MyMedR

Displaying all 6 publications

Abstract:

Sort:

Establishing a protocol for water sample processing for the detection of Blastocystis sp

Lee IL, Tan TC, Govind SK

Exp Parasitol, 2019 Mar;198:105-110.
PMID: 30695704 DOI: 10.1016/j.exppara.2019.01.007

This study was aimed at establishing a protocol for water sample processing for the detection of Blastocystis sp. using distilled water spiked with Blastocystis sp. cysts. The study established a protocol involving eight technical aspects, namely, storage temperature, storage duration, minimum water sample volume, optimum relative centrifugal force, centrifugation duration, minimum number of cyst for inoculation in Jones' medium and turn-around-time for the detection of vacuolar forms of Blastocystis sp. Results showed a minimum of 1.0 L water sample should be collected and processed on the same day. Otherwise, it should be stored at 4 °C and processed within 3 days. Water sample should be centrifuged at 1400×g for 10 min. For the isolation of Blastocystis sp. cysts, parasite pellet could be layered on top of Ficoll-Paque™ PLUS, centrifuged at 1400×g for 20 min and washed twice using 0.9% saline with centrifugation at 1400×g for 10 min. A minimum of 1 × 105 cysts could then be inoculated in Jones' medium supplement with 10% horse serum, incubated at 37 °C and examined for any presence of vacuolar forms of Blastocystis sp. after 3 days of inoculation. A protocol for water sample processing for the detection of Blastocystis sp. has successfully been established. The protocol was validated using 106 various water samples. This protocol will be very useful in determining the extent of Blastocystis sp. contamination in water sources in order to identify the seriousness of contamination.

Matched MeSH terms: Ficoll
Timing of The First Zygotic Cleavage Affects Post-Vitrification Viability of Murine Embryos Produced In Vivo

Jusof WH, Khan NA, Rajikin MH, Satar NA, Mustafa MF, Jusoh N, et al.

Int J Fertil Steril, 2015 07 27;9(2):221-9.
PMID: 26246881

BACKGROUND: Timing of the first zygotic cleavage is an accurate predictor of embryo quality. Embryos that cleaved early (EC) have been shown to exhibit higher develop- mental viability compared to those that cleaved at a later period (LC). However, the vi- ability of EC embryos in comparison to LC embryos after vitrification is unknown. The present study aims to investigate the post-vitrification developmental viability of murine EC versus LC embryos.
MATERIALS AND METHODS: In this experimental study, female ICR mice (6-8 weeks old) were superovulated and cohabited with fertile males for 24 hours. Afterwards, their ovi- ducts were excised and embryos harvested. Embryos at the 2-cell stage were catego- rized as EC embryos, while zygotes with two pronuclei were categorized as LC embryos. Embryos were cultured in M16 medium supplemented with 3% bovine serum albumin (BSA) in a humidified 5% CO2atmosphere. Control embryos were cultured until the blastocyst stage without vitrification. Experimental embryos at the 2-cell stage were vitri- fied for one hour using 40% v/v ethylene glycol, 18% w/v Ficoll-70 and 0.5 M sucrose as the cryoprotectant. We recorded the numbers of surviving embryos from the control and experimental groups and their development until the blastocyst stage. Results were analyzed using the chi-square test.
RESULTS: A significantly higher proportion of EC embryos (96.7%) from the control group developed to the blastocyst stage compared with LC embryos (57.5%, P<0.0001). Similarly, in the experimental group, a significantly higher percentage of vitrified EC embryos (69.4%) reached the blastocyst stage compared to vitrified LC embryos (27.1%, P<0.0001).
CONCLUSION: Vitrified EC embryos are more vitrification tolerant than LC embryos. Prese- lection of EC embryos may be used as a tool for selection of embryos that exhibit higher developmental competence after vitrification.

Matched MeSH terms: Ficoll
Fulltext Experimental exposure of Burkholderia pseudomallei crude culture filtrate upregulates PD-1 on T lymphocytes

Menon N, Mariappan V, Vellasamy KM, Samudi C, See JX, Ganesh PS, et al.

Access Microbiol, 2020;2(5):acmi000110.
PMID: 32974575 DOI: 10.1099/acmi.0.000110

Burkholderia pseudomallei is the causative agent for melioidosis. Because of its intracellular nature, the bacterium is capable of replicating within a plethora of eukaryotic cell lines. B. pseudomallei can remain dormant within host cells without symptoms for years, causing recrudescent infections. Here, we investigated the pathogenesis mechanism behind the suppression of T cell responses by B. pseudomallei . Peripheral blood mononuclear cells (1×106 cells/well) isolated by Ficoll Paque (Sigma-Aldrich) density gradient centrifugation were incubated with optimized concentrations of bacterial crude culture filtrate antigens (CFAs) (10 ug ml-1) and heat-killed bacteria [1 : 10 multiplicity of infection (m.o.i.)]. Following incubation, cells were investigated for surface expression of coinhibitory molecules by flow cytometry. We found that B. pseudomallei induced the upregulation of programmed death 1 (PD-1), a molecule responsible for T cell exhaustion, on T cells in vitro following exposure to crude CFAs of B. pseudomallei . This upregulation of PD-1 probably contributes to poor immune surveillance and disease pathogenesis.

Matched MeSH terms: Ficoll
Fulltext Protein and gene expression of leukemia stem cells markers in acute myeloid leukemia

Amrina Mohamad Amin, Maha Abdullah, Sabariah Md Noor, Raudhawati Osman, Wan Hayati Mohd Yaacob, Cheong Soon Keng

Malaysian Journal of Medicine and Health Sciences, 2019;15(108):23-23.
MyJurnal

Introduction: Acute myeloid leukaemia (AML) is a clonal haematological neoplasm characterised by proliferation of immature myeloid cells in the bone marrow resulting in impairment normal cell development in bone marrow. This leads to anaemia, thrombocytopenia and neutropenia. AML primarily affects older adults, with a median age at diagnosis of 69 years but is also seen in all other age groups. AML is recognized as a kind of cancer with marked heterogeneity in both biology of the cells and reactions to treatment. Treatment with intensive chemotherapy regi-mens of adult AML patients who are ≤ 60 years old results in hematologic remission in about 35% of patients, but at least 30% of these patients will experience a relapse. Mechanism leading to early relapse is still unclear. Leukaemia stem cell (LSC) is shown to correlate with poor prognosis. Biomarkers such as aldehyde dehydrogenase (ALDH) and CD34+CD38- have been identified as potential LSC biomarkers in previous studies. The objective of this study is to examine the expression of such markers for LSC and determine the association. Methods: Peripheral blood or bone marrow samples from untreated, newly diagnosed acute myeloid leukemias of all age, gender and race were collect-ed from Hospital Melaka and Kelang. Diagnosis of AML is based on WHO classification which include morphology, cytochemistry, immunophenotyping and cytogenetics. Mononuclear cells were isolated from bone marrow aspirate samples by gradient density centrifugation on Ficoll-Hypaque. Immunophenotyping using CD13, CD14, CD33, CD34, CD38 and ALDH were carried out to identify the presence and proportion of the various populations of inter-est. Results: There was a strong, positive correlation between ALDH and CD34+CD38- cell population, which was statistically significant (rs = 0.5989, p< 0.05). Conclusion: The strong correlation of ALDH activity and CD34+CD38- expression supported the potential of these biomarkers to identify LSCs cell in AML patients. However, due to the heterogeneity of AML, further studies using more markers and larger sample size are needed to determine the validity and to correlate with disease-free survival rate of AML patients.

Matched MeSH terms: Ficoll
Fulltext The effect of human mesenchymal stem cell on neutrophil oxidative burst

Ramasamy, R., Krishna, K., Maqbool, M., Vellasamy, S., Sarmadi, V. H., Abdullah, M., et al.

Malaysian Journal of Medicine and Health Sciences, 2010;6(2):11-17.
MyJurnal

Objective: Mesenchymal stem cells (MSC) are multipotent, non-haematopoietic stem cells that are
capable of differentiating into different varieties of mature cell types such as osteoblasts, chondrocytes, adipocytes, and myoblasts. There is abundant evidence showing that MSC not only affect the differentiation of haematopoietic progenitors, but also the function of mature cells like lymphocytes and neutrophils. However the effect of MSC on neutrophil function and its responses is not well studied. Therefore, this study was conducted to assess the effect of MSC on neutrophil nitric oxide production. Method: Neutrophils from heparanised venous blood were isolated using Ficoll-Hypaque density gradient centrifugation followed by Dextran sedimentation and red blood cell (RBC) lysis. Isolated neutrophils were on average of 97% purity as determined by morphologic analysis. MSC were generated from human bone marrow and characterised by immunophenotyping (monoclonal antibodies CD105, CD73 and CD34) using a flowcytometer. In order to test the effects of MSC on neutrophil function, isolated neutrophils were co-cultured in the presence or absence of MSC at different ratios for 24 and 48 hours. The amount of nitric oxide released was used as an indication of oxidative burst and measured using the Griess assay. Result: The results indicate that MSC neither elevate the NO level when cocultured with resting neutrophils nor alone. However MSC profoundly inhibit the secretion of nitric oxide in PMA stimulated neutrophils after 24hr of incubation. Conclusion: MSC exert an immunomodulatory effect on neutrophil by suppressing neutrophil oxidative burst in vitro.

Matched MeSH terms: Ficoll
On optimizing the blocking step of indirect enzyme-linked immunosorbent assay for Epstein-Barr virus serology

Lim CS, Krishnan G, Sam CK, Ng CC

Clin Chim Acta, 2013 Jan 16;415:158-61.
PMID: 23043757 DOI: 10.1016/j.cca.2012.08.031

Because blocking agent occupies most binding surface of a solid phase, its ability to prevent nonspecific binding determines the signal-to-noise ratio (SNR) and reliability of an enzyme-linked immunosorbent assay (ELISA).

Matched MeSH terms: Ficoll/chemistry