Displaying publications 1201 - 1220 of 1297 in total

Abstract:
Sort:
  1. Othman R, Vladisavljević GT, Thomas NL, Nagy ZK
    Colloids Surf B Biointerfaces, 2016 May 01;141:187-195.
    PMID: 26852102 DOI: 10.1016/j.colsurfb.2016.01.042
    Paracetamol (PCM)-loaded composite nanoparticles (NPs) composed of a biodegradable poly(d,l-lactide) (PLA) polymer matrix filled with organically modified montmorillonite (MMT) nanoparticles were fabricated by antisolvent nanoprecipitation in a microfluidic co-flow glass capillary device. The incorporation of MMT in the polymer improved both the drug encapsulation efficiency and the drug loading, and extended the rate of drug release in simulated intestinal fluid (pH 7.4). The particle size increased on increasing both the drug loading and the concentration of MMT in the polymer matrix, and decreased on increasing the aqueous to organic flow rate ratio. The drug encapsulation efficiency in the NPs was higher at higher aqueous to organic flow rate ratio due to faster formation of the NPs. The PCM-loaded PLA NPs containing 2 wt% MMT in PLA prepared at an aqueous to organic flow rate ratio of 10 with an orifice size of 200 μm exhibited a spherical shape with a mean size of 296 nm, a drug encapsulation efficiency of 38.5% and a drug loading of 5.4%. The encapsulation of MMT and PCM in the NPs was confirmed by transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis and attenuated total reflection-Fourier transform infrared spectroscopy.
    Matched MeSH terms: Microscopy, Electron, Transmission
  2. Majidnia Z, Idris A, Majid M, Zin R, Ponraj M
    Appl Radiat Isot, 2015 Nov;105:105-113.
    PMID: 26275818 DOI: 10.1016/j.apradiso.2015.06.028
    In this paper, both maghemite (γ-Fe2O3) and titanium oxide (TiO2) nanoparticles were synthesized and mixed in various ratios and embedded in PVA and alginate beads. Batch sorption experiments were applied for removal of barium ions from aqueous solution under sunlight using the beads. The process has been investigated as a function of pH, contact time, temperature, initial barium ion concentration and TiO2:γ-Fe2O3 ratios (1:10, 1:60 and 1). The recycling attributes of these beads were also considered. Furthermore, the results revealed that 99% of the Ba(II) was eliminated in 150min at pH 8 under sunlight. Also, the maghemite and titania PVA-alginate beads can be readily isolated from the aqueous solution after the process and reused for at least 7 times without significant losses of their initial properties. The reduction of Ba(II) with maghemite and titania PVA-alginate beads fitted the pseudo first order and second order Langmuir-Hinshelwood (L-H) kinetic model.
    Matched MeSH terms: Microscopy, Electron, Scanning
  3. Mohamed MI, Mohammad MK, Abdul Razak HR, Abdul Razak K, Saad WM
    Biomed Res Int, 2015;2015:183525.
    PMID: 26075217 DOI: 10.1155/2015/183525
    Emerging syntheses and findings of new metallic nanoparticles (MNPs) have become an important aspect in various fields including diagnostic imaging. To date, iodine has been utilized as a radiographic contrast medium. However, the raise concern of iodine threats on iodine-intolerance patient has led to search of new contrast media with lower toxic level. In this animal modeling study, 14 nm iron oxide nanoparticles (IONPs) with silane-polyethylene glycol (SiPEG) and perchloric acid have been assessed for toxicity level as compared to conventional iodine. The nanotoxicity of IONPs was evaluated in liver biochemistry, reactive oxygen species production (ROS), lipid peroxidation mechanism, and ultrastructural evaluation using transmission electron microscope (TEM). The hematological analysis and liver function test (LFT) revealed that most of the liver enzymes were significantly higher in iodine-administered group as compared to those in normal and IONPs groups (P < 0.05). ROS production assay and lipid peroxidation indicator, malondialdehyde (MDA), also showed significant reductions in comparison with iodine group (P < 0.05). TEM evaluation yielded the aberration of nucleus structure of iodine-administered group as compared to those in control and IONPs groups. This study has demonstrated the less toxic properties of IONPs and it may postulate that IONPs are safe to be applied as radiographic contrast medium.
    Matched MeSH terms: Microscopy, Electron, Transmission
  4. Fong EP, Bay BH
    Med Hypotheses, 2002 Apr;58(4):264-9.
    PMID: 12027517
    The aetiology of the keloid scar has not been completely elucidated. Numerous hypotheses have been proposed in the past to explain the unusual characteristics of the keloid scar. While we do know that there is excessive and ongoing collagen-deposition, the exact triggering stimulus is a subject of conjecture. We present some of our photographic records of keloids and electron microscopic findings of keloid edges and reiterate the sebum hypothesis. We also attempt to explain the features of keloids in the light of the present knowledge of immunology and cell biology.
    Matched MeSH terms: Microscopy, Electron
  5. Wen B, Rikihisa Y, Yamamoto S, Kawabata N, Fuerst PA
    Int. J. Syst. Bacteriol., 1996 Jan;46(1):149-54.
    PMID: 8573488
    The organism designated the SF agent was originally isolated in Japan in 1962 from Stellantchasmus falcatus metacercaria parasitic on gray mullet fish. The SF agent resembles members of the genus Ehrlichia morphologically and exhibits weak antigenic cross-reactivity with Ehrlichia sennetsu. This organism causes mild clinical signs in dogs, but severe splenomegaly and lymphadenopathy in mice. This suggests that the SF agent may be similar to either Neorickettsia helminthoeca, an intracellular parasite of a fluke and the cause of salmon poisoning disease in dogs, or E. sennetsu, the causative agent of human sennetsu ehrlichiosis in Japan and Malaysia. In order to determine the phylogenetic relationship between the SF agent and other ehrlichial species, the 16S rRNA gene was amplified by the PCR and sequenced. The SF agent sequence was most closely related to the sequences of Ehrlichia risticii (level of sequence similarity, 99.1%), the causative agent of Potomac horse fever, and E. sennetsu (level of sequence similarity, 98.7%). The next most similar sequence was that of N. helminthoeca, but the level of sequence similarity was only 93.7%. E. sennetsu, E. risticii, the SF agent, and N. helminthoeca formed a distinct cluster that was separated from all other ehrlichial species. As determined by immunofluorescence labeling, antiserum against the SF agent cross-reacted strongly with E. sennetsu, E. risticii, and N. helminthoeca. When three genetically distinct ehrlichial isolates obtained from horses with Potomac horse fever were compared with the SF agent, we found that the SF agent was most closely related to Ohio isolate 081, followed by IllinoisT (T = type strain) and a Kentucky isolate. We observed strong antigenic cross-reactivities and similarities in Western blot (immunoblot) reaction profiles when we compared the SF agent, E. risticii, and E. sennetsu; however, weaker antigenic cross-reactivity was observed when the SF agent and N. helminthoeca were compared. Our results indicate that the SF agent is antigenically more closely related to E. risticii and E. sennetsu than to N. helminthoeca. The biological and antigenic characteristics and the 16S rRNA sequence data suggest that the SF agent is a new species that belongs to the genus Ehrlichia.
    Matched MeSH terms: Microscopy, Electron
  6. Ibrahim D, Osman H
    J Ethnopharmacol, 1995 Mar;45(3):151-6.
    PMID: 7623478
    Ethanolic extract of Cassia alata leaves was investigated for its antimicrobial activities on several microorganisms including bacteria, yeast, dermatophytic fungi and non-dermatophytic fungi. In vitro, the extract exhibited high activity against various species of dermatophytic fungi but low activity against non-dermatophytic fungi. However, bacterial and yeast species showed resistance against in vitro treatment with the extract. The minimum inhibitory concentration (MIC) values of the extract revealed that Trichophyton mentagorphytes var. interdigitale, Trichophyton mentagrophytes var. mentagorophytes, Trichophyton rubrum and Microsporum gypseum had the MIC of 125 mg/ml, whereas Microsporum canis had the MIC of 62.5 mg/ml. The inhibition can be observed on the macroconidia of Microsporum gypseum which resulted in structural degeneration beyond repair. The mechanism of inhibition can be related to the cell leakage as observed by irregular, wrinkle shape and loss in rigidity of the macroconidia.
    Matched MeSH terms: Microscopy, Electron, Scanning
  7. Looi LM
    Hum Pathol, 1993 Jun;24(6):602-7.
    PMID: 8505038
    Congo red screening of 211 consecutive cardiac biopsy specimens obtained during cardiac surgery from 167 patients revealed 26 (16%) instances of isolated atrial amyloidosis (IAA). The ages of IAA-positive patients ranged from 25 to 52 years (mean age, 39 years). Twenty-three (88%) IAA-positive biopsy specimens were from patients with chronic rheumatic heart disease (CRHD) while three (12%) were from patients with an atrial septal defect (ASD). The prevalence of IAA in the CRHD patients was 23%, appreciably higher than that in the ASD patients (15%) and in other patients with atrial biopsies. The prevalence of IAA in both CRHD and ASD patients was significantly higher (P < .001) than in controls. Controls consisted of 247 healthy adults who were autopsied after traumatic deaths, with an age range of 18 to 89 years (mean age, 38 years). Only seven (3%) control subjects were IAA positive; all were over 40 years of age. Isolated atrial amyloidosis deposits were permanganate resistant and immunohistochemically positive for human amyloid P (AP) protein and negative for human amyloid-associated (AA) protein and immunoglobulin light chains. They were observed as fine congophilic and birefringent deposits in intramyocardial vessel walls, along the myocardial sarcolemma, and in the subendocardium. There was associated myocyte hypertrophy but no atrophy. Electron microscopy demonstrated typical nonbranching amyloid fibrils. It is postulated that stretching of the atria in chronic heart disease results in a raised prevalence of IAA. Recent reports that IAA contains atrial natriuretic peptide, a polypeptide hormone product of atrial myocytes, supports this view.
    Matched MeSH terms: Microscopy, Electron
  8. Tan WS, Ong ST, Eshaghi M, Foo SS, Yusoff K
    J Med Virol, 2004 May;73(1):105-12.
    PMID: 15042656
    The nucleocapsid (N) protein of Nipah virus (NiV) can be produced in three Escherichia coli strains [TOP10, BL21(DE3) and SG935] under the control of trc promoter. However, most of the product existed in the form of insoluble inclusion bodies. There was no improvement in the solubility of the product when this protein was placed under the control of T7 promoter. However, the solubility of the N protein was significantly improved by lowering the growth temperature of E. coli BL21(DE3) cell cultures. Solubility analysis of N- and C-terminally deleted mutants revealed that the full-length N protein has the highest solubility. The soluble N protein could be purified efficiently by sucrose gradient centrifugation and nickel affinity chromatography. Electron microscopic analysis of the purified product revealed that the N protein assembled into herringbone-like particles of different lengths. The C-terminal end of the N protein contains the major antigenic region when probed with antisera from humans and pigs infected naturally.
    Matched MeSH terms: Microscopy, Electron
  9. Chia SL, Lei J, Ferguson DJP, Dyer A, Fisher KD, Seymour LW
    Virology, 2017 05;505:162-171.
    PMID: 28260622 DOI: 10.1016/j.virol.2017.02.011
    Enadenotucirev (EnAd) is a group B oncolytic adenovirus developed for systemic delivery and currently undergoing clinical evaluation for advanced cancer therapy. For differentiated carcinomas, systemic delivery would likely expose virus particles to the basolateral surface of cancer cells rather than the apical surface encountered during natural infection. Here, we compare the ability of EnAd and adenovirus type-5 (Ad5) to infect polarised colorectal carcinoma cells from the apical or basolateral surfaces. Whereas Ad5 infection was more efficient via the apical than basolateral surface, EnAd readily infected cells from either surface. Progeny particles from EnAd were released preferentially via the apical surface for all cell lines and routes of infection. These data further support the utility of group B adenoviruses for systemic delivery and suggest that progeny virus are more likely to be released into the tumour rather than back through the basolateral surface into the blood stream.
    Matched MeSH terms: Microscopy, Electron, Transmission
  10. Tan WS
    J Gen Appl Microbiol, 2002 Apr;48(2):103-7.
    PMID: 12469306
    The long surface antigen (L-HBsAg) of hepatitis B virus (HBV) plays a central role in the production of infectious virions. During HBV morphogenesis, both the PreS and S domains of L-HBsAg form docking sites for the viral nucleocapsids. Thus, a compound that disrupts the interaction between the L-HBsAg and nucleocapsids could serve as a therapeutic agent against the virus based upon inhibition of morphogenesis. Synthetic peptides correspond to the binding sites in L-HBsAg inhibited the association of L-HBsAg with core antigen (HBcAg). A synthetic peptide carrying the epitope for a monoclonal antibody to the PreS1 domain competed weakly with L-HBsAg for HBcAg, but peptides corresponding to a linear sequence at the tip of the nucleocapsid spike did not, showing that the competing peptide does not resemble the tip of the spike.
    Matched MeSH terms: Microscopy, Electron
  11. Hassani A, Mahmood S, Enezei HH, Hussain SA, Hamad HA, Aldoghachi AF, et al.
    Molecules, 2020 May 10;25(9).
    PMID: 32397633 DOI: 10.3390/molecules25092244
    The approach of drug delivery systems emphasizes the use of nanoparticles as a vehicle, offering the optional property of delivering drugs as a single dose rather than in multiple doses. The current study aims to improve antioxidant and drug release properties of curcumin loaded gum Arabic-sodium alginate nanoparticles (Cur/ALG-GANPs). The Cur/ALG-GANPs were prepared using the ionotropic gelation technique and further subjected to physico-chemical characterization using attenuated total reflectance-Fourier transform infrared (ATR-FTIR), X-ray diffractometry (XRD), differential scanning calorimetry (DSC), size distribution, and transmission electron microscopy (TEM). The size of Cur/ALG-GANPs ranged between 10 ± 0.3 nm and 190 ± 0.1 nm and the zeta potential was -15 ± 0.2 mV. The antioxidant study of Cur/ALG-GANPs exhibited effective radical scavenging capacity for 1,1-diphenyl-2-picrylhydrazyl (DPPH) at concentrations that ranged between 30 and 500µg/mL. Cytotoxicity was performed using MTT assay to measure their potential in inhibiting the cell growth and the result demonstrated a significant anticancer activity of Cur/ALG-GANPs against human liver cancer cells (HepG2) than in colon cancer (HT29), lung cancer (A549) and breast cancer (MCF7) cells. Thus, this study indicates that Cur/ALG-GANPs have promising anticancer properties that might aid in future cancer therapy.
    Matched MeSH terms: Microscopy, Electron, Transmission
  12. Jensen K, Guyer R
    J Parasitol, 2021 01 01;107(1):1-15.
    PMID: 33429430 DOI: 10.1645/19-167
    The lecanicephalidean cestodes parasitizing the spiral intestine of the endangered giant freshwater whipray, Urogymnus polylepis (Bleeker), are investigated for the first time. Eight host specimens were collected between 2002 and 2008 at 2 collecting sites off the eastern coast of Borneo: 6 from the Kinabatangan River (Malaysia) and 2 from a fish market in Tarakan (Indonesia). Two of these individuals were found to be infected with a total of 3 new species of TetragonocephalumShipley and Hornell, 1905. Tetragonocephalum georgei n. sp. and Tetragonocephalum opimum n. sp. were recovered from a host specimen from the Kinabatangan River, and Tetragonocephalum levicorpum n. sp. was found parasitizing a host specimen purchased at a fish market in Tarakan. Specimens of each of the new species were prepared for light microscopy; specimens of 2 of the new species were prepared for scanning electron microscopy, and histological sections were prepared for 1 of the new species. The 3 new species are distinct from the 9 valid species of Tetragonocephalum and the 1 species inquirendum based on, for example, total length, number of proglottids and testes, and size of the scolex and acetabula. Tetragonocephalum georgei n. sp. and T. levicorpum n. sp. are unusual among their congeners in that they are euapolytic (i.e., gravid proglottids were not observed) rather than apolytic. They differ from one another in scolex and acetabula size. Tetragonocephalum opimum n. sp. is unusual among its congeners in its possession of vitelline follicles arranged in 2, rather than 3, regions in the proglottid. These new species increase the total number of valid species of Tetragonocephalum to 12 and the total number of known cestodes from U. polylepis to 13 species across 6 genera in 4 orders. This is the first account of lecanicephalideans reported from freshwater. The taxonomic status of each of the 32 nominal taxa historically associated with Tetragonocephalum is re-assessed. Type host identities of all valid species are revised and discussed in light of recent taxonomic efforts in the Dasyatidae Jordan and Gilbert.
    Matched MeSH terms: Microscopy, Electron, Scanning
  13. Gull N, Khan SM, Butt OM, Islam A, Shah A, Jabeen S, et al.
    Int J Biol Macromol, 2020 Nov 01;162:175-187.
    PMID: 32562726 DOI: 10.1016/j.ijbiomac.2020.06.133
    Inflammation is a key challenge in the treatment of chronic diseases. Spurred by topical advancement in polymer chemistry and drug delivery, hydrogels that release a drug in temporal, spatial and dosage controlled fashion have been trendy. This research focused on the fabrication of hydrogels with controlled drug release properties to control inflammation. Chitosan and polyvinyl pyrrolidone were used as base polymers and crosslinked with epichlorohydrin to form hydrogel films by solution casting technique. Prepared hydrogels were analyzed by swelling analysis in deionized water, buffer and electrolyte solutions and gel fraction. Functional groups confirmation and development of new covalent and hydrogen bonds, thermal stability (28.49%) and crystallinity were evaluated by FTIR, TGA and WAXRD, respectively. Rheological properties including gel strength and yield stress, elasticity (2309 MPa), porosity (75%) and hydrophilicity (73°) of prepared hydrogels were also evaluated. In vitro studies confirmed that prepared hydrogels have good biodegradability, excellent antimicrobial property and admirable cytotoxicity. Drug release profile (87.56% in 130 min) along with the drug encapsulation efficiency (84%) of prepared hydrogels was also studied. These results paved the path towards the development of hydrogels that can release the drugs with desired temporal patterns.
    Matched MeSH terms: Microscopy, Electron, Scanning
  14. Shahzad H, Giribabu N, Karim K, Kassim N, Muniandy S, Kumar KE, et al.
    Reprod Toxicol, 2017 08;71:42-54.
    PMID: 28431985 DOI: 10.1016/j.reprotox.2017.04.004
    HYPOTHESIS: Quercetin could induce changes to the fluid volume and receptivity development of the uterus during peri-implantation period.

    METHODS: Female rats were treated with quercetin (10, 25 and 50mg/kg/day) subcutaneously beginning from day-1 pregnancy. Uterus was harvested at day-4 (following three days quercetin treatment) for morphological, ultra-structural, protein and mRNA expressional changes and plasma sex-steroid levels analyses. In another cohort of rats, implantation rate was determined at day-6 (following five days quercetin treatment).

    RESULTS: Administration of 50mg/kg/day quercetin causes increased in uterine fluid volume and CFTR expression but decreased in γ-ENaC, AQP-5, AQP-9 claudin-4, occludin, E-cadherin, integrin αnβЗ, FGF, Ihh and Msx-1expression in the uterus. Pinopodes were poorly develop, tight junctions appear less complex and implantation rate decreased. Serum estradiol levels increased but serum progesterone levels decreased.

    CONCLUSIONS: Interference in the fluid volume and receptivity development of the uterus during peri-implantation period by quercetin could adversely affect embryo implantation.

    Matched MeSH terms: Microscopy, Electron, Transmission
  15. Jeevanandam J, Chan YS, Danquah MK, Law MC
    Appl Biochem Biotechnol, 2020 Apr;190(4):1385-1410.
    PMID: 31776944 DOI: 10.1007/s12010-019-03166-z
    Insulin resistance is one of the major factors that leads to type 2 diabetes. Although insulin therapies have been shown to overcome insulin resistance, overweight and hypoglycemia are still observed in most cases. The disadvantages of insulin therapies have driven the interest in developing novel curative agents with enhanced insulin resistance reversibility. Magnesium deficiency has also been recognized as a common problem which leads to insulin resistance in both type 1 and 2 diabetes. Oxide nanoparticles demonstrate highly tunable physicochemical properties that can be exploited by engineers to develop unique oxide nanoparticles for tailored applications. Magnesium supplements for diabetic cells have been reported to increase the insulin resistance reversibility. Hence, it is hypothesized that magnesium oxide (MgO) nanoparticles could be molecularly engineered to offer enhanced therapeutic efficacy in reversing insulin resistance. In the present work, morphologically different MgO nanoparticles were synthesized and evaluated for biophysical characteristics, biocompatibility, cytotoxicity, and insulin resistance reversibility. MTT assay revealed that hexagonally shaped MgO nanoparticles are less toxic to 3T3-L1 adipose cells (diabetic) compared with spherically and rod-shaped MgO nanoparticles. MTT assays using VERO cells (normal, non-diabetic) showed that 400 μg/ml of hexagonal MgO nanoparticles were less toxic to both diabetic and non-diabetic cells. DNS glucose assay and western blot showed that hexagonally shaped MgO nanoparticles had reversed 29.5% of insulin resistance whilst fluorescence microscopy studies indicated that the insulin resistance reversal is due to the activation of intracellular enzymes. The probable mechanism for MgO nanoparticles to induce cytotoxic effect and insulin resistance reversal is discussed.
    Matched MeSH terms: Microscopy, Electron, Transmission
  16. Lau SE, Schwarzacher T, Othman RY, Harikrishna JA
    BMC Plant Biol, 2015;15:194.
    PMID: 26260631 DOI: 10.1186/s12870-015-0577-3
    The R2R3-MYB genes regulate pigmentation and morphogenesis of flowers, including flower and cell shape, and therefore have importance in the development of new varieties of orchids. However, new variety development is limited by the long breeding time required in orchids. In this study, we identified a cDNA, DhMYB1, that is expressed during flower development in a hybrid orchid, Dendrobium hybrida (Dendrobium bobby messina X Dendrobium chao phraya) then used the direct application of dsRNA to observe the effect of gene silencing on flower phenotype and floral epidermal cell shape.
    Matched MeSH terms: Microscopy, Electron, Scanning
  17. Ravindran R, Jaganathan R, Periandavan K
    Cell Biochem Funct, 2020 Apr;38(3):309-318.
    PMID: 31926118 DOI: 10.1002/cbf.3490
    The aim is to test the hypothesis whether the cholesterol loaded lysosomes are capable of mediating lysosomal membrane permeabilization (LMP) during aging and to study the efficacy of epigallocatechin-3-gallate (EGCG) in preserving the lysosomal membrane stability. Aged rats were fed with high cholesterol diet (HCD) and treated with EGCG orally. Serum and tissue lipid status, cholesterol levels in lysosomal fraction, activities of lysosomal enzymes in lysosomal, and cytosolic fractions were measured. Transmission electron microscopic studies (TEM), oil red "O" (ORO) staining, and immunohistochemical analysis of oxidized low density lipoprotein (OxLDL) were carried out. Significant increase in serum, tissue lipid profile, and lysosomal cholesterol levels were observed in aged HCD-fed rats with a concomitant decrease in high density lipoprotein (HDL) levels. We also observed a significant increase in lipid accumulation in hepatocytes of aged HCD-fed rats by TEM, ORO, and immunohistochemical staining. Upon treatment with EGCG to aged HCD-fed animals, we found augmented levels of HDL with a concomitant decrease in lysosomal cholesterol levels and other lipoproteins. TEM studies and immunohistochemistry of OxLDL also showed a marked reduction in lipid deposition of hepatocytes. Thus, EGCG has preserved the lysosomal membrane stability in HCD stressed aged rats. SIGNIFICANCE OF THE STUDY: The research article is focused mainly on the effect of EGCG and its capability on mitigating the release of lysosomal enzymes in aged animals fed with HCD. The study signifies the cellular function of the organelle lysosome following administration of aged rats with HCD, which would make the readers to understand the action of EGCG and the interrelationship of both cholesterol and activity of lysosomes when cholesterol is loaded.
    Matched MeSH terms: Microscopy, Electron, Transmission
  18. Tan MS, Moore SC, Tabor RF, Fegan N, Rahman S, Dykes GA
    BMC Microbiol, 2016 09 15;16:212.
    PMID: 27629769 DOI: 10.1186/s12866-016-0832-2
    BACKGROUND: Processing of fresh produce exposes cut surfaces of plant cell walls that then become vulnerable to human foodborne pathogen attachment and contamination, particularly by Salmonella enterica. Plant cell walls are mainly composed of the polysaccharides cellulose, pectin and hemicelluloses (predominantly xyloglucan). Our previous work used bacterial cellulose-based plant cell wall models to study the interaction between Salmonella and the various plant cell wall components. We demonstrated that Salmonella attachment was favoured in the presence of pectin while xyloglucan had no effect on its attachment. Xyloglucan significantly increased the attachment of Salmonella cells to the plant cell wall model only when it was in association with pectin. In this study, we investigate whether the plant cell wall polysaccharides mediate Salmonella attachment to the bacterial cellulose-based plant cell wall models through specific carbohydrate interactions or through the effects of carbohydrates on the physical characteristics of the attachment surface.

    RESULTS: We found that none of the monosaccharides that make up the plant cell wall polysaccharides specifically inhibit Salmonella attachment to the bacterial cellulose-based plant cell wall models. Confocal laser scanning microscopy showed that Salmonella cells can penetrate and attach within the tightly arranged bacterial cellulose network. Analysis of images obtained from atomic force microscopy revealed that the bacterial cellulose-pectin-xyloglucan composite with 0.3 % (w/v) xyloglucan, previously shown to have the highest number of Salmonella cells attached to it, had significantly thicker cellulose fibrils compared to other composites. Scanning electron microscopy images also showed that the bacterial cellulose and bacterial cellulose-xyloglucan composites were more porous when compared to the other composites containing pectin.

    CONCLUSIONS: Our study found that the attachment of Salmonella cells to cut plant cell walls was not mediated by specific carbohydrate interactions. This suggests that the attachment of Salmonella strains to the plant cell wall models were more dependent on the structural characteristics of the attachment surface. Pectin reduces the porosity and space between cellulose fibrils, which then forms a matrix that is able to retain Salmonella cells within the bacterial cellulose network. When present with pectin, xyloglucan provides a greater surface for Salmonella cells to attach through the thickening of cellulose fibrils.

    Matched MeSH terms: Microscopy, Electron, Scanning
  19. Hussein MZ, Mohd Amin JB, Zainal Z, Yahaya AH
    J Nanosci Nanotechnol, 2002 Apr;2(2):143-6.
    PMID: 12908300
    Hydrotalcite-like inorganic layers of Zn-Al, a host containing an organic moiety, 2,4-dichlorophenoxy-acetate, as a guest, was prepared by the spontaneous self-assembly method from an aqueous solution for the formation of a new layered organic-inorganic hybrid nanocomposite material. In this synthesis, the host- and guest-forming species were simultaneously included in the mother liquor, aged, and separated. Various Zn/Al ratios (R = 2, 3, and 4), concentrations of 2,4-dichlorophenoxyacetic acid (0.03-0.1 M), and pH (7 and 10) were studied to optimize the formation of the layered nancomposite. It was found that the optimum conditions for the formation of the nanocomposite were R = 4, pH 7, and concentration of 2,4-dichlorophenoxyacetic acid = 0.08 M. X-ray diffraction shows that this sample affords a nanolayered structure with a basal spacing of 24.6 A.
    Matched MeSH terms: Microscopy, Electron, Scanning
  20. Rosli N, Sumathy V, Vikneswaran M, Sreeramanan S
    Trop Biomed, 2014 Dec;31(4):871-9.
    PMID: 25776614 MyJurnal
    Hymenocallis littoralis (Jacq.) Salisb (Melong kecil) commonly known as 'Spider Lily' is an herbaceous plant from the family Amaryllidaceae. Study was carried out to determine the effect of H. littoralis leaf extract on the growth and morphogenesis of two pathogenic microbes, Candida albicans and Escherichia coli. The leaf extract displayed favourable anticandidal and antibacterial activity with a minimum inhibition concentration (MIC) of 6.25 mg/mL. Time kill study showed both microbes were completely killed after treated with leaf extract at 20 h. Both microbes' cell walls were heavily ruptured based on scanning electron microscopy (SEM) analysis. The significant anticandidal and antibacterial activities showed by H. littoralis leaf extract suggested the potential antimicrobial agent against C. albicans and E. coli.
    Matched MeSH terms: Microscopy, Electron, Scanning
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links