Displaying publications 161 - 180 of 252 in total

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  1. Formulation and evaluation of controlled release Eudragit buccal patches
    Wong CF, Yuen KH, Peh KK
    Int J Pharm, 1999 Feb 01;178(1):11-22.
    PMID: 10205621
    Controlled release buccal patches were fabricated using Eudragit NE40D and studied. Various bioadhesive polymers, namely hydroxypropylmethyl cellulose, sodium carboxymethyl cellulose and Carbopol of different grades, were incorporated into the patches, to modify their bioadhesive properties as well as the rate of drug release, using metoprolol tartrate as the model drug. The in-vitro drug release was determined using the USP 23 dissolution test apparatus 5 with slight modification, while the bioadhesive properties were evaluated using texture analyzer equipment with chicken pouch as the model tissue. The incorporation of hydrophilic polymers was found to affect the drug release as well as enhance the bioadhesiveness. Although high viscosity polymers can enhance the bioadhesiveness of the patches, they also tend to cause non-homogeneous distribution of the polymers and drug, resulting in non-predictable drug-release rates. Of the various bioadhesive polymers studied, Cekol 700 appeared to be most satisfactory in terms of modifying the drug release and enhancement of the bioadhesive properties.
    Matched MeSH terms: In Vitro Techniques
  2. Fulltext Effect of supercritical fluid density on nanoencapsulated drug particle size using the supercritical antisolvent method
    Kalani M, Yunus R
    Int J Nanomedicine, 2012;7:2165-72.
    PMID: 22619552 DOI: 10.2147/IJN.S29805
    The reported work demonstrates and discusses the effect of supercritical fluid density (pressure and temperature of supercritical fluid carbon dioxide) on particle size and distribution using the supercritical antisolvent (SAS) method in the purpose of drug encapsulation. In this study, paracetamol was encapsulated inside L-polylactic acid, a semicrystalline polymer, with different process parameters, including pressure and temperature, using the SAS process. The morphology and particle size of the prepared nanoparticles were determined by scanning electron microscopy and transmission electron microscopy. The results revealed that increasing temperature enhanced mean particle size due to the plasticizing effect. Furthermore, increasing pressure enhanced molecular interaction and solubility; thus, particle size was reduced. Transmission electron microscopy images defined the internal structure of nanoparticles. Thermal characteristics of nanoparticles were also investigated via differential scanning calorimetry. Furthermore, X-ray diffraction pattern revealed the changes in crystallinity structure during the SAS process. In vitro drug release analysis determined the sustained release of paracetamol in over 4 weeks.
    Matched MeSH terms: In Vitro Techniques
  3. Fulltext Modification of palm kernel oil esters nanoemulsions with hydrocolloid gum for enhanced topical delivery of ibuprofen
    Salim N, Basri M, Rahman MB, Abdullah DK, Basri H
    Int J Nanomedicine, 2012;7:4739-47.
    PMID: 22973096 DOI: 10.2147/IJN.S34700
    During recent years, there has been growing interest in the use of nanoemulsion as a drug-carrier system for topical delivery. A nanoemulsion is a transparent mixture of oil, surfactant and water with a very low viscosity, usually the product of its high water content. The present study investigated the modification of nanoemulsions with different hydrocolloid gums, to enhanced drug delivery of ibuprofen. The in vitro characterization of the initial and modified nanoemulsions was also studied.
    Matched MeSH terms: In Vitro Techniques
  4. Fulltext In vitro permeation and in vivo anti-inflammatory and analgesic properties of nanoscaled emulsions containing ibuprofen for topical delivery
    Abdullah GZ, Abdulkarim MF, Salman IM, Ameer OZ, Yam MF, Mutee AF, et al.
    Int J Nanomedicine, 2011;6:387-96.
    PMID: 21499428 DOI: 10.2147/IJN.S14667
    As a topical delivery system, a nanoscaled emulsion is considered a good carrier of several active ingredients that convey several side effects upon oral administration, such as nonsteroidal anti-inflammatory drugs (NSAIDs).
    Matched MeSH terms: In Vitro Techniques
  5. Fulltext Topical piroxicam in vitro release and in vivo anti-inflammatory and analgesic effects from palm oil esters-based nanocream
    Abdulkarim MF, Abdullah GZ, Chitneni M, Salman IM, Ameer OZ, Yam MF, et al.
    Int J Nanomedicine, 2010 Nov 04;5:915-24.
    PMID: 21116332 DOI: 10.2147/IJN.S13305
    INTRODUCTION: During recent years, there has been growing interest in use of topical vehicle systems to assist in drug permeation through the skin. Drugs of interest are usually those that are problematic when given orally, such as piroxicam, a highly effective anti-inflammatory, anti-pyretic, and analgesic, but with the adverse effect of causing gastrointestinal ulcers. The present study investigated the in vitro and in vivo pharmacodynamic activity of a newly synthesized palm oil esters (POEs)-based nanocream containing piroxicam for topical delivery.

    METHODS: A ratio of 25:37:38 of POEs: external phase: surfactants (Tween 80:Span 20, in a ratio 80:20), respectively was selected as the basic composition for the production of a nanocream with ideal properties. Various nanocreams were prepared using phosphate-buffered saline as the external phase at three different pH values. The abilities of these formulae to deliver piroxicam were assessed in vitro using a Franz diffusion cell fitted with a cellulose acetate membrane and full thickness rat skin. These formulae were also evaluated in vivo by comparing their anti-inflammatory and analgesic activities with those of the currently marketed gel.

    RESULTS: After eight hours, nearly 100% of drug was transferred through the artificial membrane from the prepared formula F3 (phosphate-buffered saline at pH 7.4 as the external phase) and the marketed gel. The steady-state flux through rat skin of all formulae tested was higher than that of the marketed gel. Pharmacodynamically, nanocream formula F3 exhibited the highest anti- inflammatory and analgesic effects as compared with the other formulae.

    CONCLUSION: The nanocream containing the newly synthesized POEs was successful for trans-dermal delivery of piroxicam.

    Matched MeSH terms: In Vitro Techniques
  6. Fulltext In vitro inhibition of histamine release behavior of cetirizine intercalated into Zn/Al- and Mg/Al-layered double hydroxides
    Hussein-Al-Ali SH, Al-Qubaisi M, Hussein MZ, Ismail M, Zainal Z, Hakim MN
    Int J Mol Sci, 2012;13(5):5899-916.
    PMID: 22754339 DOI: 10.3390/ijms13055899
    The intercalation of cetirizine into two types of layered double hydroxides, Zn/Al and Mg/Al, has been investigated by the ion exchange method to form CTZAN and CTMAN nanocomposites, respectively. The basal spacing of the nanocomposites were expanded to 31.9 Å for CTZAN and 31.2 Å for CTMAN, suggesting that cetirizine anion was intercalated into Layered double hydroxides (LDHs) and arranged in a tilted bilayer fashion. A Fourier transform infrared spectroscopy (FTIR) study supported the formation of both the nanocomposites, and the intercalated cetirizine is thermally more stable than its counterpart in free state. The loading of cetirizine in the nanocomposite was estimated to be about 57.2% for CTZAN and 60.7% CTMAN. The cetirizine release from the nanocomposites show sustained release manner and the release rate of cetirizine from CTZAN and CTMAN nanocomposites at pH 7.4 is remarkably lower than that at pH 4.8, presumably due to the different release mechanism. The inhibition of histamine release from RBL2H3 cells by the free cetirizine is higher than the intercalated cetirizine both in CTZAN and CTMAN nanocomposites. The viability in human Chang liver cells at 1000 μg/mL for CTZAN and CTMAN nanocomposites are 74.5 and 91.9%, respectively.
    Matched MeSH terms: In Vitro Techniques
  7. Lion's Mane, Hericium erinaceus and Tiger Milk, Lignosus rhinocerotis (Higher Basidiomycetes) Medicinal Mushrooms Stimulate Neurite Outgrowth in Dissociated Cells of Brain, Spinal Cord, and Retina: An In Vitro Study
    Samberkar S, Gandhi S, Naidu M, Wong KH, Raman J, Sabaratnam V
    Int J Med Mushrooms, 2015;17(11):1047-54.
    PMID: 26853959
    Neurodegenerative disease is defined as a deterioration of the nervous system in the intellectual and cognitive capabilities. Statistics show that more than 80-90 million individuals age 65 and above in 2050 may be affected by neurodegenerative conditions like Alzheimer's and Parkinson's disease. Studies have shown that out of 2000 different types of edible and/or medicinal mushrooms, only a few countable mushrooms have been selected until now for neurohealth activity. Hericium erinaceus is one of the well-established medicinal mushrooms for neuronal health. It has been documented for its regenerative capability in peripheral nerve. Another mushroom used as traditional medicine is Lignosus rhinocerotis, which has been used for various illnesses. It has been documented for its neurite outgrowth potential in PC12 cells. Based on the regenerative capabilities of both the mushrooms, priority was given to select them for our study. The aim of this study was to investigate the potential of H. erinaceus and L. rhinocerotis to stimulate neurite outgrowth in dissociated cells of brain, spinal cord, and retina from chick embryo when compared to brain derived neurotrophic factor (BDNF). Neurite outgrowth activity was confirmed by the immu-nofluorescence method in all tissue samples. Treatment with different concentrations of extracts resulted in neuronal differentiation and neuronal elongation. H. erinaceus extract at 50 µg/mL triggered neurite outgrowth at 20.47%, 22.47%, and 21.70% in brain, spinal cord, and retinal cells. L. rhinocerotis sclerotium extract at 50 µg/mL induced maximum neurite outgrowth of 20.77% and 24.73% in brain and spinal cord, whereas 20.77% of neurite outgrowth was observed in retinal cells at 25 µg/mL, respectively.
    Matched MeSH terms: In Vitro Techniques
  8. Fulltext Recombinant human adiponectin as a potential protein for treating diabetic tendinopathy promotes tenocyte progenitor cells proliferation and tenogenic differentiation in vitro
    Rothan HA, Suhaeb AM, Kamarul T
    Int J Med Sci, 2013;10(13):1899-906.
    PMID: 24324367 DOI: 10.7150/ijms.6774
    Adiponectin is an adipocyte-secreting hormone that increases cell sensitivity to insulin. It has been previously demonstrated that this hormone protects against Type II Diabetes and, is found to concurrently promote cell proliferation and differentiation. It is postulated that diabetic patients who suffer from tendinopathy may benefit from using adiponectin, which not only improves the metabolism of diabetic ridden tenocytes but also promotes progenitor cell proliferation and differentiation in tendons. These changes may result in tendon regeneration, which, in diabetic tendinopathy, is difficult to treat. Considering that such findings have yet to be demonstrated, a study was thus conducted using diabetic ridden human tenocyte progenitor cells (TPC) exposed to recombinant adiponectin in vitro. TPC were isolated from tendons of diabetic patients and exposed to 10 μg/ml adiponectin. Cell proliferation rate was investigated at various time points whilst qPCR were used to determine the tenogenic differentiation potential. The results showed that adiponectin significantly reduced blood glucose in animal models. The proliferation rate of adiponectin-treated TPCs was significantly higher at 6, 8 and 10 days as compared to untreated cells (p<0.05). The levels of tenogenic genes expression (collagen I, III, tenomodulin and scleraxis) were also significantly upregulated; whilst the osteogenic (Runx2), chondrogenic (Sox9) and adipogenic (PPARУγ) gene expressions remained unaltered. The results of this study suggest that adiponectin is a potential promoter that not only improves diabetic conditions, but also increases tendon progenitor cell proliferation and differentiation. These features supports the notion that adiponectin may be potentially beneficial in treating diabetic tendinopathy.
    Matched MeSH terms: In Vitro Techniques
  9. Fulltext Heavy Metal in Paddy Soil and its Bioavailability in Rice Using In Vitro Digestion Model for Health Risk Assessment
    Zulkafflee NS, Mohd Redzuan NA, Hanafi Z, Selamat J, Ismail MR, Praveena SM, et al.
    Int J Environ Res Public Health, 2019 11 28;16(23).
    PMID: 31795132 DOI: 10.3390/ijerph16234769
    Rice ingestion is one of the major pathways for heavy metal bioaccumulation in human. This study aimed to measure the heavy metal content of paddy soils and its bioavailability in paddy grain in order to assess the health risk. In total, 10 rice samples (50 g each) of paddy plants were harvested from the Selangor and Terengganu areas of Malaysia to assess the bioavailability of heavy metal (As, Cd, Cu, Cr, and Pb) using the in vitro digestion model of Rijksinstituut voor Volksgezondheid en Milieu. The bioavailability of heavy metal concentrations in rice samples were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The findings showed the bioavailability of heavy metal concentrations was decreased in the order Cr > Cu > Pb > As > Cd. Chromium was found to be the most abundant bioavailable heavy metal in cooked rice, which was the result of its high content in paddy soil. Hazard Quotient values for the bioavailability of the heavy metal studied were less than one indicating no non-carcinogenic health risks for adults and children. Meanwhile, the total Lifetime Cancer Risk exceeded the acceptable value showing a potential of carcinogenic health risk for both adults and children. The application of in vitro digestion model in assessing bioavailability of heavy metal produces a more realistic estimation of human health risks exposure. However, a regular monitoring of pollution in Selangor and Terengganu areas is crucial since the exposure of heavy metals through rice consumption poses the potential non-carcinogenic and carcinogenic health risk to the local residents.
    Matched MeSH terms: In Vitro Techniques
  10. Root and canal morphology of maxillary premolar teeth in an Egyptian subpopulation using two classification systems: a cone beam computed tomography study
    Saber SEDM, Ahmed MHM, Obeid M, Ahmed HMA
    Int Endod J, 2019 Mar;52(3):267-278.
    PMID: 30225932 DOI: 10.1111/iej.13016
    AIM: To investigate the number of roots and root canal configurations using two coding systems and the root canal diverging and merging levels in extracted maxillary premolars in an Egyptian subpopulation using cone beam computed tomography (CBCT).

    METHODOLOGY: A total of 700 maxillary premolars were examined using CBCT in an Egyptian subpopulation. The number of roots was identified, and root canal configurations were classified according to Vertucci's classification and a new system for classifying root and canal morphology. In addition, the position where roots bifurcated and the levels where canals merged or diverged were identified. Fisher's exact test and independent t-test were used for statistical analysis, and the level of significance was set at 0.05 (P = 0.05).

    RESULTS: More than half of maxillary first premolars were double-rooted, and the majority of maxillary second premolars were single-rooted (P 

    Matched MeSH terms: In Vitro Techniques
  11. Epitope mapping of the Sta58 major outer membrane protein of Rickettsia tsutsugamushi
    Lachumanan R, Devi S, Cheong YM, Rodda SJ, Pang T
    Infect Immun, 1993 Oct;61(10):4527-31.
    PMID: 7691753
    Binding studies of 160 overlapping, synthetic octapeptides from the hydrophilic regions of the Sta58 major outer membrane protein of Rickettsia tsutsugamushi with sera from patients with scrub typhus revealed 15 immunodominant peptides which are recognized by all the sera tested. Further analysis of the specificity of peptide binding with five of these peptides indicated that the peptides showed significantly stronger binding to scrub typhus patients' sera than they did to sera from patients with other febrile illnesses common in the region, i.e., malaria, dengue fever, typhoid fever, and leptospirosis. The main antibody class binding to these peptides appears to be immunoglobulin M, and there appears to be little correlation between reactivity with peptides and antibody titers measured by the indirect immunoperoxidase test.
    Matched MeSH terms: In Vitro Techniques
  12. Fulltext Comparative evaluation of application of different fluoride varnishes on artificial early enamel lesion: An in vitro study
    Majithia U, Venkataraghavan K, Choudhary P, Trivedi K, Shah S, Virda M
    Indian J Dent Res, 2016 Sep-Oct;27(5):521-527.
    PMID: 27966511 DOI: 10.4103/0970-9290.195642
    INTRODUCTION: In an attempt to manage noncavitated carious lesions noninvasively through remineralization, a range of novel fluoride varnishes with additional remineralizing agents have been made available for clinical application.

    AIM AND OBJECTIVES: The aim of this study was to compare and evaluate the remineralization potential of three commercially available varnishes on artificial enamel lesions.

    MATERIALS AND METHODS: This in vitro study involves eighty intact enamel specimens prepared from premolars extracted for orthodontic purposes. After specimen preparation, the eighty samples were divided randomly into two groups (n = 40) for measurement of baseline surface Vickers microhardness and baseline calcium/phosphorus ratio (% weight) through EDAX testing. Thereafter, the specimens were subjected to demineralization for 96 h to induce initial enamel lesions and the measurements were repeated. Following demineralization, each of the two groups was divided randomly into four subgroups (n = 10) from which one was used as the control group and the others three were allotted to each of the three test varnishes. After varnish application, all the specimens were subjected to a pH cycling regimen that included alternative demineralization (3 h) and remineralization (21 h) daily, for 5 consecutive days. The Vickers microhardness and EDAX measurements were then repeated.

    RESULTS: One-way ANOVA and post hoc Tukey's tests were conducted for multiple group comparison. All the three commercially available varnishes were capable of remineralizing initial enamel lesions that were induced artificially. No difference was noted in the remineralizing efficacy of the varnishes despite their different compositions. MI Varnish™ (casein phosphopeptide-amorphous calcium phosphate fluoride varnish) showed slightly better recovery in surface microhardness as compared to the other two varnishes.

    CONCLUSION: All the varnishes used in this in vitro study are capable of reversing early enamel lesions.
    Matched MeSH terms: In Vitro Techniques
  13. Total cell pooling in vitro: an effective isolation method for bone marrow-derived multipotent stromal cells
    Wee AS, Lim CK, Merican AM, Ahmad TS, Kamarul T
    In Vitro Cell Dev Biol Anim, 2013 Jun;49(6):424-32.
    PMID: 23708918 DOI: 10.1007/s11626-013-9626-0
    In vitro cellular proliferation and the ability to undergo multilineage differentiation make bone marrow-derived multipotent stromal cells (MSCs) potentially useful for clinical applications. Several methods have been described to isolate a homogenous bone marrow-derived MSCs population; however, none has been proven most effective, mainly due to their effects on proliferation and differentiation capability of the isolated cells. It is hypothesized that our newly established total cell pooling method may provide a better alternative as compared to the standard isolation method (density gradient centrifugation method). For the total cell pooling method, MSCs were isolated from rabbit bone marrow and were subsequently cultured in the growth medium without further separation as in the standard isolation method. The total cell pooling method was 65 min faster than the standard isolation method in completing cell isolation. Nevertheless, both methods did not differ significantly in the number of primary viable cells and population doubling time in the cultures (p > 0.05). The isolated cells from both methods expressed CD29 and CD44 markers, but not CD45 markers. Furthermore, they displayed multilineage differentiation characteristics of chondroblasts, osteoblasts, and adipocytes. In conclusion, both methods provide similar efficiency in the isolation of rabbit bone marrow-derived MSCs; however, the total cell pooling method is technically simpler and more cost effective than the standard isolation method.
    Matched MeSH terms: In Vitro Techniques
  14. Anti-inflammatory activity of Crinum asiaticum plant and its effect on bradykinin-induced contractions on isolated uterus
    Samud AM, Asmawi MZ, Sharma JN, Yusof AP
    Immunopharmacology, 1999 Sep;43(2-3):311-6.
    PMID: 10596868
    Crinum asiaticum Linn plant is used in Malaysia as a rheumatic remedy and to relieve local pain. In the present study, we examined the anti-inflammatory effects of this plant extract on carrageenan-induced hind paw oedema in mice. C. asiaticum was serially extracted with petroleum ether, followed by chloroform and lastly, methanol. The chloroform and methanol extracts of the plant given orally (50 mg kg-1) caused significant (p < 0.05; n = 7) reduction in paw oedema but the petroleum ether extract did not induce significant effect (p > 0.05) on paw oedema. The methanol extract was then dissolved in water and extracted consecutively with chloroform, ethyl acetate and butanol. The chloroform fraction of methanol extract (CFME) treatment (50 mg kg(-1)) significantly reduced (p < 0.05; n = 7) the acute paw oedema. This may indicate that active anti-inflammatory compounds are present in the CFME. In an attempt to study the mechanism of action of its anti-inflammatory activity, the effects of CFME on BK- and histamine-induced contractions were investigated in isolated rat uterus and guinea-pig ileum preparations, respectively. It was found that CFME caused dose-dependent reduction (p < 0.05; n = 6) of the contractile response induced by BK and shifted the log dose-response curve of histamine to the right. The present findings suggest that C. asiaticum possessed an anti-inflammatory activity as suggested by its use in traditional medicine. The anti-inflammatory activity of this plant could not have been due to its anti-bradykinin activities as CFME non-specifically inhibited BK-induced contraction. It also suggest that CFME may contain compound(s) with anti-histaminic properties. The significance of these findings is discussed.
    Matched MeSH terms: In Vitro Techniques
  15. The interaction of selective plant lectins with neuraminidase-treated and untreated IgA1 from the sera of IgA nephropathy patients
    Hashim OH, Shuib AS, Chua CT
    Immunol Invest, 2001 Feb;30(1):21-31.
    PMID: 11419909
    A study on the binding interaction of lectins from Artocarpus heterophyllus (jacalin), Glycine max and Sambucus nigra with standardised quantity of IgA from the IgA nephropathy patients and normal controls was performed. The Glycine max lectin demonstrated higher affinity towards the serum IgA of IgAN patients as compared to normal controls. However, the affinity binding was lower in cases ofjacalin and the Sambucus nigra lectin. When serum samples were treated with neuraminidase, the differential jacalin affinity binding between IgA1 of patients and normal controls was abrogated. Our data are in support of the view that the O-linked oligosaccharide moieties of the patients IgA1 were generally lacking in galactose and sialic acid residues.
    Matched MeSH terms: In Vitro Techniques
  16. Effect of the mannose-binding Artocarpus integer lectin on the cellular proliferation of murine lymphocytes
    Lim SB, Kanthimathi MS, Hashim OH
    Immunol Invest, 1998 Dec;27(6):395-404.
    PMID: 9845424
    The effect of the mannose-binding champedak (Artocarpus integer) lectin-M on the cellular proliferation of murine lymphocytes was investigated in this study. Our data demonstrated that the lectin was the main mitogenic component in the crude extract of the champedak seeds. It stimulated the proliferation of murine T cells at an optimal concentration of 2.5 microg/ml in a 3 day culture. Lectin-M appeared to be a T-cell mitogen as it does not induce significant DNA synthesis when cultured with spleen cells from the nude mouse. In the absence of T cells, the lectin was incapable of inducing resting B cells to differentiate into immunoglobulin secreting plasma cells.
    Matched MeSH terms: In Vitro Techniques
  17. Fulltext Empty nano and micro-structured lipid carriers of virgin coconut oil for skin moisturisation
    Noor NM, Khan AA, Hasham R, Talib A, Sarmidi MR, Aziz R, et al.
    IET Nanobiotechnol, 2016 Aug;10(4):195-9.
    PMID: 27463789 DOI: 10.1049/iet-nbt.2015.0041
    Virgin coconut oil (VCO) is the finest grade of coconut oil, rich in phenolic content, antioxidant activity and contains medium chain triglycerides (MCTs). In this work formulation, characterisation and penetration of VCO-solid lipid particles (VCO-SLP) have been studied. VCO-SLP were prepared using ultrasonication of molten stearic acid and VCO in an aqueous solution. The electron microscopy imaging revealed that VCO-SLP were solid and spherical in shape. Ultrasonication was performed at several power intensities which resulted in particle sizes of VCO-SLP ranged from 0.608 ± 0.002 µm to 44.265 ± 1.870 µm. The particle size was directly proportional to the applied power intensity of ultrasonication. The zeta potential values of the particles were from -43.2 ± 0.28 mV to -47.5 ± 0.42 mV showing good stability. The cumulative permeation for the smallest sized VCO-SLP (0.608 µm) was 3.83 ± 0.01 µg/cm(2) whereas for larger carriers it was reduced (3.59 ± 0.02 µg/cm(2)). It is concluded that SLP have the potential to be exploited as a micro/nano scale cosmeceutical carrying vehicle for improved dermal delivery of VCO.
    Matched MeSH terms: In Vitro Techniques
  18. Cell viability of acute myeloid leukaemia blasts in culture correlates with treatment outcome
    Maha A, Cheong SK, Leong CF, Seow HF
    Hematology, 2008 Feb;13(1):13-20.
    PMID: 18534060 DOI: 10.1179/102453308X315762
    Despite the advances in understanding the pathophysiology of acute myeloid leukaemia (AML), the cure rate for acute myeloid leukaemia patients remains low. Cytogenetic abnormalities and age are the prognostic factors that guide treatment decisions. However, many AML patients still die. The biological factors that influence treatment outcome are largely unknown. Thus, the objective of our study was to use the in vitro viability test to correlate with treatment outcome. Acute myeloid leukaemia blasts demonstrated differing ability to survive in culture. Our examination of blast phenotype at various days in culture showed two possible growth directions. First, cells underwent maturation by increased expression of CD16 and down-regulated CD34 (a haemopoietic stem cell marker). These cells also appeared to have undergone apoptosis. Alternatively, cells continued to survive in culture and maintained high expression of CD34. An MTT assay was carried out to determine viability after three days of culture. Lower optical density values were obtained for samples that underwent apoptosis and higher values were obtained for samples that survived in culture. Apoptosis was measured by Annexin V/propidium iodide staining. A comparison between results of MTT assay and duration of disease free survival revealed that a higher viability in vitro correlated significantly with shorter survival duration in the patient (R -0.761, p=0.002, n=13). Thus, this study further supports the hypothesis that AML patients with poor survival may be related to having blasts with a biologically more immature or stem cell-like nature.
    Matched MeSH terms: In Vitro Techniques
  19. The effects of propranolol on skeletal muscle contraction, lipid peroxidation products and antioxidant activity in experimental hyperthyroidism
    Zaiton Z, Merican Z, Khalid BA, Mohamed JB, Baharom S
    Gen. Pharmacol., 1993 Jan;24(1):195-9.
    PMID: 8482496
    1. The mean levels of lipid peroxidation products, namely conjugated diene and malonaldehyde, were increased in the soleus muscles of hyperthyroid cats, while the mean glutathione peroxidase activity was decreased. No corresponding similar changes were noted in the fast extensor digitorum longus muscles and serum. 2. Propranolol administration prevented the increase in conjugated diene level in the soleus muscles of hyperthyroid cat but not the malonaldehyde level. It also prevented the reduction in glutathione peroxidase activity in the slow oxidative soleus muscles of hyperthyroid cats. 3. Maximal twitch tension, subtetanic tension and maximum tetanic tension of soleus and EDL muscles were reduced in hyperthyroid cats. Propranolol administration for 5 weeks to hyperthyroid cats did not prevent the reduction in tension of contractions of these muscles. 4. It is suggested that lipid peroxidation might not be responsible for the myopathy in hyperthyroidism and propranolol administration does not improve skeletal muscle function in hyperthyroid animals.
    Matched MeSH terms: In Vitro Techniques
  20. Opposite effects of sex steroids on 11 beta-hydroxysteroid dehydrogenase activity in the normal and adrenalectomized rat testis
    Nwe KH, Morat PB, Khalid BA
    Gen. Pharmacol., 1997 May;28(5):661-4.
    PMID: 9184798
    1. Sex steroids have been shown to regulate the biosynthesis of 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD). 2. In vitro studies showed that oestradiol (E2) or testosterone (T) can interfere with the bioassay of enzyme activity, but not progesterone (P4). 3. For in vivo studies, the activity of 11 beta-HSD in the testis of normal and adrenalectomized (ADX) adult male Wistar rats was determined following a daily IM injection of sex steroids for 7 days. 4. The 11 beta-HSD activity was significantly reduced (P < 0.01) either by E2 or T in normal and ADX rats. The enzyme activity in normal rats given both T and E2 was even lower (P < 0.001) than when E2 was given alone. 5. P4 given to normal and ADX rats increased the enzyme activity higher than normal (P < 0.001). 6. The presence of corticosteroids influenced the effects of E2, but not of T and P4, on 11 beta-HSD activity. 7. E2 and T downregulate 11 beta-HSD activity, whereas P4 increased it. E2 did not act through lowering T level.
    Matched MeSH terms: In Vitro Techniques
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