Determination of thorium isotopes in mineral and environmental water and soil samples by alpha-spectrometry and the fate of thorium in water.

A method has been developed for determination of thorium isotopes in water and soil samples by alpha-spectrometry. After fusion with Na(2)CO(3) and Na(2)O(2) at 600 degrees C, soil samples were leached with HNO(3) and HCl. Thorium in water sample or in soil leaching solution was coprecipitated together with iron (III) as hydroxides and/or carbonates at pH 9 with ammonia solution, separated from uranium and other alpha-emitters by a Microthene-TOPO (tri-octyl-phosphine oxide) chromatographic column, electrodeposited on a stainless steel disk, and measured by alpha-spectrometry. The method was checked with two certified reference materials supplied by the IAEA, and reliable results were obtained. The detection limits of the method for water (soil) samples are 0.44 microBq l(-1) (0.070 Bq kg(-1)) for (232)Th, 0.80 microBq l(-1) (0.13 Bq kg(-1)) for (230)Th and 1.0 microBq l(-1) (0.16 Bq kg(-1)) for (228)Th, respectively, if 100 l of water (0.50 g) for each sample are analysed. A variety of water or soil samples were analysed using this procedure and giving average thorium yields of 75.5+/-14.2% for water and 93.4+/-4.5% for soil. The obtained concentrations of thorium isotopes in water samples are in the range of 0.0007-0.0326 mBq l(-1) for (232)Th,

Changes in HCV viremia following LDL apheresis in a HCV positive patient with familial hypercholesterolemia.

It has been suggested that hepatitis C virus (HCV) can be associated with beta-lipoprotein in human serum. According to this, the LDL receptor could promote endocytosis of such a virus. In the present study, we evaluated the changes in HCV viremia in a HCV positive patient with familial hypercholesterolemia, undergoing both selective (DALI System, Fresenius) and non-selective (plasma exchange) LDL apheresis. HCV-RNA levels did not decrease following selective LDL apheresis, on the contrary showed a random, odd variation pattern (from -35% to +72%). Conversely, plasma exchange steadily induced a drop in HCV viremia (-35/43%), to a lower extent than that of a totally intravascular plasmaprotein, i.e., alpha 2-macroglobulin (-53/54%). These data indicate that beta-lipoprotein may not function as a plasma carrier of HCV, at least in the present case. Moreover, a continuous, quantitatively unforeseeable circulation of HCV virions from the intravascular plasma compartment to other extravascular and intracellular sites, seems to occur during an apheresis session.

Gene therapy of glioblastoma multiforme via combined expression of suicide and cytokine genes: a pilot study in humans.

Retrovirus-mediated gene therapy is a particularly attractive approach for glioblastoma multiforme (GBM), given the poor prognosis of this tumour and its localized proliferation in post-mitotic tissue. In this study we assessed, for the first time in humans, the therapeutic potential of a newly designed bicistronic Moloney vector (pLIL-2-TK), combining the expression of a suicide gene (thymidine kinase, tk) with an immunomodulatory gene (human interleukin 2, IL-2). Evidence of transgene activity in the treated tumours is presented.

Typing of hepatitis C virus by a new method based on restriction fragment length polymorphism.

A new restriction fragment length polymorphism (RFLP) analysis has been developed for hepatitis C virus (HCV) typing in the viral 5' non-coding region and contiguous core region. These genomic sequences were chosen for the relative nucleotide homology among different genotypes and for the presence of polymorphic sites. By employing two endonucleases (AccI and MboI) and, in some instances, a third one (EcoRII), we can unambiguously and reproducibly distinguish between genotypes and subtypes 1a, 1b, 1c, 2a, 2c, 2b, 3a, 3b, 4a, 5a and 6a. The method was applied for diagnosing two Italian groups of HCV-infected individuals reflecting a randomly collected population and a group of intravenous drug users. The accuracy of this method has been validated by comparison with INNOLiPA and by sequencing. Our approach represents an improvement over previous RFLP methods, since typing is accurate and simpler.

Production and characterization of a bicistronic Moloney-based retroviral vector expressing human interleukin 2 and herpes simplex virus thymidine kinase for gene therapy of cancer.

Gene-based therapeutic strategies for cancer mainly include augmentation of immunotherapeutic and chemotherapeutic approaches. In this study we report the design and functional assay of a novel bicistronic Moloney-based retroviral vector expressing human interleukin-2 (IL-2) and herpesvirus thymidine kinase (tk) through a cap-dependent translation and an internal ribosome entry site (IRES)-regulated translation, respectively. This construct has the potential for allowing combination of cytokine and suicide gene therapy, especially in areas such as the brain, composed of post-mitotic cells refractory to transduction by type C retroviral vectors. Accordingly, human glioma cells were used as targets for gene transfer after selecting a packaging cell clone that produced a reasonable titer of recombinant virus and expressed high levels of IL-2 and tk transcripts. Although transduction efficiency was reduced in glioma cells as compared with murine NIH 3T3 cells, transgene expression was effectively achieved. Transduced glioma cells were sensitive to ganciclovir and secreted around 1000 U/ml IL-2 in the culture supernatants. Simultaneous production of IL-2 and tk in vivo by genetically treated tumor cells would hopefully potentiate the effect of gangiclovir-induced metabolic suicide, possibly by boosting the immune response associated with tumor debulking or by amplifying the bystander response.

Human cytomegalovirus and restenosis of the internal carotid artery.

BACKGROUND: Although human cytomegalovirus (HCMV) has been implicated in coronary restenosis, data on the presence of HCMV in the restenosis lesion of the internal carotid artery (ICA) are lacking. SUMMARY OF REPORT: We studied endarterectomy tissue from 5 ICA restenosis and 5 primary atherosclerotic lesions and tissue from 5 normal ICAs. The extracted DNA was tested for HCMV sequences with polymerase chain reaction by use of three primer pairs that amplify different genomic regions. The AD 169 strain of HCMV served as the positive control. No trace of the HCMV genome was found in the intima or in the underlying media of endarterectomy specimens from restenosis and primary lesions. The media from control arteries was also HCMV negative. CONCLUSIONS: At variance with previous studies carried out in coronary arteries, our results do not support the hypothesis that HCMV infection is implicated in restenosis of the ICA.