Quantitation of ascorbic acid in Arabidopsis thaliana reveals distinct differences between organs and growth phases

Optimal plant growth is the result of the interaction of a complex network of plant hormones and environmental signals. Ascorbic acid (AsA) is a crucial antioxidant in plants and is involved in the regulation of cell division, cell expansion, photosynthesis and hormone biosynthesis. Quantitative analysis of AsA in Arabidopsis thaliana organs was conducted using HPLC with d -isoascorbic acid (Iso-AsA) as an internal standard. Analysis revealed Àuctuations in the levels of AsA in different organs and growth phases when plants were grown under standard conditions. AsA concentrations increased in leaves in direct proportion to leaf size and age. Young siliques (seed set stage) and Àowering buds (open and unopened) showed the highest levels of AsA. A relationship was found between the level of AsA and indole acetic acid (IAA) in leaves, stems, Àowers, and siliques and the highest level of IAA and AsAwere found in the Àowers. In contrast, the lowest level of the plant hormone, salicylic acid, was found in the Àowers and the highest quantity measured in the leaves. Consequently, AsA has been found to be a multifunctional molecule that is involved as a key regulator of plant growth and development.

Metal ions and carcinogenesis

Metals are essential for the normal functioning of living organisms. Their uses in biological systems are varied, but are frequently associated with sites of critical protein function, such as zinc finger motifs and electron or oxygen carriers. These functions only require essential metals in minute amounts, hence they are termed trace metals. Other metals are, however, less beneficial, owing to their ability to promote a wide variety of eleterious health effects, including cancer. Metals such as arsenic, for example, an produce a variety of diseases ranging from keratosis of the palms and feet to cancers in multiple target organs. The nature and type of metal-induced pathologies appear to be dependent on the concentration, speciation, and length of exposure. Unfortunately, human contact with metals is an inescapable consequence of human life, with exposures occurring from both occupational and environmental sources. A uniform mechanism of action for all harmful metals is unlikely, if not implausible, given the diverse chemical properties of each metal. In this chapter we will review the mechanisms of carcinogenesis of arsenic, cadmium, chromium, and nickel, the four known carcinogenic metals that are best understood. The key areas of speciation, bioavailability, and mechanisms of action are discussed with particular reference to the role of metals in alteration of gene expression and maintenance of genomic integrity.

"I will start treatment when I think the time is right":HIV-positive gay men talk about their decision not to access antiretroviral therapy.

In a qualitative study, 20 HIV-infected Australian gay men were interviewed about their decision not to access antiretroviral drug therapy. The main reasons given for the decision were fear of side effects; fear of long-term damage to body organs; the inconvenience of the treatment regimens; belief that the regimen's demands would be a threat to morale; and belief that there was no reason to start therapy in the absence of AIDS-related symptoms. Actions taken by the men to monitor and maintain their health included seeing a doctor regularly; having regular T-cell and viral load tests; and trying to maintain a positive outlook by not letting HIV/AIDS 'take over' their lives. Almost half the men considered they had been subjected to unreasonable pressure to access therapy and there was considerable pride at having resisted this pressure. The findings suggest that the men disagreed with the biomedical model for managing HIV/AIDS only on the question of if and when to access therapy. They also suggest that underlying the men's dissent from the biomedical model was a different mode of thinking than is required by the model: while the model demands thinking that is abstract, the men focused strongly on factors close to the 'here and now' of immediate experience. The practical implications of the findings are explored.

Settlement of Disputes Within the World Trade Organisation: A Guide to the Jurisprudence

The Urugauy Round of Multilateral Trade Negotiations led to the development of a revised set of procedures on dispute settlement. These procedures dealt with a number of significant problems that had arisen under GATT dispute settlement experience. In spite of these important reforms, there are numerous, complex and contentious questions of legal adjudication that any formal dispute settlement system must face. The article outlines the aims and organs of dispute settlement under the WTO. It addresses some of the key questions as to standing, interpetation, evidence and adjudicatory practices and processes. While ongoing moitoring and reform is necessary, an important thesis is that the inherent nature of legal adjudication forces uncertain determinations that can too easily give rise to unwarranted criticism of the system as a whole.

Steroid 21-hydroxylase expression in cultured rat astrocytes

Over the past decade or so it has become widely recognised that the brain is a significant steroidogenic organ. Many publications have highlighted the ability of the brain to synthesise and interconvert a large number of steroid products including cholesterol, progesterone and testosterone. In this study, in vitro experiments were performed to determine if 21-hydroxylation of steroids is undertaken by rat brain astrocytes in culture. This is a common reaction that occurs in the adrenal gland and other organs in mammals, catalysing the conversion of pregn-4-ene-3,20-dione (progesterone) to 21-hydroxypregn-4-ene-3,20-dione (deoxycorticosterone).

Previous reports have indicated that 21-hydroxylation occurs within the rat brain, however, the precise identity of the cells expressing 21-hydroxylase has not yet been determined. Several metabolites, such as 5α-pregnan-3α-ol-20-one (tetrahydroprogesterone) and 3α,21-dihydroxy-5-pregnan-20-one (tetrahydrodeoxycorticosterone) were of particular interest because of their modulatory role in neuronal function, such as their agonist activity at γ-aminobutyric acid (GABA_A) receptors.

Evidence was obtained for the expression of peripheral 21-hydroxylase enzyme (P450c21) in cultured rat brain astrocytes by a combination of mass spectroscopy and molecular biology techniques. This is a significant finding as expression of 21-hydroxylase within astrocytes may be indicative of a wider role for these cells in modulating neuronal behaviour.

The German two-tier board and the German corporate governance code

This paper deals with some interesting recent corporate governance developments in Germany. The focus is in particular on the German Corporate Governance Code, its parts, layout and how it deals with the various organs of German public corporations. The German Code is quite unique since it applies a Code of Good Practice to a two-tier board system, thus making it necessary to deal with the role and functions and the relationship between the management and the supervisory board. This paper concludes that several changes to the German law relating to public corporations since the middle of the 1990s and the introduction of the German Code will ensure that the two-tier board system will remain the favoured board structure for public corporations in Germany. It is, however, submitted that employee participation at supervisory board level will provide particular political challenges for Germany in the near future.

Directors' duty to use their powers for proper or permissable purposes

This article focuses generally on the interaction among several internal company law doctrines such as the supremacy of the articles of association; that other organs cannot interfere with powers exclusively conferred upon a particular organ; that courts will not readily interfere with internal company matters; that directors are under a duty to act in good faith and in the best interest of the company as a whole and under a duty to use their powers for proper or permissible purposes; and that there are some remedies available to shareholders if directors did not perform their powers for a proper or permissible purpose. The specific aim with the article is to establish when and why the courts will be prepared to set aside decisions by directors if they have taken them for an improper or impermissible purpose. The article concludes that the courts will be prepared to set the decisions of directors aside when they have used a particular power substantially or primarily for an improper or impermissible purpose. When the exercise of directors' powers is challenged under circumstances where there were both permissible and impermissible purposes for exercising a particular power, there is no alternative for the court but to inquire into the complex area of the state of mind of those who acted and the motive on which they acted. This is, in fact, second-guessing the decisions of directors.

German corporate governance in international and European context

The main aim with this book is to provide English speaking readers with a comprehensive overview of the German corporate governance model. The authors introduce the reader to the unique features of the German Business and Enterprise Law. The book deals with the most important company organs, namely the General Meeting, the Management Board and the Supervisory Board. The unique interplay among these organs are also covered and the reader is introduced to the particular dynamics of the German two-tier board structure.Further the authors deal with the dominant role of the "German banks" and new players in the German financial markets, focusing particularly on voting rights of these institutions at companies' general meetings and appointing members to companies' supervisory boards. Accounting is shown as the documentary proof of good corporate governance. The final chapter gives an overview of corporate governance in the European Union, the OECD Principles of Corporate Governance and corporate governance in the US, the UK and Australia.

Estuarine fish health assessment: evidence of wastewater impacts based on nitrogen isotopes and histopathology

Sewage effluent is a powerful agent of ecological change in estuaries. While the effects of sewage pollution on water quality are usually well documented, biological responses of exposed organisms are not. We quantified health impacts in the form of pathological tissue changes across multiple organs in estuarine fish exposed to elevated levels of treated wastewater. Structural pathologies were compared in wild populations of four fish species from two subtropical estuaries on the east coast of Australia that differ substantially in the amount of direct wastewater loadings. Uptake of sewage-derived  nitrogen by fish was traced with stable nitrogen isotopes. Pathologies were common in the liver, spleen, gill, kidney and muscle tissues, and included granulomas, melanomacrophage aggregates, and multiple deformities of the gill epithelia. Tissue deformities were more frequent in fish exposed directly to wastewater discharges. Mullet (Valamugil georgii) were most affected, with only a single specimen free of pathologies in the sewage-impacted estuary. Similarly, in those fish that had structural abnormalities, more deformities were generally found in individuals from sites receiving sewage. These spatial contrasts in impaired fish health correspond to significantly enriched δ₁₅N values in fish muscle as a consequence of fish assimilating sewage-N. Overall, the pattern of lower health and enriched δ₁₅N values in fish from sewage-impacted areas suggests that organism health is lowered by sewage inputs to estuaries. Measurements of organism health are required to understand the effects of sewage on estuarine ecosystems, and histopathology of fishes is a powerful tool to achieve this.

Exercise increases serum Hsp72 in humans

Recent evidence suggests that heat shock proteins (Hsps) may have an important systemic role as a signal to activate the immune system. Since acute exercise is known to induce Hsp72 (the inducible form of the 70-kDa family of Hsp) in a variety of tissues including contracting skeletal muscle, we hypothesized that such exercise would result in the release of Hsp72 from stressed cells into the blood. Six humans (5 males, 1 female) ran on a treadmill for 60 minutes at a workload corresponding to 70% of their peak oxygen consumption. Blood was sampled from a forearm vein at rest (R), 30 minutes during exercise, immediately postexercise (60 minutes), and 2, 8, and 24 hours after exercise. These samples were analyzed for serum Hsp72 protein. In addition, plasma creatine kinase (CK) was measured at these time points as a crude marker of muscle damage. With the exception of the sample collected at 30 minutes, muscle biopsies (n = 5 males) were also obtained from the vastus lateralis at the time of blood sampling and analyzed for Hsp72 gene and protein expression. Serum Hsp72 protein increased from rest, both during and after exercise (0.13 0.10 vs 0.87 ± 0.24 and 1.02 ± 0.41 ng/mL at rest, 30 and 60 minutes, respectively, P < 0.05, mean SE). In addition, plasma CK was elevated (P < 0.05) 8 hours postexercise. Skeletal muscle Hsp72 mRNA expression increased 6.5-fold (P < 0.05) from rest 2 hours postexercise, and although there was a tendency for Hsp72 protein expression to be elevated 2 and 8 hours following exercise compared with rest, results were not statistically significant. The increase in serum Hsp72 preceded any increase in Hsp72 gene or protein expression in contracting muscle, suggesting that Hsp72 was released from other tissues or organs. This study is the first to demonstrate that acute exercise can increase Hsp72 in the peripheral circulation, suggesting that during stress these proteins may indeed have a systemic role.

Chronological changes in tissue copper, zinc and iron in the toxic milk mouse and effects of copper loading

The toxic milk (tx) mouse is a rodent model for Wilson disease, an inherited disorder of copper overload. Here we assessed the effect of copper accumulation in the tx mouse on zinc and iron metabolism. Copper, zinc and iron concentrations were determined in the liver, kidney, spleen and brain of control and copper-loaded animals by atomic absorption spectroscopy. Copper concentration increased dramatically in the liver, and was also significantly higher in the spleen, kidney and brain of control tx mice in the first few months of life compared with normal DL mice. Hepatic zinc was increased with age in the tx mouse, but zinc concentrations in the other organs were normal. Liver and kidney iron concentrations were significantly lower at birth in tx mice, but increased quickly to be comparable with control mice by 2 months of age. Iron concentration in the spleen was significantly higher in tx mice, but was lower in 5 day old tx pups. Copper-loading studies showed that normal DL mice ingesting 300 mg/l copper in their diet for 3 months maintained normal liver, kidney and brain copper, zinc and iron levels. Copper-loading of tx mice did not increase the already high liver copper concentrations, but spleen and brain copper concentrations were increased. Despite a significant elevation of copper in the brain of the copper-loaded tx mice no behavioural changes were observed. The livers of copper-loaded tx mice had a lower zinc concentration than control tx mice, whilst the kidney had double the concentration of iron suggesting that there was increased erythrocyte hemolysis in the copper-loaded mutants.

In search of coherent jurisprudence for international criminal law : correlating universal human responsibilities with universal human rights

I. The Evolution of International Criminal Law International criminal justice concerns breaches of international rules entailing the personal criminal liability of individuals (as opposed to the State for which the individuals may act as agents or organs), and presently includes acts such as genocide, torture, crimes against humanity, aggression and terrorism. ... A rule stating: any act of armed conflict which directly causes the death of a civilian is a war crime unless it can be shown that the military advantage gained by the attack outweighs the harm. ... Thus, so far as international criminal law is concerned any act during armed conflict which results in the death or injury to a person who does not pose a direct threat to the life of the accused should be a war crime. ... Pursuant to the Rome Statute and as a matter of customary international law torture is a war crime when performed in the context of an armed conflict, and a crime against humanity when it is part of systematic criminal conduct. ... Torture can also constitute an individual international crime, even where it does not satisfy the criteria of a war crime or crime against humanity. ...

Differential effects of dietary fatty acids on genes associated with liver fat metabolism

Background – It has been recognized that specific fatty acids have the ability to directly influence the abundance of gene transcripts in organs such as the liver. However little comparison has been made between the effects of common dietary of fatty acids and there influence on gene expression.
Objectives – To determine the effect of diets rich saturated, monounsaturated and polyunsaturated on gene transcripts associated with liver fat metabolism. Specifically how these three classes of fatty acids influence mRNA levels of key transcriptional regulators (PGC1a, PPARa, PPARd, SREBP1C & ChREBP), fat oxidative (ACO, LCPT1, HMG-CoA lyase & UCP-2) and fat synthetic (ACC, MCD, GPAT & malic enzyme) genes were investigated.
Design - Rats (n=32) were evenly divided into four groups; a saturated fat diet, a monounsaturated fat diet, a polyunsaturated fat diet (each diet contained 23% fat) and standard rat chow (7% fat) diet and fed for 12 weeks. Real-time PCR analysis was performed on liver tissue.
Outcomes – PGC1a and SREBP1C increased 1.9 fold or greater in all groups. Conversely, PPARa, PPARd and ChREBP demonstrated variable changes with diet composition. Monounsaturated and polyunsaturated fat increased HMG-CoA lyase 2.8 fold, a response that was absent in the saturated fat fed animals. UCP-2 was decrease 3.0 fold by all dietary treatments. Malic enzyme was increased 2.8 and 2.4 fold with saturated and polyunsaturated diets respectively, yet was unaltered by the monounsaturated fat diet.
Conclusion – Modifications in common dietary fat composition initiated divergent gene responses in liver. These alterations were complex, with no uniform alteration in transcription factors with closely related functions (PPARfamily) and genes encoding proteins within the same metabolic pathway (fat oxidation or fat synthesis). Further studies are necessary to identify the predominant mechanisms regulating these differences in gene expression.