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1.
Med J Malaysia ; 76(6): 930-932, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34806689

ABSTRACT

Functional neurological disorder (FND) is a rare neuropsychiatric illness that commonly presents to the medical setting as opposed to the psychiatric setting. FND is characterised by signs and symptoms affecting the voluntary motor or sensory function that cannot be explained by a specific neurological or general medical condition. FND in pregnancy and postpartum is rare. We report here a case of FND in a 32-year-old woman who presented with multiple medical problems during her perinatal period. She exhibited 'la belle indifference', history of vague unexplained medical symptomatology while all relevant investigations were normal. There were longstanding psychosocial and interpersonal difficulties with significant distress including multiple personal, marital, and family issues which stemmed from her childhood. This left her feeling inadequate as a mother to her infant. The diagnosis of FND was finalised by the multidisciplinary team consisting of a neurologist, physicians, and psychiatrists, based on longitudinal assessment. Psychological intervention for the patient included psychoeducation, supportive psychotherapy, stress management, and parental intervention. The key point in our management of the patient was the delivery of the diagnosis to help her understand the illness and treatment plan. For this patient, functional and psychological recovery is achievable with a good therapeutic alliance, early diagnosis of the illness, and the acceptance of her diagnosis.


Subject(s)
Conversion Disorder , Adult , Child , Conversion Disorder/diagnosis , Conversion Disorder/psychology , Female , Humans , Marriage , Pregnancy
2.
Anal Biochem ; 544: 98-107, 2018 03 01.
Article in English | MEDLINE | ID: mdl-29305096

ABSTRACT

With the emergence of multi- and extensive-drug (MDR/XDR) resistant Mycobacterium tuberculosis (M. tb), tuberculosis (TB) persists as one of the world's leading causes of death. Recently, isothermal DNA amplification methods received much attention due to their ease of translation onto portable point-of-care (POC) devices for TB diagnosis. In this study, we aimed to devise a simple yet robust detection method for M. tb. Amongst the numerous up-and-coming isothermal techniques, Recombinase Polymerase Amplification (RPA) was chosen for a real-time detection of TB with or without MDR. In our platform, real-time RPA (RT-RPA) was integrated on a lab-on-a-disc (LOAD) with on-board power to maintain temperature for DNA amplification. Sputa collected from healthy volunteers were spiked with respective target M. tb samples for testing. A limit of detection of 102 colony-forming unit per millilitre in 15 min was achieved, making early detection and differentiation of M. tb strains highly feasible in extreme POC settings. Our RT-RPA LOAD platform has also been successfully applied in the differentiation of MDR-TB from H37Ra, an attenuated TB strain. In summary, a quantitative RT-RPA on LOAD assay with a high level of sensitivity was developed as a foundation for further developments in medical bedside and POC diagnostics.


Subject(s)
Automation , Lab-On-A-Chip Devices , Mycobacterium tuberculosis/genetics , Nucleic Acid Amplification Techniques , Polymerase Chain Reaction , Tuberculosis, Multidrug-Resistant/genetics , Healthy Volunteers , Humans , Point-of-Care Testing , Time Factors
3.
Heredity (Edinb) ; 116(3): 295-303, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26696137

ABSTRACT

Owing to the reduction of population density and/or the environmental changes it induces, selective logging could affect the demography, reproductive biology and evolutionary potential of forest trees. This is particularly relevant in tropical forests where natural population densities can be low and isolated trees may be subject to outcross pollen limitation and/or produce low-quality selfed seeds that exhibit inbreeding depression. Comparing reproductive biology processes and genetic diversity of populations at different densities can provide indirect evidence of the potential impacts of logging. Here, we analysed patterns of genetic diversity, mating system and gene flow in three Central African populations of the self-compatible legume timber species Erythrophleum suaveolens with contrasting densities (0.11, 0.68 and 1.72 adults per ha). The comparison of inbreeding levels among cohorts suggests that selfing is detrimental as inbred individuals are eliminated between seedling and adult stages. Levels of genetic diversity, selfing rates (∼16%) and patterns of spatial genetic structure (Sp ∼0.006) were similar in all three populations. However, the extent of gene dispersal differed markedly among populations: the average distance of pollen dispersal increased with decreasing density (from 200 m in the high-density population to 1000 m in the low-density one). Overall, our results suggest that the reproductive biology and genetic diversity of the species are not affected by current logging practices. However, further investigations need to be conducted in low-density populations to evaluate (1) whether pollen limitation may reduce seed production and (2) the regeneration potential of the species.


Subject(s)
Fabaceae/genetics , Gene Flow , Genetic Variation , Genetics, Population , Pollination , Trees/genetics , Africa , Forestry , Inbreeding , Models, Genetic , Population Density , Rainforest
4.
Doc Ophthalmol ; 131(3): 189-96, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26471028

ABSTRACT

PURPOSE: To assess clinical value of visual electrophysiology in identifying causes of visual dysfunction in patients referred from neuro-ophthalmology clinics. METHODS: A review of 410 subjects (aged 0.3-88 years) referred for visual electrophysiology from neuro-ophthalmologists between 2009 and 2013 was performed. Subjects were divided into those with unexplained poor vision, visual field defects, visual symptoms or other reasons (e.g. monitoring for drug toxicity or known conditions). Subjects underwent pattern, full-field and multifocal electroretinography (ERG) and pattern visual evoked potential (VEP) tests. Flash and multifocal VEP were included where indicated. RESULTS: Most subjects referred for poor vision (n = 158) had electrophysiology findings suggestive of retinopathy (37 %) or post-retinal pathology (34 %). Those with poorer vision (worse than 6/24) were more likely to have abnormal recordings (86 vs. 62 %, p = 0.002). Among subjects with unexplained visual field defects (n = 102), findings of retinopathy, post-retinal pathology and normal recordings were noted in 31, 24 and 28 %, respectively. Most subjects with other visual symptoms (n = 97) had normal findings (69 %). The multifocal ERG was most sensitive for detecting retinopathy (96 %) and maculopathy (95 %), while pattern VEP was most sensitive for post-retinal pathology (94 %). An indeterminate result was noted in 9 %. CONCLUSION: Electrophysiology was effective in differentiating between retinopathy, post-retinal pathology and normality in 91 % of subjects. Pre-testing provisional diagnoses of retinopathy and post-retinal pathology were revised in 30 and 42 %, respectively, after electrophysiology. Appreciation of characteristics of each test, correlation with the clinical picture and interpretation of results in totality are required to localize the site of pathology.


Subject(s)
Electroretinography/methods , Evoked Potentials, Visual , Optic Disk/physiopathology , Optic Nerve Diseases/diagnosis , Retinal Diseases/diagnosis , Vision Disorders/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Electrophysiology , Female , Humans , Infant , Male , Middle Aged , Optic Nerve Diseases/physiopathology , Retinal Diseases/physiopathology , Retinal Ganglion Cells/physiology , Retrospective Studies , Vision Disorders/physiopathology , Visual Fields/physiology
5.
Gene Ther ; 19(3): 246-54, 2012 Mar.
Article in English | MEDLINE | ID: mdl-21753795

ABSTRACT

The need for γ-retroviral (gRV) vectors with a self-inactivating (SIN) design for clinical application has prompted a shift in methodology of vector manufacturing from the traditional use of stable producer lines to transient transfection-based techniques. Herein, we set out to define and optimize a scalable manufacturing process for the production of gRV vectors using transfection in a closed-system bioreactor in compliance with current good manufacturing practices (cGMP). The process was based on transient transfection of 293T cells on Fibra-Cel disks in the Wave Bioreactor. Cells were harvested from tissue culture flasks and transferred to the bioreactor containing Fibra-Cel in the presence of vector plasmid, packaging plasmids and calcium-phosphate in Dulbecco's modified Eagle's medium and 10% fetal bovine serum. Virus supernatant was harvested at 10-14 h intervals. Using optimized procedures, a total of five ecotropic cGMP-grade gRV vectors were produced (9 liters each) with titers up to 3.6 × 10(7) infectious units per milliliter on 3T3 cells. One GMP preparation of vector-like particles was also produced. These results describe an optimized process for the generation of SIN viral vectors by transfection using a disposable platform that allows for the generation of clinical-grade viral vectors without the need for cleaning validation in a cost-effective manner.


Subject(s)
Bioreactors , Gammaretrovirus/genetics , Genetic Vectors/isolation & purification , Genetic Vectors/standards , Transfection/methods , Animals , Batch Cell Culture Techniques/methods , Batch Cell Culture Techniques/standards , Biotechnology , Cell Line , Gammaretrovirus/isolation & purification , Humans , Mice , Quality Control
6.
Gene Ther ; 19(8): 872-6, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22551777

ABSTRACT

Patients with X-linked severe combined immunodeficiency (SCID-X1) were successfully cured following gene therapy with a gamma-retroviral vector (gRV) expressing the common gamma chain of the interleukin-2 receptor (IL2RG). However, 5 of 20 patients developed leukemia from activation of cellular proto-oncogenes by viral enhancers in the long-terminal repeats (LTR) of the integrated vector. These events prompted the design of a gRV vector with self-inactivating (SIN) LTRs to enhance vector safety. Herein we report on the production of a clinical-grade SIN IL2RG gRV pseudotyped with the Gibbon Ape Leukemia Virus envelope for a new gene therapy trial for SCID-X1, and highlight variables that were found to be critical for transfection-based large-scale SIN gRV production. Successful clinical production required careful selection of culture medium without pre-added glutamine, reduced exposure of packaging cells to cell-dissociation enzyme, and presence of cations in wash buffer. The clinical vector was high titer; transduced 68-70% normal human CD34(+) cells, as determined by colony-forming unit assays and by xenotransplantation in immunodeficient NOD.CB17-Prkdc(scid)/J (nonobese diabetic/severe combined immunodeficiency (NOD/SCID)) and NOD.Cg-Prkdc(scid) Il2rg(tm1Wjl)/SzJ (NOD/SCID gamma (NSG))) mice; and resulted in the production of T cells in vitro from human SCID-X1 CD34(+) cells. The vector was certified and released for the treatment of SCID-X1 in a multi-center international phase I/II trial.


Subject(s)
Genetic Vectors , Interleukin Receptor Common gamma Subunit/genetics , Retroviridae/genetics , X-Linked Combined Immunodeficiency Diseases/therapy , Animals , Gene Transfer Techniques , Humans , Leukemia Virus, Gibbon Ape/genetics , Mice , Mice, Inbred NOD , Mice, SCID , Terminal Repeat Sequences , Transduction, Genetic
7.
Anal Chem ; 84(10): 4383-95, 2012 May 15.
Article in English | MEDLINE | ID: mdl-22509742

ABSTRACT

Top-down mass spectrometry has been used to investigate structural diversity within some abundant salivary protein families. In this study, we report the identification of two isoforms of protein II-2 which differed in mass by less than 1 Da, the determination of a sequence for protein IB8a that was best satisfied by including a mutation and a covalent modification in the C-terminal part, and the assignment of a sequence of a previously unreported protein of mass 10433 Da. The final characterization of Peptide P-J was achieved, and the discovery of a truncated form of this peptide was reported. The first sequence assignment was done at low resolution using a hybrid quadrupole time-of-flight instrument to quickly identify and characterize proteins, and data acquisition was switched to Fourier-transform ion cyclotron resonance (FTICR) for proteins that required additional sequence coverage and certainty of assignment. High-resolution and high mass accuracy mass spectrometry on a FTICR-mass spectrometry (MS) instrument combined with electron-capture dissociation (ECD) provided the most informative data sets, with the more frequent presence of "unique" ions that unambiguously define the primary structure. A mixture of predictable and unusual post-translational modifications in the protein sequence precluded the use of shotgun-annotated databases at this stage, requiring manual iterations of sequence refinement in many cases. This led us to propose guidelines for an iterative processing workflow of MS and MSMS data sets that allow researchers to completely assign the identity and the structure of a protein.


Subject(s)
Proteins/chemistry , Proteome , Saliva/metabolism , Spectrometry, Mass, Electrospray Ionization , Amino Acid Sequence , Chromatography, High Pressure Liquid , Histatins/chemistry , Humans , Molecular Sequence Data
8.
Arch Toxicol ; 86(5): 741-52, 2012 May.
Article in English | MEDLINE | ID: mdl-22349056

ABSTRACT

Polyphyllin D (PD) is a potent anticancer agent isolated from a traditional medicinal herb Paris polyphylla that has been used in China for many years to treat cancer. PD is not a substrate of p-glycoprotein, and it can bypass the multi-drug resistance in cancer cell line R-HepG2. However, the effect of PD on the induction of cell death in human erythrocytes remains unknown. Given that PD is a small molecule that can depolarize the mitochondrial membrane potential and release apoptosis-inducing factor (AIF) in isolated mitochondria, we hypothesized that the apoptogenic effect of PD in human erythrocytes devoid of mitochondria would be minimal. This study therefore tried to evaluate the in vitro effect of PD on hemolysis and apoptosis in human erythrocytes. Apoptosis in human red blood cells (RBCs), also known as eryptosis or erythroptosis, after PD treatment was determined by flow cytometry and confocal microscopy for the phosphatidyl-serine externalization and other apoptosis feature events. False to our prediction, PD caused hemolysis and eryptosis/erythroptosis in human RBCs. Mechanistically, elevation in the cytosolic Ca²âº ion level seems to be a key but not the only mediator in the PD-mediated eryptosis/erythroptosis because depletion of the external Ca²âº could not eliminate the PD effect. Also, PD was able to permeabilize the membrane of RBC ghosts in a way similar to digitonin. Taken together, we report here for the first time the toxicity of PD in human RBCs as well as its underlying mechanism for the hemolysis and eryptosis/erythroptosis.


Subject(s)
Apoptosis/drug effects , Cell Membrane Permeability/drug effects , Diosgenin/analogs & derivatives , Erythrocytes/drug effects , Calcium/metabolism , Caspase 3/metabolism , Cell Size/drug effects , Cells, Cultured , Cytosol/drug effects , Cytosol/metabolism , Diosgenin/pharmacology , Diosgenin/toxicity , Erythrocytes/metabolism , Erythrocytes/pathology , Humans , Mitochondrial Membranes/drug effects , Saponins
9.
Neurocrit Care ; 12(3): 324-36, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20225002

ABSTRACT

BACKGROUND: To examine if the metabolic distress after traumatic brain injury (TBI) is associated with a unique proteome. METHODS: Patients with severe TBI prospectively underwent cerebral microdialysis for the initial 96 h after injury. Hourly sampling of metabolism was performed and patients were categorized as having normal or abnormal metabolism as evidenced by the lactate/pyruvate ratio (LPR) threshold of 40. The microdialysate was frozen for proteomic batch processing retrospectively. We employed two different routes of proteomic techniques utilizing mass spectrometry (MS) and categorized as diagnostic and biomarker identification approaches. The diagnostic approach was aimed at finding a signature of MS peaks which can differentiate these two groups. We did this by enriching for intact peptides followed by MALDI-MS analysis. For the biomarker identification approach, we applied classical bottom-up (trypsin digestion followed by LC-MS/MS) proteomic methodologies. RESULTS: Five patients were studied, 3 of whom had abnormal metabolism and 2 who had normal metabolism. By comparison, the abnormal group had higher LPR (1609 +/- 3691 vs. 15.5 +/- 6.8, P < 0.001), higher glutamate (157 +/- 84 vs. 1.8 +/- 1.4 microM, P < 0.001), and lower glucose (0.27 +/- 0.35 vs. 1.8 +/- 1.1 mmol/l, P < 0.001). The abnormal group demonstrated 13 unique proteins as compared with the normal group in the microdialysate. These proteins consisted of cytoarchitectural proteins, as well as blood breakdown proteins, and a few mitochondrial proteins. A unique as yet to be characterized peptide was found at m/z (mass/charge) 4733.5, which may represent a novel biomarker of metabolic distress. CONCLUSION: Metabolic distress after TBI is associated with a differential proteome that indicates cellular destruction during the acute phase of illness. This suggests that metabolic distress has immediate cellular consequences after TBI.


Subject(s)
Brain Injuries/physiopathology , Brain/physiopathology , Energy Metabolism/physiology , Microdialysis/instrumentation , Monitoring, Physiologic/instrumentation , Proteomics , Signal Processing, Computer-Assisted/instrumentation , Blood Glucose/metabolism , Brain Ischemia/diagnosis , Brain Ischemia/physiopathology , Cerebral Hemorrhage, Traumatic/diagnosis , Cerebral Hemorrhage, Traumatic/physiopathology , Extracellular Fluid/physiology , Follow-Up Studies , Frontal Lobe/physiopathology , Glasgow Coma Scale , Humans , Hypoglycemia/diagnosis , Hypoglycemia/physiopathology , Intracranial Pressure/physiology , Lactic Acid/blood , Magnetic Resonance Imaging , Pyruvic Acid/blood , Reference Values , Tandem Mass Spectrometry/instrumentation , Temporal Lobe/physiopathology , Tomography, X-Ray Computed
10.
J Cell Biol ; 153(7): 1511-7, 2001 Jun 25.
Article in English | MEDLINE | ID: mdl-11425879

ABSTRACT

Many cellular processes rely on the ordered assembly of macromolecular structures. Here, we uncover an unexpected link between two such processes, endocytosis and transcription. Many endocytic proteins, including eps15, epsin1, the clathrin assembly lymphoid myeloid leukemia (CALM), and alpha-adaptin, accumulate in the nucleus when nuclear export is inhibited. Endocytosis and nucleocytoplasmic shuttling of endocytic proteins are apparently independent processes, since inhibition of endocytosis did not appreciably alter nuclear translocation of endocytic proteins, and blockade of nuclear export did not change the initial rate of endocytosis. In the nucleus, eps15 and CALM acted as positive modulators of transcription in a GAL4-based transactivation assay, thus raising the intriguing possibility that some endocytic proteins play a direct or indirect role in transcriptional regulation.


Subject(s)
Cell Nucleus/metabolism , Cytoplasm/metabolism , Endocytosis/physiology , Monomeric Clathrin Assembly Proteins , Saccharomyces cerevisiae Proteins , Vesicular Transport Proteins , Active Transport, Cell Nucleus/physiology , Adaptor Protein Complex alpha Subunits , Adaptor Proteins, Signal Transducing , Adaptor Proteins, Vesicular Transport , Animals , Calcium-Binding Proteins/metabolism , Carrier Proteins/metabolism , Cell Line , Chlorocebus aethiops , DNA-Binding Proteins , Fungal Proteins/genetics , Fungal Proteins/metabolism , HeLa Cells , Humans , Intracellular Signaling Peptides and Proteins , Membrane Proteins/metabolism , Nerve Tissue Proteins/metabolism , Neuropeptides/metabolism , Phosphoproteins/metabolism , Protein Transport/physiology , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Signal Transduction/physiology , Transcription Factors/genetics , Transcription Factors/metabolism , Transcription, Genetic/physiology , Transcriptional Activation/physiology
11.
Science ; 248(4952): 201-4, 1990 Apr 13.
Article in English | MEDLINE | ID: mdl-2326633

ABSTRACT

Tandem mass spectrometry has been used to obtain information related to portions of the primary sequence for an intact protein, bovine ribonuclease A. Multiply charged molecular ions, generated by electrospray ionization, were collisionally dissociated at low energies in a triple quadrupole mass spectrometer to yield singly and multiply charged fragment ions that can be assigned to the known sequence of the protein. Dissociation of the highly charged molecular ions resulted in pairs of complementary product ions. The higher order (gas-phase) protein structure affects the dissociation processes, as observed in comparisons of tandem mass spectra of the native and disulfide-reduced forms of ribonuclease A.


Subject(s)
Amino Acid Sequence , Proteins , Ribonuclease, Pancreatic , Animals , Cattle , Disulfides , Mass Spectrometry/methods , Oxidation-Reduction
12.
Br J Nutr ; 101 Suppl 1: S1-45, 2009 May.
Article in English | MEDLINE | ID: mdl-19586558

ABSTRACT

Inflammation is a stereotypical physiological response to infections and tissue injury; it initiates pathogen killing as well as tissue repair processes and helps to restore homeostasis at infected or damaged sites. Acute inflammatory reactions are usually self-limiting and resolve rapidly, due to the involvement of negative feedback mechanisms. Thus, regulated inflammatory responses are essential to remain healthy and maintain homeostasis. However, inflammatory responses that fail to regulate themselves can become chronic and contribute to the perpetuation and progression of disease. Characteristics typical of chronic inflammatory responses underlying the pathophysiology of several disorders include loss of barrier function, responsiveness to a normally benign stimulus, infiltration of inflammatory cells into compartments where they are not normally found in such high numbers, and overproduction of oxidants, cytokines, chemokines, eicosanoids and matrix metalloproteinases. The levels of these mediators amplify the inflammatory response, are destructive and contribute to the clinical symptoms. Various dietary components including long chain omega-3 fatty acids, antioxidant vitamins, plant flavonoids, prebiotics and probiotics have the potential to modulate predisposition to chronic inflammatory conditions and may have a role in their therapy. These components act through a variety of mechanisms including decreasing inflammatory mediator production through effects on cell signaling and gene expression (omega-3 fatty acids, vitamin E, plant flavonoids), reducing the production of damaging oxidants (vitamin E and other antioxidants), and promoting gut barrier function and anti-inflammatory responses (prebiotics and probiotics). However, in general really strong evidence of benefit to human health through anti-inflammatory actions is lacking for most of these dietary components. Thus, further studies addressing efficacy in humans linked to studies providing greater understanding of the mechanisms of action involved are required.


Subject(s)
Inflammation/physiopathology , Nutritional Physiological Phenomena/physiology , Arthritis, Rheumatoid/diet therapy , Arthritis, Rheumatoid/physiopathology , Cardiovascular Diseases/diet therapy , Cardiovascular Diseases/physiopathology , Celiac Disease/diet therapy , Celiac Disease/physiopathology , Humans , Inflammation/diet therapy , Inflammatory Bowel Diseases/diet therapy , Inflammatory Bowel Diseases/physiopathology , Obesity/diet therapy , Obesity/physiopathology , Respiratory Hypersensitivity/diet therapy , Respiratory Hypersensitivity/physiopathology , Skin Diseases/diet therapy , Skin Diseases/physiopathology
13.
J Appl Microbiol ; 106(3): 932-40, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19191975

ABSTRACT

AIMS: To search for nondigestible but fermentable (NDF) carbohydrates and prebiotics with a potency to promote the growth of selected bacteria in vitro. METHODS AND RESULTS: The growth of three reference bacteria strains Bacillus subtilis LMG 7135(T), Carnobacterium piscicola LMG 9839, Lactobacillus plantarum LMG 9211 and one candidate probiotic bacteria Lactobacillus delbrueckii subsp. lactis was investigated over a minimum period of 48 h in the presence of beta-glucan, xylo-oligosaccharide, arabinoxylo-oligosaccharide, inulin, oligofructose and glucose. Besides the capability to grow on inulin and oligofructose containing media, a distinct high growth in beta-glucan based substrates and a low growth in (arabino)xylooligosaccharide containing media were evident for most bacteria tested. With the exception of B. subtilis and L. plantarum, other bacteria grew equally well or even better on different substrates than on glucose. The fermentation of studied carbohydrates by these micro-organisms was dominated by the production of acetic acid as the main short chain fatty acid. CONCLUSIONS: Selected bacteria are able to ferment and grow on NDF and prebiotic carbohydrates but in a substrate dependent manner. SIGNIFICANCE AND IMPACT OF THE STUDY: This study delivers a first screening of which NDF or prebiotic carbohydrates are the most promising for aquaculture feed supplementations.


Subject(s)
Bacteria/growth & development , Carbohydrate Metabolism , Prebiotics , Probiotics , Acetic Acid/metabolism , Animals , Bacillus subtilis/growth & development , Bacteria/metabolism , Bacteriological Techniques , Carnobacterium/growth & development , Colony Count, Microbial , Culture Media , Fishes/microbiology , Glucose/metabolism , Inulin/metabolism , Lactobacillus/growth & development , Oligosaccharides/metabolism , beta-Glucans/metabolism
14.
J Clin Invest ; 102(5): 1051-61, 1998 Sep 01.
Article in English | MEDLINE | ID: mdl-9727075

ABSTRACT

Fibronectin (FN), an extracellular matrix protein, is involved in the adhesion and migration of hematopoietic cells and has been shown to enhance retroviral gene transfer into primitive hematopoietic cells by co-localization of target cells and retrovirus when used as a substrate in vitro. We have previously found that mouse hematopoietic stem cells could be transduced on a FN fragment that included the recognition sequence Arg-Gly-Asp (RGD), suggesting that stem cells may express the integrin very late antigen (VLA)-5. To address this, we investigated the binding of mouse and human hematopoietic cells to recombinant peptides that contained one or a combination of the three principle cell-binding domains of FN. These domains included the VLA-5- binding sequence RGD, the VLA-4-binding site CS1, and the high affinity heparin-binding domain. Here we show that mouse long-term in vivo repopulating stem cells, as well as primitive human NOD/SCID mouse repopulating cells, can bind extracellular matrix protein FN by using integrin VLA-5 in vitro. This binding is specific and can be inhibited by antibodies to VLA-5. In addition, preincubation of BM cells with peptide CH-296, which contains all three primary FN-binding domains, decreased the engraftment of cells in the bone marrow in vivo, while intravenous injection of the same peptide induced an increase of progenitor cells in the spleen. In summary, our data demonstrate that VLA-5 is expressed on primitive mouse and human hematopoietic cells and suggest that there may be significant cooperation between integrin receptors and proteoglycan molecules in the engraftment of bone marrow cells and hematopoietic cell adhesion in vivo.


Subject(s)
Cell Adhesion/physiology , Extracellular Matrix/metabolism , Fibronectins/metabolism , Hematopoietic Stem Cells/physiology , Receptors, Fibronectin/metabolism , Animals , Antigens, CD34/immunology , Binding Sites/genetics , Bone Marrow Cells/metabolism , Cells, Cultured , Flow Cytometry , Humans , Mice , Mice, Inbred Strains , Peptide Fragments/metabolism , Peptide Fragments/pharmacology , Protein Binding/physiology , Proteoglycans/metabolism , Recombinant Proteins/metabolism , Tissue Transplantation
15.
Mol Cell Biol ; 19(4): 3145-55, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10082581

ABSTRACT

SAG (sensitive to apoptosis gene) was cloned as an inducible gene by 1,10-phenanthroline (OP), a redox-sensitive compound and an apoptosis inducer. SAG encodes a novel zinc RING finger protein that consists of 113 amino acids with a calculated molecular mass of 12.6 kDa. SAG is highly conserved during evolution, with identities of 70% between human and Caenorhabditis elegans sequences and 55% between human and yeast sequences. In human tissues, SAG is ubiquitously expressed at high levels in skeletal muscles, heart, and testis. SAG is localized in both the cytoplasm and the nucleus of cells, and its gene was mapped to chromosome 3q22-24. Bacterially expressed and purified human SAG binds to zinc and copper metal ions and prevents lipid peroxidation induced by copper or a free radical generator. When overexpressed in several human cell lines, SAG protects cells from apoptosis induced by redox agents (the metal chelator OP and zinc or copper metal ions). Mechanistically, SAG appears to inhibit and/or delay metal ion-induced cytochrome c release and caspase activation. Thus, SAG is a cellular protective molecule that appears to act as an antioxidant to inhibit apoptosis induced by metal ions and reactive oxygen species.


Subject(s)
Apoptosis , Free Radical Scavengers/metabolism , RNA-Binding Proteins , Zinc Fingers , Amino Acid Sequence , Animals , Caspases/metabolism , Chelating Agents/pharmacology , Chromosome Mapping , Chromosomes, Human, Pair 3 , Cloning, Molecular , Conserved Sequence , Copper/pharmacology , Cytochrome c Group/metabolism , Enzyme Activation , Evolution, Molecular , Humans , Lipid Peroxidation , Lipoproteins, LDL/metabolism , Metals/pharmacology , Mice , Molecular Sequence Data , Oxidants , Phenanthrolines/pharmacology , Reducing Agents , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Signal Transduction , Tissue Distribution , Tumor Cells, Cultured , Ubiquitin-Protein Ligases
16.
Eye (Lond) ; 31(3): 475-480, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27858935

ABSTRACT

PurposeAutosomal-dominant optic atrophy (ADOA), often associated with mutations in the OPA1 gene (chromosome 3q28-q29) is rarely reported in Asia. Our aim was to identify and describe this condition in an Asian population in Singapore.Patients and methodsPreliminary cross-sectional study at the Singapore National Eye Centre, including patients with clinical suspicion of ADOA, who subsequently underwent genetic testing by direct sequencing of the OPA1 gene.ResultsAmong 12 patients (10 families) with clinically suspected ADOA, 7 patients (5 families) from 3 different ethnic origins (Chinese, Indian, and Malay) carried a heterozygous pathogenic variant in the OPA1 gene. The OPA1 mutations were located on exons 8, 9, 11, and 17: c.869G>A (p.Arg290Glu), c.892A>G (p.Ser298Gly), c.1140G>A (splicing mutation), and c.1669C>T (p.Arg557*), respectively. One splicing mutation (c.871-1G>A) was identified in intron 8. We also identified a novel mutation causing optic atrophy and deafness (c.892A>G (p.Ser298Gly)). Among the phenotypic features, colour pupillometry disclosed a dissociation between low vision and preserved pupillary light reflex in ADOA.ConclusionWe report the first cases of genetically confirmed OPA1-related ADOA from Singapore, including a novel mutation causing 'ADOA plus' syndrome. Further epidemiological studies are needed in order to determine the prevalence of ADOA in South-East Asia.


Subject(s)
GTP Phosphohydrolases/genetics , Genetic Predisposition to Disease , Mutation , Optic Atrophy, Autosomal Dominant/genetics , Adult , Aged , Asian People , Cross-Sectional Studies , DNA Mutational Analysis , Female , Humans , Male , Middle Aged , Optic Atrophy, Autosomal Dominant/ethnology , Singapore , Visual Acuity
17.
Biosens Bioelectron ; 93: 212-219, 2017 07 15.
Article in English | MEDLINE | ID: mdl-27660018

ABSTRACT

Sepsis by bacterial infection causes high mortality in patients in intensive care unit (ICU). Rapid identification of bacterial infection is essential to ensure early appropriate administration of antibiotics to save lives of patients, yet the present benchtop molecular diagnosis is time-consuming and labor-intensive, which limits the treatment efficiency especially when the number of samples to be tested is extensive. Therefore, we hereby report a microfluidic platform lab-on-a-disc (LOAD) to provide a sample-to-answer solution. Our LOAD customized design of microfluidic channels allows automation to mimic sequential analytical steps in benchtop environment. It relies on a simple but controllable centrifugation force for the actuation of samples and reagents. Our LOAD system performs three major functions, namely DNA extraction, isothermal DNA amplification and real-time signal detection, in a predefined sequence. The disc is self-contained for conducting sample heating with chemical lysis buffer and silica microbeads are employed for DNA extraction from clinical specimens. Molecular diagnosis of specific target bacteria DNA sequences is then performed using a real-time loop-mediated isothermal amplification (RT-LAMP) with SYTO-9 as the signal reporter. Our LOAD system capable of bacterial identification of Mycobacterium tuberculosis (TB) and Acinetobacter baumanii (Ab) with the detection limits 103cfu/mL TB in sputum and 102cfu/mL Ab in blood within 2h after sample loading. The reported LOAD based on an integrated approach should address the growing needs for rapid point-of-care medical diagnosis in ICU.


Subject(s)
Acinetobacter baumannii/isolation & purification , Biosensing Techniques , DNA, Bacterial/isolation & purification , Mycobacterium tuberculosis/isolation & purification , Sepsis/microbiology , Acinetobacter baumannii/pathogenicity , DNA, Bacterial/chemistry , Humans , Microfluidic Analytical Techniques , Mycobacterium tuberculosis/pathogenicity , Organic Chemicals/chemistry , Sepsis/diagnosis
18.
J Dent Res ; 85(12): 1129-33, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17122167

ABSTRACT

This paper tests the hypothesis that salivary proteins and their counterpart mRNAs co-exist in human whole saliva. Global profiling of human saliva proteomes and transcriptomes by mass spectrometry (MS) and expression microarray technologies, respectively, revealed many similarities between saliva proteins and mRNAs. Of the function-known proteins identified in saliva, from 61 to 70% were also found present as mRNA transcripts. For genes not detected at both protein and mRNA levels, we made further efforts to determine if the counterpart is present. Of 19 selected genes detected only at the protein level, the mRNAs of 13 (68%) genes were found in saliva by RT-PCR. In contrast, of many mRNAs detected only by microarrays, their protein products were found in saliva, as reported previously by other investigators. The saliva transcriptome may provide preliminary insights into the boundary of the saliva proteome.


Subject(s)
Gene Expression Profiling , Proteome/analysis , Salivary Proteins and Peptides/analysis , Adult , Humans , Mass Spectrometry , Middle Aged , Protein Array Analysis , Proteome/genetics , RNA, Messenger/analysis , Saliva/chemistry , Salivary Proteins and Peptides/genetics , Sequence Analysis, Protein , Sequence Analysis, RNA , Transcription, Genetic/genetics
19.
Nutr Res Rev ; 19(2): 216-26, 2006 Dec.
Article in English | MEDLINE | ID: mdl-19079887

ABSTRACT

Health and wellbeing are challenged constantly by pathogens. A number of defence mechanisms exist to protect the body from pathogen colonisation and invasion, with an important role to play for the natural intestinal bacterial flora (mainly by bifidobacteria and lactobacilli). The present paper reviews the evidence on the effects of inulin and oligofructose on colonisation and translocation of pathogens and the prevention of intestinal diseases. In vitro experiments have shown that lactic acid-producing bacteria have antagonistic (antibacterial) activity against pathogens partly because of the production of organic acids which are the endproducts of inulin and oligofructose fermentation. In addition, studies with epithelial layers have shown that inulin and oligofructose inhibit pathogen colonisation and that endproducts of their fermentation have the ability to support barrier function. Furthermore, studies in various animal models have shown that inulin and oligofructose accelerate the recovery of beneficial bacteria, slow down pathogen growth, decreasing pathogen colonisation and systemic translocation. Finally, data from human intervention trials either in patients with intestinal disorders or disease, or prone to critical illness, found that inulin and oligofructose restore the balance when the gut microbial community is altered, inhibit the progression of disease or prevent it from relapsing and/or developing. To conclude, the dietary use of inulin and oligofructose offers a promising approach to restore microbial communities and to support barrier function of the epithelia by their prebiotic action. This may offer the host protection against invasion and translocation of pathogens (endogenous and/or exogenous) and in the prevention of gastrointestinal diseases.

20.
Eur Ann Otorhinolaryngol Head Neck Dis ; 133 Suppl 1: S25-30, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27267231

ABSTRACT

OBJECTIVES: The Children Using Hearing Devices Quality of Life Questionnaire (CuHDQOL) is a new parent-administered hearing-specific questionnaire for children fitted with hearing devices. The aim of this study was to assess outcomes for hearing-impaired children in Singapore using this measure, as well as to examine its applicability for use in a clinical setting. MATERIALS AND METHODS: The CuHDQOL has 26 items, uses a recall period of 1 month, and is divided into three sections: parental perspectives and expectations (eight items), impact on the family (eight items) and hearing-related quality of life (QOL) of the child (10 items). Responses are made on a 5-point Likert scale, and transformed to a score from 0-100. Twenty-two parents of children with hearing aids and 14 parents of children with cochlear implants completed the CuHDQOL. RESULTS: The mean total CuHDQOL scores was 62/100 for the children using hearing aids and 53/100 for children with cochlear implants. Scores for the children using hearing aids were higher across all subscales, with a linear regression showing this to be significant for the parental perspectives and expectations subscale (B=-10.58, P=0.041). Analyses of Variance showed that both the 'Parent Perspective and Expectations' and the 'Hearing-related QOL' subscales were significantly higher than the 'Impact on Family' subscale for both groups (P≤0.003). CONCLUSIONS: The CuHDQOL was found to be a simple, efficient questionnaire that could easily be incorporated into clinical practice to provide a more holistic evaluation of a child's outcomes post intervention, and/or to monitor their progress over time.


Subject(s)
Cochlear Implants , Hearing Aids , Parents , Quality of Life , Child, Preschool , Hearing Loss/therapy , Humans , Infant , Linear Models , Singapore , Surveys and Questionnaires
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