Displaying publications 1461 - 1480 of 1728 in total

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  1. Tajidin NE, Shaari K, Maulidiani M, Salleh NS, Ketaren BR, Mohamad M
    Sci Rep, 2019 11 14;9(1):16766.
    PMID: 31727911 DOI: 10.1038/s41598-019-52905-z
    Andrographis paniculata (Burm. F.) Nees. is considered as the herb of the future due to its precious chemical compounds, andrographolide (ANDRO), neoandrographolide (NAG) and 14-deoxyandrographolide (DAG). This study aims to profile the metabolites in young and mature leaf at six different harvest ages using 1HNMR-based metabolomics combined with multivariate data analysis. Principal component analysis (PCA) indicated noticeable and clear discrimination between young and mature leaves. A comparison of the leaves stage indicated that young leaves were separated from mature leaves due to its larger quantity of ANDRO, NAG, DAG, glucose and sucrose. These similar metabolites are also responsible for the PCA separation into five clusters representing the harvest age at 14, 16, 18, 20, 22 weeks of leaves extract. Loading plots revealed that most of the ANDRO and NAG signals were present when the plant reached at the pre-flowering stage or 18 weeks after sowing (WAS). As a conclusion, A. paniculata young leaves at pre-flowering harvest age were found to be richer in ANDRO, NAG and DAG compared to mature leaves while glucose and choline increased with harvest age. Therefore, young leaves of A. paniculata should be harvested at 18 WAS in order to produce superior quality plant extracts for further applications by the herbal, nutraceutical and pharmaceutical industries.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  2. Shehzad MT, Hameed A, Al-Rashida M, Imran A, Uroos M, Asari A, et al.
    Bioorg Chem, 2019 11;92:103244.
    PMID: 31541804 DOI: 10.1016/j.bioorg.2019.103244
    The role of aldose reductase (ALR2) in diabetes mellitus is well-established. Our interest in finding ALR2 inhibitors led us to explore the inhibitory potential of new thiosemicarbazones. In this study, we have synthesized adamantyl-thiosemicarbazones and screened them as aldehyde reductase (ALR1) and aldose reductase (ALR2) inhibitors. The compounds bearing phenyl 3a, 2-methylphenyl 3g and 2,6-dimethylphenyl 3m have been identified as most potent ALR2 inhibitors with IC50 values of 3.99 ± 0.38, 3.55 ± 0.26 and 1.37 ± 0.92 µM, respectively, compared with sorbinil (IC50 = 3.14 ± 0.02 μM). The compounds 3a, 3g, and 3m also inhibit ALR1 with IC50 value of 7.75 ± 0.28, 7.26 ± 0.39 and 7.04 ± 2.23 µM, respectively. Molecular docking was also performed for putative binding of potent inhibitors with target enzyme ALR2. The most potent 2,6-dimethylphenyl bearing thiosemicarbazone 3m (IC50 = 1.37 ± 0.92 µM for ALR2) and other two compound 3a and 3g could potentially lead for the development of new therapeutic agents.
    Matched MeSH terms: Chromatography, Thin Layer
  3. Gunendren, M., Noordin S.S., Muggundha, R., Nozlena A.S.
    MyJurnal
    Conventional anticoagulant therapy is the mainstay of medical treatment for deep vein thrombosis disorders. However,there are many complications associated with these agents such as bleeding. Hence, the search for novel anticoagulant derived from natural substances such as plants origin is in high demand nowadays. Ocimum sanctum(O.sanctum) also known as Ocimum tenuiform (OT), tulsi or holy basil from the family of Lamiaceae has been widely used for thousands of years in Ayurveda and Unani systems to cure or prevent a number of illnessessuch as headache, malaria, ulcers, bronchitis, cough, flu, sore throat and asthma. The objective is to investigate theeffect ofO. sanctum(Tulsi) aqueous leaf extract on prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT) in human plasma. Coagulation activity of O. sanctum was measured via PT, APTT and TT assay in citrated plasma collected from thirty-six healthy regular blood donors. The plasma was tested against different concentrations of O. sanctum aqueous extract as follows: 0.1mg/ml, 0.5 mg/ml and 1.0 mg/ml. Result shows the aqueous extract of O. sanctum prolonged the PT and APTT assays (p0.05). The gas chromatography-mass spectrometry (GC-MS) analysis had identified the linolenic acid at 1-10% of ethanol and aqueousconcentration at different retention time which was responsible for the coagulation activities of O. sanctumin human plasma. This study suggests that O. sanctum does affect coagulation activity in human plasma and can be potentially used as naturally derived anticoagulant products in the future.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  4. Boon YH, Mohamad Zain NN, Mohamad S, Osman H, Raoov M
    Food Chem, 2019 Apr 25;278:322-332.
    PMID: 30583379 DOI: 10.1016/j.foodchem.2018.10.145
    Poly(β-cyclodextrin functionalized ionic liquid) immobilized magnetic nanoparticles (Fe3O4@βCD-Vinyl-TDI) as sorbent in magnetic µ-SPE was developed for the determination of selected polycyclic aromatic hydrocarbons (PAHs) in rice samples coupled with gas chromatographic-flame ionization detector (GC-FID). The nanocomposite was characterized by various tools and significant parameters that affected the extraction efficiency of PAHs were investigated. The calibration curves were linear for the concentration ranging between 0.1 and 500 μg kg-1 with correlation determinations (R2) from 0.9970 to 0.9982 for all analytes. Detection limits ranged at 0.01-0.18 μg kg-1 in real matrix. The RSD values ranged at 2.95%-5.34% (intra-day) and 4.37%-7.05% (inter-day) precision for six varied days. The sorbents showed satisfactory reproducibility in 2.9% to 9.9% range and acceptable recovery values at 80.4%-112.4% were obtained for the real sample analysis. The optimized method was successfully applied to access content safety of selected PAHs for 24 kinds of commercial rice available in Malaysia.
    Matched MeSH terms: Chromatography, Gas
  5. Czuppon AB, Chen Z, Rennert S, Engelke T, Meyer HE, Heber M, et al.
    J Allergy Clin Immunol, 1993 Nov;92(5):690-7.
    PMID: 8227860
    BACKGROUND: Allergy to latex-containing articles is becoming more and more important because it can result in unexpected life-threatening anaphylactic reactions in sensitized individuals.

    METHODS: A protein of 58 kd with an isoelectric point of 8.45 was purified from raw latex and from latex gloves and identified as the major allergen, completely blocking specific IgE antibodies in the serum of latex-sensitized subjects. The allergen is a noncovalent homotetramer molecule, in which the 14.6 kd monomer was identified, by amino acid composition and sequence homologies of tryptic peptides, to be the rubber elongation factor found in natural latex of the Malaysian rubber tree.

    RESULTS: Competitive immunoinhibition tests showed that the starch powder covering the finished gloves is the airborne carrier of the allergen, resulting in bronchial asthma on inhalation. The purified allergen can induce allergic reactions in the nanogram range.

    CONCLUSION: The identification of the allergen (Hev b I) may help to eliminate it during the production of latex-based articles in the future.

    Matched MeSH terms: Chromatography, Ion Exchange
  6. Briggs MT, Condina MR, Ho YY, Everest-Dass AV, Mittal P, Kaur G, et al.
    Proteomics, 2019 11;19(21-22):e1800482.
    PMID: 31364262 DOI: 10.1002/pmic.201800482
    Epithelial ovarian cancer is one of the most fatal gynecological malignancies in adult women. As studies on protein N-glycosylation have extensively reported aberrant patterns in the ovarian cancer tumor microenvironment, obtaining spatial information will uncover tumor-specific N-glycan alterations in ovarian cancer development and progression. matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) is employed to investigate N-glycan distribution on formalin-fixed paraffin-embedded ovarian cancer tissue sections from early- and late-stage patients. Tumor-specific N-glycans are identified and structurally characterized by porous graphitized carbon-liquid chromatography-electrospray ionization-tandem mass spectrometry (PGC-LC-ESI-MS/MS), and then assigned to high-resolution images obtained from MALDI-MSI. Spatial distribution of 14 N-glycans is obtained by MALDI-MSI and 42 N-glycans (including structural and compositional isomers) identified and structurally characterized by LC-MS. The spatial distribution of oligomannose, complex neutral, bisecting, and sialylated N-glycan families are localized to the tumor regions of late-stage ovarian cancer patients relative to early-stage patients. Potential N-glycan diagnostic markers that emerge include the oligomannose structure, (Hex)6 + (Man)3 (GlcNAc)2 , and the complex neutral structure, (Hex)2 (HexNAc)2 (Deoxyhexose)1 + (Man)3 (GlcNAc)2 . The distribution of these markers is evaluated using a tissue microarray of early- and late-stage patients.
    Matched MeSH terms: Chromatography, Liquid
  7. Saleem H, Htar TT, Naidu R, Nawawi NS, Ahmad I, Ashraf M, et al.
    Food Chem Toxicol, 2019 Jan;123:363-373.
    PMID: 30419323 DOI: 10.1016/j.fct.2018.11.016
    We investigated into the effects of methanol and dichloromethane extracts from aerial and roots of Filago germanica (L.) Huds (Astearaceae) on key enzymes (cholinesterases, α-glucosidase and urease), antioxidant capabilities, cytotoxic potential and secondary metabolomics profile. Total phenolic and flavonoids were determined by spectrophotometric technique and secondary metabolites composition by UHPLC-MS. Antioxidant activities were assessed employing free radical scavenging, ferric reducing power and phosphomolybdenum assays. The cell-toxicity was evaluated by MTT assay against breast (MCF-7, MDA-MB-231), cervix (CaSki) and prostate (DU-145) cancers. Overall, methanol extracts were found to have higher total bioactive contents and antioxidant potential. UHPLC-MS analysis revealed significant variation in the secondary metabolites in the methanol extracts. The most common derivatives belong to seven groups i.e. alkaloids, benzoic acids, flavones, flavonols, flavan-3-ols, terpenoids and saponins. The major polyphenolic compounds were found to be kampferol, robinin, luteolin, ferulic acid, benzoic acid and salicylic acid. All the extracts showed moderate cholinesterases inhibition, whereas methanol extracts exhibited highest urease inhibition and all extracts presented a relatively high inhibition against α-glucosidase. Similarly, all extracts showed strong to moderate cytotoxicity with IC50 values ranging from 53.02 to 382.7 μg/mL. Overall, results have suggested F. germanica to be a lead source for novel natural products.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  8. Munusamy K, Loke MF, Vadivelu J, Tay ST
    Microb Pathog, 2021 Mar;152:104614.
    PMID: 33202254 DOI: 10.1016/j.micpath.2020.104614
    Candidiasis is the most common fungal infection associated with high morbidity and mortality among immunocompromised patients. The ability to form biofilm is essential for Candida albicans pathogenesis and drug resistance. In this study, the planktonic cell and biofilm proteomes of C. albicans SC5314 strain analyzed using Liquid Chromatography-Mass Spectrometry (LC-MS) were compared. In total, 280 and 449 proteins are annotated from the planktonic cell and biofilm proteomes, respectively. The biofilm proteome demonstrated significantly higher proportion of proteins associated with the endomembrane system, mitochondrion and cytoplasm than planktonic proteome. Among proteins detected, 143 and 207 biological processes are annotated, of which, 38 and 102 are specific to the planktonic cell and biofilm proteomes, respectively, while 105 are common biological processes. The specific biological processes of C. albicans planktonic cell proteome are associated with cell polarity, energy metabolism and nucleotide (purine) metabolism, oxido-reduction coenzyme metabolic process, monosaccharide and amino acid (methionine) biosynthesis, regulation of anatomical structure morphogenesis and cell cycling, and single organism reproduction. Meanwhile, regulation of cellular macromolecule biosynthesis and metabolism, transcription and gene expression are major biological processes specifically associated with C. albicans biofilm proteome. Biosynthesis of leucine, isoleucine, and thiocysteine are highlighted as planktonic-related pathways, whereas folate metabolism, fatty acid metabolism and biosynthesis of amino acids (lysine, serine and glycine) are highlighted as biofilm-related pathways. In summary, LC-MS-based proteomic analysis reveals different adaptative strategies of C. albicans via specific biological and metabolic processes for planktonic cell and biofilm lifestyles. The mass spectrometry data are available via ProteomeXchange with identifiers PXD007830 (for biofilm proteome) and PXD007831 (for planktonic cell proteome).
    Matched MeSH terms: Chromatography, Liquid
  9. Jusril NA, Muhamad Juhari ANN, Abu Bakar SI, Md Saad WM, Adenan MI
    Molecules, 2020 Jul 24;25(15).
    PMID: 32721993 DOI: 10.3390/molecules25153353
    Alzheimer's disease (AD) is a neurodegenerative disease and the most cause of dementia in elderly adults. Acetylcholinesterase (AChE) is an important beneficial target for AD to control cholinergic signaling deficit. Centella asiatica (CA) has proven to be rich with active ingredients for memory enhancement. In the present study, the chemical profiling of three accession extracts of CA namely SECA-K017, SECA-K018, and, SECA-K019 were performed using high-performance liquid chromatography (HPLC). Four biomarker triterpene compounds were detected in all CA accessions. Quantitative analysis reveals that madecassoside was the highest triterpene in all the CA accessions. The biomarker compounds and the ethanolic extracts of three accessions were investigated for their acetylcholinesterase (AChE) inhibitory activity using Ellman's spectrophotometer method. The inhibitory activity of the triterpenes and accession extracts was compared with the standard AChE inhibitor eserine. The results from the in vitro study showed that the triterpene compounds exhibited an AChE inhibitory activity with the half-maximal inhibitory concentration (IC50) values between 15.05 ± 0.05 and 59.13 ± 0.18 µg/mL. Asiatic acid was found to possess strong AChE inhibitory activity followed by madecassic acid. Among the CA accession extracts, SECA-K017 and SECA-K018 demonstrated a moderate AChE inhibitory activity with an IC50 value of 481.5 ± 0.13 and 763.5 ± 0.16 µg/mL, respectively from the in silico docking studies, it is observed that asiatic acid and madecassic acid showed very good interactions with the active sites and fulfilled docking parameters against AChE. The present study suggested that asiatic acid and madecassic acid in the CA accessions could be responsible for the AChE inhibitory action and could be used as markers to guide further studies on CA as potential natural products for the treatment of AD.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  10. Akowuah GA, Zhari I, Mariam A
    Food Chem Toxicol, 2008 Dec;46(12):3616-20.
    PMID: 18824206 DOI: 10.1016/j.fct.2008.09.008
    A simple high-performance liquid chromatography (HPLC) method was developed to determine the content of andrographolide (AP) and 14-deoxy-11,12-dideoxyandrographolide (DIAP) in a pooled urine of rat obtained within 24h after an oral dose of Andrographis paniculata leaf extract at 1g/kg body weight. Cumulative urinary excretion of AP and DIAP in 24h after oral administration of the extract was 0.88% and 1.61% of oral dose administered, respectively. The extract showed significant reduction (p<0.05) of MDA levels and elevation of total antioxidant status in rat urine samples collected in 24 after oral administration.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  11. Nik Zainuddin NAS, Muhammad H, Nik Hassan NF, Othman NH, Zakaria Y
    J Pharm Bioallied Sci, 2020 Nov;12(Suppl 2):S768-S776.
    PMID: 33828376 DOI: 10.4103/jpbs.JPBS_262_19
    Introduction: Cervical cancer is a leading cause of death in women. Current cancer treatment comes with side effects. Clinacanthus nutans has been known traditionally to treat cancer. This study was aimed to characterize C. nutans standardized fraction (SF1) and to investigate its anticancer mechanism against SiHa cells.

    Materials and Methods: SF1 was produced by optimized methodology for bioassay-guided fractionation. Fourier transform infrared (FTIR) spectroscopy and liquid chromatography-mass spectrometry (LC-MS) were carried out to characterize the SF1. SF1 was screened for cytotoxicity activity toward HeLa, SiHa, and normal cells (NIH) cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. The anticancer mechanism of SF1 was evaluated toward SiHa cells, which showed highest cytotoxicity toward SF1 treatment. The mechanism includes cell cycle progression and protein expression, which was detected using specific antibody-conjugated fluorescent dye, p53-FITC, by flow cytometry.

    Results: Major constituents of SF1 were alkaloids with amines as functional group. SF1 showed highest cytotoxic activity against SiHa (half-maximal inhibitory concentration [IC50] < 10 µg/mL) compared to HeLa cells. Cytoselectivity of SF1 was observed with no IC50 detected on normal NIH cells. On flow cytometry analysis, SF1 was able to induce apoptosis on SiHa cells by arresting cell cycle at G1/S and upregulation of p53 protein.

    Conclusion: SF1 showed anticancer activity by inducing apoptosis through arrested G1/S cell cycle checkpoint-mediated mitochondrial pathway.

    Matched MeSH terms: Chromatography, Liquid
  12. Nasaruddin N, Jinap S, Samsudin NI, Kamarulzaman NH, Sanny M
    J Sci Food Agric, 2021 Mar 30;101(5):1812-1821.
    PMID: 32893877 DOI: 10.1002/jsfa.10795
    BACKGROUND: Corn, a main feed ingredient in the livestock industry, is one of the most susceptible crops to fungal infection and aflatoxin contamination. Livestock feeding on aflatoxin (AF)-contaminated feed have been shown to experience feed refusal, and decreased growth rate, milk production, and feed efficiency. In poultry, AF poisoning causes weight loss, poor feed efficiency, and reduced egg production and egg weight. The present work therefore aimed to determine the prevalence of mycotoxigenic fungi and the occurrence of AF contamination along the integrated corn-based poultry feed supply chain in Malaysia. A total of 51 samples were collected from different points along the feed supply chain from integrated poultry feed companies. The samples were subjected to mycological analyses (fungal isolation, enumeration, identification), and AFs were quantified by high-performance liquid chromatography equipped with a fluorescence detector (HPLC-FLD).

    RESULTS: Samples collected from sampling point 1 (company A) and sampling point 9 (company B) yielded the highest total fungal load (>log 4 CFU g-1 ). The prevalent fungal genera isolated were Aspergillus, Fusarium, and Penicillium spp. Aflatoxin B1 was detected in 8.3% of corn samples, and 7.4% of corn-based poultry feed samples along the feed supply chain, whereas AFs B2 , G1 , and G2 were not detected.

    CONCLUSION: The incidence of mycotoxigenic fungi along the integrated poultry feed supply chain warrant continuous monitoring of mycotoxin contamination to reduce the exposure risk of mycotoxin intake in poultry. © 2020 Society of Chemical Industry.

    Matched MeSH terms: Chromatography, High Pressure Liquid
  13. Chua LYW, Chua BL, Figiel A, Chong CH, Wojdyło A, Szumny A, et al.
    Molecules, 2019 Apr 24;24(8).
    PMID: 31022967 DOI: 10.3390/molecules24081625
    The preservation of active constituents in Cassia alata through the removal of moisture is crucial in producing a final product with high antioxidant activity. This study aims to determine the influences of various drying methods and drying conditions on the antioxidant activity, volatiles and phytosterols content of C. alata. The drying methods used were convective drying (CD) at 40 °C, 50 °C and 60 °C; freeze drying; vacuum microwave drying (VMD) at 6, 9 and 12 W/g; and two-stage convective pre-drying followed by vacuum microwave finish drying (CPD-VMFD) at 50 °C and 9 W/g. The drying kinetics of C. alata are best described by the thin-layer model (modified Page model). The highest antioxidant activity, TPC and volatile concentration were achieved with CD at 40 °C. GC-MS analysis identified the presence of 51 volatiles, which were mostly present in all samples but with quantitative variation. The dominant volatiles in fresh C. alata are 2-hexenal (60.28 mg 100 g-1 db), 1-hexanol (18.70 mg 100 g-1 db) and salicylic acid (15.05 mg 100 g-1 db). The concentration of phytosterols in fresh sample was 3647.48 mg 100 g-1 db, and the major phytosterols present in fresh and dried samples were β-sitosterol (1162.24 mg 100 g-1 db). CPD-VMFD was effective in ensuring the preservation of higher phytosterol content in comparison with CD at 50 °C. The final recommendation of a suitable drying method to dehydrate C. alata leaves is CD at 40 °C.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  14. Wei J, Ren W, Wang L, Liu M, Tian X, Ding G, et al.
    J Sci Food Agric, 2020 Dec;100(15):5627-5636.
    PMID: 32712996 DOI: 10.1002/jsfa.10690
    BACKGROUND: Serofluid dish, a traditional Chinese fermented food, possesses unique flavors and health beneficial effects. These properties are likely due to the sophisticated metabolic networks during fermentation, which are mainly driven by microbiota. However, the exact roles of metabolic pathways and the microbial community during this process remain equivocal.

    RESULTS: Here, we investigated the microbial dynamics by next-generation sequencing, and outlined a differential non-targeted metabolite profiling in the process of serofluid dish fermentation using the method of hydrophilic interaction liquid chromatography column with ultra-high-performance liquid chromatography-quadruple time-of-flight mass spectrometry. Lactobacillus was the leading genus of bacteria, while Pichia and Issatchenkia were the dominant fungi. They all accumulated during fermentation. In total, 218 differential metabolites were identified, of which organic acids, amino acids, sugar and sugar alcohols, fatty acids, and esters comprised the majority. The constructed metabolic network showed that tricarboxylic acid cycle, urea cycle, sugar metabolism, amino acids metabolism, choline metabolism, and flavonoid metabolism were regulated by the fermentation. Furthermore, correlation analysis revealed that the leading fungi, Pichia and Issatchenkia, were linked to organic acids, amino acid and sugar metabolism, flavonoids, and several other flavor and functional components. Antibacterial tests indicated the antibacterial effect of serofluid soup against Salmonella and Staphylococcus.

    CONCLUSION: This work provides new insights into the complex microbial and metabolic networks during serofluid dish fermentation, and a theoretical basis for the optimization of its industrial production. © 2020 Society of Chemical Industry.

    Matched MeSH terms: Chromatography, High Pressure Liquid
  15. Lew MH, Norazmi MN, Tye GJ
    Mol Immunol, 2020 Jan;117:54-64.
    PMID: 31739193 DOI: 10.1016/j.molimm.2019.10.023
    Tuberculosis (TB) is one of the deadliest human diseases worldwide caused by mycobacterial infection in the lung. Bacillus Calmette-Guerin (BCG) vaccine protects against disseminated TB in children, but its effectiveness is still questionable due to highly variable protections in adolescence and elderly individuals. Targeting the latency M.tb antigen is a recent therapeutic approach to eradicate dormant pathogen that could possibly lead to disease activation. In this study, we aimed to potentiate immune responses elicited against 16 kDa α-crystalline (HspX) tuberculosis latency antigen by incorporation of Combined Adjuvant for Synergistic Activation of Cellular immunity (CASAC). Histidine-tagged recombinant HspX protein was initially produced in Escherichia coli and purified using Ni-NTA chromatography. To evaluate its adjuvanticity, C57BL/6 mice (n = 5) were initially primed and intradermally immunised in 2-weeks interval for 4 rounds with recombinant HspX, formulated with and without CASAC. Humoral and cell-mediated immune responses elicited against HspX antigen were evaluated using ELISA and Flow Cytometry. Our findings showed that CASAC improved humoral immunity with increased antigen-specific IgG1 and IgG2a antibody response. Stronger CD8+ and Th1-driven immunity was induced by CASAC formulation as supported by elevated level of IFN-γ, TNF-α, IL-12 and IL-17A; and with low IL-10 secretion. Interestingly, adjuvanted HspX vaccine triggered a higher percentage of effector memory T-cell population than those immunised with unadjuvanted vaccine. In conclusion, CASAC adjuvant has great potential to enhance immunogenicity elicited against HspX antigen, which could be an alternative regimen to improve the efficacy of future therapeutic vaccine against Mycobacterium tuberculosis.
    Matched MeSH terms: Chromatography
  16. Abdul Satar NM, Ogawa S, Parhar IS
    Sci Rep, 2020 11 09;10(1):19361.
    PMID: 33168887 DOI: 10.1038/s41598-020-75777-0
    The habenula is a phylogenetically conserved epithalamic structure, which conveys negative information via inhibition of mesolimbic dopamine neurons. We have previously shown the expression of kisspeptin (Kiss1) in the habenula and its role in the modulation of fear responses in the zebrafish. In this study, to investigate whether habenular Kiss1 regulates fear responses via dopamine neurons in the zebrafish, Kiss1 peptides were intracranially administered close to the habenula, and the expression of dopamine-related genes (th1, th2 and dat) were examined in the brain using real-time PCR and dopamine levels using LC-MS/MS. th1 mRNA levels and dopamine levels were significantly increased in the telencephalon 24-h and 30-min after Kiss1 administration, respectively. In fish administered with Kiss1, expression of neural activity marker gene, npas4a and kiss1 gene were significantly decreased in the ventral habenula. Application of neural tracer into the median raphe, site of habenular Kiss1 neural terminal projections showed tracer-labelled projections in the medial forebrain bundle towards the telencephalon where dopamine neurons reside. These results suggest that Kiss1 negatively regulates its own neuronal activity in the ventral habenula via autocrine action. This, in turn affects neurons of the median raphe via interneurons, which project to the telencephalic dopaminergic neurons.
    Matched MeSH terms: Chromatography, Liquid
  17. Tan TK, Lim YAL, Chua KH, Chai HC, Low VL, Bathmanaban P, et al.
    Parasitol Res, 2020 Sep;119(9):2851-2862.
    PMID: 32651637 DOI: 10.1007/s00436-020-06790-5
    The field strain of Haemonchus contortus has a long history of anthelmintic resistance. To understand this phenomenon, the benzimidazole resistance profile was characterized from the Malaysian field-resistant strain by integrating phenotypic, genotypic and proteomic approaches. The faecal egg count reduction test (FECRT) demonstrated that benzimidazole resistance was at a critical level in the studied strain. The primary resistance mechanism was attributed to F200Y mutation in the isotype 1 β-tubulin gene as revealed by AS-PCR and direct sequencing. Furthermore, the protein response of the resistant strain towards benzimidazole (i.e., albendazole) treatment was investigated via two-dimensional difference gel electrophoresis (2D-DIGE) and tandem liquid chromatography-mass spectrometry (LC-MS/MS). These investigations illustrated an up-regulation of antioxidant (i.e., ATP-binding region and heat-shock protein 90, superoxide dismutase) and metabolic (i.e., glutamate dehydrogenase) enzymes and down-regulation of glutathione S-transferase, malate dehydrogenase, and other structural and cytoskeletal proteins (i.e., actin, troponin T). Findings from this study are pivotal in updating the current knowledge on anthelmintic resistance and providing new insights into the defence mechanisms of resistant nematodes towards drug treatment.
    Matched MeSH terms: Chromatography, Liquid
  18. Sthaneshwar P, Shanmugam H, Arumugam S
    Pathology, 2014 Apr;46(3):263-5.
    PMID: 24614705 DOI: 10.1097/PAT.0000000000000090
    Matched MeSH terms: Chromatography, High Pressure Liquid
  19. George E, Teh LK, Tan J, Lai MI, Wong L
    Pathology, 2013 01;45(1):62-5.
    PMID: 23222244 DOI: 10.1097/PAT.0b013e32835af7c1
    AIMS: Classical carriers of β-thalassaemia are identified by a raised HbA2 level. Earlier studies indicated that the Filipino β-deletion has high raised HbA2 levels. The introduction of automated high performance liquid chromatography (HPLC) for thalassaemia screening is an important advance in technology for haematology laboratories. The BioRad Variant II Hb analyser is a common instrument used to quantify HbA2 levels in thalassaemia screening. This study aimed to determine HbA2 levels in carriers of Filipino β-mutation using the BioRad Variant II Hb analyser.

    METHODS: The Filipino β-deletion was identified using gap-polymerase chain reaction (PCR) in the parents of transfusion dependent β-thalassaemia patients who were homozygous for the Filipino β-deletion in the indigenous population of Sabah, Malaysia. Hb subtypes were quantified on the BioRad Variant II Hb analyser. Concurrent α-thalassaemia was identified by multiplex gap-PCR for deletions and amplification refractory mutation system (ARMS)-PCR for non-deletional mutations.

    RESULTS: The mean HbA2 level for Filipino β-thalassaemia trait was 5.9 ± 0.47 and with coinheritance of α-thalassaemia was 6.3 ± 0.44 (-α heterozygous) and 6.7 ± 0.36 (-α homozygous). The HbA2 levels were all >4% in keeping with the findings of classical β-thalassaemia trait and significantly higher than levels seen in non-deletional forms of β-thalassaemia.

    CONCLUSION: The HbA2 level measured on the BioRad Variant II Hb analyser was lower than the level in the first description of the Filipino β-thalassaemia. β-thalassaemia trait with coinheritance of α-thalassaemia (-α) is associated with significantly higher HbA2 level.

    Matched MeSH terms: Chromatography, High Pressure Liquid
  20. Halim AA, Feroz SR, Tayyab S
    Biosci Biotechnol Biochem, 2013;77(1):87-96.
    PMID: 23291750
    Treatment of Bacillus licheniformis α-amylase (BLA) with guanidine hydrochloride (GdnHCl) produced both denatured and aggregated forms of the enzyme as studied by circular dichroism, fluorescence, UV difference spectroscopy, size exclusion chromatography (SEC), and enzymatic activity. The presence of CaCl(2) in the incubation mixture produced significant recovery in spectral signals, being complete in presence of 10 mM CaCl(2), as well as in enzymatic activity, which is indicative of protein stabilization. However, the SEC results obtained with GdnHCl-denatured BLA both in the absence and the presence of 10 mM CaCl(2) suggested significant aggregation of the protein in the absence of CaCl(2) and disaggregation in its presence. Although partial structural stabilization with significant retention of enzymatic activity was observed in the presence of calcium, it was far from the native state, as reflected by spectral probes. Hence, spectral results as to BLA stabilization should be treated with caution in the presence of aggregation.
    Matched MeSH terms: Chromatography, Gel
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