[Short term effect of PM(2.5) on cardiovascular mortality in residents in Changping district, Beijing].

Objective: To make a quantitative evaluation on the short term effect of particulate matter with aerodynamic diameter no more than 2.5 µm (PM(2.5)) on cumulative excess mortality rate (CER) and years of life lost (YLL) in residents in Changping district of Beijing. Methods: The death data in local residents, daily mortality, meteorology data and air pollution data (PM(2.5), SO(2) and NO(2) concentrations) in Changping from 2014 to 2017 were collected. Distributed lag non-linear model was used to assess the age and gender specific cumulative lag effects of PM(2.5) on cardiovascular CER and daily YLL in Changping. Results: The effects of PM(2.5) on cardiovascular CER and YLL were obvious on lag 7 days and lag 9 days, respectively, peaking on day 14, and lasting for 21 days. On lag0-21 days, for a 10 µg/m(3) increase in PM(2.5), the population based CER of cardiovascular disease death was 0.021% (95%CI: 0.004%-0.038%), and the YLL was 1.47 (95%CI: 0.23-2.70) years. Greater PM(2.5) effect were observed in males and the elderly. Conclusion: PM(2.5) increased the risk of cardiovascular disease death and YLL.

Out of America: tracing the genetic footprints of the global diffusion of maize.

Maize was first domesticated in a restricted valley in south-central Mexico. It was diffused throughout the Americas over thousands of years, and following the discovery of the New World by Columbus, was introduced into Europe. Trade and colonization introduced it further into all parts of the world to which it could adapt. Repeated introductions, local selection and adaptation, a highly diverse gene pool and outcrossing nature, and global trade in maize led to difficulty understanding exactly where the diversity of many of the local maize landraces originated. This is particularly true in Africa and Asia, where historical accounts are scarce or contradictory. Knowledge of post-domestication movements of maize around the world would assist in germplasm conservation and plant breeding efforts. To this end, we used SSR markers to genotype multiple individuals from hundreds of representative landraces from around the world. Applying a multidisciplinary approach combining genetic, linguistic, and historical data, we reconstructed possible patterns of maize diffusion throughout the world from American "contribution" centers, which we propose reflect the origins of maize worldwide. These results shed new light on introductions of maize into Africa and Asia. By providing a first globally comprehensive genetic characterization of landraces using markers appropriate to this evolutionary time frame, we explore the post-domestication evolutionary history of maize and highlight original diversity sources that may be tapped for plant improvement in different regions of the world.

Development of new polymorphic microsatellite markers in topmouth culter (Culter alburnus) and determination of their applicability in Culter mongolicus.

Fifteen new polymorphic microsatellite markers were developed for Culter alburnus. In 32 individuals representing a wild population of the Danjiangkou Reservoir, Hubei, China, the number of alleles at these loci varied between 2 and 10, with an average of 5.5. The average observed and expected heterozygosities were 0.664 and 0.681, respectively. The polymorphism information content of 11 loci was more than 0.5 whereas that of the other 4 loci was less than 0.5 but more than 0.25. In addition, the genomes of 30 C. mongolicus individuals were successfully amplified with these primer pairs, indicating that the primer pairs were applicable for the related species, C. mongolicus.

Molecular mapping of genes for opposite leafing in maize using simple-sequence repeat markers.

Maize with opposite phyllotaxy (OP) and also initiating ears in opposite pairs is an aberrant mutant and also precious material for maize breeding and plant evolution studies. Mapping and identifying the markers closely linked to genes for the OP trait are essential for cloning the gene and marker-assisted selection in breeding. We established H14D, a near-isogenic line of the OP trait with H53 genetic background. We found that the OP trait is regulated by two independent dominant genes with mutually complementary relations, named Opp-1 and Opp-2. Screening of seven simple-sequence repeat (SSR) markers among the 105 pairs of SSR primers showed polymorphism between the inbred lines H14D and H53. The polymorphic SSR markers were then used to determine linkage with the trait in an F(2) population with 441 progeny, suggesting that SSR marker umc2094 in the Bin2.01 region is linked with Opp-1 at 6.7 cM, and bnlg1831 in Bin2.06 is linked with Opp-2 at 6.1 cM. Further investigation showed that bnlg1092 and umc1028 are linked to Opp-1 and Opp-2 genes, with genetic distances of 12.2 and 1.9 cM. It was also found that the four SSR markers flank the two OP genes, respectively. These results will be useful for marker-assisted selection breeding of OP maize and will also strengthen the basis for cloning of the opposite leafing gene.

Digestive enzymes along digestive tract of a carnivorous fish Glyptosternum maculatum (Sisoridae, Siluriformes).

This study attempted to determine the presence, distribution and levels of digestive proteases, pepsin, amylase and lipase in the homogenates of digestive tract of a freshwater, cold-adapted, carnivorous teleost of Tibet, Glyptosternum maculatum (n= 10, mean weight: 129.6±28.9 g, mean length: 195.1±16.6 mm, approximately 6 years old), at different temperatures and pH levels. The descending order of protease activity was as follows: stomach (pepsin, 16.16±0.96 U/mg protein), anterior intestine (3.18±0.25 U/mg protein), posterior intestine (1.76±0.21 U/mg protein) and middle intestine (1.52±0.23 U/mg protein). Amylase activity levels in descending order were as follows: anterior intestine (0.0062±0.0007 U/mg protein), stomach (0.0032±0.0009 U/mg protein), middle intestine (0.0023±0.0005 U/mg protein) and posterior intestine (0.0023±0.0004 U/mg protein). The highest lipase activity was found in the anterior intestine (0.83±0.25 U/mg protein), followed by posterior intestine (0.51±0.19 U/mg protein), middle intestine (0.48±0.09 U/mg protein) and stomach (0.39±0.10 U/mg protein). The optimal temperature and pH level for protease were 50°C and 9.0-10.0, respectively, along the intestine. The pepsin optima in the stomach were 30°C and 2.0 respectively. The optimal temperature for amylase was found to be 30°C along the digestive tract and the optimal pH was 7.0 in the intestine and 6.0 in the stomach. The optimal temperature and pH levels of lipase were 30°C, pH 6.0 for the stomach and 40-50°C, pH 8.0 for the intestine, respectively. Hepato-somatic index was 1.35±0.2% and relative intestine length was 0.90±0.19. The weight ratio of the stomach and intestine to body weight was 1.63±0.43% and 1.57±0.24% respectively.

Development and characterization of 16 polymorphic microsatellite loci in the Tibet endemic fish Glyptosternum maculatum.

Sixteen novel polymorphic microsatellite loci were developed and characterized in Glyptosternum maculatum, an endemic fish inhabiting the Yarlung Zangbo River valley, Tibet, China. These loci were developed after the enrichment of microsatellite-containing genomic DNA fragments with a subtractive hybridization protocol. The polymorphism of these loci was analysed with 36 individuals representing a geographical population. The number of alleles found at these loci ranged from 3 to 10. The observed heterozygosity and expected heterozygosity ranged from 0 to 1 and from 0.31 to 0.75, respectively. These microsatellite loci will certainly facilitate the determination of the genetic structure of G. maculatum and the conservation of its genetic resource.

Immunohistochemical study of nucleoporin p62 in the hippocampus and hypothalamus of the rat brain.

We immunohistochemically studied the distribution of nucleoporin p62 in the hippocampus and hypothalamus of rat brain. Previous reports have shown the presence of p62-immunoreactivity (ir) in the nuclear rim in the non-neuronal cells, but the present study showed that of p62-ir within the nucleus in addition to the nuclear rim in the neuronal cells of the hippocampus and hypothalamic nuclei; in these areas the glucocorticoid receptor (GR) undergoes nucleocytoplasmic translocation determined by ligand. We analyzed the expression of p62-ir after adrenalectomy (ADX). ADX changed the localization of GR-ir from the nucleus to the cytoplasm, but did not change the localization or immunoreactivity of p62, suggesting that nucleoporin p62 is stable regardless of intracellular signal transduction between the cytoplasm and the nucleus.

Down-regulation of ACTH and glucocorticoid receptor immunoreactivity in hypothalamic arcuate neurons after adrenalectomy in the rat.

The expression of glucocorticoid receptor (GR) in rat adrenocorticotropin (ACTH)-containing neurons in rat brain was immunohistochemically investigated. ACTH-containing cell bodies were found mainly in the arcuate nucleus. Most of these neurons exhibited GR immunoreactivities in their nuclei. ACTH-containing nerve fibers were distributed in the bed nucleus of the stria terminalis, periventricular nucleus, retrochiasmatic nucleus, parvocellular part of paraventricular nucleus and dorsomedial hypothalamic nucleus. After adrenalectomy there was a marked decrease of ACTH immunoreactivity, as well as GR immunoreactivity, in neurons of the arcuate nucleus, but ACTH immunoreactivity in the fibers was not affected. These results indicate that glucocorticoids up-regulate ACTH and GR production in hypothalamic arcuate neurons, but that glucocorticoid-induced changes could be delayed in the fibers derived from these neurons.

Gender-related considerations in clinical pharmacology and drug therapeutics.

The pharmacokinetics and pharmacodynamics in women are different from that in men because of women's unique anatomy and physiology. Recently, gender-related studies in clinical pharmacology have been emerging, supporting the observation of gender-induced variations in drug response. The hormonal fluctuations during a woman's life span may influence pharmacotherapy. Therefore, gender-related pharmacology should be taken into consideration when prescribing medication for a woman. Data from drug developmental studies, FDA approved label directions, and other clinical research evaluation women's responses to medications are necessary to make optimal pharmacotherapeutic decisions.

Intraneuronal aluminum potentiates iron-induced oxidative stress in cultured rat hippocampal neurons.

Aluminum can facilitate Fe-mediated oxidative injury, which may contribute to Al neurotoxicity. It has been reported that Al potentiates Fe-induced oxidative stress in cultured granule cells, suggesting a mechanism for Al facilitation of Fe-mediated oxidative injury. However, the relationship of intracellular Al concentration to Fe-induced oxidative stress has not been reported. In the present study, neuronal oxidative stress and survival were investigated. Embryo rat hippocampal neuron cultures were treated with Al2(SO4)3 and/or FeSO4. An ionophore, A23187, was utilized to facilitate cellular Al uptake. Intraneuronal Al concentration was ascertained by laser microprobe mass spectrometry (LMMS). Neuronal oxidative stress was measured by confocal laser scanning microscopy, using 2,7-dichlorofluorescin diacetate (DCFH-DA) as a probe. The study showed that neuronal Al uptake was facilitated by the ionophore and that an increase of intraneuronal Al concentration potentiated Fe-induced oxidative stress and neuronal death. The results indicate that Al potentiation of Fe-induced oxidative stress might contribute to Al facilitation of oxidative injury, and thus to Al neurotoxicity.

Aluminum facilitation of iron-mediated lipid peroxidation is dependent on substrate, pH and aluminum and iron concentrations.

It has been suggested that aluminum (Al) plays a role in neurological disorders. The mechanism of its neurotoxicity has not been established. Brain lipid peroxidation (LP) contributes to neurodegeneration. There have been conflicting reports concerning the Al effect on LP. In the present study, LP of three Folch Fractions from bovine brain and five pure phospholipids was determined in the presence of varying concentrations of iron (Fe) and Al at pH 5.5 and 7.4. Lipid peroxidation was measured as thiobarbituric acid reactive substances. Iron initiated LP, whereas Al did not. However, Al significantly facilitated Fe-mediated LP of bovine brain Folch Fractions I and III, bovine brain-derived phosphatidylserine, and egg yolk phosphatidylcholine. Bovine brain phosphatidylserine was the most susceptible substrate among the lipids tested. Aluminum facilitation of LP was Al and Fe concentration dependent. The peroxidation was greater at pH 5.5 than 7.4. There was no significant Al effect with Folch Fraction V, bovine brain-derived phosphatidylethanolamine, phosphatidylcholine, or sphingomyelin. This study confirmed the ability of Al to facilitate Fe-mediated LP and identified the substrates, pH, and Al concentrations favoring the peroxidation. A potential mechanism for Al facilitation of Fe-mediated LP is proposed.

Hydroxyl radical generation in rat brain is initiated by iron but not aluminum, as determined by microdialysis with salicylate trapping and GC-MS analysis.

Free radical-induced brain oxidative injury is thought to play a role in the etiology and pathogenesis of neurodegenerative disorders. Iron (Fe) can catalyze the Fenton reaction and mediate hydroxyl radical (HO.) generation to initiate lipid peroxidation (LP). The neurotoxin aluminum (Al) can facilitate Fe-mediated LP. However, the mechanism of Al-facilitated LP has not been determined. In this study, microdialysis (MD) of the ventral hippocampus was performed in rats exposed to Fe and/or Al sulfate via the MD probe. Salicylate (SA) was included in the dialysate to trap the HO. by forming 2,3-dihydroxybenzoic acid (2,3-DHBA). 2,3-DHBA was quantified by capillary column gas chromatography-mass spectrometry (GC-MS) as a trimethylsilyl (TMS) derivative with 2,4-DHBA as an internal standard. Fe-catalyzed HO. generation was shown in brain interstitial fluid. Aluminum alone did not initiate HO. generation. Al did not facilitate Fe-catalyzed HO. generation. Therefore, the previously reported Al facilitation of Fe-mediated oxidative injury must be due to mechanisms other than increased extracellular HO. generation.