Oxidative damage to RNA: mechanisms, consequences, and diseases

Overproduction of free radicals can damage cellular components resulting in progressive physiological dysfunction, which has been implicated in many human diseases. Oxidative damage to RNA received little attention until the past decade. Recent studies indicate that RNA, such as messenger RNA and ribosomal RNA, is very vulnerable to oxidative damage. RNA oxidation is not a consequence of dying cells but an early event involved in pathogenesis. Oxidative modification to RNA results in disturbance of the translational process and impairment of protein synthesis, which can cause cell deterioration or even cell death. In this review, we discuss the mechanisms of oxidative damage to RNA and the possible biological consequences of damaged RNA. Furthermore, we review recent evidence suggesting that oxidative damage to RNA may contribute to progression of many human diseases.     

Fleas (Siphonaptera) in nests of boles ( Microtus spp.) in montane habitats of three regions of Utah

As a parallel study of a survey of fleas of trapped small mammals in montane southern Utah, we removed 77 adult fleas from 12 of 13 nests of voles ( Microtus longicaudus, M. montanus and M. richardsoni ) collected from montane meadows in the Abajo and La Sal Mountains, the Markagunt Plateau and Pine Valley Mountains, and the Uinta Mountains, May 1991-July 2002. Six species and subspecies of fleas parasitic on Microtus spp. were found, 1-3 species in each nest. Three specimens of the ubiquitous deer mouse ( Peromyscus spp.) flea Aetheca wagneri (Baker) were also found. We collected the following 7 taxa from the locations indicated: Catallagia decipiens Rothschild in 5 nests: Abajo and Pine Valley Mountains and Markagunt Plateau; Hystrichopsylla dippiei truncata Holland in 2 nests: La Sal and Uinta Mountains; H. occidentalis sylvaticus Campos & Stark in 5 nests: Pine Valley Mountains; Peromyscopsylla selenis (Rothschild) in 1 nest: Markagunt Plateau; A. wagneri in 2 nests: Abajo and Pine Valley Mountains; Megabothris abantis (Rothschild) in 5 nests: Abajo and Uinta Mountains and Markagunt Plateau; Malaraeus telchinus (Rothschild) in 2 nests: Abajo and Pine Valley Mountains. One preserved larva was identified as Hystrichopsylla prob. occidentalis sylvaticus , and 2 dead larvae, the only specimens found in nest 13, were identified as probably the same. Kane County is a new record for C. decipiens and P. selenis ; Kane and Summit Counties are new for M. abantis . Nest surveys can generally supplement rather than replace trapped-host surveys. Their main value is in population studies. They are also a source of larvae for morphology and taxonomy research.     

Thrombin-stimulated cell division involves proteolysis of its cell surface receptor.

A cell-surface component of molecular weight 43,000 is cleaved by thrombin on cells that divide after thrombin treatment, but is not cleaved on cells that are unresponsive to its mitogenic action. Studies with a photoreactive derivative of thrombin showed that its cell surface receptor has a molecular weight of 43,000. This indicates that thrombin must cleave its receptor to stimulate cell division.     

Chronology of the early Solar System from chondrule-bearing calcium-aluminium-rich inclusions

Chondrules and Ca-Al-rich inclusions (CAIs) are high-temperature components of meteorites that formed during transient heating events in the early Solar System. A major unresolved issue is the relative timing of CAI and chondrule formation. From the presence of chondrule fragments in an igneous CAI, it was concluded that some chondrules formed before CAIs (ref. 5). This conclusion is contrary to the presence of relict CAIs inside chondrules, as well as to the higher abundance of 26Al in CAIs; both observations indicate that CAIs pre-date chondrules by 1-3 million years (Myr). Here we report that relict chondrule material in the Allende meteorite, composed of olivine and low-calcium pyroxene, occurs in the outer portions of two CAIs and is 16O-poor (Delta17O approximately -1 per thousand to -5 per thousand). Spinel and diopside in the CAI cores are 16O-rich (Delta17O up to -20 per thousand), whereas diopside in their outer zones, as well as melilite and anorthite, are 16O-depleted (Delta17O = -8 per thousand to 2 per thousand). Both chondrule-bearing CAIs are 26Al-poor with initial 26Al/27Al ratios of (4.7 +/- 1.4) x 10(-6) and <1.2 x 10(-6). We conclude that these CAIs had chondrule material added to them during a re-melting episode approximately 2 Myr after formation of CAIs with the canonical 26Al/27Al ratio of 5 x 10(-5).     

Collaborative Inquiry as a Critical Systemic Approach to Improving Ethics and Governance in the Philippine National Police

Improving ethics and governance in policing is often considered an institutional function that police agencies do as ??expert?? institutions. Participation by other stakeholders may be welcome so long as police are able to control the processes and mechanisms of participation. This paper, based on research done with the Philippine National Police, argues that collaborative inquiry could be an effective critical systemic approach to participation by the wider society in police reform. This could enable both police and non-police stakeholders to work together towards mutual understanding and cooperation as equals towards better policing. This participatory approach is not meant to replace the institutional mechanisms that the police use for their own reform effort, but it is supposed to complement them. The research on which this paper is based was an attempt to design a model for collaborative inquiry at the local municipal level of policing in the Philippines, since the municipality is the lowest operational level for the Philippines?? police service. The results of that study suggest that it is possible to establish such a mechanism and make it work, in effect establishing a Close Knit Knowledge Organisation at the lowest level of operational policing.     

A plasma protein marker for population genetic studies of the desert tortoise ( Xerobates agassizi )

Fifty-seven individual plasma samples from desert tortoises ( Xerobates agassizi ) representing 10 separate populations were analyzed by polyacrylamide gel electrophoresis using alkaline buffers. An albumin-like protein was found to be polymorphic for two electromorphs in northern populations inhabiting the Mohave Desert Province while Sonoran Desert populations to the south were monomorphic. The genetic divergence demonstrated in this survey is similar to earlier studies and provides evidence for the Colorado River as a potential barrier to gene flow among tortoise populations. These data suggest that tortoise plasma, examined by various electrophoretic methods, may provide a nondestructive means of determining the broad regional origin of desert tortoises.     

Book reviews

Affiliated to Astrophysics Div., Space Science Department, European Space Agency.