Cypa 1993

[Nadal Braymiller]

Pyreneis commonly found in PAH mixtures, and its urinary metabolite, 1-hydroxypyrene, has been used as an indicator of exposure to PAH chemicals [Becher and Bjorseth 1983; Granella and Clonfero 1993; Popp 1997; Santella et al. 1993, CDC 2005]. The ACGIH recommends measurement of 1-hydroxypyrene in the end-of-shift, end-of-work-week urine samples as a biological exposure index (BEI) for assessment of exposure to mixtures containing PAHs.

PAHs are absorbed through ingestion, inhalation, and dermal contact, according to animal study data. The percent absorbed varies in these studies for several reasons, including the vehicle (transport medium) in which the PAHs are found [Kawamura et al. 1988]. In general, PAHs not bound to particulate matter may be absorbed in the lungs better than the same dose found on the surface of airborne particulate matter [Cresia et al. 1976; Seto 1993].

PAHs differ with respect to distribution patterns and lipophilic properties [Busbee et al. 1990]. Because of their lipophilic nature, PAHs can accumulate in breast milk and adipose tissue. However, biliary and urinary excretion of PAHs is relatively efficient because of the wide distribution of enzymes that transform PAHs into polar metabolites.

PAHs are transformed initially to epoxides, which are converted to dihydrodiol derivatives and phenols. Glucuronide and sulfate conjugates of these metabolites are excreted in the bile and urine. Glutathione conjugates are further metabolized to mercapturic acids in the kidney and are excreted in the urine.

The hydroxylated metabolites of the PAHs are excreted in human urine both as free hydroxylated metabolites and as hydroxylated metabolites conjugated to glucuronic acid and sulfate [CDC 2005]. A commonly measured urinary metabolite is 1-hydroxypyrene [Becher and Bjorseth 1983; Granella and Clonfero 1993; Popp 1997; Santella 1993].

Kyusik Kim, Ann Dauphin, Sevnur Komurlu, Sean M. McCauley, Leonid A. Yurkovetskiy, Claudia Carbone, William E. Diehl, Caterina Strambio-De-Castillia, Edward M. Campbell, and Jeremy Luban. Cyclophilin A protects HIV-1 from restriction by human TRIM5α. Nature Microbiology is online today and the full PDF can be accessed here.

In 1993, in one of the first two-hybrid screens of a mammalian cDNA library for encoded proteins that interact with a protein of interest, undergraduate student Karen Bossolt discovered that the HIV-1 Gag polyprotein, as well as the mature capsid protein (CA) embedded within it, bind to the cellular protein cyclophilin A (CypA). In 2001, graduate student Douglas Braaten formally demonstrated the importance of this interaction for HIV-1 replication in what was perhaps the first targeted gene disruption experiment by homologous recombination in somatic cells. Over the years, attempts to determine the mechanism of action of cyclophilin A have nonetheless taken many unexpected turns.

Several observations suggested that cyclophilin A protected the incoming HIV-1 CA core from a dominant-acting, antiviral factor within human target cells. Among other properties, the putative antiviral factor was cell type-specific, species-specific, saturated by large amounts of susceptible virion cores, and disrupted by arsenic. Then, in 2004, two screens identified TRIM5 as a species-specific, capsid-specific, restriction factor. The first screen, which used a macaque cDNA expression library, was conducted by graduate student Matt Stremlau in the Sodroski lab. He showed that the macaque TRIM5α orthologue restricted HIV-1; he was unable to detect this anti-HIV-1 activity with the human TRIM5α orthologue. The second screen was conducted by graduate student David Sayah who screened an owl monkey cDNA library. David discovered that the potent anti-HIV-1 restriction activity in this species was also due to the TRIM5 gene, but with a twist: a CypA cDNA had retrotransposed into the owl monkey TRIM5 locus to create a TRIM5-CypA fusion gene that is among the most potent anti-HIV-1 restriction factors. Amazingly, there is now evidence that CypA cDNA has retrotransposed into the TRIM5 locus at least 9 separate times over the course of phylogeny to create fusion genes. Presumably these TRIM5-CypA fusion genes were selected for by challenges with lentiviral ancestors of HIV-1.

The above experiments suggested that, in human cells, CypA might protect HIV-1 from restriction by TRIM5α. Experiments conducted by Elena in the early days of RNAi indicated that the effects of CypA and TRIM5α were independent of each other when HIV-1 infection was measured on tumor cell lines. Since then, working on a range of different projects, a line of graduate students that includes Thomas Pertel, Nadia Rahm, Martha Neagu, Alberto De Iaco, and Sean McCauley, have improved the efficiency of lentiviral vector-based reverse genetic tools for gene disruption, and for gene delivery, in primary human blood cells. Most recently, graduate students Kyusik Kim and Sean McCauley developed what are the most efficient lentiviral vectors yet.

While studying unrelated host factors that he hypothesized to regulate HIV-1 infection, Kyusik Kim fortuitously disrupted CypA in primary human dendritic cells; CypA had been intended as a negative control since he expected it to have little effect in that specific experiment. To his surprise, CypA knockdown had a qualitatively bigger effect on HIV-1 replication in primary human dendritic cells than it had had in the tumor cell lines that had been used previously. Prior to this, our lentiviral vectors were not efficient enough to disrupt CypA to this extent in dendritic cells. Kyusik found the same impressive CypA knockdown phenotype in primary human macrophages and CD4+ T cells. As described in his new paper, Kyusik shows pretty conclusively that HIV-1 replication is very dependent on CypA in primary cells. But then, most surprising, and perhaps most important of all, Kyusik found that CypA protects HIV-1 from the potent restriction activity of endogenous human TRIM5α in these cells. Until now, the human orthologue of TRIM5α was thought to have little effect on HIV-1 replication.

Being named in the press can be an extremely damaging and intrusive experience for many children and their families. Children involved with criminal proceedings may be unconcerned about being identified at the time and only realise the significance years after the publication, by which time it is too late. Once named, it is very difficult to undo the damage.1

Most children appearing before the criminal courts will be the subject of reporting restrictions which prevent the publication of their name, or other details that are likely to lead to their identification. However, there are circumstances where such reporting restrictions are not put in place. It is incumbent on any professional involved in a case, particularly the lawyer for the child, to check that the appropriate reporting restrictions are in place, or at least that they have been properly applied for and considered by the court.

A brief summary of this guide is as follows. The guide first considers the powers or duties the courts have to make orders restricting reporting, publicity and access to legal proceedings involving a child:

Courts have a duty under s44 CYPA 1933 to have regard to the welfare of any child before it. The court must also bear in mind the principal aim of the youth justice system, which is to prevent offending by children and young persons.2

However, disclosure of the fact that a child is under criminal investigation for an offence, but has not yet been charged for it, normally interferes with their right under Article 8 ECHR. It will be unlawful unless justified, as set out in ZXC v Bloomberg LP.5

William Cornick was 15 when he was arrested for the murder of his teacher Ann Maguire. He was named prior to being charged with the offence. A few days after being charged, the Crown Court made an order preventing his identification pursuant to s39 CYPA 1933. That restriction was lifted after he pled guilty: R v Cornick (William).9

Section 49 CYPA 1933 continues to apply throughout the trial and sentence while the matter remains in the youth court unless specifically lifted by the court. The court has the power to lift the reporting restriction once the child has been convicted, under s49(4A), which provides that:

If a court is satisfied that it is in the public interest to do so, it may, in relation to a child or young person who has been convicted of an offence, by order dispense to any specified extent with the restrictions imposed by subsection (1) above in relation to any proceedings before it to which this section applies by virtue of subsection (2)(a) or (b) above, being proceedings relating to:

Section 49(5) CYPA 1933 provides for additional circumstances where it is permitted to lift reporting restrictions prior to the defendant being found guilty. These are very limited: they are where the defendant is unlawfully at large in respect of a serious offence and needs to be found, or where it would cause an injustice to the defendant not to be named.

The reporting restrictions in s49 CYPA 1933 extend beyond the youth court when a youth court hearing is appealed (either directly to the Crown Court or by way of case stated) and to proceedings on appeal for breach/revocation/amendment of a youth rehabilitation order.15

However, the automatic prohibition on public attendance at youth court hearings does not continue in an appeal. Practitioners can apply to have an appeal held in private. The Crown Prosecution Service (CPS) guidance on reporting restrictions advises that prosecutors should make such an application unless the appeal concerns a matter of law of general importance.16

The relevant factors the court must consider when exercising its power under s45A YJCEA 1999 are set out at s45A(6) and (7), and include considering the welfare of the child, the views expressed by that child, the interests of justice as well as the public interest in avoiding substantial restrictions on reporting.

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