1.Sample Preparation and Imaging of Single Adenovirus Particle Using Atomic Force Microscopy in Liquid.
Yan LIANG ; Li CHEN ; Mariska G M van ROSMALEN ; Gijs J L WUITE ; Wouter H ROOS
Chinese Journal of Virology 2015;31(6):601-606
Atomic force microscopy (AFM), as a sophisticated imaging tool with nanoscale resolution, is widely used in virus research and the application of functional viral particles. To investigate single viruses by AFM in a physiologically relevant environment (liquid), an appropriate surface treatment to properly adhere the viruses to the substrate is essential. Here we discuss hydrophobic treated glass coverslips as a suitable substrate for the adhesion of single adenovirus particle (Adenovirus type 5 F35, Ad5F35) when studied with AFM in liquid. From the high resolution AFM images, the orientation of the adhered virus particles can be distinguished. Furthermore, the particles exhibit the expected height of -90 nm. This illustrates that the viruses adhere to the substrate firmly without large deformations. Hence, the described method works well on (fragile) viruses. The described experimental approach can be widely used for AFM studies in liquid of virus structure and mechanics as well as for investigating the interaction of viruses with cellular receptors.
Adenoviridae
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chemistry
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Imaging, Three-Dimensional
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Microscopy, Atomic Force
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methods
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Virion
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chemistry
2.Xiang Study: an association of breastmilk composition with maternal body mass index and infant growth during the first 3 month of life
Xuyi PENG ; Jie LI ; Shuyuan YAN ; Juchun CHEN ; Jonathan LANE ; Patrice MALARD ; Feitong LIU
Nutrition Research and Practice 2021;15(3):367-381
BACKGROUND/OBJECTIVES:
This study aimed to establish a mother and child cohort in the Chinese population, and investigate human breastmilk (HBM) composition and its relationship with maternal body mass index (BMI) and infant growth during the first 3 mon of life.
SUBJECTS/METHODS:
A total of 101 Chinese mother and infant pairs were included in this prospective cohort. Alterations in the milk macronutrients of Chinese mothers at 1 mon (T1), 2 mon (T2), and 3 mon (T3) lactation were analyzed. HBM fatty acid (FA) profiles were measured by gas chromatography (GC), and HBM proteomic profiling was achieved by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS).
RESULTS:
During the first 3 mon of lactation (P < 0.05), significant decreases were determined in the levels of total energy, fat, protein, and osteopontin (OPN), as well as ratios of long-chain saturated FA (including C16:0, C22:0 and C24:0), monounsaturated FA (including C16:1), and n-6 poly unsaturated FA (PUFA) (including C20:3n-6 and C20:4n-6, and n-6-3). Conversely, butyrate, C6:0 and n-3 PUFA C18:3n-3 (α-linolenic acid, ALA) were significantly increased during the first 3 mon (P < 0.05). HBM proteomic analyses distinguished compositional protein differences over time (P = 0.001). Personalized motherinfant analyses demonstrated that HBM from high BMI mothers presented increased total energy, fat, protein and OPN, and increased content of n-6 PUFA (including C18:3n-6, C20:3n-6 and n-6-3 ratio) as compared with low BMI mothers (P < 0.05). Furthermore, BMI of the mothers positively correlated with the head circumference (HC) of infants as well as the specific n-6 PUFA C20:3n-6 over the 3 time points examined. Infant HC was negatively associated with C18:0.
CONCLUSION
This study provides additional evidence to the Chinese HBM database, and further knowledge of FA function. It also helps to establish future maternal strategies that support the healthy growth and development of Chinese infants.
3.Xiang Study: an association of breastmilk composition with maternal body mass index and infant growth during the first 3 month of life
Xuyi PENG ; Jie LI ; Shuyuan YAN ; Juchun CHEN ; Jonathan LANE ; Patrice MALARD ; Feitong LIU
Nutrition Research and Practice 2021;15(3):367-381
BACKGROUND/OBJECTIVES:
This study aimed to establish a mother and child cohort in the Chinese population, and investigate human breastmilk (HBM) composition and its relationship with maternal body mass index (BMI) and infant growth during the first 3 mon of life.
SUBJECTS/METHODS:
A total of 101 Chinese mother and infant pairs were included in this prospective cohort. Alterations in the milk macronutrients of Chinese mothers at 1 mon (T1), 2 mon (T2), and 3 mon (T3) lactation were analyzed. HBM fatty acid (FA) profiles were measured by gas chromatography (GC), and HBM proteomic profiling was achieved by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS).
RESULTS:
During the first 3 mon of lactation (P < 0.05), significant decreases were determined in the levels of total energy, fat, protein, and osteopontin (OPN), as well as ratios of long-chain saturated FA (including C16:0, C22:0 and C24:0), monounsaturated FA (including C16:1), and n-6 poly unsaturated FA (PUFA) (including C20:3n-6 and C20:4n-6, and n-6-3). Conversely, butyrate, C6:0 and n-3 PUFA C18:3n-3 (α-linolenic acid, ALA) were significantly increased during the first 3 mon (P < 0.05). HBM proteomic analyses distinguished compositional protein differences over time (P = 0.001). Personalized motherinfant analyses demonstrated that HBM from high BMI mothers presented increased total energy, fat, protein and OPN, and increased content of n-6 PUFA (including C18:3n-6, C20:3n-6 and n-6-3 ratio) as compared with low BMI mothers (P < 0.05). Furthermore, BMI of the mothers positively correlated with the head circumference (HC) of infants as well as the specific n-6 PUFA C20:3n-6 over the 3 time points examined. Infant HC was negatively associated with C18:0.
CONCLUSION
This study provides additional evidence to the Chinese HBM database, and further knowledge of FA function. It also helps to establish future maternal strategies that support the healthy growth and development of Chinese infants.
4.Targeting the PI3K-AKT-mTOR signaling network in cancer.
Khurum H KHAN ; Timothy A YAP ; Li YAN ; David CUNNINGHAM
Chinese Journal of Cancer 2013;32(5):253-265
The phosphoinositide 3-kinase-AKT-mammalian target of rapamycin (PI3K-AKT-mTOR) pathway is a frequently hyperactivated pathway in cancer and is important for tumor cell growth and survival. The development of targeted therapies against mTOR, a vital substrate along this pathway, led to the approval of allosteric inhibitors, including everolimus and temsirolimus, for the treatment of breast, renal, and pancreatic cancers. However, the suboptimal duration of response in unselected patients remains an unresolved issue. Numerous novel therapies against critical nodes of this pathway are therefore being actively investigated in the clinic in multiple tumor types. In this review, we focus on the progress of these agents in clinical development along with their biological rationale, the need of predictive biomarkers and various combination strategies, which will be useful in counteracting the mechanisms of resistance to this class of drugs.
Antineoplastic Agents
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therapeutic use
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Drug Resistance, Neoplasm
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Humans
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Molecular Targeted Therapy
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Neoplasms
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drug therapy
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genetics
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metabolism
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PTEN Phosphohydrolase
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genetics
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metabolism
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Phosphatidylinositol 3-Kinases
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antagonists & inhibitors
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metabolism
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Proto-Oncogene Proteins c-akt
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antagonists & inhibitors
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metabolism
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Proto-Oncogene Proteins c-ret
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metabolism
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Sirolimus
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therapeutic use
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TOR Serine-Threonine Kinases
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antagonists & inhibitors
;
metabolism
5.Right atrial isomerism: preponderance in Asian fetuses. Using the stomach-distance ratio as a possible diagnostic tool for prediction of right atrial isomerism.
Ying Liu YAN ; Kenny B L TAN ; George S H YEO
Annals of the Academy of Medicine, Singapore 2008;37(11):906-912
INTRODUCTIONTo present the characteristics and spectrum of associated anomalies in right- and left-sided isomerism in our local population and to assess the possibility of using stomach-distance ratio (SDR) of less than 0.34 as a diagnostic tool to predict right atrial isomerism.
MATERIALS AND METHODSThis was a retrospective study of fetuses in our department over a period of 8 years with postnatally confirmed prenatal diagnosis of atrial isomerism.
RESULTSIn 22 cases, atrial isomerism was confirmed by post-mortem or postnatal echocardiography. Eighteen (81.8%) fetuses had right isomerism. Their main abnormal ultrasound findings were pulmonary stenosis or atresia (n = 9), atrioventricular septal defect (n = 10), right-sided stomach (n = 9), transposition of great arteries (n = 6), dextrocardia (n = 8), single ventricle (n = 4), juxtaposition of inferior vena cava and descending aorta (n = 5), ventricular septal defect (n = 2), interrupted inferior vena cava with azygous drainage (n = 2) and double outlet right ventricle (n = 3). Four (18.2%) fetuses had left isomerism. Their abnormal ultrasound findings were dextrocardia (n = 3), right-sided stomach (n = 3), atrioventricular septal defect (n = 2), double outlet ventricle (n = 2), ventricular septal defect (n = 1), pulmonary stenosis (n = 2) and interrupted inferior vena cava with azygous drainage (n = 1). 66.7% (12/18) of cases with right isomerism had SDR of less than 0.34 compared to 0% (0/4) of the cases with left isomerism (P = 0.02).
CONCLUSIONOur study suggests an Asian predilection towards right isomerism compared to Western populations. We postulate that there may be racial differences in the expression of these 2 forms of isomerism. The ultrasound findings of complex heart disease and abnormal arrangement of great vessels in abdominal cavity, though important, are varied and non-specific evidence for either form of fetal atrial isomerism. There is a possibility of using the SDR <0.34 (representing stomach proximity to the fetal spine) as a possible diagnostic tool to predict right-sided atrial isomerism.
Asia ; epidemiology ; Diagnosis, Differential ; Echocardiography ; Female ; Follow-Up Studies ; Gestational Age ; Heart Atria ; abnormalities ; Heart Defects, Congenital ; diagnostic imaging ; epidemiology ; Humans ; Pregnancy ; Prenatal Diagnosis ; methods ; Prevalence ; Retrospective Studies ; Stomach ; anatomy & histology ; Time Factors
6.Capillary blood flow with dynamical change of tissue pressure caused by exterior force.
Yufeng LIU ; Shixiong XU ; Juntao YAN ; Guoquan SHEN ; Wuquan SUN ; Y CHEW ; H LOW ; Jun XU
Journal of Biomedical Engineering 2004;21(5):699-703
A hemodynamic model of capillary and tissue, in which tissue pressure changed with swing manipulation of Traditional Chinese Medical Massage (TCMM), is presented in this paper to explain the hemodynamic mechanism of swing manipulation. Blood flowed in capillary with low Reynolds number. Plasma exuded through capillary according to the Starling's Law. Tissue pressure changed linearly with the massage force measured. Blood apparent viscosity, plasma protein concentration and red cell's hematocrit were taken into account. Capillary flow rate, blood apparent viscosity, filtration rate and filtration fraction with dynamical change of tissue pressure were calculated numerically, and were compared with those in static tissue pressure condition. Results showed that, dynamical change of tissue pressure led to the increase of capillary flow rate and the decrease of blood apparent viscosity, which qualitatively explained the hemodynamic mechanism of "promoting blood circulation and removing blood stasis" in swing manipulation of TCMM.
Biomechanical Phenomena
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Blood Flow Velocity
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Blood Viscosity
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Capillaries
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physiology
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Hematocrit
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Hemodynamics
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Humans
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Massage
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Models, Cardiovascular
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Pressure
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Regional Blood Flow
7.Application of McAbs against rabies nucleocapsid in diagnosis of rabies street virus.
Ge-lin XU ; Jia-xin YAN ; F LARROUS ; Yu-tao ZHU ; P COZETTE ; Hong-gang XUE ; Qiao-ling HU ; H BOURHY
Chinese Journal of Epidemiology 2005;26(2):113-115
OBJECTIVEMcAbs against rabies nucleocapsid were used to detect rabies street viruses in animal brain specimens with indirect immunofluorescent assay to evaluate the sensitivity and specificity of this assay.
METHODS62 specimen from rabid animal brains including genotype 1 to 7 and 271 specimens from different normal animal brains collected in Pasteur Institute in 2003 were tested and compared, using indirect immunofluorescent assay. All these specimens were identified and compared using rapid rabies enzyme immunodiagnosis, fluorescent antibody test and rabies virus isolation assay in neuroblastoma cell culture which were all provided by Pasteur Institute.
RESULTSBoth sensitivity and the specificity of the indirect immunofluorescent assay were 100%.
CONCLUSIONThe results showed a positive of rabies virus detection with these methods.
Animals ; Antibodies, Monoclonal ; immunology ; Antibodies, Viral ; immunology ; Brain ; virology ; Dogs ; Fluorescent Antibody Technique ; methods ; Genotype ; Nucleocapsid ; immunology ; Rabies virus ; isolation & purification ; Sensitivity and Specificity
8.Reconstruction of Leptospira interrogans lipL21 gene and characteristics of its expression product.
Dong-jiao LUO ; Ye HU ; R H DENNIN ; Jie YAN
Journal of Zhejiang University. Medical sciences 2007;36(5):458-464
OBJECTIVETo reconstruct the nucleotide sequence of Leptospira interrogans lipL21 gene for increasing the output of prokaryotic expression and to understand the changes on immunogenicity of the expression products before and after reconstruction, and to determine the position of envelope lipoprotein LipL21 on the surface of leptospiral body.
METHODSAccording to the preferred codons of E.coli, the nucleotide sequence of lipL21 gene was designed and synthesized, and then its prokaryotic expression system was constructed. By using SDS-PAGE plus BioRad agarose image analysor, the expression level changes of lipL21 genes before and after reconstruction were measured. A Western blot assay using rabbit anti-TR/Patoc I serum as the first antibody was performed to identify the immunoreactivity of the two target recombinant proteins rLipL21s before and after reconstruction. The changes of cross agglutination titers of antisera against two rLipL21s before and after reconstruction to the different leptospiral serogroups were demonstrated using microscope agglutination test (MAT). Immuno-electronmicroscopy was applied to confirm the location of LipL21s.
RESULTThe expression outputs of original and reconstructed lipL21 genes were 8.5 % and 46.5 % of the total bacterial proteins, respectively. Both the two rLipL21s could take place immune conjugation reaction with TR/Patoc I antiserum. After immunization with each of the two rLipL21s in rabbits, the animals could produce specific antibody. Similar MAT titers with 1:80 - 1:320 of the two antisera against rLipL21s were present. LipL21 was confirmed to locate on the surface of leptospiral envelope.
CONCLUSIONLipL21 is a superficial antigen of Leptospira interrogans. The expression output of the reconstructed lipL21 gene is remarkably increased. The expression rLipL21 maintains fine antigenicity and immunoreactivity and its antibody still shows an extensive cross immunoagglutination activity. The high expression of the reconstructed lipL21 gene will offer a favorable condition to use its product for further developing a novel universal vaccine as well as detection kit of leptospirosis.
Amino Acid Sequence ; Animals ; Antigens, Bacterial ; genetics ; immunology ; metabolism ; Bacterial Outer Membrane Proteins ; genetics ; immunology ; metabolism ; Bacterial Vaccines ; immunology ; Base Sequence ; Blotting, Western ; Cloning, Molecular ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; genetics ; Immune Sera ; immunology ; Leptospira interrogans ; genetics ; immunology ; ultrastructure ; Lipoproteins ; genetics ; immunology ; metabolism ; Microscopy, Immunoelectron ; Molecular Sequence Data ; Rabbits ; Recombinant Fusion Proteins ; genetics ; immunology ; metabolism ; Sequence Analysis, DNA ; Vaccines, DNA ; immunology
9.Patent blue dye in lymphaticovenular anastomosis.
Yan Lin YAP ; Jane LIM ; Timothy W H SHIM ; Shenthilkumar NAIDU ; Wei Chen ONG ; Thiam Chye LIM
Annals of the Academy of Medicine, Singapore 2009;38(8):704-706
INTRODUCTIONLymphaticovenular anastomosis (LVA) has been described as a treatment of chronic lymphoedema. This microsurgical technique is new and technically difficult. The small caliber and thin wall lymphatic vessels are difficult to identify and easily destroyed during the dissection.
MATERIALS AND METHODSWe describe a technique of performing lymphaticovenular anastomosis with patent blue dye enhancement. Our patient is a 50-year-old lady who suffers from chronic lymphoedema of the upper limb after mastectomy and axillary clearance for breast cancer 8 years ago.
RESULTSPatent blue dye is injected subdermally and is taken up readily by the draining lymphatic channels. This allows for easy identification of their course. The visualisation of the lumen of the lymphatic vessel facilitates microsurgical anastomosis. The patency of the anastomosis is also demonstrated by the dynamic pumping action of the lymphatic within the vessels.
CONCLUSIONPatent blue dye staining during lymphaticovenular anastomosis is a simple, effective and safe method for mapping suitable subdermal lymphatics, allowing for speedier dissection of the lymphatic vessels intraoperatively. This technique also helps in the confirmation of the success of the lymphaticovenular anastomosis.
Anastomosis, Surgical ; methods ; Coloring Agents ; Female ; Humans ; Lymphatic Metastasis ; Lymphatic Vessels ; Lymphedema ; etiology ; surgery ; Mastectomy ; adverse effects ; Microsurgery ; methods ; Middle Aged ; Rosaniline Dyes ; Sentinel Lymph Node Biopsy
10.Stroke Prevention in Atrial Fibrillation: Focus on Asian Patients
Yan Guang LI ; So Ryoung LEE ; Eue Keun CHOI ; Gregory Y H LIP
Korean Circulation Journal 2018;48(8):665-684
Atrial fibrillation (AF) is the most common arrhythmia conferring a fivefold increased risk of stroke. Stroke prevention is the cornerstone of management of patients with AF. Asians have a generally higher incidence of AF-related risks of stroke and bleeding (particularly intracranial bleeding), compared with non-Asians. Despite the well-documented efficacy and relative safety of oral anticoagulation for stroke prevention among Asians, the suboptimal use of oral anticoagulation remains common. The current narrative review aims to provide a summary of the available evidence on stroke prevention among patients with AF focused on the Asia region, regarding stroke and bleeding risk evaluation, the performance of oral anticoagulation, and current use of thromboprophylaxis.
Anticoagulants
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Arrhythmias, Cardiac
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Asia
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Asian Continental Ancestry Group
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Atrial Fibrillation
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Hemorrhage
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Humans
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Incidence
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Stroke