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。     

Coupled oscillation and spinning of photothermal particles in Marangoni optical traps

Cyclic actuation is critical for driving motion and transport in living systems, ranging from oscillatory motion of bacterial flagella to the rhythmic gait of terrestrial animals. These processes often rely on dynamic and responsive networks of oscillators—a regulatory control system that is challenging to replicate in synthetic active matter. Here, we describe a versatile platform of light-driven active particles with interaction geometries that can be reconfigured on demand, enabling the construction of oscillator and spinner networks. We employ optically induced Marangoni trapping of particles confined to an air–water interface and subjected to patterned illumination. Thermal interactions among multiple particles give rise to complex coupled oscillatory and rotational motions, thus opening frontiers in the design of reconfigurable, multiparticle networks exhibiting collective behavior.

Motion in living systems often relies on coupled dynamics of oscillatory and active networks (1–4). Examples spanning a wide range of size scales include the swimming of lamprey coordinated by oscillatory neuronal networks and the synchronized rotation of flagella coupled by hydrodynamic interactions (5, 6). Synthetic platforms that mimic key elements of these natural systems promise new fundamental understanding and next-generation active material systems: recent advances include chemomechanical oscillators built upon the Belousov–Zhabotinsky reaction (7, 8), synthetic genetic circuits (9), self-regulatory microfluidic devices (10–12), and organic chemical reactions (13). However, in most synthetic systems that rely on complex chemical or biochemical reactions, the nature of interactions between different elements is typically hardwired with limited ability to dynamically adjust coupling parameters. Similar limitations on geometric reconfigurability and tunability of coupling are found in physical particle oscillator networks, such as in acoustically levitated oscillators (14). In contrast, the effectiveness of natural control systems stems from oscillatory elements that can reconfigure their interactions rapidly, as observed in transitions of insect flight modes or animal gait patterns (2, 15). Therefore, developing simple yet versatile experimental platforms that mimic adaptive and active living systems with synthetic components remains a critical challenge.As an important step in this direction, we describe particles at fluid interfaces, driven by two-dimensional (2D) patterns of light, as a powerful approach to coupled motion across easily tunable geometries. In nature, insects such as Microvelia secrete chemicals to generate gradients in surface tension and propel themselves across water surfaces (i.e., Marangoni propulsion) (16). This concept has been exploited to drive translation and rotation of objects on fluid surfaces using both chemical (17, 18) and light-induced photothermal (19–21) gradients. Some of us previously demonstrated how photothermal Marangoni forces incite oscillatory motion of interfacially adsorbed particles, but as this approach relied on the use of curved droplets and permitted only very coarse “patterns” of light defined by the field of view of a microscope objective, it was not amenable to the study of multiparticle systems with well-controlled geometries (22). Indeed, the rational design of systems exhibiting reconfigurable Marangoni interactions between multiple particles remains elusive. In contrast, optical tweezers operating by momentum transfer offer spatial control over trapped objects in almost limitless arrangements (23–25), enabling oscillatory motion of colloids via continuous repositioning of traps (26) and sustained rotation of particles by transferring spin angular momentum (27). However, scaling this platform to larger collections of particles is challenging, since the high-intensity light (∼10⁶ W/cm²) required (28) becomes problematic over large areas and can drive large temperature increases. Here, we show that the Marangoni forces developed during illumination of hydrogel nanocomposite disks (HNDs), consisting of polymer gels with patterned gold nanoparticles (Au NPs), can incite a gamut of coordinated and reconfigurable multiparticle behavior at very modest light intensities (∼1 W/cm²). Arbitrary gray-scale light patterns provide optical boundary conditions to define coupled systems of HNDs, culminating in a versatile materials toolbox of active matter exhibiting complex rhythmic motion.     

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.     

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.     

Contemporary Negative Assessments of Alcoholics Anonymous: A Response

This article is a response to unfounded assessments of the value and effectiveness of Alcoholic Anonymous (AA) as an agent of recovery from alcohol/other drug disorders. Three recent examples are identified: Dodes and Dodes (2014), Glaser (2015), and Mohammad (2016). To challenge these assessments, three publications offering scientific support for AA are presented: Emrick et al. (1993); Vaillant (2012); and Humphreys, Blodgett, and Wagner (2014). A detailed examination is then undertaken of how Dodes and Dodes arrive at the conclusion that AA’s long-term sobriety rate is between 5% and 8%. Our review of the studies cited by Dodes and Dodes reveals that long-term abstinence rates for actively involved members of AA and other 12-Step groups are impressively high.