Fibre optic biosensors with immobilized bioluminescence enzymes

A fibre optic biosensor involving immobilized bioluminescence enzymes associated with a glass fibre bundle has been designed. The firefly luciferase fromPhotinus pyralis, as well as the bacterial luciferase-oxidoreductase system from eitherVibrio fischeri orVibrio harveyi, have been immobilized on preactivated polyamide membranes. First, the validity of the approach is demonstrated by performing the microdetermination of adenosine triphosphate (ATP) and sodium dehydrogenase (NADH) in a batch system. The detection limits are equal to 0.1nm for ATP and 0.3nm for NADH. With the NADH-based system, the extension of the biosensor potential to other analytes (ethanol, sorbitol and oxaloacetate) has been achieved using suitable dehydrogenases co-immobilized with the bacterial system. Second, the fibre optic biosensor is associated with a specially designed flow cell for the continuous-flow bioluminescent assay of NADH over the range 2 pmol-1 nmol with an r.s.d. of 3.4% at 0.1 nmol. Finally, a multifunction biosensor for the determination of either ATP or NADH using a single bioluminescence-based fibre optic probe is described. This was made possible by co-immobilizing the firefly luciferase with the bacterial system on the same preactivated polyamide membrane.     

Risk factors and prevention of early infection after implantation or revision of transjugular intrahepatic portosystemic shunts: results of a randomized study

The aim of this study was to evaluate the efficacy of a single dose of a second-generation cephalosporine to prevent postinterventional infection and to identify risk factors for postinterventional infection in patients receiving implantation or revision of a transjugular intrahepatic portosystemic shunt (TIPS). Eighty-four patients (105 transjugular interventions) were randomized receiving no antibiotic treatment (46 interventions) or 2 g cefotiam (56 interventions) given at the beginning of the procedure. Patients with overt infection or those receiving antibiotic treatment in the preceding two weeks were excluded. Groups were comparable with respect to biographic and medical data. Postinterventional infection was defined as an increase in WBC count (> or =15,000/microl), fever (> or =38.5 degrees C), or a positive blood culture. Infection occurred in 17% of the patients. Patients not receiving cefotiam had a slightly higher incidence of infection (20%) than patients treated with cefotiam (14%, NS). Multivariate analysis demonstrated prognostic relevance for multiple stenting and periprocedural use of a central venous line. The clinical outcome of the patients was unaffected by cefotiam treatment. In conclusion, a single dose of intrainterventional cefotiam does not prevent postinterventional infection. This may be due to the antimicrobial spectrum and short half-time of cefotiam. Strict adherence to aseptic conditions during intervention and early removal of central venous lines may reduce the rate of post interventional infection considerably. Antibiotic prophylaxis with cefotiam does not seem to be useful since it will not influence outcome and costs.     

Cytokine and hepatitis B virus DNA co-immunizations enhance cellular and humoral immune responses to the middle but not to the large hepatitis B virus surface antigen in mice

Genetic immunization is a potentially useful strategy to prevent or treat hepatitis B virus (HBV) infection. We have previously shown that HBV envelope proteins are highly immunogenic using this technique. The large envelope protein (LHBs), however, induced significantly weaker humoral and cellular immune responses when compared with the middle envelope protein (MHBs). We studied the effect of co-immunizations with cytokine DNA expression constructs encoding for interleukin (IL)-2 and (GM-CSF) on the immunogenicity of LHBs at the B-and T-cell level. Co-immunizations of mice with plasmids encoding for MHBs and IL-2 or GM-CSF increased anti-HBs responses, helper T-cell proliferative activity, and cytotoxic T lymphocyte (CTL) killing. In contrast, co-immunizations of plasmids encoding for LHBs and IL-2 or GM-CSF had no effect on humoral and cellular immune responses. LHBs did not inhibit the production or secretion of IL-2 and GM-CSF. In addition, IL-2, tumor necrosis factor alfa (TNF-alpha), and interferon gamma (IFN-gamma) had no suppressive effect on HBV envelope protein expression in vitro. Based on these data, MHBs, but not LHBs, genetic immunization can be augmented by IL-2 or GM-CSF cytokines.     

System Design and Implementation of a National Image Registry for Orthopaedic Oncology Image Management, Research and Teaching

Orthopaedic oncology is highly dependent on imaging studies to diagnose and treat patients. However, many types of bone tumors are rare creating a lack of teaching and research cases. We have developed a system to locally document and nationally register electronic images for teaching and research on bone tumors. The system minimizes storage requirements and maintains confidentiality using a unique approach. This paper demonstrates the system design and current implementation.     

Role of autobiographical memory in social problem solving and depression.

Depressed patients frequently exhibit deficiencies in social problem solving (SPS). A possible cause of this deficit is an impairment in patients' ability to retrieve specific autobiographical memories. A clinically depressed group and a hospital control group performed the Means-End Problem-Solving (MEPS; J. J. Platt & G. Spivack, 1975a) task, during which they were required to attend to the memories retrieved during solution generation. Memories were categorized according to whether they were specific, categoric, or extended and whether the valence of the memories was positive or negative. Results support the general hypothesis that SPS skill is a function of autobiographical memory retrieval as measured by a cuing task and by the types of memories retrieved during the MEPS. However, the dysfunctional nature of categoric memories in SPS, rather than the importance of specific memories, was highlighted in the depressed group. Valence proved to be an unimportant variable in SPS ability. The cyclical links among autobiographical memory retrieval, SPS skills, and depression are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reovirus induction of and sensitivity to beta interferon in cardiac myocyte cultures correlate with induction of myocarditis and are determined by viral core proteins

Reovirus-induced acute myocarditis in mice serves as a model to investigate non-immune-mediated mechanisms of viral myocarditis. We have used primary cardiac myocyte cultures infected with a large panel of myocarditic and nonmyocarditic reassortant reoviruses to identify determinants of viral myocarditic potential. Here, we report that while both myocarditic and nonmyocarditic reoviruses kill cardiac myocytes, viral myocarditic potential correlates with viral spread through cardiac myocyte cultures and with cumulative cell death. To address the role of secreted interferon (IFN), we added anti-IFN-alpha/beta antibody to infected cardiac myocyte cultures. Antibody benefited nonmyocarditic more than myocarditic virus spread (P < 0.001), and this benefit was associated with the reovirus M1 and L2 genes. There was no benefit for a differentiated skeletal muscle cell line culture (C2C12 cells), suggesting cell type specificity. IFN-beta induction in reovirus-infected cardiac myocyte cultures correlated with viral myocarditic potential (P = 0.006) and was associated with the reovirus M1, S2, and L2 genes. Sensitivity to the antiviral effects of IFN-alpha/beta added to cardiac myocyte cultures also correlated with viral myocarditic potential (P = 0.004) and was associated with the same reovirus genes. Several reoviruses induced IFN-beta levels discordant with their myocarditic phenotypes, and for those tested, sensitivity to IFN-alpha/beta compensated for the anomalous induction levels. Thus, the combination of induction of and sensitivity to IFN-alpha/beta is a determinant of reovirus myocarditic potential. Finally, a nonmyocarditic reovirus induced cardiac lesions in mice depleted of IFN-alpha/beta, demonstrating that IFN-alpha/beta is a determinant of reovirus-induced myocarditis. This provides the first identification of reovirus genes associated with IFN induction and sensitivity and provides the first evidence that IFN-beta can be a determinant of viral myocarditis and reovirus disease.     

Regulation of astroglial-derived dopaminergic neurotrophic factors by interleukin-1 beta in the striatum of young and middle-aged mice

Interleukin-1 beta (IL-1 beta) can induce dopaminergic axonal sprouting in the denervated striatum of parkinsonian animals. In order to determine whether IL-1 beta effects on dopaminergic axonal sprouting are mediated by the induction of astroglial-derived dopaminergic neurotrophic factors, effects of IL-1 beta treatment on acidic and basic fibroblast growth factor (aFGF and bFGF) and glial cell line-derived growth factor (GDNF) gene expression were examined in primary striatal astrocyte cultures and after in vivo administration. We found a selective induction of bFGF mRNA synthesis but not aFGF or GDNF mRNA after IL-1 beta treatment both in vitro and in vivo. This suggests that bFGF may be the putative endogenous dopaminergic neurotrophic factor mediating lesion-induced plasticity of dopamine neurons. In addition, to determine why recovery from injury becomes reduced with age, we examined whether there was an aging-associated decline in the ability of IL-1 beta to induce the synthesis of neurotrophic factors in middle-aged animals compared to young mice. Interestingly, IL-1 beta stimulated a greater induction in bFGF mRNA levels in the middle-aged mice compared to young mice. These results suggest that the regulation of bFGF and possibly its receptor signaling efficacy may vary as the brain ages.     

Whole body spiral CT in primary diagnosis of patients with multiple trauma in emergency situations

PURPOSE: The aim of this study was to evaluate the role of a fast whole body helical CT scanner for primary diagnosis in trauma patients. METHODS: 27 severely injured patients (9 women, 18 men; mean age 43 years) were first examined with a helical CT scanner allowing for digital radiograms up to a length of 1024 mm and continuous helical scans of up to 70 seconds (slice thickness 3 to 10 mm, pitch factor up to 2). The primary CT diagnosis was verified either by x-ray after the CT examination or during the subsequent days, by abdominal ultrasound, by additional CT scans in the following days, and by clinical follow-up. RESULTS: CT showed all clinically relevant injuries of the head, spine, chest, abdomen and pelvis. The diagnosis and classification of vertebral fractures was performed immediately. 4% of the fractures of the extremities and the ribs were not seen primarily. 6% of the injuries were outside the CT scan field. CONCLUSION: Helical CT is a reliable and fast method to obtain vital information and to improve management planning in severely injured patients. It reduces the number of conventional x-ray examinations. In certain cases, additional x-rays of extremity fractures may be required.