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1.  Determination of 16 Selected Trace Elements in Children Plasma from China Economical Developed Rural Areas Using High Resolution Magnetic Sector Inductively Coupled Mass Spectrometry 
A rapid, accurate, and high performance method of high resolution sector field inductively coupled plasma mass spectrometry (HR-ICP-MS) combined with a small-size sample (0.1 mL) preparation was established. The method was validated and applied for the determination of 16 selected plasma trace elements (Fe, Cu, Zn, Rb, B, Al, Se, Sr, V, Cr, Mn, Co, As, Mo, Cd, and Pb). The linear working ranges were over three intervals, 0-1 μg/L, 0–10 μg/L and 0–100 μg/L. Correlation coefficients (R2) ranged from 0.9957 to 0.9999 and the limits of quantification (LOQ) ranged from 0.02 μg/L (Rb) to 1.89 μg/L (Se). The trueness (or recovery) spanned from 89.82% (Al) to 119.15% (Se) and precision expressed by the relative standard deviation (RSD %) for intra-day ranging from 1.1% (Zn) to 9.0% (Se), while ranged from 3.7% (Fe) to 12.7% (Al) for interday. A total of 440 plasma samples were collected from Chinese National Nutrition and Health Survey Project 2002 (CNNHS 2002), which represented the status of plasma trace elements for the children aged 3–12 years from China economical developed rural areas. The concentrations of 16 trace elements were summarized and compared by age groups and gender, which can be used as one of the basic components for the formulation of the baseline reference values of trace elements for the children in 2002.
PMCID: PMC3950582  PMID: 24701366
2.  Early Cambrian Pentamerous Cubozoan Embryos from South China 
PLoS ONE  2013;8(8):e70741.
Extant cubozoans are voracious predators characterized by their square shape, four evenly spaced outstretched tentacles and well-developed eyes. A few cubozoan fossils are known from the Middle Cambrian Marjum Formation of Utah and the well-known Carboniferous Mazon Creek Formation of Illinois. Undisputed cubozoan fossils were previously unknown from the early Cambrian; by that time probably all representatives of the living marine phyla, especially those of basal animals, should have evolved.
Microscopic fossils were recovered from a phosphatic limestone in the Lower Cambrian Kuanchuanpu Formation of South China using traditional acetic-acid maceration. Seven of the pre-hatched pentamerous cubozoan embryos, each of which bears five pairs of subumbrellar tentacle buds, were analyzed in detail through computed microtomography (Micro-CT) and scanning electron microscopy (SEM) without coating.
The figured microscopic fossils are unequivocal pre-hatching embryos based on their spherical fertilization envelope and the enclosed soft-tissue that has preserved key anatomical features arranged in perfect pentaradial symmetry, allowing detailed comparison with modern cnidarians, especially medusozoans. A combination of features, such as the claustrum, gonad-lamella, suspensorium and velarium suspended by the frenula, occur exclusively in the gastrovascular system of extant cubozoans, indicating a cubozoan affinity for these fossils. Additionally, the interior anatomy of these embryonic cubozoan fossils unprecedentedly exhibits the development of many new septum-derived lamellae and well-partitioned gastric pockets unknown in living cubozoans, implying that ancestral cubozoans had already evolved highly specialized structures displaying unexpected complexity at the dawn of the Cambrian. The well-developed endodermic lamellae and gastric pockets developed in the late embryonic stages of these cubozoan fossils are comparable with extant pelagic juvenile cubomedusae rather than sessile cubopolyps, whcih indicates a direct development in these fossil taxa, lacking characteristic stages of a typical cnidarian metagenesis such as planktonic planula and sessile polyps.
PMCID: PMC3741300  PMID: 23950993
3.  Comparison between coronary plaque 64-slice spiral CT characteristics and risk factors of coronary artery disease patients in Chinese Han population and Mongolian 
Objective : To compare the coronary atherosclerotic plaque 64-slice spiral CT characteristics and the risk factors of Han (in Inner Mongolia) and Mongolian coronary artery disease patients.
Metho d s: The plaques of 126 Mongolian and 269 Han patients were analyzed by 64-slice spiral CT coronary angiography. Their gender, age, height, body mass, the history of hypertension, diabetes, smoking and family diseases, the levels of triglycerides (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) were compared.
Results: The incidence of plaques (P <0.05), the proportion of plaques in the circumflex branch (P <0.05), the proportion of medium-severe lumen stenosis induced by plaques (P <0.05), and the proportion of obstructive plaque involved multi-branch (P <0.05) of the Mongolian patients were higher. The plaque compositions of the two groups did not differ significantly (P> 0.05). The body mass index of the Mongolian patients was higher (P <0.05). The hypertension, diabetes, smoking history, TG, TC, HDL-C and LDL-C of the two groups did not differ significantly (P> 0.05).
Conclusion: The higher incidence of coronary atherosclerotic plaques and the more severe lesions of the Mongolian patients may be related to their higher body mass index.
PMCID: PMC3817759  PMID: 24353662
64-slice spiral CT; Coronary artery disease; Coronary angiography; Mongolian
4.  Joint Association of Dietary Pattern and Physical Activity Level with Cardiovascular Disease Risk Factors among Chinese Men: A Cross-Sectional Study 
PLoS ONE  2013;8(6):e66210.
The purpose of this cross-sectional study was to investigate the joint associations of physical activity level (PAL) and dietary patterns in relation to cardiovascular disease (CVD) risk factors among Chinese men. The study population consisted of 13 511 Chinese males aged 18–59 years from the 2002 China National Nutrition and Health Survey. Based on dietary data collected by a food frequency questionnaire, four dietary patterns were identified and labeled as “Green Water” (high consumption of rice, vegetables, seafood, pork, and poultry), “Yellow Earth” (high consumption of wheat flour products and starchy tubers), “New Affluent” (high consumption of animal sourced foods and soybean products), and “Western Adopter” (high consumption of animal sourced foods, cakes, and soft drinks). From the information collected by a 1-year physical activity questionnaire, PAL was calculated and classified into 4 categories: sedentary, low active, active, and very active. As compared with their counterparts from the New Affluent pattern, participants who followed the Green Water pattern had a lower likelihood of abdominal obesity (AO; 50.2%), hypertension (HT; 37.9%), hyperglycemia (HG; 41.5%), elevated triglyceride (ETG; 14.5%), low HDL (LHDL; 39.8%), and metabolic syndrome (MS; 51.9%). When compared to sedentary participants, the odds ratio of participants with very active PAL was 0.62 for AO, 0.85 for HT, 0.71 for HG, 0.76 for ETG, 0.74 for LHDL, and 0.58 for MS. Individuals who followed both very active PAL and the Green Water pattern had a lower likelihood of CVD risk factors (AO: 65.8%, HT: 39.1%, HG: 57.4%, ETG: 35.4%, LHDL: 56.1%, and MS: 75.0%), compared to their counterparts who followed both sedentary PAL and the New Affluent pattern. In addition, adherence to both healthy dietary pattern and very active PAL presented a remarkable potential for CVD risk factor prevention.
PMCID: PMC3686814  PMID: 23840426
5.  Fashion, Cooperation, and Social Interactions 
PLoS ONE  2013;8(1):e49441.
Fashion plays such a crucial rule in the evolution of culture and society that it is regarded as a second nature to the human being. Also, its impact on economy is quite nontrivial. On what is fashionable, interestingly, there are two viewpoints that are both extremely widespread but almost opposite: conformists think that what is popular is fashionable, while rebels believe that being different is the essence. Fashion color is fashionable in the first sense, and Lady Gaga in the second. We investigate a model where the population consists of the afore-mentioned two groups of people that are located on social networks (a spatial cellular automata network and small-world networks). This model captures two fundamental kinds of social interactions (coordination and anti-coordination) simultaneously, and also has its own interest to game theory: it is a hybrid model of pure competition and pure cooperation. This is true because when a conformist meets a rebel, they play the zero sum matching pennies game, which is pure competition. When two conformists (rebels) meet, they play the (anti-) coordination game, which is pure cooperation. Simulation shows that simple social interactions greatly promote cooperation: in most cases people can reach an extraordinarily high level of cooperation, through a selfish, myopic, naive, and local interacting dynamic (the best response dynamic). We find that degree of synchronization also plays a critical role, but mostly on the negative side. Four indices, namely cooperation degree, average satisfaction degree, equilibrium ratio and complete ratio, are defined and applied to measure people’s cooperation levels from various angles. Phase transition, as well as emergence of many interesting geographic patterns in the cellular automata network, is also observed.
PMCID: PMC3561397  PMID: 23382799
6.  Role of Aβ-RAGE interaction in oxidative stress and cPLA2 activation in astrocytes and cerebral endothelial cells 
Neuroscience  2011;199:375-385.
Blood-brain barrier (BBB) dysfunctions have been implicated in the development and progression of Alzheimer's disease. Cerebral endothelial cells (CECs) and astrocytes are the main cell components of the BBB. Although amyloid-β oligomers (Aβ42) have been reported to mediate oxidative damage to the CECs and astrocytes and trigger the downstream MAPK/ERK pathway, the cell surface binding site for Aβ42 and exact sequence of these events have yet to be elucidated. In this study, the receptor for advanced glycation endproducts (RAGE) was postulated to function as a signal transducing cell surface receptor for Aβ42 to induce ROS generation from NADPH oxidase and trigger downstream pathways for the phosphorylation of extracellular-signal-regulated kinases (ERK1/2) and cytosolic phosphorilase A2 (cPLA2). We found that Aβ42 competed with the anti-RAGE antibody (AbRAGE) to bind to RAGE on the surfaces of CECs and primary astrocytes. In addition, AbRAGE abrogate Aβ42-induced ROS production and the co-localization between the cytosolic (p47-phox) and membrane (gp91-phox) subunits of NADPH oxidase in both cell types. AbRAGE, as well as NADPH oxidase inhibitor and ROS scavenger suppressed Aβ42-induced ERK1/2 and cPLA2 phosphorylation in CECs. At the same time, only AbRAGE, but not NADPH oxidase inhibitor or ROS scavenger, inhibited the ERK1/2 pathway and cPLA2 phosphorylation in primary astrocytes. Therefore, this study demonstrates that NADPH oxidase complex assembly and ROS production are not required for Aβ42 binding to RAGE at astrocytic surface leading to sequential phosphorylation of ERK1/2 and cPLA2, and suggests the presence of two different RAGE-dependent downstream pathways in the CECs and astrocytes.
PMCID: PMC3237818  PMID: 21978883
Aβ42; RAGE; NADPH oxidase; ERK; cPLA2
7.  Exposure to the Chinese Famine in Early Life and the Risk of Metabolic Syndrome in Adulthood 
Diabetes Care  2011;34(4):1014-1018.
To examine whether exposure to the Chinese famine during fetal life and early childhood is associated with the risks of metabolic syndrome and whether this association is modified by later life environment.
We used data of 7,874 adults born between 1954 and 1964 from the 2002 China National Nutrition and Health Survey. Famine exposure groups were defined as nonexposed; fetal exposed; and early childhood, midchildhood, or late childhood exposed. Excess death rate was used to determine the severity of the famine. The ATP III criteria were used for the definition of metabolic syndrome (three or more of the following variables: elevated fasting triglyceride levels, lower HDL cholesterol levels, elevated fasting glucose levels, higher waist circumference, high blood pressure).
In severely affected famine areas, adults who were exposed to the famine during fetal life had a higher risk of metabolic syndrome, as compared with nonexposed subjects (odds ratio 3.13 [95% CI 1.24–7.89, P = 0.016]). Similar associations were observed among adults who were exposed to the famine during early childhood, but not for adults exposed to the famine during mid- or late childhood. Participants who were born in severely affected famine areas and had Western dietary habits in adulthood or were overweight in adulthood had a particularly high risk of metabolic syndrome in later life.
Exposure to the Chinese famine during fetal life or infancy is associated with an increased risk of metabolic syndrome in adulthood. These associations are stronger among subjects with a Western dietary pattern or who were overweight in adulthood.
PMCID: PMC3064015  PMID: 21310886
8.  Effects of fatty acid unsaturation numbers on membrane fluidity and α-secretase-dependent amyloid precursor protein processing 
Neurochemistry international  2010;58(3):321-329.
Fatty acids may integrate into cell membranes to change physical properties of cell membranes, and subsequently alter cell functions in an unsaturation number-dependent manner. To address the roles of fatty acid unsaturation numbers in cellular pathways of Alzheimer's disease (AD), we systematically investigated the effects of fatty acids on cell membrane fluidity and α-secretase-cleaved soluble amyloid precursor protein (sAPPα) secretion in relations to unsaturation numbers using stearic acid (SA, 18:0), oleic acid (OA, 18:1), linoleic acid (LA, 18:2), α-linolenic acid (ALA, 18:3), arachidonic acid (AA, 20:4), eicosapentaenoic acid (EPA, 20:5), and docosahexaenoic acid (DHA, 22:6). Treatments of differentiated human neuroblastoma (SH-SY5Y cells) with AA, EPA and DHA for 24 h increased sAPPα secretion and membrane fluidity, whereas those treatments with SA, OA, LA and ALA did not. Treatments with AA and DHA did not alter the total expressions of amyloid precursor protein (APP) and α-secretases in SH-SY5Y cells. These results suggested that not all unsaturated fatty acids but only those with 4 or more double bonds, such as AA, EPA and DHA, are able to increase membrane fluidity and lead to increase in sAPPα secretion. This study provides insights into dietary strategies for the prevention of AD.
PMCID: PMC3040984  PMID: 21184792
Fatty acids; membrane fluidity; sAPPα; Alzheimer's disease
9.  Low energy laser light (632.8 nm) suppresses amyloid-β peptide-induced oxidative and inflammatory responses in astrocytes 
Neuroscience  2010;171(3):859-868.
Oxidative stress and inflammation are important processes in the progression of Alzheimer's disease (AD). Recent studies have implicated the role of amyloid β-peptides (Aβ) in mediating these processes. In astrocytes, oligomeric Aβ induces the assembly of NADPH oxidase complexes resulting in its activation to produce anionic superoxide. Aβ also promotes production of pro-inflammatory factors in astrocytes. Since low energy laser has previously been reported to attenuate oxidative stress and inflammation in biological systems, the objective of this study was to examine whether this type of laser light was able to abrogate the oxidative and inflammatory responses induced by Aβ. Primary rat astrocytes were exposed to Helium-Neon laser (λ=632.8 nm), followed by the treatment with oligomeric Aβ. Primary rat astrocytes were used to measure Aβ-induced production of superoxide anions using fluorescence microscopy of dihydroethidium (DHE), assembly of NADPH oxidase subunits by the colocalization between the cytosolic p47phox subunit and the membrane gp91phox subunit using fluorescent confocal microscopy, phosphorylation of cytosolic phospholipase A2 (cPLA2), and expressions of pro-inflammatory factors including interleukin-1β (IL-1β) and inducible nitric-oxide synthase (iNOS) using Western blot Analysis. Our data showed that laser light at 632.8 nm suppressed Aβ-induced superoxide production, colocalization between NADPH oxidase gp91phox and p47phox subunits, phosphorylation of cPLA2, and the expressions of IL-1β and iNOS in primary astrocytes. We demonstrated for the first time that 632.8 nm laser was capable of suppressing cellular pathways of oxidative stress and inflammatory responses critical in the pathogenesis in AD. This study should prove to provide the groundwork for further investigations for the potential use of laser therapy as a treatment for AD.
PMCID: PMC2987533  PMID: 20884337
phospholipase A2; interleukin-1β; iNOS; NADPH oxidase; oxidative stress; phosphorylation; inflammation
10.  Dietary patterns and hypertension among Chinese adults: a nationally representative cross-sectional study 
BMC Public Health  2011;11:925.
Several healthful dietary patterns appear to be effective at lowering blood pressure and preventing hypertension. However, the relationship between dietary patterns and hypertension among a representative Chinese population sample is unclear.
A nationally representative sample of 23 671 participants aged 18-59 years were recruited by the 2002 China National Nutrition and Health Survey. All participants had their blood pressure measured with standardized mercury sphygmomanometers. Hypertension was defined as systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg. We conducted factor analysis using dietary information from a validated food frequency questionnaire to derive dietary patterns. Information of participants on physical activities, education level, annual household income, smoking status and family history of hypertension was collected by interviewer-administrated questionnaires.
Three major dietary patterns, defined as 'Western', 'traditional northern', and 'traditional southern', were identified. Participants with the highest quartile for the score of the Western pattern had significantly higher blood pressure comparing with counterparts in the lowest quartile. In contrast, participants in the top quartile for the score of the traditional southern pattern presented significantly lower blood pressure comparing with counterparts in the lowest quartile. In multivariate analyses the traditional northern pattern score was associated with an odds ratio (OR) of 1.30 (95% confidence interval (CI) 1.11-1.53, P for trend = 0.0001) comparing with the lowest quartile. The OR for the top quartile of score for the traditional southern pattern was 0.73 (95% CI, 0.59-0.89, P for trend = 0.0040) compared with the lowest quartile of traditional southern pattern score. However, the significant association between the traditional northern pattern and prevalence of hypertension disappeared after further adjusting for body mass index (BMI) (P for trend = 0.3), whereas the association between the traditional southern pattern and prevalence of hypertension persisted after further adjusting for BMI (P for trend = 0.01).
We observed a positive relationship between the traditional northern pattern and hypertension that was mediated through differences in BMI. In addition, the traditional southern pattern was significantly associated with lower odds of presenting with hypertension.
PMCID: PMC3299712  PMID: 22168909
11.  Exposure to the Chinese Famine in Early Life and the Risk of Hyperglycemia and Type 2 Diabetes in Adulthood 
Diabetes  2010;59(10):2400-2406.
Early developmental adaptations in response to undernutrition may play an essential role in susceptibility to type 2 diabetes, particularly for those experiencing a “mismatched rich nutritional environment” in later life. We examined the associations of exposure to the Chinese famine (1959–1961) during fetal life and childhood with the risk of hyperglycemia and type 2 diabetes in adulthood.
We used the data for 7,874 rural adults born between 1954 and 1964 in selected communities from the cross-sectional 2002 China National Nutrition and Health Survey. Hyperglycemia was defined as fasting plasma glucose ≥6.1 mmol/l and/or 2-h plasma glucose ≥7.8 mmol/l and/or a previous clinical diagnosis of type 2 diabetes.
Prevalences of hyperglycemia among adults in nonexposed, fetal exposed, early-childhood, mid-childhood, and late-childhood exposed cohorts were 2.4%, 5.7%, 3.9%, 3.4%, and 5.9%, respectively. In severely affected famine areas, fetal-exposed subjects had an increased risk of hyperglycemia compared with nonexposed subjects (odds ratio = 3.92; 95% CI: 1.64–9.39; P = 0.002); this difference was not observed in less severely affected famine areas (odds ratio = 0.57; 95% CI: 0.25–1.31; P = 0.185). The odds ratios were significantly different between groups from the severe and less severe famine areas (P for interaction = 0.001). In severely affected famine areas, fetal-exposed subjects who followed an affluent/Western dietary pattern (odds ratios = 7.63; 95% CI: 2.41–24.1; P = 0.0005) or who had a higher economic status in later life experienced a substantially elevated risk of hyperglycemia (odds ratios = 6.20; 95% CI: 2.08–18.5; P = 0.001).
Fetal exposure to the severe Chinese famine increases the risk of hyperglycemia in adulthood. This association appears to be exacerbated by a nutritionally rich environment in later life.
PMCID: PMC3279550  PMID: 20622161
12.  A new long-proboscid genus of Pseudopolycentropodidae (Mecoptera) from the Middle Jurassic of China and its plant-host specializations 
ZooKeys  2011;281-297.
We describe a new genus and species of Mecoptera with siphonate mouthparts, Sinopolycentropus rasnitsyni gen. et sp. n., assigned to the family Pseudopolycentropodidae Handlirsch, 1925. The specimen was collected from late Middle Jurassic nonmarine strata of the Jiulongshan Formation in Inner Mongolia, northeastern China. The new material provides additional evidence for an early diversification of pseudopolycentropodids that was ongoing during the Middle Jurassic. This diversity also adds to the variety of known pseudopolycentropodids with tubular proboscides that apparently fed on ovulate fluids produced by Mesozoic gymnosperms.
PMCID: PMC3260766  PMID: 22259283
Pseudopolycentropodidae; fossil scorpionfly; new taxon; Jiulongshan Formation; proboscis; insect-plant associations; gymnosperms
13.  Impacts of Membrane Biophysics in Alzheimer's Disease: From Amyloid Precursor Protein Processing to Aβ Peptide-Induced Membrane Changes 
An increasing amount of evidence supports the notion that cytotoxic effects of amyloid-β peptide (Aβ), the main constituent of senile plaques in Alzheimer's disease (AD), are strongly associated with its ability to interact with membranes of neurons and other cerebral cells. Aβ is derived from amyloidogenic cleavage of amyloid precursor protein (AβPP) by β- and γ-secretase. In the nonamyloidogenic pathway, AβPP is cleaved by α-secretases. These two pathways compete with each other, and enhancing the non-amyloidogenic pathway has been suggested as a potential pharmacological approach for the treatment of AD. Since AβPP, α-, β-, and γ-secretases are membrane-associated proteins, AβPP processing and Aβ production can be affected by the membrane composition and properties. There is evidence that membrane composition and properties, in turn, play a critical role in Aβ cytotoxicity associated with its conformational changes and aggregation into oligomers and fibrils. Understanding the mechanisms leading to changes in a membrane's biophysical properties and how they affect AβPP processing and Aβ toxicity should prove to provide new therapeutic strategies for prevention and treatment of AD.
PMCID: PMC3087431  PMID: 21547213
14.  Prevalence of Diabetes and Impaired Fasting Glucose in Chinese Adults, China National Nutrition and Health Survey, 2002 
Preventing Chronic Disease  2010;8(1):A13.
As a result of rapid economic development in China, the lifestyles and dietary habits of its people have been changing, and the rates of obesity, diabetes, and other chronic conditions have increased substantially. We report the prevalence of type 2 diabetes and impaired fasting glucose (IFG) and the association between diabetes and overweight and obesity in Chinese adults. We also compare the results with those from the US National Health and Nutrition Examination Survey, 1999-2002.
Data were from adults aged 20 years or older who participated in the China National Nutrition and Health Survey, 2002 (n = 47,729). Diabetes and IFG were defined by the American Diabetes Association 2009 criteria. We assessed the prevalence of diabetes, IFG, and overweight and obesity by sex, age, region of residence, and ethnicity.
The prevalence of diabetes and IFG in Chinese adults was 2.7% and 4.9%, respectively. The prevalence of diabetes increased with age and body mass index. Men and women had a similar prevalence of diabetes, but men had a significantly higher prevalence of IFG. The prevalence of diabetes among Chinese who lived in urban areas was 2 to 3 times higher than the prevalence among those who lived in rural areas (3.9% for urban areas and 6.1% for large cities vs 1.9% for rural areas), and the prevalence of IFG was 1.5 to 2 times higher (6.1% and 8.1% vs 4.2%, respectively). The prevalence of diabetes among Chinese women and young (20-39 y) and middle-aged (40-59 y) adults who lived in large cities was similar to the prevalence of diabetes in the US population.
The prevalence of diabetes and IFG was much higher in urban than rural areas, particularly in the large cities of China. Prevention must be emphasized among adults to reduce the future social and economic burden of diabetes in China.
PMCID: PMC3044024  PMID: 21159225
15.  Dietary Patterns and Glucose Tolerance Abnormalities in Chinese Adults 
Diabetes Care  2009;32(11):1972-1976.
To investigate the association of the dietary pattern with the presence of newly diagnosed glucose tolerance abnormalities among Chinese adults.
A total of 20,210 adults aged 45–69 years from the 2002 China National Nutrition and Health Survey were included. Information on dietary intake was collected using a validated food frequency questionnaire. Factor analysis and cluster analysis were used to identify the food factors and dietary pattern clusters.
Four dietary pattern clusters were identified (“Green Water,” “Yellow Earth,” “Western Adopter,” and “New Affluence”). The prevalence of glucose tolerance abnormalities ranged from 3.9% in the Green Water to 8.0% in the New Affluence. After adjustment for area, age, sex, current smoking, and physical activity, subjects in the Yellow Earth cluster (prevalence ratio 1.22 [95% CI 1.04–1.43]) and New Affluence cluster (2.05 [1.76–2.37]) had significantly higher prevalence rates compared with those for the Green Water cluster. After further adjustment for BMI and waist-to-height ratio, the elevated risk in the New Affluence remained statistically significant.
Dietary patterns and food factors are associated with the presence of glucose tolerance abnormalities in China, even independent of obesity. A New Affluence diet is an important modifiable risk factor, which needs attention from the prevention point of view.
PMCID: PMC2768212  PMID: 19675202
16.  Amyloid-β peptide induces temporal membrane biphasic changes in astrocytes through cytosolic phospholipase A2 
Biochimica et biophysica acta  2008;1778(11):2512-2519.
Oligomeric amyloid-β peptide (Aβ) is known to induce cytotoxic effects and to damage cell functions in Alzheimer’s disease. However, mechanisms underlying the effects of Aβ on cell membranes have yet to be fully elucidated. In this study, Aβ 1–42 (Aβ42) was shown to cause a temporal biphasic change in membranes of astrocytic DITNC cells using fluorescence microscopy of Laurdan. Aβ42 made astrocyte cell membranes became more molecularly-disordered within the first 30 minutes to 1 hour, but gradually changed to more molecularly-ordered after 3 hours. However, Aβ42 caused artificial membranes of vesicles made of rat whole brain lipid extract to become more disordered only. The trend for more molecularly-ordered membranes in astrocytes induced by Aβ42 was abrogated by either an NADPH oxidase inhibitor, apocynin, or an inhibitor of cytosolic phospholipase A2 (cPLA2), but not by an inhibitor of calcium-independent PLA2 (iPLA2). Apocynin also suppressed the increased production of superoxide anions (O2.−) and phosphorylation of cPLA2 induced by Aβ42. In addition, hydrolyzed products of cPLA2, arachidonic acid (AA), but not lysophosphatidylcholine (LPC) caused astrocyte membranes to become more molecularly-ordered. These results suggest (1) a direct interaction of Aβ42 with cell membranes making them more molecularly-disordered, and (2) Aβ42 also indirectly makes membranes become more molecularly-ordered by triggering the signaling pathway involving NADPH oxidase and cPLA2 in astrocytes.
PMCID: PMC2592609  PMID: 18725190
17.  The Mechanisms of Codon Reassignments in Mitochondrial Genetic Codes 
Journal of Molecular Evolution  2007;64(6):662-688.
Many cases of nonstandard genetic codes are known in mitochondrial genomes. We carry out analysis of phylogeny and codon usage of organisms for which the complete mitochondrial genome is available, and we determine the most likely mechanism for codon reassignment in each case. Reassignment events can be classified according to the gain-loss framework. The “gain” represents the appearance of a new tRNA for the reassigned codon or the change of an existing tRNA such that it gains the ability to pair with the codon. The “loss” represents the deletion of a tRNA or the change in a tRNA so that it no longer translates the codon. One possible mechanism is codon disappearance (CD), where the codon disappears from the genome prior to the gain and loss events. In the alternative mechanisms the codon does not disappear. In the unassigned codon mechanism, the loss occurs first, whereas in the ambiguous intermediate mechanism, the gain occurs first. Codon usage analysis gives clear evidence of cases where the codon disappeared at the point of the reassignment and also cases where it did not disappear. CD is the probable explanation for stop to sense reassignments and a small number of reassignments of sense codons. However, the majority of sense-to-sense reassignments cannot be explained by CD. In the latter cases, by analysis of the presence or absence of tRNAs in the genome and of the changes in tRNA sequences, it is sometimes possible to distinguish between the unassigned codon and the ambiguous intermediate mechanisms. We emphasize that not all reassignments follow the same scenario and that it is necessary to consider the details of each case carefully.
Electronic supplementary material
The online version of this article (doi:10.1007/s00239-006-0284-7) contains supplementary material, which is available to authorized users.
PMCID: PMC1894752  PMID: 17541678
Codon reassignment; Mitochondrial genetic codes; Codon disappearance mechanism; Unassigned codon mechanism; Ambiguous intermediate mechanism

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