1
|
Nguyen LA, Nguyen TTT, Ngo QA, Retailleau P, Nguyen TB. A solvent-free and catalyst-free reaction of o-aminobenzophenone with aryl isothiocyanates: expedient access to congested 4-phenyl-4-hydroxyquinazolin-2-thione derivatives. Org Biomol Chem 2024; 22:9353-9356. [PMID: 39480663 DOI: 10.1039/d4ob01452a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2024]
Abstract
An efficient method to construct 4-phenyl-4-hydroxyquinazolin-2-thiones 3via solvent-free and catalyst-free addition of o-aminobenzophenone 1 with aryl isothiocyanates 2 under thermal conditions has been developed, providing new congested 4-phenyl-4-hydroxyquinazolin-2-thiones 3 in practically quantitative yields via simple purification by filtration/recrystallization. Extension of these conditions to o-aminoacetophenone 4 in place of o-aminobenzophenone 1 led to 4-methylenequinazoline-thione 5 as a result of a subsequent dehydration reaction.
Collapse
|
2
|
Nguyen LA, Ngo QA, Retailleau P, Nguyen TB. Room temperature dithiocarbamation of 2-tetralones with elemental sulfur and isothiocyanates S 8/R-NCS: atom-efficient access to 4-hydroxythiazolidine-2-thiones. Chem Commun (Camb) 2024; 60:13586-13589. [PMID: 39480192 DOI: 10.1039/d4cc05053c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2024]
Abstract
2-Tetralones were found to undergo dithiocarbamation with elemental sulfur and isothiocyanates S8/R-NCS in the presence of N-methylpiperidine as a base catalyst under solvent-free conditions. The reaction could proceed quickly at room temperature to provide convenient access to substituted 4-hydroxythiazolidine-2-thiones with complete atom efficiency. The adducts could be easily dehydrated in neat TFA to give thiazole-2-thiones.
Collapse
|
3
|
Nguyen LA, Mac DH, Retailleau P, Nguyen TB. Redox condensation of o-halonitrobenzenes, sulfur and isothiocyanates: access to 2-aminobenzothiazoles. Org Biomol Chem 2024; 22:8586-8590. [PMID: 39373946 DOI: 10.1039/d4ob01512f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/08/2024]
Abstract
The elemental sulfur and isothiocyanate (S8/RNCS) couple was found to undergo redox condensation with o-halonitrobenzenes in the presence of N-methylpiperidine as a base in N-methylpyrrolidin-2-one to provide step- and redox-economical access to 2-aminobenzothiazoles. Alternatively, dithiocarbamate salts generated in situ from addition of amines and CS2 could be used in place of the S8/RNCS couple.
Collapse
|
4
|
Nguyen LA, Tran TY, Ngo QA, Mac DH, Retailleau P, Nguyen TB. Sulfur-Promoted Access to 3-Arylquinoxalin-2-ones by Oxidative Coupling of o-Phenylenediamines with Arylacetates. Org Lett 2024; 26:6098-6102. [PMID: 39008563 DOI: 10.1021/acs.orglett.4c01624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/17/2024]
Abstract
We disclose the synthesis of 3-arylquinoxalin-2-ones from o-phenylenediamines and readily available arylacetates. The method harnesses the selective oxidative property of elemental sulfur in the presence of amine base catalyst and DMSO. The reactions are operationally simple and tolerate a wide range of functional groups.
Collapse
|
5
|
Le DL, Nguyen LA, Vo NB, Nguyen TTT, Ngo QA, Retailleau P, Nguyen TB. Sodium sulfide-promoted regiodefined redox condensation of o-nitroanilines with aryl ketones to benzo[ a]phenazines and quinoxalines. Org Biomol Chem 2024; 22:1167-1171. [PMID: 38226902 DOI: 10.1039/d3ob02028b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
Inexpensive sodium sulfide trihydrate was found to promote unprecedented 6e-regio-predefined redox condensation of o-nitroanilines with α-tetralones to benzo[a]phenazines. The method was also successfully extended to acetophenones and higher homologs as reducing partners to provide 2-phenylquinoxalines. Compared to traditional approaches toward benzo[a]phenazine and quinoxaline cores starting with o-phenylenediamines, the present strategy could afford these heterocycles with well-defined regiochemistry based on the structure of starting o-nitroanilines.
Collapse
|
6
|
Phaenok S, Nguyen LA, Soorukram D, Nguyen TTT, Retailleau P, Nguyen TB. Sulfur- and Amine- Promoted Multielectron Autoredox Transformation of Nitromethane: Multicomponent Access to Thiourea Derivatives. Chemistry 2024; 30:e202303703. [PMID: 37953668 DOI: 10.1002/chem.202303703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 11/12/2023] [Accepted: 11/13/2023] [Indexed: 11/14/2023]
Abstract
Thiourea derivatives are in-demand motifs in organic synthesis, medicinal chemistry and material science, yet redox methods for the synthesis that start from safe, simple, inexpensive and readily available feedstocks are scarce. In this article, we disclose the synthesis of these motifs using elemental sulfur and nitromethane as the starting materials. The method harnesses the multi-electron auto-redox property of nitromethane in the presence of sulfur and amines, delivering thiourea products without any added oxidant or reductant. Extension of this reaction to cyclizable amines and/or higher homologues of nitromethane led to a wide range of nitrogen heterocycles and thioamides. Operationally simple, the reactions are scalable, tolerate a wide range of functional groups, and can be employed for the direct functionalization of natural products. Mechanistically, the nitro group was found to act as an oxidant leaving group, being reduced to ammonia whereas sulfur, along with the role of a sulfur building block for the thiocarbonyl group, behaved as a complementary reductant, being oxidized to sulfate.
Collapse
|
7
|
Nguyen LA, Phaenok S, Le DL, Nguyen TTT, Ngo QA, Nguyen TB. Fe/S-Catalyzed Redox Condensation of o-Nitrophenols with Isothiocyanates to 2-Aminobenzoxazoles. Org Lett 2023. [PMID: 37393601 DOI: 10.1021/acs.orglett.3c01897] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
As frequently encountered byproducts of isocyanate chemistry, hydrogen sulfide and related sulfur containing compounds should be treated in a safe way to lower their adverse health and environmental effects, especially in large scale syntheses. As a proof of concept, we report herein an example of in situ recycling of sulfur byproduct to reductant in the synthesis of bioactive 2-aminobenzoxazoles 3. Using an Fe/S catalytic system, this heterocyclic scaffold could be obtained from o-nitrophenols 1 with isothiocyates 2 via direct redox condensation consisting of reduction of the nitro group of 1 by the sulfur moiety of 2.
Collapse
|
8
|
Nguyen LA, Nguyen TTT, Ngo QA, Nguyen TB. Sulfur‐Catalyzed Oxidative Condensation of Aryl Alkyl Ketones with o‐Phenylenediamines: Access to Quinoxalines. Adv Synth Catal 2022. [DOI: 10.1002/adsc.202200527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
9
|
Nguyen LA, Nguyen TTT, Ngo QA, Nguyen TB. Fe/S-Catalyzed synthesis of 2-benzoylbenzoxazoles and 2-quinolylbenzoxazoles via redox condensation of o-nitrophenols with acetophenones and methylquinolines. Org Biomol Chem 2021; 19:6015-6020. [PMID: 34156054 DOI: 10.1039/d1ob00976a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
An Fe/S catalyst generated in situ from FeCl2·4H2O and elemental sulfur S8 in the presence of a tertiary amine as a base was found to catalyze efficiently a 6e- redox condensation of o-nitrophenols with acetophenones and methylquinolines. The condensed products 2-benzoylbenzoxazoles and 2-quinolylbenzoxazoles were obtained in reasonable yields with water as the only byproduct at a temperature as low as 80 °C.
Collapse
|
10
|
Nguyen LA, Ngo QA, Retailleau P, Nguyen TB. Break‐and‐Build Strategy for the Synthesis of 2‐Benzoylbenzoxazoles from
o
‐Aminophenols and Acetophenones. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202100150] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
11
|
Nguyen TTT, Nguyen LA, Ngo QA, Koleski M, Nguyen TB. The catalytic role of elemental sulfur in the DMSO-promoted oxidative coupling of methylhetarenes with amines: synthesis of thioamides and bis-aza-heterocycles. Org Chem Front 2021. [DOI: 10.1039/d0qo01654c] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The S8/DMSO combination was found to be particularly effective to promote oxidative coupling of methylhetarenes with amines to synthesize thioamides/bis-aza-heterocycles.
Collapse
|
12
|
Nguyen LA, Dang TD, Ngo QA, Nguyen TB. Sulfur-Promoted Synthesis of Benzoxazoles from 2-Aminophenols and Aldehydes. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000523] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
13
|
Nguyen TB, Nguyen LA, Retailleau P. Strategy for Contiguous Tetramination of Cyclohexanones with o-Phenylenediamines with Elemental Sulfur and DMSO. Org Lett 2019; 21:6570-6574. [DOI: 10.1021/acs.orglett.9b02558] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
14
|
Thi THN, Thi YT, Nguyen LA, Vo NB, Ngo QA. Design, Synthesis and Biological Activities of New Pyrazole Derivatives Possessing Both Coxib and Combretastatins Pharmacophores. Chem Biodivers 2019; 16:e1900108. [PMID: 30977306 DOI: 10.1002/cbdv.201900108] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 04/11/2019] [Indexed: 12/30/2022]
Abstract
In our efforts to discover novel multi-target agents having better antitumor activities than celecoxib, 21 new aryl-substituted pyrazole derivatives possessing cis-diphenylethylene scaffold were mostly synthesized by a one-pot approach to ethyl 1,4,5-triaryl-1H-pyrazole-3-carboxylates via an improved Claisen condensation - Knorr reaction sequence. The cytotoxic effects of these compounds against three human cancer cell lines HT-29, Hep-G2, MCF-7 as well as their inhibition of NO production were studied. Results showed that incorporation of the important pharmacophoric groups of two original molecules celecoxib and combretastatin A-4 in a single molecule plays an important role in determining a better biological activities of the new coxib-hybrided compounds.
Collapse
|
15
|
Nguyen LA, Retailleau P, Nguyen TB. Elemental Sulfur/DMSO‐Promoted Multicomponent One‐pot Synthesis of Malonic Acid Derivatives from Maleic Anhydride and Amines. Adv Synth Catal 2019. [DOI: 10.1002/adsc.201900160] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
16
|
Yen T, Chen FW, Witteles RM, Liedtke M, Nguyen LA. Clinical implications of gastrointestinal symptoms in systemic amyloidosis. Neurogastroenterol Motil 2018; 30:e13229. [PMID: 29024324 DOI: 10.1111/nmo.13229] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 09/15/2017] [Indexed: 12/14/2022]
Abstract
BACKGROUND Gastrointestinal (GI) symptoms in systemic amyloidosis patients are poorly characterized. This purpose of this study is to define the epidemiology and clinical implications of such symptoms. METHODS This was a retrospective cohort study of 583 amyloid patients seen at a tertiary referral center. Of 96 symptomatic patients, 82 received endoscopic biopsies, subsequently grouped into those with histologic evidence of GI amyloid (biopsy proven) vs without (biopsy absent). KEY RESULTS 16.8% of patients had GI symptoms, and had more abnormal NT-proBNP, cardiac ejection fraction, serum albumin, and alkaline phosphatase (P < .01). Of those who received endoscopy, the sites of highest diagnostic yield were stomach, duodenum and colon. The most common symptom was abdominal pain, nausea, or vomiting (50.0%). Of the symptomatic patients, only 37 (45%) had biopsy proven GI amyloid. Biopsy proven patients more often had cardiac involvement (P < .005), and more often received hematologic therapy or transplant (P = .01). Biopsy absent patients had more frequent neurologic involvement (P = .17). Biopsy status had no significant correlation with other indicators of amyloid burden, GI symptoms or management. CONCLUSIONS & INFERENCES Nearly one in six amyloid patients have GI symptoms, and half do not have GI amyloid. The type of symptom does not predict endoscopic findings. Most biopsy absent patients are not managed as a functional disorder despite no alternative etiology. Gastroenterologists may have an increased role to play in the care of systemic amyloidosis beyond performing endoscopies, such as evaluating cardiac amyloid patients for concurrent GI amyloid.
Collapse
|
17
|
Hasler WL, May KP, Wilson LA, Van Natta M, Parkman HP, Pasricha PJ, Koch KL, Abell TL, McCallum RW, Nguyen LA, Snape WJ, Sarosiek I, Clarke JO, Farrugia G, Calles-Escandon J, Grover M, Tonascia J, Lee LA, Miriel L, Hamilton FA. Relating gastric scintigraphy and symptoms to motility capsule transit and pressure findings in suspected gastroparesis. Neurogastroenterol Motil 2018; 30:10.1111/nmo.13196. [PMID: 28872760 PMCID: PMC6004323 DOI: 10.1111/nmo.13196] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 07/25/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND Wireless motility capsule (WMC) findings are incompletely defined in suspected gastroparesis. We aimed to characterize regional WMC transit and contractility in relation to scintigraphy, etiology, and symptoms in patients undergoing gastric emptying testing. METHODS A total of 209 patients with gastroparesis symptoms at NIDDK Gastroparesis Consortium centers underwent gastric scintigraphy and WMCs on separate days to measure regional transit and contractility. Validated questionnaires quantified symptoms. KEY RESULTS Solid scintigraphy and liquid scintigraphy were delayed in 68.8% and 34.8% of patients; WMC gastric emptying times (GET) were delayed in 40.3% and showed 52.8% agreement with scintigraphy; 15.5% and 33.5% had delayed small bowel (SBTT) and colon transit (CTT) times. Transit was delayed in ≥2 regions in 23.3%. Rapid transit was rarely observed. Diabetics had slower GET but more rapid SBTT versus idiopathics (P ≤ .02). GET delays related to greater scintigraphic retention, slower SBTT, and fewer gastric contractions (P ≤ .04). Overall gastroparesis symptoms and nausea/vomiting, early satiety/fullness, bloating/distention, and upper abdominal pain subscores showed no relation to WMC transit. Upper and lower abdominal pain scores (P ≤ .03) were greater with increased colon contractions. Constipation correlated with slower CTT and higher colon contractions (P = .03). Diarrhea scores were higher with delayed SBTT and CTT (P ≤ .04). CONCLUSIONS & INFERENCES Wireless motility capsules define gastric emptying delays similar but not identical to scintigraphy that are more severe in diabetics and relate to reduced gastric contractility. Extragastric transit delays occur in >40% with suspected gastroparesis. Gastroparesis symptoms show little association with WMC profiles, although lower symptoms relate to small bowel or colon abnormalities.
Collapse
|
18
|
Vo NB, Nguyen LA, Pham TL, Doan DT, Nguyen TB, Ngo QA. Straightforward access to new vinca-alkaloids via selective reduction of a nitrile containing anhydrovinblastine derivative. Tetrahedron Lett 2017. [DOI: 10.1016/j.tetlet.2017.05.054] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
19
|
Nguyen LA, Do DH, Nguyen LT, Do NT, Nguyen HH, Nguyen VT, Vu DQ, Nguyen HT, Kato M, Jordan MR, Bui DD. A13 HIV drug resistance over a decade of antiretroviral therapy scale-up for HIV/AIDS patients in Vietnam. Virus Evol 2017; 3:vew036.012. [PMID: 28845273 PMCID: PMC5565985 DOI: 10.1093/ve/vew036.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
20
|
Ngo QA, Nguyen LA, Vo NB, Nguyen TH, Roussi F, Nguyen TH, Nguyen VT. Synthesis and antiproliferativeactivity of new vinca alkaloids containing an α,β-unsaturated aromatic side chain. Bioorg Med Chem Lett 2015; 25:5597-600. [DOI: 10.1016/j.bmcl.2015.10.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 10/12/2015] [Accepted: 10/15/2015] [Indexed: 12/17/2022]
|
21
|
Tagata Y, Yoshida H, Nguyen LA, Kato H, Ichikawa H, Tashiro F, Kitabayashi I. Phosphorylation of PML is essential for activation of C/EBPɛ and PU.1 to accelerate granulocytic differentiation. Leukemia 2007; 22:273-80. [DOI: 10.1038/sj.leu.2405024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
22
|
Rau U, Nguyen LA, Roeper H, Koch H, Lang S. Fed-batch bioreactor production of mannosylerythritol lipids secreted by Pseudozyma aphidis. Appl Microbiol Biotechnol 2005; 68:607-13. [PMID: 15729556 DOI: 10.1007/s00253-005-1906-5] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2004] [Revised: 12/10/2004] [Accepted: 12/14/2004] [Indexed: 11/25/2022]
Abstract
Two strains of Pseudozyma aphidis, DSM 70725 and DSM 14930, were used for the bioreactor production of mannosylerythritol lipids (MELs). Foam formation interfered substantially with the cultivation process. Soybean oil was simultaneously employed as both carbon source and anti-foam agent. Primary MEL formation occurred after nitrate limitation. After a first short time-period of nitrate limitation and further nitrate addition, MELs were secreted in spite of nitrate excess. The sedimentation of MEL-enriched beads indicated enhanced product formation. Maximum yield, productivity and yield coefficient of 165 g l(-1), 13.9 g l(-1) day(-1) and 0.92 g g(-1) were achieved using strain DSM 14930 with additional substrate-feeding (glucose, sodium nitrate, yeast extract) and a foam-controlled soybean oil supply.
Collapse
|
23
|
Rau U, Nguyen LA, Schulz S, Wray V, Nimtz M, Roeper H, Koch H, Lang S. Formation and analysis of mannosylerythritol lipids secreted by Pseudozyma aphidis. Appl Microbiol Biotechnol 2004; 66:551-9. [PMID: 15248042 DOI: 10.1007/s00253-004-1672-9] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2004] [Revised: 05/17/2004] [Accepted: 05/21/2004] [Indexed: 10/26/2022]
Abstract
Pseudozyma aphidis DSM 70725 was found to be a novel producer of mannosylerythritol lipids (MELs). The MELs were quantified by HPLC. Glucose as carbon source for precultivation supported growth well. By contrast, at concentrations >30 g l(-1) in preculture, subsequent MEL formation in the main culture with soybean oil as sole carbon source was reduced. The type of substrate supply considerably influenced MEL formation. High concentrations of soybean oil (80 ml l(-1)) at init favored the production process when compared to a stepwise (20 ml l(-1)) addition. Mannose or erythritol were suitable second carbon sources that enhanced the MEL yield with soybean oil as preferred primary substrate. After 10 days, a maximum yield of 75 g l(-1) was attained during shake-flask cultivation. Biofuel (rapeseed oil methyl ester) also resulted in high yields of MEL, but glucose reduced the MEL yield. Analysis by GC-MS showed that all fatty acids contained in MEL and derived from soybean oil or related methyl ester were degraded by C2-units to differing extents. The surface (water/air) and interfacial (water/hexadecane) tension of the MELs produced from different carbon sources were reduced to a minimum of 26.2 mN m(-1) and 1 mN m(-1), respectively.
Collapse
|
24
|
Togo M, Toda T, Nguyen LA, Kubota S, Tsukamoto K, Satoh H, Hara M, Iso-o N, Noto H, Kimura S, Nakahara K, Seyama Y, Hashimoto Y. Genetic analysis of phytosterolaemia. J Inherit Metab Dis 2001; 24:43-50. [PMID: 11286381 DOI: 10.1023/a:1005650605042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Two women with multiple xanthomas, intermittent arthritis and thrombocytopenia were diagnosed as phytosterolaemia, an autosomal-recessive lipid storage disease, based on their increased serum concentrations of beta-sitosterol, campesterol and sitostanol. The gene responsible for this disease is located within a distance of 18 cM between microsatellite markers of D2S 1788 and D2S1352 at chromosome 2p21. We genotyped the patients and their family members with 16 microsatellite markers around this locus. The results from the homozygosity mapping of one family suggested that the gene was located within the distance of 12.6 cM between D2S2328 and D2S1352. We have shortened the genetic distance by 5.4 cM.
Collapse
|
25
|
Holland WG, Luong TT, Nguyen LA, Do TT, Vercruysse J. The epidemiology of nematode and fluke infections in cattle in the Red River Delta in Vietnam. Vet Parasitol 2000; 93:141-7. [PMID: 11035232 DOI: 10.1016/s0304-4017(00)00363-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Over a period of 13 months, faecal samples were collected monthly from approximately 45 cattle over 3 months of age. Additionally, 74 calves of 1-2 months were sampled to determine the presence of Toxocara vitulorum eggs. Individual egg counts and infective strongyle larvae from pooled faecal samples were examined. Post-mortem worm counts were carried out on six groups of tracer calves (n=12) that had been kept for 4 weeks on pasture in and around the village studied. The following helminths were identified: T. vitulorum, Cooperia punctata, C. pectinata, C. oncophora, Oesophagostomum radiatum, Trichostrongylus axei, T. colubriformis, Haemonchus spp., Fasciola spp. and Paramphistomum spp. In 8% of the samples collected from young calves, individual egg counts for T. vitulorum were found indicative for pathogenic worm burdens. Strongyle egg counts and worm counts indicated that transmission is low without a distinct seasonality. In animals of 3-9 months old, a strongyle egg count peak can be demonstrated which at a higher age steadily and significantly decreased. In faecal cultures Cooperia spp. were most prominent in all age groups throughout the year with the exception of the period September-November when Haemonchus spp. and Oesophagostomum spp. were most prevalent. Fasciola spp. eggs were found in 22% of the collected faecal samples and the egg counts were low indicating that the intensity of Fasciola spp. infection is mild. Based on the present data, regular anthelmintic treatments seem not to be justified, except for a single treatment at the age of 2 weeks against toxocariosis.
Collapse
|