的作用与剂量有关，蛛网膜下腔ED50明显低于腹腔ED50比率超过20倍。D－NAME对局麻耐药无显著影响（P＞0．05），精氨酸显著增加局麻药耐药（P＜0．05）并抑制L－NAME抗耐药的作用。结论 该实验表明L－NAME通过NO脊髓受体作用抑制局麻药耐药反应的发生。     

Murine JAK3 is preferentially expressed in hematopoietic tissues and lymphocyte precursor cells

To elucidate the role of cytokine receptor signal transduction in T- cell development, we have investigated the expression pattern and biochemical characteristics of the murine Janus family tyrosine kinase, JAK3. Previous studies have shown that JAK3 is expressed in lymphoid and myeloid tumor cell lines and in a small number of lymphoid tissues. To further characterize JAK3 expression, we used a quantitative polymerase chain reaction approach to compare JAK3 mRNA levels at multiple stages of T-cell differentiation and in a broad range of mouse tissues. These studies, in conjunction with analyses of JAK3 protein expression, show that the highest levels of JAK3 are in adult, 2-week- old, and fetal thymus, followed by somewhat lower levels in bone marrow, spleen, fetal liver, and adult CD4-CD8- thymocytes. We also show that different forms of JAK3 mRNA arise by alternative splicing. Finally, our biochemical studies show that the JAK3 kinase domain, but not the pseudo-kinase domain, has tyrosine kinase activity and, furthermore, that JAK3 kinase activity is abolished by an amino acid substitution of the conserved lysine in the kinase domain (K851R). These studies show that JAK3 expression is profoundly skewed to hematopoietic and lymphoid precursor cells, strongly suggesting a role for JAK3 in hematopoiesis and T- and B-cell development.     

Hepatosplenic T-cell lymphoma: a distinct clinicopathologic entity of cytotoxic gamma delta T-cell origin

We identified eight cases of T-cell lymphoma with evidence of a gamma delta phenotype over a 13-year period. Seven of these cases conformed to a distinct clinicopathologic entity of hepatosplenic gamma delta T- cell lymphoma. Nearly all of these patients were young adult males (five of seven), with a median age at presentation of 20 years. They presented with marked hepatosplenomegaly, without lymphadenopathy or significant peripheral blood lymphocytosis. Thrombocytopenia was seen in all patients, and five of seven were mildly anemic. The clinical course was aggressive, and despite multiagent chemotherapy, the median survival duration was less than 1 year. The morphologic findings were uniform; a monomorphic population of medium-sized lymphoid cells with moderately clumped chromatin and a rim of pale cytoplasm infiltrated the sinusoids of the spleen, liver, and bone marrow. The cells had a characteristic immunophenotype: CD2+, CD3+, CD4-, CD5-, CD7+, CD16+, CD57-, CD25-, T-cell receptor (TCR)delta +, beta F1-. CD8 was positive in four of seven cases tested, and CD56 was positive in five of six. All cases expressed the cytotoxic granule-associated protein, TIA1, but perforin was detected in only one case. All cases with assessable DNA had a TCR gamma gene rearrangement, and lacked Epstein-Barr virus sequences. Isochromosome 7q was identified in two cases with cytogenetic information. The one case of cutaneous gamma delta T-cell lymphoma differed in its clinical manifestations, histologic appearance, and immunophenotype. We conclude that hepatosplenic gamma delta T-cell lymphoma is a distinct clinicopathologic entity derived from cytotoxic gamma delta T cells, and should be distinguished from other lymphomas of T-cell and natural-killer cell (NK)-like T-cell derivation.     

Paediatric nodal marginal zone B‐cell lymphadenopathy of the neck: a Haemophilus influenzae‐driven immune disorder?

Many hyperplasias and lymphomas of marginal zone B‐cells are associated with infection. We identified six children and one adolescent with cervical lymphadenopathy showing prominent polyclonal nodal marginal zone hyperplasia (pNMZH) and four adolescents with monoclonal paediatric nodal marginal zone lymphoma (pNMZL). The clonality status was assessed using BIOMED‐2‐IG PCR analysis. Haemophilus influenzae was identified in all six cases of pNMZH that could be tested by direct culture (N = 3) or a very sensitive PCR for the H. influenzae gyrase gene in frozen materials (N = 5). H. influenzae was not detected in three pNMZLs and 28 non‐specific reactive cervical lymph nodes of age‐matched controls, except for a single control node that was obtained during oropharyngeal surgery for a cleft palate showing very low copy numbers of H. influenzae. pNMZH patients were younger than pNMZL patients (median age 12 versus 21 years). pNMZH showed a prominent nodular appearance with variable fibrosis without acute inflammation. Within the nodules, the expanded germinal centres and variably sized marginal zones were colonized by activated B‐cells with weak expression of IgD and lack of CD10 and/or BCL6 expression. Some areas showed skewed light chain expression in plasma cells (4/5 cases lambda). In four cases tested, this was confirmed by flow cytometry for surface Ig (3/4 cases lambda). In contrast, pNMZL showed more extensive expansion of marginal zones by centrocytoid cells and often expression of BCL2 protein. Several H. influenzae strains are known to interact with the constant part of IgD on human B‐cells, leading to their polyclonal proliferation and activation. We speculate that in vivo stimulation of IgD+ marginal zone B‐cells by this bacterium may be implicated in this particular lymphadenopathy that should be distinguished from monoclonal pNMZL. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Surveillance of active human cytomegalovirus infection in hematopoietic stem cell transplantation (HLA sibling identical donor): search for optimal cutoff value by real-time PCR

Background  

Human cytomegalovirus (CMV) infection still causes significant morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). Therefore, it is extremely important to diagnosis and monitor active CMV infection in HSCT patients, defining the CMV DNA levels of virus replication that warrant intervention with antiviral agents in order to accurately prevent CMV disease and further related complications.