Genetic factors affecting the consistency and magnitude of changes in plasma cholesterol in response to dietary challenge

We examined the role of common genetic variation in determining the consistency and magnitude of change in plasma total cholesterol (TC) levels in response to two separate changes from a high-saturated (SFA) to a low-saturated/high-polyunsaturated-fat (PUFA) diet, in a group of free-living healthy men and women. Consistent responders were defined as those whose mean difference in the change in TC was within one SD of the mean for all participants, and the remainder were defined as variable responders. DNA was obtained from 55 individuals and genotype determined at the apolipoprotein (apo) B locus (signal peptide, SP), apoCIII (C1100-T) and lipoprotein lipase (LPL) gene loci (HindIII). In the 38 consistent responders, the apoBSP24 allele was significantly more common than in the 17 individuals with a variable response (0.29 vs. 0.12; p < 0.05). No other polymorphism showed a significant frequency difference between groups. In the group as a whole, the correlation between the change in TC level in response to the first and second dietary change was 0.28 (p = 0.05), but those with one or more apoB SP24 alleles and those with the apoCIII genotype CC had a significantly higher correlation than those with other genotypes (0.46 (p = 0.05) vs. 0.12 (NS) and 0.31 (p = 0.05) vs. 0.02 (NS), respectively). In the group as a whole, mean response left TC 10% higher on the SFA than on the PUFA diet, and neither apoB nor apoCIII genotypes affected the magnitude of this response. However, individuals with the LPL HindIII genotype H+ H+ had a significantly smaller change in mean TC in response to diet than those with one or more H- allele (9.3% vs. 14.4%; p = 0.03). Thus variation at the apoB and apoCIII loci affects the consistency of response to change in dietary fat content, while variation at the LPL gene locus affects magnitude of response.      

Characteristics of volunteers responding to emergencies in the Public Access Defibrillation Trial

OBJECTIVES: To evaluate the characteristics of volunteers responding to emergencies in the North American Public Access Defibrillation (PAD) Trial. METHODS: The PAD Trial was a prospective evaluation of cardiac arrest survival in community facilities randomized to cardiopulmonary resuscitation (CPR) or to CPR with automated external defibrillators (AEDs). The PAD volunteers' characteristics were analyzed using Poisson regression clustered on the facility and offset by the number of emergency episodes to which volunteers were exposed. RESULTS: A total of 19,320 volunteers in 1260 facilities were trained to provide emergency care. Of these, 8169 volunteers were participating actively at their facility during a time when one or more emergency episodes occurred. There were 1971 emergency episodes responded to by 1245 volunteers. The treatment arm (CPR-only versus CPR+AED) was not associated with the likelihood of volunteer participation in an episode. Likewise, the volunteers' age or sex did not affect response. Volunteers more likely to respond were supervisory/management or security personnel, non-minority participants, volunteers with previous CPR training, volunteers with previous experience in emergency care and those who passed the PAD CPR skills follow-up test. Volunteers who had a formal education beyond a high school level were less likely to respond. CONCLUSIONS: Volunteers with previous emergency training and positions of responsibility in their facility had a greater likelihood of participation in medical emergencies in the PAD Trial.     

Cellular basis for the negative inotropic effects of tumor necrosis factor-alpha in the adult mammalian heart.

To define the mechanism(s) responsible for the negative inotropic effects of tumor necrosis factor-alpha (TNF alpha) in the adult heart, we examined the functional effects of TNF alpha in the intact left ventricle and the isolated adult cardiac myocyte. Studies in both the ventricle and the isolated adult cardiac myocyte showed that TNF alpha exerted a concentration- and time-dependent negative inotropic effect that was fully reversible upon removal of this cytokine. Further, treatment with a neutralizing anti-TNF alpha antibody prevented the negative inotropic effects of TNF alpha in isolated myocytes. A cellular basis for the above findings was provided by studies which showed that treatment with TNF alpha resulted in decreased levels of peak intracellular calcium during the systolic contraction sequence; moreover, these findings did not appear to be secondary to alterations in the electrophysiological properties of the cardiac myocyte. Further studies showed that increased levels of nitric oxide, de novo protein synthesis, and metabolites of the arachidonic acid pathway were unlikely to be responsible for the TNF alpha-induced abnormalities in contractile function. Thus, these studies constitute the initial demonstration that the negative inotropic effects of TNF alpha are the direct result of alterations in intracellular calcium homeostasis in the adult cardiac myocyte.     

Hemopoietic colony growth-promoting activities in the plasma of bone marrow transplant recipients.

Plasma samples were obtained from 34 bone marrow transplant (BMT) recipients before and after administration of the preparative regimen and tested for their ability to promote and/or support growth of hemopoietic colonies. The ability of plasma samples to promote colony formation on their own was tested on normal nonadherent target cells without addition of exogenous growth factors. The growth-supporting activity was examined in the presence of medium conditioned by phytohemagglutinin-stimulated leukocytes (PHA-LCM) and/or erythropoietin (EPO). A series of kinetic changes was routinely observed. Pretransplant samples rarely gave rise to colonies without addition of exogenous growth factors. Plasma samples obtained after completion of the preparative regimen demonstrated increments of growth-promoting activities for megakaryocyte and granulocyte-macrophage progenitors (CFU-Meg and CFU-GM), respectively, that peaked between 7 and 21 d after transplantation. By day 30, activity levels of some patients had returned to pretransplant values, whereas in other patients, activities remained elevated. Persisting activity levels were associated with delayed engraftment. In contrast, activities for progenitors committed to erythropoiesis (BFU-E) and pluripotent precursors (CFU-GEMM) were only rarely observed. The activities were independent of febrile episodes. Their growth-promoting influence on CFU-GM could be neutralized completely by anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) antibodies. These data suggest that at least some of the observed activities in post-BMT plasma are related to GM-CSF. The growth-supporting activities of pretransplant plasma samples are lower than normal plasma when tested on CFU-Meg and CFU-GM. The growth-supporting activities improved transiently within the first month after BMT. A decline during the second and third month was followed by a gradual return to activity levels that were comparable to normal plasma. The effects of these plasma samples on BFU-E and CFU-GEMM were assessed with PHA-LCM and EPO. Similar to CFU-Meg- and CFU-GM-supporting capabilities, they improved transiently after BMT with a return of normal support function after 5-6 mo. The observed endogenous production of growth-promoting and growth-supporting activities for hemopoietic progenitors may serve as a background to design clinical trials for the timely administration of recombinant hemopoietic growth factors to BMT recipients.     

L'analgésie contr?lée par le patient agé

L'analgésie postopératoire contr?lée par le patient (ACP) est encore sous utilisé chez la personne agée. Cette technique permet toutefois d'apporter une réponse efficace adaptée aux difficiles problèmes posés par la prise en charge de la douleur chez l'opéré agé. D'une part, le patient peut gérer lui-même le traitement de sa douleur. D'autre part, l'ACP permet une titration continue des analgésiques. Ainsi, avec les morphiniques, dont l'activité intrinsèque augmente avec l'age, le risque de surdosage est réduit. L'ACP morphine permet d'obtenir un meilleur niveau d'analgésie que la technique conventionnelle par voie intramusculaire avec une qualité supérieure des suites opératoires. Cette technique s'avère toutefois inférieure aux possibilités de l'analgésie locorégionale. L'existence de troubles cognitifs préopératoires, éventualité fréquente chez les personnes agées, contreindiquent toutefois la mise en place d'une ACP. Les paramètres de réglage de la pompe d'ACP morphine sont identiques à ceux décrits pour l'adulte jeune. Chez le patient à risque, une dose de bolus de 1 mg ne devrait pas être dépassée. A la surveillance habituelle de la qualité d'analgésie, de la fonction respiratoire et du niveau de vigilance, il est utile d'adjoindre chez le vieillard, une évaluation quotidienne du statut mental pour dépister l'apparition éventuelle d'un délire postopératoire.     

Inhibitors of prostaglandin transport and metabolism augment protease-activated receptor-2-mediated increases in prostaglandin E2 levels and smooth muscle relaxation in mouse isolated trachea

Stimulants of protease-activated receptor-2 (PAR(2)), such as Ser-Leu-Ile-Gly-Arg-Leu-NH(2) (SLIGRL), cause airway smooth muscle relaxation via the release of the bronchodilatory prostanoid prostaglandin E(2) (PGE(2)). The principal aim of the current study was to determine whether compounds that inhibit PGE(2) reuptake by the prostaglandin transporter [bromocresol green and U46619 (9,11-dideoxy-9alpha,11alpha-methanoepoxy PGF2alpha) and PGE(2) metabolism by 15-hydroxyprostaglandin dehydrogenase (thiazolidenedione compounds rosiglitazone and ciglitazone) significantly enhanced the capacity of SLIGRL to elevate PGE(2) levels and produce relaxation in isolated segments of upper and lower mouse trachea. SLIGRL produced concentration-dependent increases in PGE(2) levels and smooth muscle relaxation, although both effects were significantly greater in lower tracheal segments than in upper tracheal segments. SLIGRL-induced increases in PGE(2) levels were significantly enhanced in the presence of ciglitazone and rosiglitazone, and these effects were not inhibited by GW9662 (2-chloro-5-nitrobenzanilide), a peroxisome proliferator-activated receptor-gamma antagonist. SLI-GRL-induced relaxation responses were also significantly enhanced by ciglitazone and rosiglitazone, whereas responses to isoprenaline, a PGE(2)-independent smooth muscle relaxant, were unaltered. Ciglitazone and rosiglitazone alone produced concentration-dependent increases in PGE(2) levels and smooth muscle relaxation, and these responses were inhibited by indomethacin, a cyclooxygenase inhibitor. Bromocresol green, an inhibitor of prostaglandin transport, significantly enhanced SLIGRL-induced increases in PGE(2) levels and relaxation. Immunohistochemical staining for 15-hydroxyprostaglandin dehydrogenase was relatively intense over airway smooth muscle, as was staining for the prostaglandin transporter over both airway smooth muscle and epithelium. In summary, inhibitors of PGE(2) reuptake and metabolism significantly potentiate PAR(2)-mediated increases in PGE(2) levels and smooth muscle relaxation in murine-isolated airways.     

Paramedic interventions increase the rate of return of spontaneous circulation in out of hospital cardiac arrests.

OBJECTIVE: To determine whether paramedic interventions increased the rate of return of spontaneous circulation in the victims of out of hospital cardiac arrest. METHODS: A retrospective analysis of 276 out of hospital cardiac arrests was made. Data analysed included age, sex, presenting rhythm, ambulance response time, presence of a pulse at any point, interventions performed by the ambulance crews, and survival to discharge. RESULTS: 146 patients were treated by paramedics and 130 by technicians. There was no difference in the rate of return of spontaneous circulation or survival to discharge in patients presenting in ventricular fibrillation (VF). In non-VF arrests there was no increase in survival to discharge, but 15% of patients in non-VF arrests achieved a return of spontaneous circulation when treated by paramedics compared to none treated by technicians. There were no other significant differences in any of the variables assessed. CONCLUSIONS: Out of hospital cardiac arrests presenting in VF are managed equally well by paramedics and technicians. However, in non-VF arrests there is a significantly increased rate of return of spontaneous circulation in those patients attended by paramedics.     

First prenatal case of proximal 19p13.12 microdeletion syndrome: New insights and new delineation of the syndrome

Proximal 19p13.12 microdeletion has been rarely reported. Only five postnatal cases with intellectual disability, facial dysmorphism, branchial arch defects and overlapping deletions involving proximal 19p13.12 have been documented. Two critical intervals were previously defined: a 700 kb for branchial arch defects and a 350 kb for hypertrichosis-synophrys-protruding front teeth. We describe the first prenatal case, a fetal death in utero at 39 weeks of gestation. Agilent 180K array-CGH analysis identified a heterozygous interstitial 745 kb deletion at 19p13.12 chromosome region, encompassing both previously reported critical intervals, including at least 6 functionally relevant genes: NOTCH3, SYDE1, AKAP8, AKAP8L, WIZ and BRD4. Quantitative PCR showed that the deletion occurred de novo with a median size of 753 kb. NOTCH3 and SYDE1 were candidate genes for placental pathology whilst AKAP8, AKAP8L, WIZ and BRD4 were highly expressed in the branchial arches. Molecular characterization and sequencing of candidate genes for placental pathology and branchial arch defects were carried out in order to correlate the genotype-phenotype relationship and unravel the underlying mechanism of proximal 19p13.12 microdeletion syndrome. This case also contributes to define the novel critical interval and expand the clinical phenotype spectrum of proximal 19p13.12 microdeletion syndrome.     

Modulation of agonist binding to human dopamine receptor subtypes by L-prolyl-L-leucyl-glycinamide and a peptidomimetic analog

The present study was undertaken to investigate the role of the hypothalamic tripeptide L-prolyl-L-leucyl-glycinamide (PLG) and its conformationally constrained analog 3(R)-[(2(S)-pyrrolidinylcarbonyl)amino]-2-oxo-1-pyrrolidineacetamide (PAOPA) in modulating agonist binding to human dopamine (DA) receptor subtypes using human neuroblastoma SH-SY5Y cells stably transfected with respective cDNAs. Both PLG and PAOPA enhanced agonist [3H]N-propylnorapomorphine (NPA) and [3H]quinpirole binding in a dose-dependent manner to the DA D2L,D2S, and D4 receptors. However, agonist binding to the D1 and D3 receptors and antagonist binding to the D2L receptors by PLG were not significantly affected. Scatchard analysis of [3H]NPA binding to membranes in the presence of PLG revealed a significant increase in affinity of the agonist binding sites for the D2L, D2S, and D4 receptors. Analysis of agonist/antagonist competition curves revealed that PLG and PAOPA increased the population and affinity of the high-affinity form of the D2L receptor and attenuated guanosine 5'-(beta,gamma-imido)-triphosphate-induced inhibition of high-affinity agonist binding sites for the DA D2L receptor. Furthermore, direct NPA binding with D2L cell membranes pretreated with suramin, a compound that can uncouple receptor/G protein complexes, and incubated with and without DA showed that both PLG and PAOPA had only increased agonist binding in membranes pretreated with both suramin and DA, suggesting that PLG requires the D2L receptor/G protein complex to increase agonist binding. These results suggest that PLG possibly modulates DA D2S, D2L, and D4 receptors in an allosteric manner and that the coupling of D2 receptors to the G protein is essential for this modulation to occur.     

Effect of the Soluble TNF‐Antagonist Etanercept on Tumor Necrosis Factor Bioactivity and Stability

Background: Targeted anti‐tumor necrosis factor (TNF) strategies in patients with rheumatoid arthritis have resulted in new and/or worsening heart failure in individuals who were free of cardiovascular disease. Methods and Results: To determine the mechanism of new and/or worsening heart failure in patients who were receiving the soluble TNF‐antagonist etanercept, we analyzed frozen plasma samples from a previous clinical trial with etanercept in heart failure patients, and conducted complimentary mechanistic in vitro studies. Analysis of the clinical trial data showed that use of etanercept resulted in a significant 70‐fold increase in the level of immunoreactive TNF. Complimentary in vitro studies using an L929 bioassay showed that at low concentrations of etanercept relative to TNF there was an unexpected 1.5‐ to 1.75‐fold increase in the absolute level of TNF bioactivity. We also examined the effect of etanercept on TNF stability and the results showed that there was a two‐fold increase in the mass of bioactive homotrimeric TNF when the molar ratio of TNF to etanercept was approximately 200:1. Conclusion: Etanercept increases the immunoreactive mass of TNF in heart failure patients, as well as augments TNF cytotoxicity in certain settings, thus suggesting one potential mechanism for the worsening heart failure in some patients who were receiving this agent.