The cost of inappropriateness of coagulation testing [I costi dell'inappropriatezza in coagulazione]

Background. Laboratory utilization has steadily increased with a corresponding increase in overall costs; several authors have attempted to measure the impact of inappropriateness on clinical outcomes but data are insufficient. The aim of the study is to assess the cost of inappropriateness of test-ordering behaviour for second-level coagulation tests (hemorrhagic diathesisand thrombophilia). Methods. We reviewed all second-level coagulation testrequests received by our department during a six months period. Clinicians must fill out a specific order form for these kind of tests, containing all informations deemed necessary for the laboratory specialist to evaluatethe appropriateness of the request. We identified all inappropriate requests and counted the numbers and types of all coagulation tests that were not performed during the period. An analysis of the laboratory activity costs was done in order to calculate the global costof each test in our department and to estimate the savings achieved. Results. On a total of 1664 second-level coagulationtest requests, we estimated 150 as completely inappropriate. We found an overall of 295 inappropriate testswhich were not performed. This resulted in an economic saving of 20.000 euro in 6 months. Conclusions. The analysis of cost of our intervention shows the urgent need for a definite and sustained reduction in inappropriate requests of second-level coagulation tests. Even though we estimated only the economic aspect of inappropriate testing, this is also associated with the overuse of diagnostic tests which entailsthe risk of generating erroneous results with potentialnegative consequences on patients' health.

Molecular basis of coagulation factor V deficiency caused by the R1698W inter-domain mutation.

Coagulation factor V (FV) deficiency is characterised by variable bleeding phenotypes and heterogeneous mutations. To add new insights into the FV genotype-phenotype relationship, we characterised the R1698W change in the A3 domain, at the poorly investigated interface with the A2 domain. The FV R1698W mutation was responsible for a markedly reduced expression level (10% of FV-WT) and specific activity in thrombin generation (0.39). Interestingly, the FVa1698W showed rapid activity decay upon activation due to increased dissociation rate between the heavy and light chains. The importance of the size and charge of the residue at position 1698 was investigated by three additional recombinant mutants, FVR1698A, FVR1698Q, and FVR1698E. FVR1698A and FVR1698Q expression (30 and 45% of FV-WT), specific activity (both 0.57) and stability were all reduced. Noticeably, FVR1698E showed normal activity and stability despite poor expression (10% of FV-WT). These data indicate the essential role of R1698 for normal biosynthetic process and support local flexibility for positively or negatively charged residues to produce stable and functional A3-A2 domain interactions. Their experimental alteration produces a gradient of FV defects, which help to interpret the wide spectrum of phenotypes in FV-deficient patients.

Basis set effects on the energy and hardness profiles of the hydrogen fluoride dimer

In earlier work, the present authors have shown that hardness profiles are less dependent on the level of calculation than energy profiles for potential energy surfaces (PESs) having pathological behaviors. At variance with energy profiles, hardness profiles always show the correct number of stationary points. This characteristic has been used to indicate the existence of spurious stationary points on the PESs. In the present work, we apply this methodology to the hydrogen fluoride dimer, a classical difficult case for the density functional theory methods

Patients with AIDS-defining cancers are not universally screened for HIV: a 10-year retrospective analysis of HIV-testing practices in a Swiss university hospital.

OBJECTIVES: Kaposi's sarcoma (KS), invasive cervical carcinoma (ICC) and non-Hodgkin lymphoma (NHL) have been listed as AIDS-defining cancers (ADCs) by the Centers for Disease Control and Prevention since 1993. Despite this, HIV screening is not universally mentioned in ADC treatment guidelines. We examined screening practices at a tertiary centre serving a population where HIV seroprevalence is 0.4%. METHODS: Patients with KS, ICC, NHL and Hodgkin lymphoma (HL), treated at Lausanne University Hospital between January 2002 and July 2012, were studied retrospectively. HIV testing was considered part of the oncology work-up if performed between 90 days before and 90 days after the cancer diagnosis date. RESULTS: A total of 880 patients were examined: 10 with KS, 58 with ICC, 672 with NHL and 140 with HL. HIV testing rates were 100, 11, 60 and 59%, and HIV seroprevalence was 60, 1.7, 3.4 and 5%, respectively. Thirty-seven patients (4.2%) were HIV-positive, of whom eight (22%) were diagnosed at oncology work-up. All newly diagnosed patients had CD4 counts < 200 cells/μL and six (75%) had presented to a physician 12-236 weeks previously with conditions warranting HIV testing. CONCLUSIONS: In our institution, only patients with KS were universally screened. Screening rates for other cancers ranged from 11 to 60%. HIV seroprevalence was at least fourfold higher than the population average. As HIV-positive status impacts on cancer patient medical management, HIV screening should be included in oncology guidelines. Further, we recommend that opt-out screening should be adopted in all patients with ADCs and HL.

Non-invasive RF built-in testing using on-chip temperature sensors

This poster shows how to efficiently observe high-frequency figures of merit in RF circuits by measuring DC temperature with CMOS-compatible built-in sensors.

Recent developments in the use of isotope ratio mass spectrometry in sports drug testing.

According to the annual report of the World Anti-Doping Agency, steroids are the most frequently detected class of doping agents. Detecting the misuse of endogenously occurring steroids, i.e. steroids such as testosterone that are produced naturally by humans, is one of the most challenging issues in doping control analysis. The established thresholds for urinary concentrations or concentration ratios such as the testosterone/epitestosterone quotient are sometimes inconclusive owing to the large biological variation in these parameters.For more than 15 years, doping control laboratories focused on the carbon isotope ratios of endogenous steroids to distinguish between naturally elevated steroid profile parameters and illicit administration of steroids. A variety of different methods has been developed throughout the last decade and the number of different steroids under investigation by isotope ratio mass spectrometry has recently grown considerably. Besides norandrosterone, boldenone was found to occur endogenously in rare cases and the misuse of corticosteroids or epitestosterone can now be detected with the aid of carbon isotope ratios as well. In addition, steroids excreted as sulfoconjugates were investigated, and the first results regarding hydrogen isotope ratios recently became available.All of these will be presented in detail within this review together with some considerations on validation issues and on identification of parameters influencing steroidal isotope ratios in urine.

Large TCR diversity of virus-specific CD8 T cells provides the mechanistic basis for massive TCR renewal after antigen exposure.

Ex vivo analysis of virus-specific CD8 T cell populations by anchored PCR has shown that the CD8 TCR repertoire was less oligoclonal (seven to nine clonotypes per individual epitope) than previously thought. In the current study, TCR diversity was investigated by assessing both the overall TCR β-chain variable regions usage as well as the CDR3 regions in ex vivo-isolated CMV- and EBV-specific CD8 T cells from 27 healthy donors. The average number of clonotypes specific to most single viral epitopes comprised between 14 and 77. Changes in the CD8 TCR repertoire were also longitudinally assessed under conditions of HIV-1 chronic infection (i.e., in patients with suppressed virus replication and after treatment interruption and Ag re-exposure). The results showed that a large renewal (≤80%) of the TRB repertoire occurred after Ag re-exposure and was eventually associated with an increased T cell recognition functional avidity. These results demonstrate that the global CD8 TCR repertoire is much more diverse (≤9-fold) than previously estimated and provide the mechanistic basis for supporting massive repertoire renewal during chronic virus infection and Ag re-exposure.

Crystal structure of yeast peroxisomal multifunctional enzyme: structural basis for substrate specificity of (3R)-hydroxyacyl-CoA dehydrogenase units.

(3R)-hydroxyacyl-CoA dehydrogenase is part of multifunctional enzyme type 2 (MFE-2) of peroxisomal fatty acid beta-oxidation. The MFE-2 protein from yeasts contains in the same polypeptide chain two dehydrogenases (A and B), which possess difference in substrate specificity. The crystal structure of Candida tropicalis (3R)-hydroxyacyl-CoA dehydrogenase AB heterodimer, consisting of dehydrogenase A and B, determined at the resolution of 2.2A, shows overall similarity with the prototypic counterpart from rat, but also important differences that explain the substrate specificity differences observed. Docking studies suggest that dehydrogenase A binds the hydrophobic fatty acyl chain of a medium-chain-length ((3R)-OH-C10) substrate as bent into the binding pocket, whereas the short-chain substrates are dislocated by two mechanisms: (i) a short-chain-length 3-hydroxyacyl group ((3R)-OH-C4) does not reach the hydrophobic contacts needed for anchoring the substrate into the active site; and (ii) Leu44 in the loop above the NAD(+) cofactor attracts short-chain-length substrates away from the active site. Dehydrogenase B, which can use a (3R)-OH-C4 substrate, has a more shallow binding pocket and the substrate is correctly placed for catalysis. Based on the current structure, and together with the structure of the 2-enoyl-CoA hydratase 2 unit of yeast MFE-2 it becomes obvious that in yeast and mammalian MFE-2s, despite basically identical functional domains, the assembly of these domains into a mature, dimeric multifunctional enzyme is very different.