Search

A significant amount of European basic and clinical neuroscience research includes the use of transcranial magnetic stimulation (TMS) and low intensity transcranial electrical stimulation (tES), mainly transcranial direct current stimulation (tDCS). Two recent changes in the EU regulations, the introduction of the Medical Device Regulation (MDR) (2017/745) and the Annex XVI have caused significant problems and confusions in the brain stimulation field. The negative consequences of the MDR for non-invasive brain stimulation (NIBS) have been largely overlooked and until today, have not been consequently addressed by National Competent Authorities, local ethical committees, politicians and by the scientific communities. In addition, a rushed bureaucratic decision led to seemingly wrong classification of NIBS products without an intended medical purpose into the same risk group III as invasive stimulators. Overregulation is detrimental for any research and for future developments, therefore researchers, clinicians, industry, patient representatives and an ethicist were invited to contribute to this document with the aim of starting a constructive dialogue and enacting positive changes in the regulatory environment., (Copyright © 2024 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Endotracheal intubation is a life-saving procedure for many newborns. Historically, it has been achieved by obtaining an airway view through the mouth via direct laryngoscopy. It is a skill that takes time and practice to achieve proficiency. Increasing evidence for the benefit of videolaryngoscopy in adults and the new development of technology has allowed videolaryngoscopy to become a reality in neonatal care. Studies have examined its use as both a technique to improve intubation safety and success, and as a training tool for those learning the skill in this vulnerable population. We present the current evidence for videolaryngoscopy in neonates in different settings where intubation may be required, in addition to exploring the challenges and practicalities of implementing this technique into clinical practice., Competing Interests: Declaration of competing interest No conflict of interest to declare and the work was not funded., (Copyright © 2023. Published by Elsevier Ltd.)

Background: Intermittent theta-burst stimulation (i) (TBS) is a transcranial magnetic stimulation (TMS) plasticity protocol. Conventionally, TBS is applied using biphasic pulses due to hardware limitations. However, monophasic pulses are hypothesised to recruit cortical neurons more selectively than biphasic pulses, predicting stronger plasticity effects. Monophasic and biphasic TBS can be generated using a custom-made pulse-width modulation-based TMS device (pTMS)., Objective: Using pTMS, we tested the hypothesis that monophasic iTBS would induce a stronger plasticity effect than biphasic, measured as induced increases in motor corticospinal excitability., Methods: In a repeated-measures design, thirty healthy volunteers participated in three separate sessions, where monophasic and biphasic iTBS was applied to the primary motor cortex (M1 condition) or the vertex (control condition). Plasticity was quantified as increases in motor corticospinal excitability after versus before iTBS, by comparing peak-to-peak amplitudes of motor evoked potentials (MEP) measured at baseline and over 60 min after iTBS., Results: Both monophasic and biphasic M1 iTBS led to significant increases in MEP amplitude. As predicted, linear mixed effects (LME) models showed that the iTBS condition had a significant effect on the MEP amplitude (χ 2 (1) = 27.615, p < 0.001) with monophasic iTBS leading to significantly stronger plasticity than biphasic iTBS (t (693) = 2.311, p = 0.021). Control vertex iTBS had no effect., Conclusions: In this study, monophasic iTBS induced a stronger motor corticospinal excitability increase than biphasic within participants. This greater physiological effect suggests that monophasic iTBS may also have potential for greater functional impact, of interest for future fundamental and clinical applications of TBS., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Timothy Denison, Majid Memarian Sorkhabi and Karen Wendt have pending patent applications for TMS device circuits and control algorithms. Timothy Denison and Karen Wendt have received grant funding (including an MRC iCASE studentship) and materials through collaboration agreements from Magstim Ltd. Majid Memarian Sorkhabi is currently employed by Magstim Ltd. Jacinta O'Shea has acted as a consultant for Welcony Inc. And serves on the Scientific Advisory Board of Plato Science. Charlotte J. Stagg and Melanie K. Fleming have no conflicts of interest., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

A secure and patent airway is a prerequisite to safe interhospital transfer and this has traditionally been via endotracheal tubes. Neonatal intubation success rates are falling as there is declining opportunities amongst paediatric junior doctors and consultants, therefore being able to successfully intubate an infant before or during a transfer, especially if they have an airway anomaly, may be very challenging. The use of supraglottic airways is increasingly popular in neonatology as an alternative to facemask ventilation or endotracheal intubation. This review considers the role of supraglottic airway devices during the stabilisation and transfer of neonates., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objective: This report describes a novel simulator, euthanized pigs on cardiopulmonary bypass, and validates this simulator with a controlled trial in general surgery residents learning aortic anastomosis. We evaluated this novel simulator with the following hypothesis: our porcine perfused simulator is as good as or better than the standard rubber tubing, low-fidelity models used for vascular anastomotic training., Methods: Euthanized pigs were placed on cardiopulmonary bypass, creating a perfused, ex vivo model on which to perform surgical procedures. The participants in the study were postgraduate year 2, 3, and 4 general surgery residents. Residents were randomized to practice aortic anastomosis in the pig laboratory (PL) simulator or in a dry laboratory. The PL residents and control residents performed a first vascular anastomosis on the rubber tube model. Anastomosis creation was filmed. The anastomosis and video were stored for later grading. Next, all residents underwent an ungraded, one-on-one training session with the attending vascular surgeon. After the training session, all residents completed a second videotaped rubber tubing anastomosis. The grading scales used were validated by other authors: Global Assessment Score, Final Product Score, and Checklist Scoring Instrument. Survey data describing this experience were collected using a 13-question prelaboratory and 16-question postlaboratory questionnaires consisting of yes/no, multiple selection, and 5-point Likert-type scale questions., Results: All residents had a statistically significant improvement in time to completion and in the Global Assessment Score with tutored practice. The PL residents showed statistically significant improvement in completion time between the first and second videotaped anastomosis; however, there was no statistically significant improvement in the scoring metrics. The control residents showed statistically significant improvement in all three scoring metrics, but no statistically significant difference was found in completion time. The survey data showed a statistically significant shift in considering vascular surgery as a career after the experience in the PL group (P = .05) compared with the control group, who had no change in interest (P = .91)., Conclusions: Our prospective, randomized clinical trial shows that the porcine cardiopulmonary bypass model achieves similar results to a previously validated bench top model while improving general surgery resident interest in vascular surgery as a career., (Copyright © 2017 Society for Vascular Surgery. All rights reserved.)

Background: The difficulty in treating mood disorders has brought about clinical interest in alternative treatments, such as transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex (DLPFC). However, the optimal parameters for stimulation and underlying mechanisms of action are unclear. Psychiatric treatments have acute effects on emotional processing that predict later therapeutic action. Such effects have been proposed as cognitive biomarkers for screening novel treatments for depression and anxiety., Methods: This study assessed the effect of tDCS on a battery of emotional processing measures sensitive to antidepressant action. To refine optimal stimulation parameters, DLPFC stimulation using two common electrode montages was compared with sham. Sixty healthy volunteers received 20 minutes of active or sham DLPFC stimulation before completing computerized emotional processing tasks, including a dot-probe measure of vigilance to threat., Results: Relative to sham stimulation, participants receiving simultaneous anodal stimulation of left DLPFC and cathodal stimulation of right DLPFC (bipolar-balanced montage) showed reduced vigilance to threatening stimuli. There was no such significant effect when the cathode was placed on the supraorbital ridge (bipolar-unbalanced montage). There were no effects of tDCS on other measures of emotional processing., Conclusions: Our findings provide the first experimental evidence that modulating activity in the DLPFC reduces vigilance to threatening stimuli. This significant reduction in fear vigilance is similar to that seen with anxiolytic treatments in the same cognitive paradigm. The finding that DLPFC tDCS acutely alters the processing of threatening information suggests a potential cognitive mechanism that could underwrite treatment effects in clinical populations., (Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Background: The Enhanced Suppression of the Platelet glycoprotein IIb/IIIa Receptor with Integrilin Therapy (ESPRIT) trial compared the use of eptifibatide with placebo in 2064 coronary intervention patients. It was previously reported that Canadian patients had reduced rates of 30-day and one-year death, myocardial infarction (MI) or target vessel revascularization (TVR) compared with patients in the United States (US)., Objective: To examine whether operator or institutional volume differences explain the regional variation in clinical outcome., Methods and Results: Each site received an operator and institutional volume survey. Fifty-seven sites (62%) returned complete data on 1338 patients. In this smaller cohort, Canadian patients had reduced rates of 30-day and one-year death, MI or TVR compared with US patients (6.3% versus 10.3% and 14.9% versus 20.1%, respectively; P<0.05 for both comparisons). Among 176 physicians with a median of 13 years experience, the median operator volume was 200 cases per year. Operators with fewer than 100 cases per year had higher rates of 30-day death, MI or TVR (13.2% versus 8.7%; P=0.18) and large MI (7.7% versus 3.3%; P=0.06) than those with 100 or more cases per year. The median institutional volume was 1064 cases per year. Canadian and US centres had similar operator and institutional volumes. By multivariate modelling, operator volume was not predictive of adverse clinical events. However, the rates of 30-day and one-year death, MI or TVR fell by 3% for every 100 patients treated by the institution (OR 0.97; P=0.058 and P=0.002, respectively). Enrollment in Canada was associated with improved outcomes at 30 days (OR 0.50; P=0.001) and one year (OR 0.66; P=0.001) despite inclusion of volume variables in the models., Conclusions: In the ESPRIT study, institutional volume was associated with a modest reduction in risk of death, MI or TVR over short- and long-term follow-up periods. The Canadian and US investigators and institutions selected in ESPRIT had similar annual procedural volumes. Therefore, volume variables did not explain the differential risk of clinical events observed for patients enrolled in the two countries.

Loss of CD4(+) T cells in the gut is necessary but not sufficient to cause AIDS in animal models, raising the possibility that a differential loss of CD4(+) T-cell subtypes may be important. We found that CD4(+) T cells that produce interleukin (IL)-17, a recently identified lineage of effector CD4(+) T-helper cells, are infected by SIV(mac251)in vitro and in vivo, and are found at lower frequency at mucosal and systemic sites within a few weeks from infection. In highly viremic animals, Th1 cells predominates over Th17 T cells and the frequency of Th17 cells at mucosal sites is negatively correlated with plasma virus level. Because Th17 cells play a central role in innate and adaptive immune response to extracellular bacteria, our finding may explain the chronic enteropathy in human immunodeficiency virus (HIV) infection. Thus, therapeutic approaches that reconstitute an adequate balance between Th1 and Th17 may be beneficial in the treatment of HIV infection.

Background: Practice patterns for percutaneous coronary interventions (PCIs) may differ between Canada and the United States. Few data are available comparing PCI outcomes between the two countries in the era of coronary stenting and adjunctive glycoprotein IIb/IIIa inhibition., Methods: In the Enhanced Suppression of the Platelet IIb/IIIa Receptor with Integrilin Therapy (ESPRIT) trial, 2064 patients were randomly assigned to receive eptifibatide or placebo during nonurgent PCI. The 30-day and one-year rates of death, myocardial infarction (MI) and target vessel revascularization (TVR) were compared between Canadian and American patients enrolled in the ESPRIT trial., Results: There were 1531 American patients and 533 Canadian patients enrolled. Americans were older and heavier, and had a higher incidence of cardiac risk factors than Canadians (P<0.05 for all variables). Canadian patients had a lower incidence of death, MI and TVR at 30 days (6.2% versus 10.4%, P=0.004) and at one year (14.8% versus 21.5%, P=0.0006). After adjusting for known baseline differences, enrollment in Canada remained a significant predictor of reduced ischemic complications at 30 days (OR=0.53, c2=9.0, P=0.003). Similar results were observed at one year. Eptifibatide was superior to placebo in both groups of patients., Conclusions: This analysis is among the first to show Canadian patients to have fewer adverse events than American patients after nonurgent PCI. This effect was independent of known baseline differences between the patients in each country. The relative treatment effect of eptifibatide in Canadian patients paralleled that observed in the main ESPRIT trial and in American patients.

Discovered during the past ten years, Janus kinases and signal transducers and activators of transcription have emerged as critical elements in cytokine signaling and immunoregulation. Recently, knockout mice for all the members of these families have been generated, with remarkably specific outcomes. Equally exciting is the discovery of a new class of inhibitors, the suppressor of cytokine signaling family. The phenotypes of mice deficient in these molecules are also striking, underscoring the importance of negative regulation in cytokine signaling.

Interleukin-12 (IL-12) is a key immunoregulatory cytokine that promotes Th1 differentiation and cell-mediated immune responses. The transcription factor STAT4 (signal transducer and activator of transcription 4) is an important element in mediating IL-12 signals, as evidenced by the fact that STAT4(-/-) mice display impaired responsiveness to IL-12 and deficient Th1 differentiation. STAT4 is inducibly phosphorylated on tyrosine and serine in response to IL-12, but the kinase(s) responsible for the latter event is unknown. Here we show that IL-12 induces STAT4 phosphorylation on serine 721 and that mutation of serine 721 interferes with STAT4 transcriptional activity. In addition, we show that mutation of tyrosine 693 abrogates IL-12-induced STAT4 tyrosine phosphorylation and transcriptional activity. Although the site surrounding serine 721 is an optimum consensus sequence for mitogen-activated family of protein kinases (MAPKs)-mediated phosphorylation, we demonstrate that IL-12 does not induce extracellular signal-regulated kinase (ERK) or c-Jun N-terminal kinase (JNK) activation in T and natural killer (NK) cells and that IL-12-induced STAT4 transcriptional activity is not affected by these kinases. Rather, we show that IL-12 induces p38 activation. Moreover, we demonstrate that p38alpha and its upstream activator, MKK6, phosphorylate STAT4 on serine 721, and are required for STAT4 full transcriptional activity induced by IL-12, establishing the MKK6/p38alpha/STAT4 pathway as an important mediator of IL-12 actions. (Blood. 2000;96:1844-1852)

The autoinflammatory syndromes are systemic disorders characterized by apparently unprovoked inflammation in the absence of high-titer autoantibodies or antigen-specific T lymphocytes. One such illness, TNF-receptor-associated periodic syndrome (TRAPS), presents with prolonged attacks of fever and severe localized inflammation. TRAPS is caused by dominantly inherited mutations in TNFRSF1A (formerly termed TNFR1), the gene encoding the 55 kDa TNF receptor. All known mutations affect the first two cysteine-rich extracellular subdomains of the receptor, and several mutations are substitutions directly disrupting conserved disulfide bonds. One likely mechanism of inflammation in TRAPS is the impaired cleavage of TNFRSF1A ectodomain upon cellular activation, with diminished shedding of the potentially antagonistic soluble receptor. Preliminary experience with recombinant p75 TNFR-Fc fusion protein in the treatment of TRAPS has been favorable.

Familial Mediterranean fever (FMF) is a recessive disorder characterized by episodes of fever and neutrophil-mediated serosal inflammation. We recently identified the gene causing FMF, designated MEFV, and found it to be expressed in mature neutrophils, suggesting that it functions as an inflammatory regulator. To facilitate our understanding of the normal function of MEFV, we extended our previous studies. MEFV messenger RNA was detected by reverse transcriptase-polymerase chain reaction in bone marrow leukocytes, with differential expression observed among cells by in situ hybridization. CD34 hematopoietic stem-cell cultures induced toward the granulocytic lineage expressed MEFV at the myelocyte stage, concurrently with lineage commitment. The prepromyelocytic cell line HL60 expressed MEFV only at granulocytic and monocytic differentiation. MEFV was also expressed in the monocytic cell lines U937 and THP-1. Among peripheral blood leukocytes, MEFV expression was detected in neutrophils, eosinophils, and to varying degrees, monocytes. Consistent with the tissue specificity of expression, complete sequencing and analysis of upstream regulatory regions of MEFV revealed homology to myeloid-specific promoters and to more broadly expressed inflammatory promoter elements. In vitro stimulation of monocytes with the proinflammatory agents interferon (IFN) gamma, tumor necrosis factor, and lipopolysaccharide induced MEFV expression, whereas the antiinflammatory cytokines interleukin (IL) 4, IL-10, and transforming growth factor beta inhibited such expression. Induction by IFN-gamma occurred rapidly and was resistant to cycloheximide. IFN-alpha also induced MEFV expression. In granulocytes, MEFV was up-regulated by IFN-gamma and the combination of IFN-alpha and colchicine. These results refine understanding of MEFV by placing the gene in the myelomonocytic-specific proinflammatory pathway and identifying it as an IFN-gamma immediate early gene.

The Janus kinase, JAK3 plays an important role in interleukin-2 (IL-2)-dependent signal transduction and proliferation of T lymphocytes. Our findings show that prostaglandin E2 (PGE2) can inhibit upregulation of JAK3 protein in naive T cells and can downregulate its expression in primed cells. Reduction in JAK3 was selective because expression of other tyrosine kinases (JAK1, p56(lck), and p59(fyn)) and signal transducer and activator of transcription (STAT)5, which are linked to IL-2 receptor (IL-2R) signaling pathway, were not affected. Inhibition of JAK3 may be controlled by intracellular cyclic adenosine monophosphate (cAMP) levels, as forskolin, a direct activator of adenylate cyclase and dibutyryl cAMP (dbcAMP), a membrane permeable analogue of cAMP suppressed JAK3 expression. Moreover, 3-isobutyl-1-methylxanthine (IBMX), an inhibitor of cAMP phosphodiesterase, potentiated PGE2-induced suppression of JAK3. In naive T cells, but not primed T cells, PGE2 and other cAMP elevating agents also caused a modest reduction in surface expression of the common gamma chain (gammac) that associates with JAK3. The absence of JAK3, but not IL-2R in T cells correlated with impaired IL-2-dependent signal transduction and proliferation. The alteration in IL-2 signaling included decreased tyrosine phosphorylation and DNA binding activity of STAT5 and poor induction of the c-Myc and c-Jun pathways. In contrast, IL-2-dependent induction of Bcl-2 was unaffected. These findings suggest that suppression of JAK3 levels may represent one mechanism by which PGE2 and other cAMP elevating agents can inhibit T-cell proliferation.

Janus kinases (JAK) play a crucial role in the initial steps of cytokine signaling. Each of the four members (JAK1, JAK2, JAK3, TYK2) of this non-receptor tyrosine kinase family is indispensable for the effects of distinct cytokines. Moreover, recent reports have added to our knowledge on their highly specific functions: JAK3 knockout mice and JAK3 deficient patients cannot signal through the interleukin-2,4,7,9, or 15 receptors and suffer from severe combined immunodeficiency (SCID). JAK1 and JAK2 knockout mice do not survive, their cells again showing distinct patterns of cytokine signaling deficits. At the other end of the spectrum, JAK fusion proteins have been shown to play a role in leukemias. In addition, a new class of JAK-specific inhibitors was described by several groups, the CIS/SOCS/Jab family. This review on the rapidly growing field focuses on JAK function and regulation, and on their emerging role in development and human disease.

In comparison with HLA-matched sibling bone marrow transplants, unrelated donor transplants are associated with increased graft-versus-host disease and graft failure. This is likely in part due to HLA incompatibilities not identified by current matching strategies. High resolution DNA-based typing methods for HLA class II loci have improved donor selection and treatment outcome in unrelated donor bone marrow transplantation. By using DNA-based typing methods for HLA-A and -B on a cohort of 100 potential bone marrow donor/patient pairs, we find that serological typing for HLA class I is limited in its ability to identify incompatibilities in unrelated pairs. Furthermore, the incompatibilities identified are associated with the presence at high frequency of alloreactive cytotoxic T-lymphocyte precursors. DNA typing also indicates that HLA-C mismatches are common in HLA-A and -B serologically matched pairs. Such mismatches appear to be significantly less immunogenic with respect to cytotoxic T-lymphocyte recognition, but are expected to influence natural killer cell activity. Thus, improved resolution of HLA class I shows many previously undisclosed mismatches that appear to be immunologically functional. Use of high resolution typing methods in routine matching is expected to improve unrelated donor selection and transplant outcome.

Humanized monoclonal antibodies that recognize the alpha chain of the IL-2 receptor (e.g. daclizumab) have been used to prevent allograft rejection, since this chain is expressed by T cells participating in allograft rejection but not by resting T cells. In a randomized trial, when added to standard cyclosporin-based immunosuppression, daclizumab significantly reduced the frequency of acute rejection of renal transplants.

Mutations of the Janus family kinase JAK3 have been found to be responsible for autosomal recessive severe combined immunodeficiency (SCID) in humans. We report here the analysis of four new unrelated patients affected by JAK3-deficient SCID. The genetic defects were heterogeneous and included a large intragenic deletion as well as different point mutations, leading to missense substitutions, early stop codons, or splicing defects. We performed a series of studies of the biochemical events induced by cytokines on lymphoblastoid B-cell lines obtained from these patients. Abnormalities in tyrosine phosphorylation of JAK3 in response to interleukin-2 (IL-2) and IL-4 were present in all patients. Accordingly, IL-2-mediated phosphorylation of STAT5 was also absent or barely detectable. On the contrary, in all cases, we could show reduced but clear phosphorylation of STAT6 upon IL-4 stimulation. In one patient carrying a single amino acid change (Glu481Gly) in the JH3 domain of JAK3, we observed partially conserved IL-2 responses resulting in reduced but detectable levels of JAK3 and STAT5 phosphorylation. Interestingly, the patient bearing this mutation developed a substantial number of circulating CD4(+)/CD45RO+ activated T lymphocytes that were functionally impaired. In two cases, patients' cells expressed JAK3 proteins with mutations in the JH2 pseudo-kinase domain. A single cysteine to arginine substitution (Cys759Arg) in this region resulted in high basal levels of constitutive JAK3 tyrosine phosphorylation unresponsive to either downregulation by serum starvation or cytokine-mediated upregulation. The characterization of the genetic defects and biochemical abnormalities in these JAK3-deficient patients will help define the role of JAK3 in the ontogeny of a competent immune system and may lead to a better understanding of the JAK3 functional domains.

Despite the similarities between natural killer (NK) and T cells, these lymphocytes have dramatically different functional phenotypes. To identify potential biochemical parameters that correlate with the "primed" NK phenotype, we have investigated protein tyrosine phosphorylation in NK and T cells. Examination of tyrosyl phosphorylation in NK cells showed that they have higher levels of phosphorylation than resting T cells. Consistent with this, the concentrations of the tyrosine kinase inhibitor, herbimycin A, required to inhibit FcR-mediated Ca2+ flux in NK cells were much higher than those required for inhibition of T cell receptor-mediated Ca2+ mobilization. Differences in phosphorylation were not due to purification artifact lymphocyte src-family kinase, p56lck or the protein tyrosine phosphatase CD45. Thus, we have identified high basal tyrosyl phosphorylation as a striking biochemical feature of NK cells that correlates with the unique functions of this subset.

X-linked severe combined immunodeficiency (XSCID) is a lethal disease caused by a defect in the gene encoding the common gamma chain (gamma-c) of the receptor for interleukin-2 (IL-2), IL-4, IL-7, IL-9, and IL-15. Allogeneic bone marrow transplantation, the current therapy of choice for this defect, is often complicated by graft-versus-host disease and/or incomplete reconstitution of B-lymphocyte functions. Correction of the gene defect at the level of the autologous lymphohematopoietic progenitors could therefore represent an improvement in the medical management of these patients. To study the feasibility of a gene therapy approach for XSCID, a retroviral vector expressing gamma-c was used to transduce Epstein-Barr virus-transformed B-cell lines derived from patients with XSCID. After transduction, XSCID cells newly expressed gamma-c on the cell surface at levels comparable to those observed on B-cell lines obtained from normal donors. Moreover, the reconstituted gamma-c restored function to the IL-2 and IL-4 receptors as shown by signal transduction mediated by phosphorylation of the JAK1 and JAK3 members of the Janus family of tyrosine kinases and by restoration of cellular proliferation in response to IL-2.

Thrombopoietin (TPO) is a recently characterized growth and differentiation factor for megakaryocytes and platelets that exerts its effects via the receptor, c-MpI. This receptor is a member of the hematopoietin receptor superfamily and is essential for megakaryocyte maturation; however, the molecular mechanisms of TPO and c-MpI action have not been elucidated. Recently, the Janus kinases have emerged as important elements in signaling via this family of receptors. In this report, we show that, in the M07e megakaryocytic cell line, which expresses c-MpI and proliferates in response to TPO, TPO induces phosphorylation of a number of substrates between 80 and 140 kD. Specifically, we show that stimulation with TPO induces the rapid tyrosine phosphorylation of a 130-kD protein that we identify as the Janus kinase, JAK2. However, no detectable tyrosine phosphorylation of JAK1, JAK3, or TYK2 was observed. TPO also induced activation of JAK2 phosphotransferase activity in vitro. Taken together, these data indicate that JAK2 likely plays a key role in TPO-mediated signal transduction.

The aim of this study was to investigate the role of heat-shock proteins after heat-shock stress on the post-ischemic recovery of cardiac mechanical and endothelial function following a prolonged cardiac arrest. Isolated working rat hearts were subjected to a cardioplegic arrest for 4 hours at 4 degrees C. Three groups (n = 8 in each) were studied: (1) control, (2) sham-treated, and (3) heat-shocked rats. Postischemic recovery of cardiac output and endothelial function (as percent of preischemic control values) was 57.8% +/- 2.8% and 20.8% +/- 3.9% in group 1, 50.9% +/- 4.0% and 26.3% +/- 5.9% in group 2, and 74.0% +/- 2.4% and 51.2% +/- 8.0% in group 3, respectively. Both postischemic myocardial and endothelial function were improved by heat stress.

Unusual concentric laminar bodies in the RER of ovine hepatocytes treated with tunicamycin are described. These bodies are probably proteinaceous in nature and related to inhibition of protein glycosylation by tunicamycin in the RER.

In guinea-pigs given 400 micrograms per kg of tunicamycin, the toxin responsible for the disease known as annual ryegrass toxicity, alterations in blood-brain barrier permeability were assessed with vascular tracers of differing particle size. The toxin caused loss of integrity of the barrier to the smallest diameter tracer, horseradish peroxidase, but the cerebral endothelium was able to retain larger particles of ferritin and colloidal gold in the circulation. The effect of tunicamycin on cultured endothelial cells was characterized by dose-dependent lethal damage to these cells, marked dilatation of cisternae of RER, severe cytoplasmic vacuolation and a reduced incidence of mitosis in surviving endothelial cells. It was concluded that tunicamycin is able to damage directly endothelial cells, with a resultant increase in cerebral vascular permeability.

Plasma fibronectin (Fn) induces phagocytosis of C3b-opsonized sheep erythrocytes (EC3b) by human peripheral blood monocytes. However, Fn does not induce erythrophagocytosis of EC3b by human polymorphonuclear leukocytes (PMN), unless the PMN have been exposed to C5a or N-formyl-methionyl-leucyl-phenylalanine. Because of this difference, it is of great interest to examine Fn binding to cells that possess the capacity to differentiate into either granulocytes or monocytes. Hence, we have examined the consequences of Fn binding to the human myelomonocytic cell line, HL-60, both before and after in vitro differentiation of the HL-60, along a monocytoid or a granulocytoid pathway. Fn receptors were not found on undifferentiated HL-60, but several differentiating agents promoted the HL-60 binding of Fn-coated microspheres (Fn-ms). The peak of Fn-ms binding occurred four to five days after the induction of differentiation with dimethylsulfoxide (DMSO), and two days after induction by PMA. In addition, cells that differentiated along either the monocytoid or the granulocytoid pathway showed a marked increase in the phagocytosis of both IgG-coated erythrocytes (EA) and EC3b when they were exposed to Fn. Comparison of the effects of anti-Fn monoclonals on the binding of Fn-ms to the monocytes, PMN, and HL-60 showed that the same monoclonals block Fn-ms-binding and Fn-induced EC3b phagocytosis by all three cell types. Two monoclonal antibodies, M1/70 and A6F10, directed against membrane antigens on PMN and monocytes, inhibited Fn-ms binding. Both also blocked Fn-induced EC3b ingestion by these cells. However, neither antibody blocked Fn-ms binding or EC3b ingestion by differentiated HL-60. We conclude that differentiated HL-60 cells express functionally active Fn receptors, similar to monocytes and activated PMN, which, nonetheless, differ from normal cells in their association with the antigens recognized by M1/70 and A6F10.

The cardiovascular autonomic function of 13 boys with Duchenne muscular dystrophy was examined in order to test the hypothesis that the labile sinus tachycardia of that disorder is due to autonomic dysfunction. Five non-invasive procedures evaluated the responses of heart rate and blood pressure to postural change, the Valsalva maneuver, sustained hand grip and deep breathing. No individual had sufficient evidence of autonomic dysfunction. Most tests were normal (76%), 16% were borderline, and 8% were abnormal. None had more than one abnormal test. Although most had some difficulty with the Valsalva maneuver, the study demonstrated that simple clinical non-invasive testing of autonomic function can be carried out on a young severely handicapped population.

Phenothiazine (PTZ) given indoors to calves artificially infected with Ostertagia ostertagi and Cooperia oncophora showed ovicidal activities of 100, 93, 98 and 85% respectively at daily doses of 9, 8, 7 and 6 mg kg-1. In a grazing study, one group of calves was treated with PTZ via the drinking water, using a "Profel" liquid dispenser. The dispenser was calibrated to add PTZ to the water at a daily dose of 7 mg kg-1, but in practice the dose far exceeded this amount. A dose of 7 mg kg-1 day-1 was given manually to a second group and a third group acted as control, receiving no PTZ. PTZ-induced photosensitivity was widespread in the first group due to over-dosage of medicament by the dispenser and was suspected in one calf in the manually dosed group. PTZ in both treated groups showed marked ovicidal activity and, apparently as a result of this, caused striking reductions in trichostrongylid infection on the pasture and in the calves as evidenced by pasture larval counts, calves' egg counts, pepsinogen levels and live weight gains. Necropsy worm counts showed that the PTZ medication prevented heavy infection by arrested as well as by adult Ostertagia. The reduced infection on the treated calves' pasture was carried over for a second grazing season. Untreated calves grazing the pasture in that season showed lower infection and improved weight gains up to mid-September compared with calves on the control pasture. These effects did not persist for the whole of the second season.

Addition of cAMP to cells has been shown to inhibit phosphatidylinositol (PI) metabolism. cAMP has been reported to inhibit an enzyme in this pathway, PI kinase and it has been suggested that this inhibition is due to phosphorylation of PI kinase by the cAMP dependent protein kinase (PKA). In the present study we directly investigated if the inhibitory effect of cAMP was mediated by PKA. In membranes derived from murine hepatocytes we found that cAMP inhibited PI kinase but other adenine derivatives were more potent inhibitors. Moreover, it was found that the effects of the derivatives were unlikely to be due secondarily to the production of cAMP via their interaction with adenosine receptors. Through studies employing an inhibitor of PKA, mutant cells lacking PKA, and addition of purified catalytic subunit of PKA, we found that the inhibitory effect of cAMP was not mediated by PKA. In addition, the inhibitory effect of cAMP and adenosine was retained upon partial purification of PI kinase. Pulse chase experiments affirmed that the inhibitory effect was not due to breakdown of PI but rather to inhibition of its synthesis. We conclude that the inhibitory effect of cAMP and related compounds on PI kinase is not mediated by PKA dependent phosphorylation but rather appears to be a direct effect of these agents.

Pressure-heat treatment of beef semitendinosus samples post-rigor gave shear and tensile results similar to those obtained with pressure treatment pre-rigor. Post-rigor pressure-heat treatment did not affect the contraction state, unlike pre-rigor pressure treatment which caused samples to contract by about 40%. Maximum tenderizing effect by pressure-heat treatment (150 M Nm(-2) at 60°C for 30 min) was achieved when samples were heated at 45°C for 45-180 min immediately before application of the treatment. As the pre-pressurization temperature was increased, the duration of heating became more critical until at temperatures ≥ 60°C the effects of subsequent pressure-heat treatment became very small. Pressure-heat treated samples did not show the increase in shear force values for cooking temperatures ≥ 60°C associated with myofibrillar hardening. It was concluded that pressure-heat treatment primarily affected the myofibrillar structure., (Copyright © 1977. Published by Elsevier Ltd.)

The enzyme phosphatidylinositol kinase was partially purified from murine livers. The purification scheme involved solubilization of proteins with Triton X-100 and deoxycholate, followed by gel filtration chromatography in ACA 44, affinity chromatography with Blue Sepharose and hydroxylapatite. The purification achieved from membranes was 490 fold. We found that partially purified phosphatidylinositol kinase was unable to catalyze the formation of phosphatidylinositol-4,5-bisphosphate.