133 research outputs found
Lack of knowledge and experience highlights the need for a clear paediatric organ and tissue donation protocol in the Netherlands
Aim This study explored the attitudes of medical professionals to organ and tissue donation in paediatric intensive care units (PICUs) and neonatal intensive care units (NICUs) in the Netherlands. It also examined their compliance with the existing Dutch donation protocol and assessed whether a paediatric donation protocol was needed. Methods We invited 966 professionals working in all eight PICUs and the two largest NICUs to complete an online survey from December 2016 until April 2017. Results A quarter (25%) took part and they included PICU intensivists, neonatologists, nurses and other health and allied professionals. Most were female and nurses. More than half (54%) of the PICU respondents considered paediatric organ donation to be very important and 53% supported tissue donation. In contrast, only 22% of the NICU respondents believed that both neonatal organ and tissue donation were very important. Familiarity and compliance with the existing national donation protocol were low. PICU nurses had significantly less experience than PICU intensivists and felt less comfortable with the donation process. None of the NICU respondents had prior donation experience. Conclusion Paediatric intensive care units and NICU professionals lack specialised knowledge and experience on organ and tissue donation. A comprehensive and clear paediatric donation protocol is clearly needed
Isolation and partial characterization of infectious molecular clones of feline immunodeficiency virus obtained directly from bone marrow DNA of a naturally infected cat.
Replication-competent molecular clones of feline immunodeficiency virus (FIV) were isolated directly from the DNA of bone marrow cells of a naturally FIV-infected cat. After transfection in a feline kidney cell line (CrFK) and subsequent cocultivation with peripheral blood mononuclear cells (PBMC), the viral progeny of the clones was infectious for PBMC but not for CrFK cells. PBMC infected with these clones showed syncytium formation, a decrease in cell viability, and gradual loss of CD4+ cells. The restriction maps of these clones differed from those obtained for previously described molecular clones of FIV derived from cats in the United States. The predicted amino acid sequence similarity of the envelope genes of the two clones was 99.3%, whereas the similarities of the sequences of the clones to those of two molecular clones from the United States, Petaluma and PPR, were 86 and 88%, respectively. Most of the differences between the amino acid sequences of the two clones and those of the clones from the United States were found in five different hypervariable (HV) regions, HV-1 through HV-5. The viral progeny of one of these clones was inoculated into two specific-pathogen-free cats. The animals seroconverted, and the virus could be reisolated from their PBMC
Gag- and env-specific serum antibodies in cats after natural and experimental infection with feline immunodeficiency virus.
In order to monitor the antibody response to feline immunodeficiency virus (FIV) in cats, following experimental and natural infection, enzyme-linked immunosorbent assays (ELISAs) were developed using recombinant env and gag proteins and p24-specific monoclonal antibodies. It was shown that in experimentally infected cats an env protein-specific antibody response was directly followed by a gag protein-specific response. Furthermore, an ELISA for the detection of env protein-specific serum antibodies proved more sensitive in identifying experimentally and naturally infected cats than ELISAs demonstrating gag protein-specific antibodies. It was concluded that, like in HIV infection of humans, the detection of env protein-specific serum antibodies in addition to gag protein-specific antibodies is not only an important tool in the diagnosis of the infection but also in studies concerning the pathogenesis of the disease
On the Lagrangian Realization of Non-Critical -Strings
A large class of non-critical string theories with extended worldsheet gauge
symmetry are described by two coupled, gauged Wess-Zumino-Witten Models. We
give a detailed analysis of the gauge invariant action and in particular the
gauge fixing procedure and the resulting BRST symmetries. The results are
applied to the example of strings.Comment: 19 pages, LaTeX (REVTEX macro's
Regional myocardial blood flow reserve impairment and metabolic changes suggesting myocardial ischemia in patients with idiopathic dilated cardiomyopathy
AbstractOBJECTIVESWe performed positron emission tomography (PET) to evaluate myocardial ischemia in patients with idiopathic dilated cardiomyopathy (IDC).BACKGROUNDPatients with IDC have anatomically normal coronary arteries, and it has been assumed that myocardial ischemia does not occur.METHODSWe studied 22 patients with IDC and 22 control subjects using PET with nitrogen-13 ammonia to measure myocardial blood flow (MBF) at rest and during dipyridamole-induced hyperemia. To investigate glucose metabolism, fluorine-18 deoxyglucose (18FDG) was used. For imaging of oxygen consumption, carbon-11 acetate clearance rate constants (kmono) were assessed at rest and during submaximal dobutamine infusion (20 μg/kg body weight per min).RESULTSGlobal MBF reserve (dipyridamole-induced) was impaired in patients with IDC versus control subjects (1.7 ± 0.21 vs. 2.7 ± 0.10, p < 0.05). In patients with IDC, MBF reserve correlated with left ventricular (LV) systolic wall stress (r = −0.61, p = 0.01). Furthermore, in 16 of 22 patients with IDC (derived by dipyridamole perfusion) mismatch (decreased flow/increased 18FDG uptake) was observed in 17 ± 8% of the myocardium. The extent of mismatch correlated with LV systolic wall stress (r = 0.64, p = 0.02). The MBF reserve was lower in the mismatch regions than in the normal regions (1.58 ± 0.13 vs. 1.90 ± 0.18, p < 0.05). During dobutamine infusion kmonowas higher in the mismatch regions than in the normal regions (0.104 ± 0.017 vs. 0.087 ± 0.016 min−1, p < 0.05). In the mismatch regions 18FDG uptake correlated negatively with rest kmono(r = −0.65, p < 0.05), suggesting a switch from aerobic to anaerobic metabolism.CONCLUSIONSPatients with IDC have a decreased MBF reserve. In addition, low MBF reserve was paralleled by high LV systolic wall stress. These global observations were associated with substantial myocardial mismatch areas showing the lowest MBF reserves. In geographically identical regions an abnormal oxygen consumption pattern was seen together with a switch from aerobic to anaerobic metabolism. These data support the notion that regional myocardial ischemia plays a role in IDC
Unravelling the immune signature of Plasmodium falciparum transmission-reducing immunity
Infection with Plasmodium can elicit antibodies that inhibit parasite survival in the mosquito, when they are ingested in an infectious blood meal. Here, we determine the transmission-reducing activity (TRA) of naturally acquired antibodies from 648 malaria-exposed individuals using lab-based mosquito-feeding assays. Transmission inhibition is significantly associated with antibody responses to Pfs48/45, Pfs230, and to 43 novel gametocyte proteins assessed by protein microarray. In field-based mosquito-feeding assays the likelihood and rate of mosquito infection are significantly lower for individuals reactive to Pfs48/45, Pfs230 or to combinations of the novel TRA-associated proteins. We also show that naturally acquired purified antibodies against key transmission-blocking epitopes of Pfs48/45 and Pfs230 are mechanistically involved in TRA, whereas sera depleted of these antibodies retain high-level, complement-independent TRA. Our analysis demonstrates that host antibody responses to gametocyte proteins are associated with reduced malaria transmission efficiency from humans to mosquitoes
Genetic diversity of Brazilian isolates of feline immunodeficiency virus
We isolated Feline immunodeficiency virus (FIV) from three adult domestic cats, originating from two open shelters in Brazil. Viruses were isolated from PBMC following co-cultivation with the feline T-lymphoblastoid cell line MYA-1. All amplified env gene products were cloned directly into pGL8MYA. The nucleic acid sequences of seven clones were determined and then compared with those of previously described isolates. The sequences of all of the Brazilian virus clones were distinct and phylogenetic analysis revealed that all belong to subtype B. Three variants isolated from one cat and two variants were isolated from each of the two other cats, indicating that intrahost diversity has the potential to pose problems for the treatment and diagnosis of FIV infection
Comparison of (18)F SPECT with PET in myocardial imaging: A realistic thorax-cardiac phantom study
BACKGROUND: Positron emission tomography (PET) imaging with fluorine-18 ((18)F) Fluorodeoxyglucose (FDG) and flow tracer such as Rubidium-82 ((82)Rb) is an established method for evaluating an ischemic but viable myocardium. However, the high cost of PET imaging restricts its wider clinical use. Therefore, less expensive (18)F FDG single photon emission computed tomography (SPECT) imaging has been considered as an alternative to (18)F FDG PET imaging. The purpose of the work is to compare SPECT with PET in myocardial perfusion/viability imaging. METHODS: A nonuniform RH-2 thorax-heart phantom was used in the SPECT and PET acquisitions. Three inserts, 3 cm, 2 cm and 1 cm in diameter, were placed in the left ventricular (LV) wall to simulate infarcts. The phantom acquisition was performed sequentially with 7.4 MBq of (18)F and 22.2 MBq of Technetium-99m ((99m)Tc) in the SPECT study and with 7.4 MBq of (18)F and 370 MBq of (82)Rb in the PET study. SPECT and PET data were processed using standard reconstruction software provided by vendors. Circumferential profiles of the short-axis slices, the contrast and viability of the inserts were used to evaluate the SPECT and PET images. RESULTS: The contrast for 3 cm, 2 cm and 1 cm inserts were for (18)F PET data, 1.0 ± 0.01, 0.67 ± 0.02 and 0.25 ± 0.01, respectively. For (82)Rb PET data, the corresponding contrast values were 0.61 ± 0.02, 0.37 ± 0.02 and 0.19 ± 0.01, respectively. For (18)F SPECT the contrast values were, 0.31 ± 0.03 and 0.20 ± 0.05 for 3 cm and 2 cm inserts, respectively. For (99m)Tc SPECT the contrast values were, 0.63 ± 0.04 and 0.24 ± 0.05 for 3 cm and 2 cm inserts respectively. In SPECT, the 1 cm insert was not detectable. In the SPECT study, all three inserts were falsely diagnosed as "viable", while in the PET study, only the 1 cm insert was diagnosed falsely "viable". CONCLUSION: For smaller defects the (99m)Tc/(18)F SPECT imaging cannot entirely replace the more expensive (82)Rb/(18)F PET for myocardial perfusion/viability imaging, due to poorer image spatial resolution and poorer defect contrast
The role of the chemokine receptor CXCR4 in infection with feline immunodeficiency virus
Infection with feline immunodeficiency virus (FIV) leads to the development of a disease state similar to AIDS in man. Recent studies have identified the chemokine receptor CXCR4 as the major receptor for cell culture-adapted strains of FIV, suggesting that FIV and human immunodeficiency virus (HIV) share a common mechanism of infection involving an interaction between the virus and a member of the seven transmembrane domain superfamily of molecules. This article reviews the evidence for the involvement of chemokine receptors in FIV infection and contrasts these findings with similar studies on the primate lentiviruses HIV and SIV (simian immunodeficiency virus)
Rape-related symptoms in adolescents: short- and long-term outcome after cognitive behavior group therapy
Background: Efficacy studies on treatment in adolescent victims of single rape are lacking, even though sexual victimization is most likely to occur during adolescence and despite the fact that adolescents are at risk to develop subsequent posttraumatic stress disorder. Aim: The aim of this prospective observational study was to evaluate the short- and long-term outcomes of a nine-session cognitive behavior group therapy (STEPS), including a parallel six-session parents’ group on rape-related symptomatology in female adolescents (13–18 years). STEPS includes psychoeducation, exposure in sensu as well as in vivo, cognitive restructuring, and relapse prevention. Methods: Fifty-five female adolescents with mental health problems due to single rape, but without prior sexual trauma, received STEPS while their parents participated in a support group. Subjects were assessed on posttraumatic stress (PTS) and comorbid symptoms using self-report questionnaires prior to and directly after treatment, and at 6 and 12 months follow-up. Results: Repeated measures analysis showed a significant and large decrease in symptoms of PTS, anxiety, depression, anger, dissociation, sexual concerns, and behavior problems directly after treatment, which maintained at 12 months follow-up. Time since trauma did not influence the results. Dropout during STEPS was 1.8%. Conclusions: The results potentially suggest that the positive treatment outcomes at short- and long-term may be caused by STEPS. The encouraging findings need confirmation in future controlled studies on the effectiveness of STEPS because it may be possible that the treatment works especially well for more chronic symptoms, while the less chronic part of the sample showed considerable improvement on its own
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