How to perform a comprehensive search for FDG-PET literature

In this study, a comprehensive, unbiassed search strategy for identifying literature on fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in Medline, Embase and Current Contents was developed, with specific search strategies for each database, using MeSH terms as well as free text words for PET and FDG. To examine which text words apply to FDG, we evaluated the ways of spelling FDG in a random sample of FDG-PET articles (n=100). These words were used as free text words in the two databases and overlap was determined. PET publications were identified using the text words ”positron emission tomography” and ”pet$” combined with the respective MeSH terms for each database. To compare the yield of the combined FDG-PET strategy in each database, the retrieved citations were downloaded to Pro-Cite 4.0. Finally, we added search terms for lung cancer, breast cancer, melanoma, head and neck cancer and lymphoma to our strategy and to a short strategy (consisting of the text words ”positron emission tomography” and ”fdg”). In order to measure the yield and precision (positive predictive value, PPV) of our search strategy and compare it with the short one, we screened the title and abstract of the retrieved citations. Reviewing a random sample of the FDG-PET literature yielded 56 different ways of spelling FDG. We confined the list to 11 text words, without missing articles. Of the publications retrieved by these text words, only 4% were indexed by the MeSH term ”Fludeoxyglucose F18” in Medline and 29% by the MeSH-term ”Fluorodeoxyglucose F18” in Embase. Only 51% of PET articles were indexed by the MeSH term ”Tomography, emission-computed” in Medline and 40% by the MeSH term ”Positron emission tomography” in Embase. The combined search strategy for identifying studies on FDG and PET resulted in 2865 publications in Medline and 2646 in Embase. Medline identified 1662 publications not found by Embase; Embase identified 1422 publications not found by Medline. Compared with the short strategy, our search strategy yielded on average 52% more publications (94%, 41% and 20% more in Medline, Embase and Current Contents, respectively). The PPV of our strategy (percent of publications that were really on PET, FDG and the specified subject) was 70%, compared with 76% using the short strategy. Regardless of the strategy used, Embase yielded more publications and was also slightly more specific than Medline. With the recommended strategy, FDG-PET publications can be identified more efficiently. We have shown the importance of searching more than one database and emphasize the use of both MeSH terms and text words in a search strategy. Standardization of the spelling of FDG and indexing of articles on FDG would substantially simplify searching. Received 5 July and in revised form 25 September 1999     

Influence of three potential genetic risk factors for thrombosis in 43 families carrying the factor V Arg 506 to Gln mutation

The factor V (FV) Arg 506 to Gln mutation is the most common abnormality observed in familial thrombophilia. Many studies have shown that its clinical expression differs among families and among carriers. Some thrombotic patients carry an additional genetic risk factor such as protein C, protein S or antithrombin deficiency. We sought to identify other genetic risk factors potentially favouring expression of the thrombotic phenotype in 370 members of 43 families with the FV Arg 506 to Gln mutation. We analysed three candidate polymorphisms in genes involved in the PC anticoagulant pathway, consisting of two polymorphic sites in the 5' non-transcribed region of the PC gene, -1654 C/T and -1641 A/G, with three known combinations (TA, CA and CG) that influence the protein C plasma level; one polymorphic site (4070 A/G) in exon 13 of the FV gene, which influences the plasma factor V concentration, and one polymorphic site (677 C/T) in the methylenetetrahydrofolate reductase gene, which is often associated with moderate hyperhomocysteinaemia. The distribution of these different polymorphisms was similar in patients with a history of thrombosis and those who remained asymptomatic, ruling out the possibility that each of these polymorphisms alone can play a role in the onset of thrombosis in carriers of the FV Arg 506 to Gln mutation.     

New molecular marker for Trypanosoma (Duttonella) vivax identification.

Trypanosoma vivax is a widespread hemoparasite in tropical areas and is pathogenic to ruminant domestic livestock as well as wild ruminants. The accurate identification of parasites in both hosts and vectors is crucial for epidemiological studies and disease control programs. We describe here the development of molecular markers specific for T. vivax identification. These markers were used to identify mouthpart infections in field-collected tsetse flies from Cameroon. The markers target the genomic sequence of a species-specific antigen from the bloodstream stages. No cross amplification with other trypanosome species was observed, which makes the markers a reliable tool to detect T. vivax infections, both in hosts and vectors. The PCR-amplified sequence contains a (CA)_n microsatellite repeat for which 11 different alleles were identified. This microsatellite, which showed high polymorphism, provides a suitable marker for population genetic studies.     

Matrix metalloproteinase inhibitor, CTS-1027, attenuates liver injury and fibrosis in the bile duct-ligated mouse

Aim:  Excessive matrix metalloproteinase (MMP) activity has been implicated in the pathogenesis of acute and chronic liver injury. CTS-1027 is an MMP inhibitor, which has previously been studied in humans as an anti-arthritic agent. Thus, our aim was to assess if CTS-1027 is hepato-protective and anti-fibrogenic during cholestatic liver injury.
Methods:  C57/BL6 mice were subjected to bile duct ligation (BDL) for 14 days. Either CTS-1027 or vehicle was administered by gavage.
Results:  BDL mice treated with CTS-1027 demonstrated a threefold reduction in hepatocyte apoptosis as assessed by the TUNEL assay or immunohistochemistry for caspase 3/7-positive cells as compared to vehicle-treated BDL animals ( P  < 0.01). A 70% reduction in bile infarcts, a histological indicator of liver injury, was also observed in CTS-1027-treated BDL animals. These differences could not be ascribed to differences in cholestasis as serum total bilirubin concentrations were nearly identical in the BDL groups of animals. Markers for stellate cell activation (α-smooth muscle actin) and hepatic fibrogenesis (collagen 1) were reduced in CTS-1027 versus vehicle-treated BDL animals ( P  < 0.05). Overall animal survival following 14 days of BDL was also improved in the group receiving the active drug ( P  < 0.05).
Conclusion:  The BDL mouse, liver injury and hepatic fibrosis are attenuated by treatment with the MMP inhibitor CTS-1027. This drug warrants further evaluation as an anti-fibrogenic drug in hepatic injury.     

High Cup Angle and Microseparation Increase the Wear of Hip Surface Replacements

High wear rates and high patient ion levels have been associated with high (> 55°) cup inclination angles for metal-on-metal surface replacements. Wear rates and patterns have been simulated for ceramic-on-ceramic bearings by applying microseparation to replicate head offset deficiency. We tested 39-mm metal-on-metal surface replacements (n = 5) in a hip simulator with (A) an increased cup inclination angle of 60° and (B) an increased cup inclination angle and microseparation over 2 million cycles. (A) resulted in a ninefold increase in wear rate and (B) resulted in a 17-fold increase in wear rate compared to a standard gait condition study. Wear particles produced under microseparation conditions were larger than those produced under standard conditions but of similar shape (round to oval). The data suggest both head and cup position influence the wear of surface replacements; we believe it likely bearings with high wear either have a high cup inclination angle, an offset deficient head, or a combination of both. One or more of the authors have received funding from The Engineering and Physical Sciences Research Council (JF, EI), the Arthritis Research Campaign (JF, EI, PC,IL), and the National Institute for Health Research (JF). Graham Isaac is an employee of DePuy International (Leeds, UK). John Fisher and Sophie Williams are paid consultants of DePuy International.     

Dy-DTPA derivatives as relaxation agents for very high field MRI: the beneficial effect of slow water exchange on the transverse relaxivities.

Proton longitudinal and transverse relaxivities of Dy(DTPA)(2-) and Dy-DTPA bisamide derivatives (Dy(DTPA-BA): Dy-DTPA bisamide, Dy(DTPA-BEA): Dy-DTPA bisethylamide, Dy(DTPA-BnBA): Dy-DTPA bis-n-butylamide, and Dy(DTPA-BBMA): Dy-DTPA bisbismethylamide) were analyzed between 0.47 T and 18.8 T. Curie longitudinal relaxation was clearly observed at magnetic fields larger than 2.4 T, but the longitudinal relaxivities are limited by the fast rotation of the complexes. Rotational correlation times were separately assessed by deuterium relaxometry of the diamagnetic deuterated lanthanum analogs. Transverse relaxivity, which depends on the square of the magnetic field and on the residence time of the coordinated water molecule (tau(M)), was more than 7.5 times larger at 18.8 T and 310 K for Dy(DTPA-BA) and Dy(DTPA-BEA) as compared to Dy(DTPA)(2-). This difference is mainly related to the slower water exchange of the bisamide complexes, as confirmed by the values of tau(M) measured by oxygen-17 relaxometry. Such Dy-complexes, characterized by relatively long tau(M) values (tauM310 larger than 100 ns but smaller than 1 micros), thus appear to be useful as negative T(2) (or transverse) contrast agents for high-field imaging. This was demonstrated by the spin-echo images of phantoms obtained at 4.7 T on samples containing Dy(DTPA)(2-) and Dy(DTPA-BEA).     

Zeitpunkt der Weichteilrekonstruktion bei schweren Quetschtraumen im Bereich der oberen Extremität

Complex injuries of the distal forearm and the hand by industrial machines often require extensive reconstructive procedures. Crush injuries with soft tissue damage extending over the limits of visible injury require a special approach. Large soft tissue defects often have to be covered by extensive flap procedures. The optimum point of time for plastic reconstruction is an essential question and represents a controversial issue in the literature. To be able to compare different patient cohorts in the future, we classify crush injuries into five clinically relevant categories. In the course of this review article, three different cases of severe crush injuries of the upper extremity are representatively discussed. Two patients were reconstructed in a secondary procedure, one patient in the acute phase. Definite coverage of soft tissue defects in severe crush injuries should be performed secondarily after 5-7 days since the extent of damage in this special form of trauma can often only be judged after a few days and the reconstruction of bones, vessels and tendons is completed.