人类基因组多样性保护与伦理学和法律问题初探

人类基因组计划（ｈｕｍａｎ ｇｅｎｏｍｅ ｐｒｏｊｅｃｔ,ＨＧＰ）不研究中的一项重要内容－－基因组研究中的社会学、伦理学和法律问题已引起了我们的普遍关注。本文针对基因组多样性保护中所涉及的人类本身的生存与发展、人与自然及与其他物种的相互关系中的伦理道德的法律问题进行初步探讨。     

The multifaceted capacity of Dps proteins to combat bacterial stress conditions: Detoxification of iron and hydrogen peroxide and DNA binding

Background

The widely expressed Dps proteins, so named after the DNA-binding properties of the first characterized member of the family in Escherichia coli, are considered major players in the bacterial response to stress.

Scope of review

The review describes the distinctive features of the “ferritin-like” ferroxidation reaction, which uses hydrogen peroxide as physiological iron oxidant and therefore permits the concomitant removal of the two reactants that give rise to hydroxyl radicals via Fenton chemistry. It also illustrates the structural elements identified to date that render the interaction of some Dps proteins with DNA possible and outlines briefly the significance of Dps–DNA complex formation and of the Dps interaction with other DNA-binding proteins in relation to the organization of the nucleoid and microbial survival.

General significance

Understanding in molecular terms the distinctive role of Dps proteins in bacterial resistance to general and specific stress conditions.

Major conclusions

The state of the art is that the response to oxidative and peroxide-mediated stress is mediated directly by Dps proteins via their ferritin-like activity. In contrast, the response to other stress conditions derives from the concerted interplay of diverse interactions that Dps proteins may establish with DNA and with other DNA-binding proteins.     

Caffeic acid, tyrosol and p-coumaric acid are potent inhibitors of 5-S-cysteinyl-dopamine induced neurotoxicity

Parkinson’s disease is characterized by a progressive and selective loss of dopaminergic neurons in the substantia nigra. Recent investigations have shown that conjugates such as the 5-S-cysteinyl-dopamine, possess strong neurotoxicity and may contribute to the underlying progression of the disease pathology. Although the neuroprotective actions of flavonoids are well reported, that of hydroxycinnamates and other phenolic acids is less established. We show that the hydroxycinnamates caffeic acid and p-coumaric acid, the hydroxyphenethyl alcohol, tyrosol, and a Champagne wine extract rich in these components protect neurons against injury induced by 5-S-cysteinyl-dopamine in vitro. The protection induced by these polyphenols was equal to or greater than that observed for the flavonoids, (+)-catechin, (−)-epicatechin and quercetin. For example, p-coumaric acid evoked significantly more protection at 1 μM (64.0 ± 3.1%) than both (−)-epicatechin (46.0 ± 4.1%, p < 0.05) and (+)-catechin (13.1 ± 3.0%, p < 0.001) at the same concentration. These data indicate that hydroxycinnamates, phenolic acids and phenolic alcohol are also capable of inducing neuroprotective effects to a similar extent to that seen with flavonoids.     

Glycyrrhizin protection against 3-morpholinosydnonime-induced mitochondrial dysfunction and cell death in lung epithelial cells

The present study was designed to assess the preventive effect of licorice compounds glycyrrhizin and 18beta-glycyrrhetinic acid against mitochondrial damage and cell death in lung epithelial cells exposed to 3-morpholinosydnonime, a donor of nitric oxide and superoxide. Treatment of lung epithelial cells with 3-morpholinosydnonime resulted in the nuclear damage, decrease in the mitochondrial transmembrane potential, cytosolic accumulation of cytochrome c, activation of caspase-3, increase in the formation of reactive oxygen species and depletion of GSH. Treatment of glycyrrhizin and 18beta-glycyrrhetinic acid attenuated the 3-morpholinosydnonime-induced mitochondrial damage, formation of reactive oxygen species and GSH depletion and revealed a maximal inhibitory effect at 10 and 1 muM, respectively; beyond these concentrations the inhibitory effect declined. Melatonin, carboxy-PTIO, rutin and uric acid reduced the 3-morpholinosydnonime-induced cell death. The results show that glycyrrhizin and 18beta-glycyrrhetinic acid seem to prevent the toxic effect of 3-morpholinosydnonime against lung epithelial cells by suppressing the mitochondrial permeability transition that leads to the release of cytochrome c and activation of caspase-3. The preventive effect may be ascribed to the inhibitory action on the formation of reactive oxygen species and depletion of GSH. The findings suggest that licorice compounds seem to prevent the nitrogen species-mediated lung cell damage.     

Rapporteur report: Basics and technology and metrology and standards

The first and second sessions of the Workshop focussed on the basics of ultrasound and infrasound, their applications in both industry and medicine, and metrology and protection standards for ultrasound applications.     

Development and evaluation of intermediate frequency magnetic field exposure system for studies of in vitro biological effects

We have developed an intermediate frequency (IF) magnetic field exposure system for in vitro studies. Since there are no previous studies on exposure to heating-frequency magnetic fields generated from an induction heating (IH) cook top, there is a strong need for such an exposure system and for biological studies of IF magnetic fields. This system mainly consists of a magnetic-field-generating coil housed inside an incubator, inside which cultured cells can be exposed to magnetic field. Two systems were prepared to allow the experiment to be conducted in a double-blind manner. The level of the generated magnetic field was set to 532 microT rms in the exposure space, 23 kHz, 80 times the value in the International Commission on Non-ionizing Radiation Protection (ICNIRP) guidelines, with a spatial field uniformity better than 3.8%. The waveforms were nearly sinusoidal. It was also confirmed that the parasitic electric field was 157 V/m rms and the induced electric field was 1.9 V/m rms. The temperature was maintained at 36.5 +/- 0.5 degrees C for 2 h. Furthermore, leaked magnetic flux density was 0.7 microT rms or lower at extremely low frequency (ELF) and IF in the stopped system when the other system was being operated, and the environmental magnetic flux density was 0.1 microT rms or lower at the center of the coils. As a result, it was confirmed that this system could be successfully used to evaluate the biological effects of exposure to IF magnetic fields.     

The effect of land use change on the vascular plant species turnover in boreal lakes

The effects of different land use types on nutrient and chemical run-off have been widely researched, but the total effect of change in land use on the aquatic species community is not well-known. For this study we researched the effect of land use change on the vascular plant communities in lakes. The study was conducted with aerial photographs and GIS-techniques in the countryside of central Finland. We compared the change in vascular plant species community structure with the change in land use around 25 lakes, between the years 1933–1934 and 1996. The change in land use was analyzed in two different riparian zones. We found several indications of links between changes in land use and aquatic vascular plant species. According to our data a decrease in agricultural land use, in particular fields and meadows, appears to influence species turnover and increases the number of new vascular plant species. When the changes in fields and meadows were added together and compared to the change in species turnover, the correlation was even more evident. Changes in land use types in a zone 0–100 m from the lake shoreline correlated with a change in vascular plant species more often than changes in a larger, adjacent zone, 100–400 m from the shore. This indicates that changes in the few hundred meters nearest the lake have the most elemental consequences for aquatic vascular plant species, giving an indication of the breadth of the protection zones needed between freshwaters and agricultural lands.     

Protective effect of zinc supplementation on blood antioxidant defense system in rats exposed to cadmium

The aim of this study was to assess the effects of subchronic exposure to cadmium (Cd) on the antioxidant defense system of red blood cells (RBCs) and lipid peroxide concentration in the plasma, as well as the possible protective role of zinc (Zn). For this purpose, 60 male Wistar rats (8 weeks old) were divided into three groups: the first group was exposed to Cd in the form of CdCl₂, administered in five doses (each of 0.4 mg Cd/kg BW) on days 5, 10, 15, 20 and 25, giving a total dose of 2 mg Cd/kg BW, i.p.; the second group was simultaneously exposed to Zn and Cd with the same timeline and the same doses of Cd as the first group but with, in addition, injections of Zn in the form of ZnCl₂, administered in doses of 0.8 mg Zn/kg BW, giving a total dose of 4 mg Zn/kg BW, i.p.; a control group received 0.5 mL of physiological saline in an identical manner.

It was shown that exposure to Cd induced a significant decrease (p<0.05) in superoxide dismutase (Zn/Cu SOD) and catalase (CAT) activities in RBCs. Increased lipid peroxide concentration, measured by thiobarbituric acid reactive substances (TBARS), was also observed in the plasma of cadmium-exposed rats. Cd had no effect on glutathione peroxidase (GSH-Px) activity. Zn administration had a beneficial effect on the Cd-induced decrease in Zn/Cu SOD activity (p<0.05) but not on CAT activity. Animals receiving Cd and Zn simultaneously had significantly (p<0.05) lower concentrations of lipid peroxides than rats exposed to Cd alone. Our results indicate that Cd causes oxidative stress and that Zn supply in conditions of exposure to Cd can partially protect against Cd-induced oxidative stress.     

医学干预对武警某部军事训练伤的影响

目的：探讨医学干预对南方某武警部队战士训练伤发生情况的影响。方法：随机将南方某武警部队的一大队,按照干预措施施训,作为干预组;另一大队按照以往常规方法进行训练,不加任何干预措施,作为对照组。观察6个月内的两大队（干预组和对照组）的训练伤发生情况。结果：骨关节和软组织损伤为常见。实施医疗干预可有效降低军事训练伤的发生率（17．95％〈29．18％）,其主要效果在于大幅度降低了骨关节损伤的发生率（6．53％〈10.31％）和软组织损伤的发生率（5．59％〈9．92％）。结论：实施医学干预可有效降低我武警部队军事训练伤的发生率。     

Growth parameters and photosynthetic pigments in leaf segments of Zea mays exposed to cadmium, as related to protection mechanisms

The influence of cadmium on growth parameters and photosynthetic pigment content was studied in maize leaf segments differing in tissue maturity. Experiments were carried out with maize seedlings Zea mays L. cv. Hidosil treated with 25, 50, 100, 150 and 200 microM Cd for 14 days under low light conditions. Tissue age-dependent decrease of fresh mass, dry mass and area of the leaf segments was correlated with Cd concentration in the growth medium. Cd induced changes in chlorophyll and carotenoid contents, and the specific areas and densities of the leaf segments were dependent on age and metal concentration. Results are discussed with respect to the protection mechanisms in the leaf segments.