α-Synuclein induces deficiency in clathrin-mediated endocytosis through inhibiting synaptojanin1 expression.

Parkinson's disease (PD) is an age-related chronic neurological disorder, mainly characterized by the pathological feature of α-synuclein (α-syn) aggregation, with the exact disease pathogenesis unclear. During the onset and progression of PD, synaptic dysfunction, including dysregulation of axonal transport, impaired exocytosis, and endocytosis are identified as crucial events of PD pathogenesis. It has been reported that over-expression of α-syn impairs clathrin-mediated endocytosis (CME) in the synapses. However, the underlying mechanisms still needs to be explored. In this study, we investigated the molecular events underlying the synaptic dysfunction caused by over-expression of wild-type human α-syn and its mutant form, involving series of proteins participating in CME. We found that excessive human α-syn causes impaired fission and uncoating of clathrin-coated vesicles during synaptic vesicle recycling, leading to reduced clustering of synaptic vesicles near the active zone and increased size of plasma membrane and number of endocytic intermediates. Furthermore, over-expressed human α-syn induced changes of CME-associated proteins, among which synaptojanin1 (SYNJ1) showed significant reduction in various brain regions. Over-expression of SYNJ1 in primary hippocampal neurons from α-syn transgenic mice recovered the synaptic vesicle density, clustering and endocytosis. Using fluorescence-conjugated transferrin, we demonstrated that SYNJ1 re-boosted the CME activity by restoring the phosphatidylinositol-4,5-bisphosphate homeostasis. Our data suggested that over-expression of α-syn disrupts synaptic function through interfering with vesicle recycling, which could be alleviated by re-availing of SYNJ1. Our study unrevealed a molecular mechanism of the synaptic dysfunction in PD pathogenesis and provided a potential therapeutic target for treating PD.

Heterologous expression and biochemical characterization of a cold-active lipase from Rhizopus microsporus suitable for oleate synthesis and bread making.

OBJECTIVES: Cold-active lipases which show high specific activity at low temperatures are attractive in industrial applications in terms of product stability and energy saving. We aimed to identify novel cold-active lipase suitable for oleates synthesis and bread making. RESULTS: A novel lipase gene (RmLipA) from Rhizopus microsporus was cloned and heterologously expressed in Pichia pastoris. The encoding sequence displayed 75% identity to the lipase from R. niveus. The highest extracellular lipase activity of 7931 U/mL was achieved in a 5-L fermentation. The recombinant enzyme (RmLipA) was optimally active at pH 8.0 and 20-25 °C, respectively, and stable over a wide pH range of 2.0-11.0. The enzyme was a cold-active lipase, exhibiting > 80% of its maximal activity at 0 °C. RmLipA was a sn-1,3 regioselective lipase, and preferred to hydrolyze pNP esters and triglycerides with relatively long chain fatty acids. RmLipA synthesized various oleates using oleic acid and different alcohols as substrates (> 95%). Moreover, it significantly improved the quality of bread by increasing its specific volume (21.7%) and decreasing its crumb firmness (28.6%). CONCLUSIONS: A novel cold-active lipase gene from R. microsporus was identified, and its application potentials were evaluated. RmLipA should be a potential candidate in oleates synthesis and bread making industries.

High-level expression and characterization of a novel phospholipase C from Thielavia terrestris suitable for oil degumming.

A novel phospholipase C gene (TtPLC) from Thielavia terrestris CAU709 was cloned and efficiently expressed in Pichia pastoris. The deduced protein sequence of TtPLC shared the highest identity of 33% with the characterized phospholipase C from Arabidopsis thaliana. The highest phospholipase C yield of 98, 970 U mL-1, with a protein concentration of 4.9 mg mL-1 was obtained by high-cell density fermentation in a 5-L fermentor. The recombinant enzyme (TtPLC) was purified to homogeneity with a recovery yield of 59.1% and a specific activity of 22, 910 U mg-1. TtPLC was most active at pH 6.5 and 55 °C, respectively. It was stable within the pH range of 4.5-8.0 and up to 45 °C. The enzyme exhibited excellent stability in different surfactants and organic solvents, including Tween 20 (147.6%), Tween 40 (180.6%), Tween 60 (205.4%), cyclohexane (160.0%), n-octane (178.2%), n-heptane (180.7%), acetone (187.5%) etc. The application of TtPLC in crude soybean oil degumming process significantly reduced the residual phosphorus content from 135.4 mg kg-1 to 7.9 mg kg-1 under the optimized conditions, which satisfied the requirement of environmental friendly physical refining process for oil refining industry. Therefore, TtPLC should be a good candidate in oil refining industry.

Psychosocial Mechanism of Adolescents' Depression: A Dose-Response Relation with Physical Activity.

Depression has become the most prevalent mental health problem in developing countries, and especially among adolescents. Lubans and his colleagues proposed a psychosocial mechanism to understand the trajectory of mental health (i.e., depression). Thus, this study aimed (1) to examine the relations between different doses of physical activity (PA), light PA (LPA), moderate PA (MPA), and vigorous PA (VPA), academic self-efficacy, and depression among adolescents, and (2) to investigate the direct and indirect relations of various doses of PA to depression through academic self-efficacy among middle school adolescents. Participants were 428 (235 boys, Mean age = 13.7) adolescents recruited from two middle schools in China. They completed previously validated questionnaires to measure different intensity levels of PA (LPA, MPA, and VPA), academic self-efficacy, and depression. There were significant associations of academic self-efficacy with three different doses of PA (p < 0.01). Both LPA and MPA were negatively associated with depression but not VPA. Structural equation modeling (SEM) revealed a well-fit model suggesting the psychosocial pathway from different doses of PA to depression through academic self-efficacy. Findings of this study indicated that academic self-efficacy regulates adolescents' depression. Tailoring different intensities of PA benefits adolescents' academic self-efficacy by framing the positive and supportive environment in schools, which can potentially reduce the prevalence of depression during adolescence.

Biochemical characterization of a novel lipase from Malbranchea cinnamomea suitable for production of lipolyzed milkfat flavor and biodegradation of phthalate esters.

A novel lipase gene (McLipB) was cloned from a thermophilic fungus Malbranchea cinnamomea and expressed in Pichia pastoris. The deduced amino acid sequence of the lipase (McLipB) shared the highest identity of 46% with the Candida rugosa lipase LIP4. The extracellular lipase activity of 4304 U/mL with protein concentration of 7.7 mg/mL was achieved in a 5-L fermentor. The optimal pH and temperature of McLipB were 7.5 and 40 °C, respectively. The lipase showed high specificity towards triglycerides with short and medium chain fatty acids, and had non-position specificity. McLipB hydrolyzed butter to produce mainly butyric acid, hexanoic acid and a small amount of octanoic acid and decanoic acid. Furthermore, it degraded more than 90% dipropyl phthalate, dibutyl phthalate and dihexyl phthalate to their corresponding monoalkyl phthalates. The properties of McLipB indicate that it has great application potential for production of lipolyzed milkfat flavor and biodegradation of phthalate esters.

High-level expression of codon-optimized Thielavia terrestris cutinase suitable for ester biosynthesis and biodegradation.

A codon-optimized cutinase gene (TtCutopt) from Thielavia terrestris was over-expressed in Pichia pastoris. An extracellular activity reached 10,200 U/mL using high cell density fermentation. The optimal pH and temperature of TtCutopt were 7.0 and 50 °C, respectively. It displayed high stability over a wide range of pH from 3.0 to 11.0 and up to 85 °C. Among tested p-nitrophenyl esters and triglycerides, TtCutopt showed the highest activity towards p-nitrophenyl butyrate and tributyrin, with specificity activity of 2322.4 U/mg and 1152.5 U/mg, respectively. It was extremely stable in organic solvents and surfactants. TtCutopt efficiently catalyzed the synthesis of butyl butyrate, hexyl butyrate, butyl hexanoate and hexyl hexanoate with esterification efficiency of >95%. Furthermore, it catalyzed the degradation of >90% of dimethyl phthalate, diethyl phthalate, dipropyl phthalate and dibutyl phthalate to release their corresponding monoalkyl phthalates within 24 h. Thus, high yield, high stability, and esterification efficiency of TtCutopt make it an attractive candidate for ester biosynthesis and biodegradation.

Protective effects of lipoic acid against acrylamide-induced neurotoxicity: involvement of mitochondrial energy metabolism and autophagy.

Acrylamide (ACR) is a chronic neurotoxin that is generated in high-starch foods during heat processing. Alpha-lipoic acid (LA) is an antioxidant that occurs in most plants and animals. The objective of this study was to reveal the mechanism of ACR-triggered neurotoxicity and identify the protective role of LA in SH-SY5Y cells. In this study, LA restored ACR-stimulated depletion of glutathione content and mitochondrial membrane potential, moderated the activation of inflammatory pathways, and recovered the Keap1/Nrf2 pathway. Moreover, LA upregulated the activities of oxidative phosphorylation complexes and diminished ACR-induced variation in AMPK/GSK3ß, Ca2+ disturbance, and ATP depletion. The Sirt1/PGC-1α pathway was inhibited by ACR. Notably, autophagy was activated in the mitochondria-mediated apoptosis induced by ACR, which was also blocked by LA. Overall, our study demonstrated the pivotal roles of the mitochondrial energy metabolism and autophagy in the protective effects of LA and cytotoxicity of ACR in SH-SY5Y cells.

[Implementation Situation and Application Evaluation of "Standards for Control and Elimination of Malaria"].

The application evaluation of "Standards for Control and Elimination of Malaria" was carried out in 11 epidemic provinces/autonomous regions by questionnaires, field investigation and special interviews from January to May, 2014. Two hundred and forty questionnaires were completed by the personnel from the health administrations and the institutions of disease control and prevention. The questionnaire response rate was 84% (240/285). Totally 90% participants had known and used this standards. In detail, managers from the health administration departments had a percent of 100.0% (26/26), while professionals in the institutions of disease control and prevention had a percent of 88.8% (190/214). In malaria-endemic provinces/autonomous regions/municipalities, 18 training classes of malaria control and prevention were held from January 2012 to December 2013. This standards was one of the main contents. One hundred and fifty-two pieces of suggestion and recommendation were obtained, with 84.2% (128/152) relating to personnel and supporting conditions, and 15.8% (24/152) on technical issues.

[Cluster analysis of cystic echinococcosis in non Tibetan Plateau regions].

OBJECTIVE: To understand the endemic characteristics and regularity of cystic echinococcosis by evaluating and classifying its endemic situation in Non Tibetan Plateau regions, so as to provide the evidence for formulating effective preventive and control measures. METHODS: The prevalence data of cystic echinococcosis in 174 counties (cities, districts, banners) in Non Tibetan Plateau regions from a national survey were collected and analyzed by the sample cluster method in 2012. RESULTS: The 174 counties (cities, districts, banners) could be classified into 4 clusters by spatial distribution. The first cluster with human high prevalence rate, low infection rate of livestock, and positive rate of dog stool antigen included 3 counties. The second cluster with high infection rate of livestock, low prevalence rate of human, and positive rate of dog stool antigen included 20 counties (cities). The third cluster with high positive rate of dog stool antigen, low prevalence rate of human, and low infection rate of livestock included 39 counties (cities, districts, banners). The fourth cluster with low rates of the above 3 indices included the rest 112 counties. CONCLUSIONS: The results of the cluster analysis conform to the current epidemiological status of cystic echinococcosis in the Non Tibetan Plateau regions. The epidemiological characteristics and geographical distributions of the four area types will provide a basis for the classified management and guidance of cystic echinococcosis control in these areas.

[Detection of microvasculature in rat hind limb using synchrotron radiation].

OBJECTIVE: To detect deep-level microvascular structure in rat hind limb by synchrotron radiation and microangiographic technique. METHODS: Microangiography in vivo and ex vivo was performed by synchrotron radiation based absorption imaging and phase contrast imaging, with omnipaque and barium sulfate solution as contrast media, respectively, and synchrotron radiation-based micro-computed tomography (SRmCT) was also performed to reveal three-dimensional morphology of the blood vessel in rat hind limb. RESULTS: Using microangiographic technique in vivo and in vitro (with barium sulfate), blood vessels in the rat limb muscle could be visualized with high resolution, and the fourth branches of iliac artery in rat hind limb could be detected with the minimum visualized blood vessels about 40 µm and 9 µm in diameter, respectively. In addition, the vascular network could be defined and analyzed at the micrometer scale from the 3D renderings of limb vessel as shown by SRmCT. CONCLUSION: Synchrotron radiation-based microangiography and SRmCT thus provided a practical and effective means to observe the microvasculature of rat hindlimb, which might be useful in assessment of angiogenesis in lower limbs.

Functional endothelial cells derived from embryonic stem cells labeled with HIV transactivator peptide-conjugated superparamagnetic nanoparticles.

BACKGROUND: The development of regenerative therapies using derivatives of embryonic stem (ES) cells would be facilitated by a non-invasive method to monitor transplanted cells in vivo, for example, magnetic resonance imaging of cells labeled with superparamagnetic iron oxide (SPIO) nanoparticles. Although ES cells have been labeled with SPIO particles, the potential adverse effects of the label have not been fully examined. The objective of this study was to determine whether SPIO labeling affects murine ES cell viability, proliferation, or ability to differentiate into functional endothelial cells (ECs). METHODS: Cross-linked iron oxide (CLIO, an SPIO) was conjugated with human immunodeficiency virus transactivator of transcription (HIV-Tat) peptides, and murine ES cells were labeled with either CLIO-Tat, CLIO, or HIV-Tat. After labeling, ES cells were cultured for 4 days and Flk-1(+) ES cells identified and sorted by immunocytochemistry and fluorescence activated cell sorting (FACS). Flk-1(+) cells were replated on fibronectin-coated dishes, and ECs were obtained by culturing these for 4 weeks in endothelial cell growth medium supplemented with vascular endothelial growth factor (VEGF). ES cell viability was determined using trypan blue exclusion, and the proportion of SPIO(+) cells was evaluated using Prussian blue staining and transmission electron microscopy. After differentiation, the behavior and phenotype of ECs were analyzed by reverse transcription-polymerase chain reaction, flow cytometry, immunocytochemistry, DiI-labeled acetylated low-density lipoprotein (AcLDL) uptake, and Matrigel tube formation assay. RESULTS: CLIO-Tat was a highly effective label for ES cells, with > 96% of cells incorporating the particles, and it did not alter the viability of the labeled cells. ECs derived from CLIO-Tat(+) ES cells were very similar to murine aortic ECs in their morphology, expression of endothelial cell markers, ability to form vascular-like channels, and scavenging of AcLDL from the culture medium. CONCLUSIONS: CLIO-Tat is a highly effective label for ES cells and does not adversely affect cell viability, differentiation, or behavior. CLIO-Tat could be a useful marker for the non-invasive monitoring of transplanted stem cells.

Polymorphisms in MMP-9 and TIMP-2 in Chinese patients with varicose veins.

BACKGROUND: Varicose veins (VVs), a common vascular disease, are functionally characterized by dilation and tortuosity and are widely prevalent in the adult population. The pathophysiology and molecular mechanism of VVs are still unclear. A genetic risk for VVs has been demonstrated, although no genetic variant pertaining to VVs has been identified. Matrix metalloproteinases (MMPs) and their endogenous tissue inhibitors (TIMPs), which can prevent excessive extracellular matrix (ECM) degradation, greatly impact vascular remodeling and may play a vital role in patients with VVs. We evaluated a potential association between polymorphisms in the promoters of MMP-9 and TIMP-2 and the risk for VVs in the Chinese population. MATERIALS AND METHODS: Genotyping of the promoter region polymorphisms -1562C/T in MMP-9 and -418G/C in TIMP-2 was performed with PCR and restriction fragment length polymorphism (PCR-RFLP) assays with a group of 60 patients with VVs and 60 healthy controls. Purified PCR products were sequenced. RESULTS: A significant correlation was found between patients with VVs and controls at -1562C/T in MMP-9. The TIMP-2 gene polymorphism -418G/C was also associated with VVs. CONCLUSIONS: Our results suggest that polymorphisms in the promoter region of MMP-9 and TIMP-2 are associated with VVs in the Chinese population.

Functional endothelial cells derived from embryonic stem cells labeled with HIV transactivator peptide-conjugated superparamagnetic nanoparticles / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The development of regenerative therapies using derivatives of embryonic stem (ES) cells would be facilitated by a non-invasive method to monitor transplanted cells in vivo, for example, magnetic resonance imaging of cells labeled with superparamagnetic iron oxide (SPIO) nanoparticles. Although ES cells have been labeled with SPIO particles, the potential adverse effects of the label have not been fully examined. The objective of this study was to determine whether SPIO labeling affects murine ES cell viability, proliferation, or ability to differentiate into functional endothelial cells (ECs).</p><p><b>METHODS</b>Cross-linked iron oxide (CLIO, an SPIO) was conjugated with human immunodeficiency virus transactivator of transcription (HIV-Tat) peptides, and murine ES cells were labeled with either CLIO-Tat, CLIO, or HIV-Tat. After labeling, ES cells were cultured for 4 days and Flk-1(+) ES cells identified and sorted by immunocytochemistry and fluorescence activated cell sorting (FACS). Flk-1(+) cells were replated on fibronectin-coated dishes, and ECs were obtained by culturing these for 4 weeks in endothelial cell growth medium supplemented with vascular endothelial growth factor (VEGF). ES cell viability was determined using trypan blue exclusion, and the proportion of SPIO(+) cells was evaluated using Prussian blue staining and transmission electron microscopy. After differentiation, the behavior and phenotype of ECs were analyzed by reverse transcription-polymerase chain reaction, flow cytometry, immunocytochemistry, DiI-labeled acetylated low-density lipoprotein (AcLDL) uptake, and Matrigel tube formation assay.</p><p><b>RESULTS</b>CLIO-Tat was a highly effective label for ES cells, with > 96% of cells incorporating the particles, and it did not alter the viability of the labeled cells. ECs derived from CLIO-Tat(+) ES cells were very similar to murine aortic ECs in their morphology, expression of endothelial cell markers, ability to form vascular-like channels, and scavenging of AcLDL from the culture medium.</p><p><b>CONCLUSIONS</b>CLIO-Tat is a highly effective label for ES cells and does not adversely affect cell viability, differentiation, or behavior. CLIO-Tat could be a useful marker for the non-invasive monitoring of transplanted stem cells.</p>

A novel economic method for high throughput production of recombinant baculovirus by infecting insect cells with Bacmid-containing diminopimelate-auxotrophic Escherichia coli.

Developing cost-effective methods for high throughput production of recombinant baculoviruses in insect cells is very challenging, because the baculovirus DNA preparation and the following transfection procedure are labour-intensive and time consuming. We developed a new method of introducing recombinant Bacmid DNA from bacteria into insect cells simply using invasive diaminopimelate (DAP) auxotrophic Escherichia coli to infectSpodoptera frugiperda 9 cells. The E. coli cells with recombinant Bacmids enter insect cells with the help of the invasion factor from Yersinia pseudotubercolusis. Without DAP in medium, the cell wall of DAP auxotrophic E. coli cannot be synthesized so that the bacterial cell will disrupt and release recombinant Bacmid. The released Bacmids will generate infective recombinant baculovirus particles in insect cells. We combined this E. coli invasion method with the zero background transposition system to generate recombinant baculovirus in a rapid and simple way. Without preparation and purification of recombinant Bacmids from E. coli and the labour-intensive and complex transfection procedure, this transfection reagent free method enables a convenient and economic high throughput production of recombinant baculoviruses.

[Effects and trends of stroke and life expectancy among older adults--from 1990s to 2000s].

OBJECTIVE: To explore the experience of stroke influencing the life expectancy (LE), active life expectancy (ALE), inactive life expectancy (IALE), and the trend of life expectancy among older adults, from 1990s to 2000s in Beijing, China. METHODS: A representative sample of 3257 elderly people living in urban or rural communities in Beijing were followed up from 1990 until 2004. Their health and survival status had been surveyed every 3-5 years. Activity Daily Living (ADL) scale, recommended by WHO was used to evaluate the physical function capability of the elderly. SAS was used to estimate LE, ALE and IALE for both periods of 1992-1997 and 2000-2004 by age and by areas of residency (rural or urban). RESULTS: LE and ALE were shorter, and IALE was longer, among the elderly with stroke than those without stroke at all age groups. Functional status at baseline was also a very important factor in determining ALE and IALE. For those active at baseline, ALE in the elderly with stroke was shorter than those without. There were no differences found in IALE between those with or without stroke, but ALE was longer than IALE. For the elderly with stroke and inactive at baseline, their IALE were longer than ALE and their ALE were at low levels in all age groups. Among those with stroke and living in urban, their LE and ALE were longer than those living in the rural area. When comparing with the period of 1992-1997, both LE and ALE increased during the period of 2000-2004 in all the elderly groups, both in urban and rural areas. The largest increment occurred among those with stroke who originated in an inactive state. CONCLUSION: Stroke reduced both quality and quantity of life of the elderly. The reductions of LE and ALE were greater among the elderly with stroke in rural than in urban areas. Both LE and ALE increased from 1992-1997 to 2000-2004 among the elderly with stroke in both urban and rural areas.

Stroke and active life expectancy among older adults in Beijing, China.

PURPOSE: Increasing stroke prevalence, population ageing and economic change in China necessitate a better understanding of the impact of stroke. This study examines the impact of stroke on disability and trends over time. METHOD: Data are from longitudinal surveys conducted in the Beijing municipality from 1992 to 1997 and 2000 to 2004. Multi-state life tables constructed from hazard models are used to estimate life expectancy (LE) and active life expectancy (ALE). The active state is defined using six functional tasks and mortality is determined using interviewer follow-ups. RESULTS: LE and ALE are higher among those without stroke. Population-based estimates for the cohort observed beginning in 1992 indicate LE at age 55 of about 17 for those who have had a stroke and about 21 for others, whereas years of active life are about 14 and 19, respectively. Disability status at baseline is important for determining ALE. For those active, LE and ALE patterns are similar regardless of stroke status. For those inactive, the stroke group lives almost their entire lives inactive. Stroke reduces years of life by 20-40%, but active life by up to 90%. CONCLUSION: Trends in ALE among those with stroke suggest possible influences of rapid development, concomitant improvement in health care and an increased focus on disease management.

[Screening for peptides of anti-rotavirus by phage-displayed technique].

In this study, a 15-mer phage display peptide library was employed to pan against human rotavirus immobilized on solid phase. 4 different peptides were selected and could bind with rotavirus particles specifically. Plaque reduction neutralization test and MTT analysis results indicated that 3 of the peptides can inhibit rotavirus infecting in vitro. A peptide which sequence is QSNPIHIITNTRNHP showed the best efficiency--93% neutralization infectivity. Two other peptides, A and B, showed 40% and 50% neutralization infectivity respectively. Amino sequence analysis results indicate the 3 peptides containing 2 conserved motifs: SNPIHII and NIP. No putative trypsin hydrolysis site was found in C peptide, however, 4 and 3 potential sites were found in A and B peptides respectively. Using trypsin inhibitor, both A and B peptides showed the similar antiviral effect as that of C peptide. It suggests that the intactness of the 2 conserved motifs play an important role in counteracting virus infection. According to the results of this study, peptide C is hopeful to be exploited as an antiviral peptide drug.

A highly efficient method for the generation of a recombinant Bombyx mori nuclear-polyhedrosis-virus Bacmid and large-scale expression of foreign proteins in silkworm (B. mori) larvae.

In the post-genomic era, one of the challenges and a source of competition is the development of high-throughput, large-scale and low-cost eukaryotic cDNA cloning and expression systems. The baculovirus expression system is the most popular one and plays an important role in the high-level expression of eukaryotic proteins. In the present study, a convenient, rapid and highly efficient method for the construction of recombinant BmNPV (Bombyx mori nuclear polyhedrosis virus)-Bacmid vector (BmBacmid) for low-cost protein expression in silkworm (B. mori) larvae was established by using the MAGIC (mating-assisted genetically integrated cloning) strategy. By simply mixing the donor bacteria strain containing the constructed donor vector pCTdual harbouring foreign genes and the recipient strain containing modified BmBacmid, 99.8% positive recombinant BmNPV-Bacmids were obtained. Reporter genes egfp (enhanced green fluorescent protein gene) and DsRed (Discosoma sp. red fluorescent protein gene) and target gene man (beta-mannanase gene) encoding beta-mannanase were expressed in the silkworm larvae of B. mori at high level by injection of recombinant BmBacmid DNA directly with the standard calcium phosphate transfection procedure. The possibility of constructing a high-quality baculovirus cDNA library by transferring an ordinal plasmid cDNA library into the recipient BmBacmid in Escherichia coli was explored.

Screening for peptides of anti-rotavirus by phage-displayed technique / 生物工程学报

In this study, a 15-mer phage display peptide library was employed to pan against human rotavirus immobilized on solid phase. 4 different peptides were selected and could bind with rotavirus particles specifically. Plaque reduction neutralization test and MTT analysis results indicated that 3 of the peptides can inhibit rotavirus infecting in vitro. A peptide which sequence is QSNPIHIITNTRNHP showed the best efficiency--93% neutralization infectivity. Two other peptides, A and B, showed 40% and 50% neutralization infectivity respectively. Amino sequence analysis results indicate the 3 peptides containing 2 conserved motifs: SNPIHII and NIP. No putative trypsin hydrolysis site was found in C peptide, however, 4 and 3 potential sites were found in A and B peptides respectively. Using trypsin inhibitor, both A and B peptides showed the similar antiviral effect as that of C peptide. It suggests that the intactness of the 2 conserved motifs play an important role in counteracting virus infection. According to the results of this study, peptide C is hopeful to be exploited as an antiviral peptide drug.

[Study on the active life expectancy of the elderly and its longitudinal transition in Beijing].

OBJECTIVE: Focus on the Active Life Expectancy (ALE) of elderly in Beijing and the transition in recent years. METHODS: A representative sample of 3257 elderly people who lived in the urban, suburban and rural communities in Beijing that had been followed up for 12 years. Their health and survival status had been surveyed every 2-3 years. Activity Daily Living scale (ADL), recommended by WHO was used to evaluate the physical function capability of the elderly. IMaCH 0.8 was used to estimate life expectancy (LE) and active life expectancy (ALE) for both periods while age, sex and rural/urban residence areas were adjusted. RESULTS: Longitudinally, data showed that the main characters remained unchange throughout the two periods including 1) LE, ALE, ALE/LE of elderly living in urban area were higher than those living in rural area; 2) LE seemed longer in women than men, but ALE/LE was less in women. The transition between two period showed that 1) LE increased modestly in all groups but less prominent in urban residents and in females; 2) ALE was not significantly changed in the rural elderly but declined markedly in women living in the urban area; 3) ALE/LE of the elderly declined in all groups, especially in urban and oldest old groups. CONCLUSION: In Beijing, elderly AL-E did not increase in parallel with the increase of LE while ALE/LE of the elderly declined significantly in recent years. In order to improve quality of life of the elderly and to increase their ALE, emphasis should be given to prevention of cardiovascular, cerebrovascular and other chronic diseases while reducing the occurrence of physical disability and strengthening on rehabilitation would be the basic health care measures.