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1.
Org Biomol Chem ; 18(29): 5652-5659, 2020 08 07.
Article in English | MEDLINE | ID: mdl-32648870

ABSTRACT

We report a method for condensation between ortho-phenylenediamines and ortho-hydroxyacetophenones to afford benzofuroquinoxalines. The reactions proceeded in the presence of an elemental sulfur mediator, DABCO base, and DMSO solvent. Functionalities such as nitrile, ester, and halogen groups were compatible. The conditions could be applicable for the synthesis of benzothienoquinoxalines from ortho-chloroacetophenones.

2.
BMC Nephrol ; 21(1): 142, 2020 04 22.
Article in English | MEDLINE | ID: mdl-32321449

ABSTRACT

BACKGROUND: Early detection of iron-deficiency anemia (IDA) can enhance the efficiency and effectiveness of clinical treatment and quality of life for end-stage renal disease (ESRD) patients. This study aimed to evaluate the validity of CHr and %Hypo in screening IDA among ESRD patients and compare their performance with screening IDA among non-ESRD patients. METHOD: A retrospective analysis of 312 participants was conducted at Cho Ray Hospital, Vietnam, including healthy control participants and ESRD patients. Receiver operator characteristics curves and the area under the curve (AUC) of models were used to evaluate the performance of CHr, %Hypo. Optimal cut-off values were determined using Youden's index. RESULTS: Detecting IDA in ESRD patients is more complicated, as the screening performance of CHr and %Hypo in predicting IDA among ESRD patients were lower than non ESRD group, but still reasonable with AUC = 0.748 (95% CI: 0.656-0.840, power = 0.997) and 0.740 (95% CI: 0.647-0.833, power = 0.996), respectively. Cut-off values of CHr < 31.5 pg and %Hypo> 10.0 pg are recommended to obtain optimal screening ability for Vietnamese ESRD patients. CONCLUSION: CHr and %Hypo appears to be useful tools for screening IDA among both non ESRD and ESRD patients. The low cost and accessible of the two markers encourage their utility as effective screening tools in clinical practice.


Subject(s)
Anemia, Iron-Deficiency , Erythrocyte Indices , Hemoglobins/analysis , Kidney Failure, Chronic , Reticulocytes/metabolism , Anemia, Iron-Deficiency/blood , Anemia, Iron-Deficiency/epidemiology , Anemia, Iron-Deficiency/therapy , Area Under Curve , Cost-Benefit Analysis , Female , Humans , Kidney Failure, Chronic/blood , Kidney Failure, Chronic/diagnosis , Kidney Failure, Chronic/epidemiology , Male , Mass Screening/economics , Mass Screening/methods , Middle Aged , Reproducibility of Results , Retrospective Studies , Vietnam/epidemiology
4.
J Bacteriol ; 197(18): 2965-80, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26148714

ABSTRACT

UNLABELLED: Most acetogens can reduce CO2 with H2 to acetic acid via the Wood-Ljungdahl pathway, in which the ATP required for formate activation is regenerated in the acetate kinase reaction. However, a few acetogens, such as Clostridium autoethanogenum, Clostridium ljungdahlii, and Clostridium ragsdalei, also form large amounts of ethanol from CO2 and H2. How these anaerobes with a growth pH optimum near 5 conserve energy has remained elusive. We investigated this question by determining the specific activities and cofactor specificities of all relevant oxidoreductases in cell extracts of H2/CO2-grown C. autoethanogenum. The activity studies were backed up by transcriptional and mutational analyses. Most notably, despite the presence of six hydrogenase systems of various types encoded in the genome, the cells appear to contain only one active hydrogenase. The active [FeFe]-hydrogenase is electron bifurcating, with ferredoxin and NADP as the two electron acceptors. Consistently, most of the other active oxidoreductases rely on either reduced ferredoxin and/or NADPH as the electron donor. An exception is ethanol dehydrogenase, which was found to be NAD specific. Methylenetetrahydrofolate reductase activity could only be demonstrated with artificial electron donors. Key to the understanding of this energy metabolism is the presence of membrane-associated reduced ferredoxin:NAD(+) oxidoreductase (Rnf), of electron-bifurcating and ferredoxin-dependent transhydrogenase (Nfn), and of acetaldehyde:ferredoxin oxidoreductase, which is present with very high specific activities in H2/CO2-grown cells. Based on these findings and on thermodynamic considerations, we propose metabolic schemes that allow, depending on the H2 partial pressure, the chemiosmotic synthesis of 0.14 to 1.5 mol ATP per mol ethanol synthesized from CO2 and H2. IMPORTANCE: Ethanol formation from syngas (H2, CO, and CO2) and from H2 and CO2 that is catalyzed by bacteria is presently a much-discussed process for sustainable production of biofuels. Although the process is already in use, its biochemistry is only incompletely understood. The most pertinent question is how the bacteria conserve energy for growth during ethanol formation from H2 and CO2, considering that acetyl coenzyme A (acetyl-CoA), is an intermediate. Can reduction of the activated acetic acid to ethanol with H2 be coupled with the phosphorylation of ADP? Evidence is presented that this is indeed possible, via both substrate-level phosphorylation and electron transport phosphorylation. In the case of substrate-level phosphorylation, acetyl-CoA reduction to ethanol proceeds via free acetic acid involving acetaldehyde:ferredoxin oxidoreductase (carboxylate reductase).


Subject(s)
Carbon Dioxide/metabolism , Clostridium/metabolism , Energy Metabolism/physiology , Ethanol/metabolism , Hydrogen/metabolism , Acetic Acid/chemistry , Acetic Acid/metabolism , Acetyl Coenzyme A/metabolism , Adenosine Diphosphate/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Clostridium/classification , Electron Transport , Gene Expression Regulation, Bacterial/physiology , Gene Expression Regulation, Enzymologic/physiology , Membrane Proteins , Oxidoreductases/genetics , Oxidoreductases/metabolism , Phosphoproteins
5.
Cell Oncol (Dordr) ; 2024 May 28.
Article in English | MEDLINE | ID: mdl-38806997

ABSTRACT

Cancer is a highly heterogeneous disease, and thus treatment responses vary greatly between patients. To improve therapy efficacy and outcome for cancer patients, more representative and patient-specific preclinical models are needed. Organoids and tumoroids are 3D cell culture models that typically retain the genetic and epigenetic characteristics, as well as the morphology, of their tissue of origin. Thus, they can be used to understand the underlying mechanisms of cancer initiation, progression, and metastasis in a more physiological setting. Additionally, co-culture methods of tumoroids and cancer-associated cells can help to understand the interplay between a tumor and its tumor microenvironment. In recent years, tumoroids have already helped to refine treatments and to identify new targets for cancer therapy. Advanced culturing systems such as chip-based fluidic devices and bioprinting methods in combination with tumoroids have been used for high-throughput applications for personalized medicine. Even though organoid and tumoroid models are complex in vitro systems, validation of results in vivo is still the common practice. Here, we describe how both animal- and human-derived tumoroids have helped to identify novel vulnerabilities for cancer treatment in recent years, and how they are currently used for precision medicine.

6.
J Med Case Rep ; 18(1): 92, 2024 Mar 08.
Article in English | MEDLINE | ID: mdl-38454521

ABSTRACT

BACKGROUND: Orbital ischemic syndrome is a rare entity. The clinical signs typically demonstrate acute loss of visual acuity, chemosis, proptosis, ptosis, and total ophthalmoparesis. We report a case of a man who suffered an acute internal carotid artery occlusion and developed orbital ischemic syndrome after a mechanical thrombectomy. CASE PRESENTATION: A 57-year-old Vietnamese (Kinh ethnicity) man was brought to the emergency room with complaints of a speech disturbance, facial palsy, and severe weakness of the left arm and leg, which had started 4 hours earlier, after waking up. The National Institutes of Health Stroke Scale 12 (NIHSS 12) revealed the neurological score at admission. A head computed tomography scan showed no intracranial bleeding and an Alberta Stroke Program Early Computed Tomography Score (ASPECTS) of 8 on the right brain. Computed tomography angiography showed an occlusion of the right internal carotid artery. After that, a mechanical thrombectomy was performed, and the internal carotid artery was completely reperfused. After 10 hours, he experienced orbital pain, proptosis, ptosis, chemosis, and ophthalmoplegia of the right orbit. He also had acute loss of visual acuity, and fundoscopic examination revealed papilledema, no retinal hemorrhage, and no bruit in orbital auscultation. Intraocular pressure in the right eye was measured at 50.5 mmHg. Computed tomography angiography showed no carotid-cavernous fistula, but slight enlargement of the right medial and lateral rectus muscles. He was treated with steroids and hyperosmolar agents and recovered 7 days later, but had persistent loss of visual acuity in the right eye. CONCLUSION: Orbital ischemic syndrome is a rare complication after mechanical thrombectomy treatment in acute ischemic stroke that can lead to loss of visual acuity.


Subject(s)
Exophthalmos , Ischemic Stroke , Ophthalmoplegia , Stroke , Humans , Male , Middle Aged , Carotid Artery, Internal/diagnostic imaging , Infarction/complications , Ischemia , Ophthalmoplegia/etiology , Stroke/complications , Thrombectomy/adverse effects , Thrombectomy/methods
7.
N Biotechnol ; 83: 1-15, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38871051

ABSTRACT

Microbes able to convert gaseous one-carbon (C1) waste feedstocks are increasingly important to transition to the sustainable production of renewable chemicals and fuels. Acetogens are interesting biocatalysts since gas fermentation using Clostridium autoethanogenum has been commercialised. However, most acetogen strains need complex nutrients, display slow growth, and are not robust for bioreactor fermentations. In this work, we used three different and independent adaptive laboratory evolution (ALE) strategies to evolve the wild-type C. autoethanogenum to grow faster, without yeast extract and to be robust in operating continuous bioreactor cultures. Multiple evolved strains with improved phenotypes were isolated on minimal media with one strain, named "LAbrini", exhibiting superior performance regarding the maximum specific growth rate, product profile, and robustness in continuous cultures. Whole-genome sequencing of the evolved strains identified 25 mutations. Of particular interest are two genes that acquired seven different mutations across the three ALE strategies, potentially as a result of convergent evolution. Reverse genetic engineering of mutations in potentially sporulation-related genes CLAU_3129 (spo0A) and CLAU_1957 recovered all three superior features of our ALE strains through triggering significant proteomic rearrangements. This work provides a robust C. autoethanogenum strain "LAbrini" to accelerate phenotyping and genetic engineering and to better understand acetogen metabolism.

8.
Cell Mol Gastroenterol Hepatol ; 15(6): 1391-1419, 2023.
Article in English | MEDLINE | ID: mdl-36868311

ABSTRACT

BACKGROUND & AIMS: Patient-derived organoid cancer models are generated from epithelial tumor cells and reflect tumor characteristics. However, they lack the complexity of the tumor microenvironment, which is a key driver of tumorigenesis and therapy response. Here, we developed a colorectal cancer organoid model that incorporates matched epithelial cells and stromal fibroblasts. METHODS: Primary fibroblasts and tumor cells were isolated from colorectal cancer specimens. Fibroblasts were characterized for their proteome, secretome, and gene expression signatures. Fibroblast/organoid co-cultures were analyzed by immunohistochemistry and compared with their tissue of origin, as well as on gene expression levels compared with standard organoid models. Bioinformatics deconvolution was used to calculate cellular proportions of cell subsets in organoids based on single-cell RNA sequencing data. RESULTS: Normal primary fibroblasts, isolated from tumor adjacent tissue, and cancer associated fibroblasts retained their molecular characteristics in vitro, including higher motility of cancer associated compared with normal fibroblasts. Importantly, both cancer-associated fibroblasts and normal fibroblasts supported cancer cell proliferation in 3D co-cultures, without the addition of classical niche factors. Organoids grown together with fibroblasts displayed a larger cellular heterogeneity of tumor cells compared with mono-cultures and closely resembled the in vivo tumor morphology. Additionally, we observed a mutual crosstalk between tumor cells and fibroblasts in the co-cultures. This was manifested by considerably deregulated pathways such as cell-cell communication and extracellular matrix remodeling in the organoids. Thrombospondin-1 was identified as a critical factor for fibroblast invasiveness. CONCLUSION: We developed a physiological tumor/stroma model, which will be vital as a personalized tumor model to study disease mechanisms and therapy response in colorectal cancer.


Subject(s)
Cancer-Associated Fibroblasts , Colorectal Neoplasms , Humans , Fibroblasts/metabolism , Coculture Techniques , Organoids/metabolism , Cancer-Associated Fibroblasts/metabolism , Colorectal Neoplasms/pathology , Tumor Microenvironment
9.
Cell Metab ; 35(11): 1931-1943.e8, 2023 11 07.
Article in English | MEDLINE | ID: mdl-37804836

ABSTRACT

The intestinal epithelium has a high turnover rate and constantly renews itself through proliferation of intestinal crypt cells, which depends on insufficiently characterized signals from the microenvironment. Here, we showed that colonic macrophages were located directly adjacent to epithelial crypt cells in mice, where they metabolically supported epithelial cell proliferation in an mTORC1-dependent manner. Specifically, deletion of tuberous sclerosis complex 2 (Tsc2) in macrophages activated mTORC1 signaling that protected against colitis-induced intestinal damage and induced the synthesis of the polyamines spermidine and spermine. Epithelial cells ingested these polyamines and rewired their cellular metabolism to optimize proliferation and defense. Notably, spermine directly stimulated proliferation of colon epithelial cells and colon organoids. Genetic interference with polyamine production in macrophages altered global polyamine levels in the colon and modified epithelial cell proliferation. Our results suggest that macrophages act as "commensals" that provide metabolic support to promote efficient self-renewal of the colon epithelium.


Subject(s)
Polyamines , Spermine , Mice , Animals , Spermine/metabolism , Polyamines/metabolism , Colon , Intestinal Mucosa/metabolism , Homeostasis , Macrophages/metabolism , Mechanistic Target of Rapamycin Complex 1/metabolism
10.
Environ Sci Technol ; 46(12): 6698-704, 2012 Jun 19.
Article in English | MEDLINE | ID: mdl-22612278

ABSTRACT

Isoflavones are plant-derived chemicals that are potential endocrine disruptors. Although some recent studies have detected isoflavones in natural waters, little is known about their aquatic fates. The photochemical behaviors of the isoflavones daidzein, formononetin, biochanin A, genistein, and equol were studied under simulated solar light and natural sunlight. All of these phytoestrogens were found to be photolabile under certain conditions. Daidzein and formononetin degraded primarily by direct photolysis. Their expected near-surface summer half-lives in pH 7 water at 47° latitude are expected to be 10 and 4.6 h, respectively. Biochanin A, genistein, and equol degraded relatively slowly by direct photolysis at environmentally realistic pH values, though they showed significant degradation rate enhancements in the presence of natural organic matter (NOM). The indirect photolysis rates for these compounds scaled with NOM concentration, and NOM from microbial origin was found to be a more potent photosensitizer than NOM from terrestrial sources. Mechanistic studies were performed to determine the indirect photolysis pathways responsible for the rate enhancements. Results of these studies implicate reaction with both singlet oxygen and excited state triplet NOM. Environmental half-lives for biochanin A, genistein, and equol are expected to vary on the basis of pH as well as NOM source and concentration.


Subject(s)
Isoflavones/chemistry , Photochemistry , Phytoestrogens/chemistry , Water Pollutants, Chemical/chemistry , Hydrogen-Ion Concentration , Kinetics , Spectrophotometry, Ultraviolet
11.
Pharmaceuticals (Basel) ; 15(2)2022 Feb 14.
Article in English | MEDLINE | ID: mdl-35215337

ABSTRACT

Personalized treatment of cancer patients demands specific and validated biomarkers for tumor diagnosis and therapy. The development and validation of such require translational preclinical models that recapitulate human diseases as accurately as possible. Moreover, there is a need for convergence of different (pre)clinical disciplines that openly share their knowledge and methodologies. This review sheds light on the differential perception of biomarkers and gives an overview of currently used models in tracer development and approaches for biomarker discovery.

12.
Nat Commun ; 13(1): 3058, 2022 06 01.
Article in English | MEDLINE | ID: mdl-35650184

ABSTRACT

Carbon-negative synthesis of biochemical products has the potential to mitigate global CO2 emissions. An attractive route to do this is the reverse ß-oxidation (r-BOX) pathway coupled to the Wood-Ljungdahl pathway. Here, we optimize and implement r-BOX for the synthesis of C4-C6 acids and alcohols. With a high-throughput in vitro prototyping workflow, we screen 762 unique pathway combinations using cell-free extracts tailored for r-BOX to identify enzyme sets for enhanced product selectivity. Implementation of these pathways into Escherichia coli generates designer strains for the selective production of butanoic acid (4.9 ± 0.1 gL-1), as well as hexanoic acid (3.06 ± 0.03 gL-1) and 1-hexanol (1.0 ± 0.1 gL-1) at the best performance reported to date in this bacterium. We also generate Clostridium autoethanogenum strains able to produce 1-hexanol from syngas, achieving a titer of 0.26 gL-1 in a 1.5 L continuous fermentation. Our strategy enables optimization of r-BOX derived products for biomanufacturing and industrial biotechnology.


Subject(s)
Carbon Cycle , Escherichia coli , Autotrophic Processes , Escherichia coli/metabolism , Fermentation , Oxidation-Reduction
13.
Nat Biotechnol ; 40(3): 335-344, 2022 03.
Article in English | MEDLINE | ID: mdl-35190685

ABSTRACT

Many industrial chemicals that are produced from fossil resources could be manufactured more sustainably through fermentation. Here we describe the development of a carbon-negative fermentation route to producing the industrially important chemicals acetone and isopropanol from abundant, low-cost waste gas feedstocks, such as industrial emissions and syngas. Using a combinatorial pathway library approach, we first mined a historical industrial strain collection for superior enzymes that we used to engineer the autotrophic acetogen Clostridium autoethanogenum. Next, we used omics analysis, kinetic modeling and cell-free prototyping to optimize flux. Finally, we scaled-up our optimized strains for continuous production at rates of up to ~3 g/L/h and ~90% selectivity. Life cycle analysis confirmed a negative carbon footprint for the products. Unlike traditional production processes, which result in release of greenhouse gases, our process fixes carbon. These results show that engineered acetogens enable sustainable, high-efficiency, high-selectivity chemicals production. We expect that our approach can be readily adapted to a wide range of commodity chemicals.


Subject(s)
2-Propanol , Acetone , Carbon/metabolism , Carbon Cycle , Fermentation
14.
Clin Chim Acta ; 531: 309-317, 2022 Jun 01.
Article in English | MEDLINE | ID: mdl-35500877

ABSTRACT

BACKGROUND: Asymptomatic transmission was found to be the Achilles' heel of the symptom-based screening strategy, necessitating the implementation of mass testing to efficiently contain the transmission of COVID-19 pandemic. However, the global shortage of molecular reagents and the low throughput of available realtime PCR facilities were major limiting factors. METHODS: A novel semi-nested and heptaplex (7-plex) RT-PCR assay with melting analysis for detection of SARS-CoV-2 RNA has been established for either individual testing or 96-sample pooled testing. The complex melting spectrum collected from the heptaplex RT-PCR amplicons was interpreted with the support of an artificial intelligence algorithm for the detection of SARS-CoV-2 RNA. The analytical and clinical performance of the semi-nested RT-PCR assay was evaluated using RNAs synthesized in-vitro and those isolated from nasopharyngeal samples. RESULTS: The LOD of the assay for individual testing was estimated to be 7.2 copies/reaction. Clinical performance evaluation indicated a sensitivity of 100% (95% CI: 97.83-100) and a specificity of 99.87% (95% CI: 99.55-99.98). More importantly, the assay supports a breakthrough sample pooling method, which makes possible parallel screening of up to 96 samples in one real-time PCR well without loss of sensitivity. As a result, up to 8,820 individual pre-amplified samples could be screened for SARS-CoV-2 within each 96-well plate of realtime PCR using the pooled testing procedure. CONCLUSION: The novel semi-nested RT-PCR assay provides a solution for highly multiplex (7-plex) detection of SARS-CoV-2 and enables 96-sample pooled detection for increase of testing capacity. .


Subject(s)
COVID-19 , SARS-CoV-2 , Artificial Intelligence , COVID-19/diagnosis , Humans , Pandemics , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2/genetics , Sensitivity and Specificity
15.
Article in English | MEDLINE | ID: mdl-31244769

ABSTRACT

[11C]SNAP-7941 and its radiofluorinated, fluoro-ethyl derivative [18F]FE@SNAP have been developed as the first positron emission tomography tracers for melanin-concentrating hormone receptor 1 (MCHR1) imaging. Accumulation of these MCHR1 PET-tracers in rat brown adipose tissue (BAT) in vivo provided first indication of MCHR1 expression in rodent BAT. To rule out off-target binding, affinity of both MCHR1 ligands toward adrenergic beta-3 receptors (ADRB3) was examined. Further, specific binding of [11C]SNAP-7941 to brown adipocytes and effects of MCHR1 ligands on brown adipocyte activation were investigated. SNAP-7941 and FE@SNAP evinced to be highly selective toward MCHR1. [11C]SNAP-7941 binding to brown adipocytes was shown to be mainly MCHR1-specific. This data strongly indicates MCHR1 expression in rodent BAT and moreover, a peripheral, anti-obesity effect of MCHR1 antagonists directly exerted in BAT is proposed. Moreover, MCHR1 expression in murine brown adipocytes was confirmed by protein and mRNA analysis. We conclude that MCHR1 PET imaging contributes to basic research in endocrinology by elucidating the involvement of the MCH system in peripheral tissues, such as BAT.

16.
RSC Adv ; 8(55): 31455-31464, 2018 Sep 05.
Article in English | MEDLINE | ID: mdl-35548194

ABSTRACT

A Cu2(OBA)2(BPY) metal-organic framework was utilized as a productive heterogeneous catalyst for the synthesis of 3-aroylquinolines via one-pot domino reactions of 2-aminobenzylalcohols with propiophenones. This Cu-MOF was considerably more active towards the one-pot domino reaction than a series of transition metal salts, as well as nano oxide and MOF-based catalysts. The MOF-based catalyst was reusable without a significant decline in catalytic efficiency. To the best of our knowledge, the transformation of 2-aminobenzylalcohols to 3-aroylquinolines was not previously reported in the literature, and this protocol would be complementary to previous strategies for the synthesis of these valuable heterocycles.

17.
Jpn J Infect Dis ; 70(5): 522-527, 2017 Sep 25.
Article in English | MEDLINE | ID: mdl-28367882

ABSTRACT

Severe acute respiratory infections (SARI) are leading causes of hospitalization, morbidity, and mortality in children worldwide. The aim of this study was to identify viral pathogens responsible for SARI in northern Vietnam in the period from 2011 to 2014. Throat swabs and tracheal aspirates were collected from SARI patients according to WHO guidelines. The presence of 13 different viral pathogens (influenza A[H1N1]pdm09; A/H3N2; A/H5; A/H7 and B; para influenza 1,2,3; RSV; HMPV; adeno; severe acute respiratory syndrome-CoV and rhino) was tested by conventional/real-time reverse transcription-polymerase chain reaction. During the study period, 975 samples were collected and tested. More than 30% (32.1%, 313 samples) of the samples showed evidence of infection with influenza viruses, including A/H3N2 (48 samples), A (H1N1) pdm09 (221 samples), influenza B (42 samples), and co-infection of A (H1N1) pdm09 or A/H3N2 and influenza B (2 samples). Other respiratory pathogens were detected in 101 samples, including rhinovirus (73 samples), adenovirus (10 samples), hMPV (9 samples), parainfluenza 3 (5 samples), parainfluenza 2 (3 samples), and RSV (1 sample). Influenza A/H5, A/H7, or SARS-CoV were not detected. Respiratory viral infection, particularly infection of influenza and rhinoviruses, were associated with high rates of SARI hospitalization, and future studies correlating the clinical aspects are needed to design interventions, including targeted vaccination.


Subject(s)
Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/virology , Virus Diseases/epidemiology , Virus Diseases/virology , Viruses/classification , Viruses/isolation & purification , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Epidemiological Monitoring , Female , Hospitalization , Humans , Infant , Male , Middle Aged , Pharynx/virology , Prevalence , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Trachea/virology , Vietnam/epidemiology , Young Adult
18.
PLoS One ; 10(7): e0132520, 2015.
Article in English | MEDLINE | ID: mdl-26186665

ABSTRACT

This study aims to develop a reproducible rat model for post-traumatic bisphosphonate-related osteonecrosis of the jaw (BRONJ). In our previous studies using dental extraction as an inducing factor, only 30%-60% of zoledronate-treated animals fulfilled the definition of clinical BRONJ. We modified the zoledronate regimen and introduced repeated surgical extraction to illicit quantifiable BRONJ in all animals. Eighty retired-breeder female Sprague-Dawley rats were divided between the treatment (i.v. zoledronate; 80 µg/kg/week for 13 weeks) and control (saline) groups. On week 13, the left mandibular first molar was surgically extracted, followed by the second molar a week later. Animals were euthanized at 1-week, 2-weeks, and 8-weeks following extraction. The occurrence and severity of BRONJ were scored in each animal based on gross and MicroCT analysis. Parameters of bone formation and osteoclast functions at the extraction site were compared between groups. All zoledronate-treated animals developed a severe case of BRONJ that fulfilled the clinical definition of the condition in humans. Osteoclast attachment continued to be defective eight weeks after stopping the treatment. There were no signs of kidney or liver toxicity. Our data confirmed that repeated surgical extraction (major trauma) by itself consistently precipitated massive bone necrosis in ZA-treated animals, eliminating the need to induce pre-existing infection or comorbidity. These results will be the basis for further studies examining the in-vivo pathogenesis and prevention of BRONJ.


Subject(s)
Bisphosphonate-Associated Osteonecrosis of the Jaw/etiology , Bisphosphonate-Associated Osteonecrosis of the Jaw/pathology , Diphosphonates/adverse effects , Imidazoles/adverse effects , Wounds and Injuries/complications , Acid Phosphatase/metabolism , Animals , Bisphosphonate-Associated Osteonecrosis of the Jaw/diagnostic imaging , Disease Models, Animal , Female , Isoenzymes/metabolism , Kidney/drug effects , Kidney/pathology , Liver/drug effects , Liver/pathology , Mandible/diagnostic imaging , Mandible/drug effects , Mandible/pathology , Osteoclasts/drug effects , Osteoclasts/pathology , Rats, Sprague-Dawley , Tartrate-Resistant Acid Phosphatase , Tooth Extraction , Wound Healing/drug effects , X-Ray Microtomography , Zoledronic Acid
19.
Influenza Other Respir Viruses ; 9(4): 216-24, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25966032

ABSTRACT

OBJECTIVES: Influenza A/H1N1pdm09 virus was first detected in Vietnam on May 31, 2009, and continues to circulate in Vietnam as a seasonal influenza virus. This study has monitored genotypic and phenotypic changes in this group of viruses during 2010-2013 period. DESIGN AND SETTING: We sequenced hemagglutinin (HA) and neuraminidase (NA) genes from representative influenza A/H1N1pdm09 and compared with vaccine strain A/California/07/09 and other contemporary isolates from neighboring countries. Hemagglutination inhibition (HI) and neuraminidase inhibition (NAI) assays also were performed on these isolates. SAMPLE: Representative influenza A/H1N1pdm09 isolates (n = 61) from ILI and SARI surveillances in northern Vietnam between 2010 and 2013. MAIN OUTCOME MEASURES AND RESULTS: The HA and NA phylogenies revealed six and seven groups, respectively. Five isolates (8·2%) had substitutions G155E and N156K in the HA, which were associated with reduced HI titers by antiserum raised against the vaccine virus A/California/07/2009. One isolate from 2011 and one isolate from 2013 had a predicted H275Y substitution in the neuraminidase molecule, which was associated with reduced susceptibility to oseltamivir in a NAI assay. We also identified a D222N change in the HA of a virus isolated from a fatal case in 2013. CONCLUSIONS: Significant genotypic and phenotypic changes in A/ H1N1pdm09 influenza viruses were detected by the National Influenza Surveillance System (NISS) in Vietnam between 2010 and 2013 highlighting the value of this system to Vietnam and to the region. Sustained NISS and continued virological monitoring of seasonal influenza viruses are required for vaccine policy development in Vietnam. 3.


Subject(s)
Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza, Human/virology , Humans , Influenza A Virus, H1N1 Subtype/classification , Influenza A Virus, H1N1 Subtype/genetics , Influenza, Human/epidemiology , Molecular Sequence Data , Phylogeny , Vietnam/epidemiology , Viral Proteins/genetics
20.
J Atheroscler Thromb ; 19(7): 680-90, 2012.
Article in English | MEDLINE | ID: mdl-22653163

ABSTRACT

AIM: Intima-media thickness (IMT) is considered a surrogate measurement of atherosclerosis but this is still under debate. METHODS: To evaluate the relationship between carotid IMT and atherosclerosis, postmortem specimens of the distal segments of the left common carotid artery (CCA) from 133 Korean men aged from 20 to 78 years were used for histopathology and computer-assisted morphometry. Blood lipids and atherosclerosis-associated collagen and elastin were quantitatively analyzed. RESULTS: Correlation coefficients of IMT were smaller than those of intima thickness but IMT was well associated with age (r= 0.55, p <0.00001), atherosclerosis score (or grade, AS, r= 0.73, p < 0.00001), plaque area (PA, r= 0.72, p <0.00001), total cholesterol (TC, r= 0.69, p <0.00001), low-density lipoprotein cholesterol (LDL-c, r= 0.72, p <0.00001) and triglyceride (TG, r= 0.38, p < 0.001). Coronary artery stenosis (CAS) and coronary calcification were also well associated with age (p <0.00001), IMT (p <0.005) and PA (p <0.00001). When IMT was thicker than 1 mm, the possibility of carotid atherosclerosis accompanied with CAS and coronary calcification, TC, LDL-c and TG was much higher (CAS with coronary calcification,p <0.005; TC, p <0.00001; LDL-c, p < 0.00005; TG, p <0.00001). Collagen tended to increase while elastin tended to decrease as AS increased (p <0.005); collagen increased and elastin decreased (p <0.00001) when comparing plaque to the plaque-free area in the same segment. CONCLUSION: These results support that the carotid IMT in association with TC, LDL-c and TG can be used as a good surrogate marker of atherosclerosis and predictor of coronary heart disease. Plaque formation may influence significant quantitative changes in collagen and elastin.


Subject(s)
Atherosclerosis/diagnosis , Biomarkers/metabolism , Carotid Intima-Media Thickness , Cholesterol, LDL/metabolism , Cholesterol/metabolism , Triglycerides/metabolism , Adult , Aged , Atherosclerosis/etiology , Atherosclerosis/metabolism , Collagen/metabolism , Elastin/metabolism , Humans , Lipids/blood , Male , Middle Aged , Risk Factors , Young Adult
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