Elastin calcification in in vitro models and its prevention by MGP’s N-terminal peptide

Medial calcification has been associated with diabetes, chronic kidney disease, and genetic disorders like pseudoxanthoma elasticum. Recently, we showed that genetic reduction of arterial elastin content reduces the severity of medial calcification in matrix Gla protein (MGP)-deficient and Eln haploinsufficient Mgp?/?;Eln+/? mice. This study suggests that there might be a direct effect of elastin amount on medial calcification. We studied this using novel in vitro systems, which are based on elastin or elastin-like polypeptides. We first examined the mineral deposition properties of a transfected pigmented epithelial cell line that expresses elastin and other elastic lamina proteins. When grown in inorganic phosphate-supplemented medium, these cells deposited calcium phosphate minerals, which could be prevented by an N’-terminal peptide of MGP (m3pS) carrying phosphorylated serine residues. We next confirmed these findings using a cell-free elastin-like polypeptide (ELP₃) scaffold, where the peptide prevented mineral maturation. Overall, this work describes a novel cell culture model for elastocalcinosis and examines the inhibition of mineral deposition by the m3pS peptide in this and a cell-free elastin-based scaffold. Our study provides strong evidence suggesting the critical functional roles of MGP’s phosphorylated serine residues in the prevention of elastin calcification and proposes a possible mechanism of their action.     

International non-governmental actors in HIV/AIDS prevention in China

International non-governmental organizations were among the first international actors that responded to the emergence of AIDS crisis in China. Since 1994, the number of international non-governmental organizations and charitable foundations working in AIDS related issue areas in China has grown steadily and substantially. Despite their organizational differences, most of these non-governmental actors present the characteristics of independent mission, localized practice and diverse working focus. Even though they are constrained by financial and other factors compared with multilateral and bilateral official assistance agencies, they have still played a unique role in fighting against AIDS in China as technical experts, public educators, and civil society supporters.     

International non-governmental actors in HIV/AIDS prevention in China

INTRODUCTION This research examines a group of international non- governmental organizations (NGOs) and private founda- tions that have worked and/or are still working in HIV/ AIDS prevention related issue areas in China. Main char- acteristics of this tr…     

AIDS Research and Its Role in China＇s AIDS Prevention and Control Policies

By the end of 2005, the estimated number of HIV infected people in China was 650,000. The seriousness of the epidemic calls for effective control measures to tackle the problems in order to avoid the tragedy in Africa from happening in China. ＂Prevention First＂ is the cornerstone of the country＇s health policy. On 2003 World AIDS Day, Premier Jiabao Wen announced a new national AIDS control policy, ＂Four Frees and One Care＂. This policy clearly shows that the Chinese government has once again taken full responsibility to solve public health problems and has profound impact far beyond the AIDS field. In early 2006, the central government put scientific and technology innovation as a national priority and set the target to build an innovative China by year 2020. Since then, the government has been increasing investment in science and technology with major emphasis on both infectious diseases control and new drug research and development. For the first time, development of 100 new drugs and control of major infectious diseases （AIDS, HBV, TB and other emerging infectious diseases） have been selected as national key scientific projects. China＇s best minds in related fields will be pooled to work together in order to remove the technical barriers blocking efficient control of the major infectious disease in China. Knowledge on molecular epidemiology, immunology, pathogenesis, HAART, as well as HIVDR strains will certainly provide urgently needed scientific information for China＇s AIDS control program. Only evidence-based strategy from good research will provide long-term effective control of AIDS.     

Ubiquitin-protein ligase parkin and its role in the development of Parkinson’s disease

Parkin is a protein encoded by the corresponding parkin gene. It exhibits ubiquitin-protein ligase activity. In this review, we analyze domain structure, substrate specificity, subcellular localization of parkin, and regulation of its activity. Then we discuss data on the effects of various mutations in the parkin gene on structure and functions of this protein and results obtained with parkin knock-out animals. Better understanding of parkin biochemistry, its compartmentalization, functions, and altered functions would help the development of new approaches for the treatment of both inherited and sporadic cases of Parkinson’s disease. Published in Russian in Biokhimiya, 2006, Vol. 71, No. 8, pp. 1050–1061.     

Ecosystem carbon stocks and their changes in China’s grasslands

The knowledge of carbon (C) stock and its dynamics is crucial for understanding the role of grassland ecosystems in China’s terrestrial C cycle. To date, a comprehensive assessment on C balance in China’s grasslands is still lacking. By reviewing published literature, this study aims to evaluate ecosystem C stocks (both vegetation biomass and soil organic C) and their changes in China’s grasslands. Our results are summarized as follows: (1) biomass C density (C stock per area) of China’s grasslands differed greatly among previous studies, ranging from 215.8 to 348.1 g C m⁻² with an average of 300.2 g C m⁻². Likewise, soil C density also varied greatly between 8.5 and 15.1 kg C m⁻². In total, ecosystem C stock in China’s grasslands was estimated at 29.1 Pg C. (2) Both the magnitude and direction of ecosystem C changes in China’s grasslands differed greatly among previous studies. According to recent reports, neither biomass nor soil C stock in China’s grasslands showed a significant change during the past 20 years, indicating that grassland ecosystems are C neutral. (3) Spatial patterns and temporal dynamics of grassland biomass were closely correlated with precipitation, while changes in soil C stocks exhibited close associations with soil moisture and soil texture. Human activities, such as livestock grazing and fencing could also affect ecosystem C dynamics in China’s grasslands.     

The ‘requirement of total evidence’ and its role in phylogenetic systematics

The question of whether or not to partition data for the purposes of inferring phylogenetic hypotheses remains controversial. Opinions have been especially divided since Kluge's (1989, Systematic Zoology 38, 7–25) claim that data partitioning violates the requirement of total evidence (RTE). Unfortunately, advocacy for or against the RTE has not been based on accurate portrayals of the requirement. The RTE is a basic maxim for non-deductive inference, stipulating that evidence must be considered if it has relevance to an inference. Evidence is relevant if it has a positive or negative effect on a given conclusion. In the case of ℈partitioned’ phylogenetic inferences, the RTE is violated, and the basis for rational belief in any conclusion is compromised, unless it is shown that the partitions are evidentially irrelevant to one another. The goal of phylogenetic systematics is to hypothesize past causal conditions to account for observed shared similarities among two or more species. Such inferences are non-deductive, necessitating consideration of the RTE. Some phylogeneticists claim the parsimony criterion as justification for the RTE. There is no relation between the two – parsimony is a relation between a hypothesis and causal question(s). Parsimony does not dictate the content of premises prior to an inference. ℈Taxonomic congruence,’ ℈supertrees,’ and ℈conditional combination’ methods violate the RTE. Taxonomic congruence and supertree methods also fail to achieve the intended goal of phylogenetic inference, such that ℈consensus trees’ and ℈supertrees’ lack an empirical basis. ℈Conditional combination’ is problematic because hypotheses derived from partitioned data cannot be compared – a causal hypothesis inferred to account for a set of effects only has relevance to those effects, not any comparative relevance to other causal hypotheses. A similar problem arises in the comparisons of hypotheses derived from different causal theories.     

Dam-Induced Displacement and Agricultural Livelihoods in China’s Mekong Basin

Households in China’s Yunnan Province were surveyed to understand the impacts of hydropower development and resettlement on the agricultural livelihoods of rural villagers. Household-level data from this survey are analyzed to test whether income and landholdings vary by resettlement status. Independent sample t-tests and one-way ANOVAs are used to examine how resettlement status relates to income, land allotments, agricultural crops, and government subsides. Results showed that, contrary to predictions, resettlement corresponds to higher household incomes, while differences in landholdings were mixed. Results indicate that while productive landholdings are less for resettled households, new wage labor, government subsidies, and intensified agriculture may contribute to a higher annual mean income at the household level. However, the tradeoff of receiving wage income for reduced landholdings may be a significant vulnerability for the affected households of the Mekong River Basin, since this loss in productive land corresponds to a long-term loss in social security.     

Physiological functions of Wilms’ tumor 1-associating protein and its role in tumourigenesis

The Wilms’ tumor-associated gene WT1 encodes a tumor suppressor gene, which is implicated in renal differentiation and development of adult urogenital system. Wilms’ tumor 1-associating protein (WTAP) is initially identified as a nuclear protein that specifically interacts with WT1 in both in vitro and in vivo assays. WTAP is ubiquitously expressed in different tissues and various growth periods, and its expression is involved in cell cycle, RNA splicing and stabilization, N6-methyladenosine RNA modification, cell proliferation, and apoptosis as well as embryonic development. In the present review, we aimed to summarize the functions of WTAP in various physiological and pathological processes, in particular with regard to the current knowledge about the role of WTAP in tumorigenesis of different cancers.     

Governmental policies on HIV infection in China

This article is a general review of the evolvement of HIV/AIDS-related public policies in China since 1980＇s. It tracks the important laws, regulations and other governmental documents in regard to HIV/AIDS prevention mainly at central level.     

Biomechanism of impact resistance in the woodpecker’s head and its application

The woodpecker does not suffer head/eye impact injuries while drumming on a tree trunk with high acceleration(more than 1000×g) and high frequency.The mechanism that protects the woodpecker’s head has aroused the interest of ornithologists,biologists and scientists in the areas of mechanical engineering,material science and electronics engineering.This article reviews the literature on the biomechanisms and materials responsible for protecting the woodpecker from head impact injury and their applications in engineering and human protection.     

Is there a role for plant-made vaccines in the prevention of HIV/AIDS?

Although educational programs have had some impact, immunization against HIV will be necessary to control the AIDS pandemic. To be effective, vaccination will need to be accessible and affordable, directed against multiple antigens, and delivered in multiple doses. Plant-based vaccines that are heat-stable and easy to produce and administer are suited to this type of strategy. Pilot studies by a number of groups have demonstrated that plant viral expression systems can produce HIV antigens in quantities that are appropriate for use in vaccines. In addition, these plant-made HIV antigens have been shown to be immunogenic. However, given the need for potent cross-clade humoral and T-cell immunity for protection against HIV, and the uncertainty surrounding the efficacy of protein subunit vaccines, it is most likely that plant-made HIV vaccines will find their niche as booster immunizations in prime-boost vaccination schedules.     

Latitudinal and elevational patterns of phylogenetic structure in forest communities in China’s mountains

Science China Life Sciences - The phylogenetic structure incorporates both ecological and evolutionary processes to explain assembly of a local community. The “phylogenetic niche...     

Distribution of α-D-mannose residue on zona pellucida and its role(s) in fertilization in pigs

The present study aims to identify the distribution of α-D-mannose residues on zona pellucida (ZP) and their role(s) in fertilization in pigs. In experiment 1, in vitro matured pig oocytes were freed from cu- mulus cells and treated with fluorescein isothiocyanate-labelled Lens culinaris (FITC-LCA), a D-mannose specific binding lectin. After 30 min of treatment, LCA bound evenly throughout the ZP with strong fluorescence. In experiment 2, when LCA-treated oocytes were used for in vitro fertilization, the number of sperm bound to ZP was significantly decreased, and sperm penetration was almost com- pletely blocked. In experiment 3, polysaccharide mannan was added to the in vitro fertilization medium as a competitive inhibitor. Both the number of sperm bound to ZP and the rate of fertilized oocytes were significantly reduced in the mannan-treated group compared with the control group. In experiment 4, spermatozoa were incubated with mannan in vitro. The number of acrosome-reacted spermatozoa was evidently increased in a time-dependent manner during the incubation. These results suggest that α-D-mannose residues presenting on pig ZP might be an important component of sperm receptor and might induce sperm acrosome reaction and thus facilitate the sperm penetration into the ZP.     

Maltotriose transport and utilization in Baker’s and Brewer’s yeast

Maltotriose is metabolized by baker’s and brewer’s yeast only oxidatively, with a respiratory quotient of 1.0, the being, depending on the strain used, 0–11, as compared with of 6–42μL CO₂ per h per mg dry substance. The transport appeared to proceed by facilitated diffusion (no effects of NaF, iodoacetamide and 3-chlorophenylhydrazonomalononitrile) with a K_T of more than 50mm and was inhibited by maltose > maltotriose > methyl-α-D-glucoside > maltotetraose >D-fruetose >D-glucose. The transport was present constitutively in bothSaccharomyces cerevisiae (baker’s yeast) and inS. uvarum (brewer’s yeast) and it was not significantly stimulated by preincubation with glucose or maltose. The pH optimum was 4.5–5.5, the temperature dependence yielded an activation energy of 26 kJ/mol.