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2.
Intern Med J ; 53(1): 27-36, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36269315

RESUMEN

BACKGROUND AND AIMS: A relationship between diabetes, glucose and COVID-19 outcomes has been reported in international cohorts. This study aimed to assess the relationship between diabetes, hyperglycaemia and patient outcomes in those hospitalised with COVID-19 during the first year of the Victorian pandemic prior to novel variants and vaccinations. DESIGN, SETTING: Retrospective cohort study from March to November 2020 across five public health services in Melbourne, Australia. PARTICIPANTS: All consecutive adult patients admitted to acute wards of participating institutions during the study period with a diagnosis of COVID-19, comprising a large proportion of patients from residential care facilities and following dexamethasone becoming standard-of-care. Admissions in patients without known diabetes and without inpatient glucose testing were excluded. RESULTS: The DINGO COVID-19 cohort comprised 840 admissions. In 438 admissions (52%), there was no known diabetes or in-hospital hyperglycaemia, in 298 (35%) patients had known diabetes, and in 104 (12%) patients had hyperglycaemia without known diabetes. ICU admission was more common in those with diabetes (20%) and hyperglycaemia without diabetes (49%) than those with neither (11%, P < 0.001 for all comparisons). Mortality was higher in those with diabetes (24%) than those without diabetes or hyperglycaemia (16%, P = 0.02) but no difference between those with in-hospital hyperglycaemia and either of the other groups. On multivariable analysis, hyperglycaemia was associated with increased ICU admission (adjusted odds ratio (aOR) 6.7, 95% confidence interval (95% CI) 4.0-12, P < 0.001) and longer length of stay (aOR 173, 95% CI 11-2793, P < 0.001), while diabetes was associated with reduced ICU admission (aOR 0.55, 95% CI 0.33-0.94, P = 0.03). Neither diabetes nor hyperglycaemia was independently associated with in-hospital mortality. CONCLUSIONS: During the first year of the COVID-19 pandemic, in-hospital hyperglycaemia and known diabetes were not associated with in-hospital mortality, contrasting with published international experiences. This likely mainly relates to hyperglycaemia indicating receipt of mortality-reducing dexamethasone therapy. These differences in published experiences underscore the importance of understanding population and clinical treatment factors affecting glycaemia and COVID-19 morbidity within both local and global contexts.


Asunto(s)
COVID-19 , Diabetes Mellitus , Hiperglucemia , Adulto , Humanos , Glucosa , Pandemias , COVID-19/epidemiología , Estudios Retrospectivos , Diabetes Mellitus/epidemiología , Hiperglucemia/epidemiología , Hospitales , Mortalidad Hospitalaria , Dexametasona/uso terapéutico , Unidades de Cuidados Intensivos
3.
ACS Appl Mater Interfaces ; 14(45): 50773-50782, 2022 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-36318084

RESUMEN

Electrochemical ion storage behaviors of Fe3O4 nanoparticles, as a representative transition metal oxide for an environmentally benign and low-cost anode for a sodium-ion battery, are thoroughly investigated through a combination of electrochemical analysis and diagnostics of Fe3O4 electrode cells, X-ray-based and spectroscopic analysis of material structure evolution as functions of depth of discharge (DoD) and state of charge (SoC), and first principle modeling. The gravimetric capacity is found to be 50 mA h/g for bulk Fe3O4 (50 nm average crystallite size) and 100 mA h/g─about a tenth of the theoretical prediction for complete conversion─for Fe3O4 nanoparticles (8.7 nm average particle size), respectively. A fundamental and mechanistic study of material evolution as functions of DoD and SoC shows that Fe3O4 does not allow electrochemical incorporation of Na+ ions into the empty cation positions of the inverse spinel structure, leading to our assertion that electrochemical intercalation of Na+ ions to conversion of the Fe3O4 anode in sodium-ion batteries is nonviable. A density functional theory investigation points to the impracticality of the intercalation of Na+ ions into Fe3O4 and further validates our experimental findings. We propose several possible mechanisms corresponding to the observed low capacity, including formation of solid electrolyte interphases with unfavorable properties and adsorption of Na+ ions onto surfaces of nanoparticles and/or at heterointerfaces in Fe3O4 composite electrodes in a NaPF6-based electrolyte system.

4.
Nanomaterials (Basel) ; 12(6)2022 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-35335743

RESUMEN

As a contribution to the graphene-based nanoferrite composites, this article is intended to present Mn, Co, and Co-Mn nanoferrites for the preparation and investigation of such samples. Nanoparticles of Co ferrite, Mn ferrite, and Co-Mn ferrite were chemically synthesized by the coprecipitation method. The composites of ferrite/graphene were made by incorporating weight ratios of 25% graphene to 75% ferrite. Various structural and characterizing investigations of ferrite samples and ferrite/graphene composites were performed, including XRD, EDX, SEM, VSM hysteresis loops, AC conductivity, and dielectric behavior. The investigations ensured the formation of the intended nanoferrite powders, each having a single-phase crystal structure with no undesired phases or elements. All samples exhibit a soft magnetic behavior. They show a semiconducting behavior of AC electrical conductivity as well. This was proved by the temperature dependence of the AC's electrical conductivity. Whereas the dielectric function and loss tangent show an expected, well-explained behavior, the ferrite/graphene composite samples have lower saturation magnetization values, lower AC conductivity, and dielectric constant values than the pure ferrites but still have the same behavior trends as those of the pure ferrites. The values obtained may represent steps on developing new materials for expected applications, such as manufacturing supercapacitors and/or improved battery electrodes.

5.
Materials (Basel) ; 14(23)2021 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-34885360

RESUMEN

A new type of nano-adsorbent zinc-silver nanoparticles ornamented by multi-walled carbon nanotubes (Zn-Ag MWCNT) was efficiently synthesized by double arc discharge using a newly designed rotating cylinder electrode. Zn-Ag MWCNT was characterized by different instrumental methods to get information about the sample shape, size, and crystallinity. Without irradiation, Zn-Ag MWCNT indicated significant potential for elimination against methylene blue (MB) which is dissolved in deionized water. When the adsorbent concentration was 0.1 g/L at normal 8 pH, the Zn-Ag MWCNTs were efficient in removing 97% of the MB from 40 mg/L that was dissolved in water for 10 min. The dye removal activity of (Zn-Ag) decorated MWCNTs was attributed to the influence of silver and zinc nanoparticles on the MWCNTs. Finally, this approach was both cost-effective and efficient.

6.
Bioengineering (Basel) ; 7(2)2020 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-32486381

RESUMEN

DNA sequencing is a critical functionality in biomedical research, and technical advances that improve it have important implications for human health. Novel methods by which sequencing can be accomplished in more accurate, high-throughput, and faster ways are in development. Here, we review VLSI biosensors for nucleotide detection and DNA sequencing. Implementation strategies are discussed and split into function-specific architectures that are presented for reported design examples from the literature. Lastly, we briefly introduce a new approach to sequencing using Gate All-Around (GAA) nanowire Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) that has significant implications for the field.

7.
Nanotechnology ; 29(7): 075403, 2018 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-29244653

RESUMEN

Cobalt nanoparticle thin films were electrophoretically deposited on copper current collectors and were annealed into thin films of hollow Co3O4 nanoparticles. These thin films were directly used as the anodes of lithium ion batteries (LIBs) without the addition of conducting carbons and bonding agents. LIBs thus fabricated show high gravimetric capacities and long cycle lives. For ≈1.0 µm thick Co3O4 nanoparticle films the gravimetric capacities of the batteries were more than 800 mAh g-1 at a current rate of C/15, which is about 90% of the theoretical maximum. Additionally, the batteries were able to undergo 200 charge/discharge cycles at a relatively fast rate of C/5 and maintain 50% of the initial capacity. In order to understand the electrochemistry of lithiation in the context of nanoparticles, Raman spectra were collected at different stages of the electrode cycles to determine the chemical and structural changes in the nanomaterials. Our results indicate that initially the electrode nanoparticles were under significant strain and as the battery underwent many cycles of charging/discharging the nanoparticles experienced progressive strain relaxation.

8.
Front Microbiol ; 8: 2120, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29180984

RESUMEN

Multidrug-resistant Escherichia coli infections are a growing public health concern. This study analyzed the possibility of contamination of commercial poultry meat (broiler and free-range) with pathogenic and or multi-resistant E. coli in retail chain poultry meat markets in India. We analyzed 168 E. coli isolates from broiler and free-range retail poultry (meat/ceca) sampled over a wide geographical area, for their antimicrobial sensitivity, phylogenetic groupings, virulence determinants, extended-spectrum-ß-lactamase (ESBL) genotypes, fingerprinting by Enterobacterial Repetitive Intergenic Consensus (ERIC) PCR and genetic relatedness to human pathogenic E. coli using whole genome sequencing (WGS). The prevalence rates of ESBL producing E. coli among broiler chicken were: meat 46%; ceca 40%. Whereas, those for free range chicken were: meat 15%; ceca 30%. E. coli from broiler and free-range chicken exhibited varied prevalence rates for multi-drug resistance (meat 68%; ceca 64% and meat 8%; ceca 26%, respectively) and extraintestinal pathogenic E. coli (ExPEC) contamination (5 and 0%, respectively). WGS analysis confirmed two globally emergent human pathogenic lineages of E. coli, namely the ST131 (H30-Rx subclone) and ST117 among our poultry E. coli isolates. These results suggest that commercial poultry meat is not only an indirect public health risk by being a possible carrier of non-pathogenic multi-drug resistant (MDR)-E. coli, but could as well be the carrier of human E. coli pathotypes. Further, the free-range chicken appears to carry low risk of contamination with antimicrobial resistant and extraintestinal pathogenic E. coli (ExPEC). Overall, these observations reinforce the understanding that poultry meat in the retail chain could possibly be contaminated by MDR and/or pathogenic E. coli.

9.
Innate Immun ; 22(8): 682-695, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27688705

RESUMEN

Pulmonary alveolar macrophages (AMs) are important in defense against bacterial lung inflammation. Cluster of differentiation 14 (CD14) is involved in recognizing bacterial lipopolysaccharide (LPS) through MyD88-dependent and TRIF pathways of innate immunity. Sulforaphane (SFN) shows anti-inflammatory activity and suppresses DNA methylation. To identify CD14 epigenetic changes by SFN in the LPS-induced TRIF pathway, an AMs model was investigated in vitro. CD14 gene expression was induced by 5 µg/ml LPS at the time point of 12 h and suppressed by 5 µM SFN. After 12 h of LPS stimulation, gene expression was significantly up-regulated, including TRIF, TRAF6, NF-κB, TRAF3, IRF7, TNF-α, IL-1ß, IL-6, and IFN-ß. LPS-induced TRAM, TRIF, RIPK1, TRAF3, TNF-α, IL-1ß and IFN-ß were suppressed by 5 µM SFN. Similarly, DNMT3a expression was increased by LPS but significantly down-regulated by 5 µM SFN. It showed positive correlation of CD14 gene body methylation with in LPS-stimulated AMs, and this methylation status was inhibited by SFN. This study suggests that SFN suppresses CD14 activation in bacterial inflammation through epigenetic regulation of CD14 gene body methylation associated with DNMT3a. The results provide insights into SFN-mediated epigenetic down-regulation of CD14 in LPS-induced TRIF pathway inflammation and may lead to new methods for controlling LPS-induced inflammation in pigs.


Asunto(s)
Infecciones Bacterianas/inmunología , Epigénesis Genética/efectos de los fármacos , Isotiocianatos/farmacología , Receptores de Lipopolisacáridos/metabolismo , Macrófagos Alveolares/efectos de los fármacos , Neumonía/inmunología , Alveolos Pulmonares/patología , Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Animales , Células Cultivadas , Metilación de ADN , Inmunidad Innata , Lipopolisacáridos/inmunología , Macrófagos Alveolares/inmunología , Transducción de Señal/efectos de los fármacos , Sulfóxidos , Porcinos
10.
Nano Lett ; 16(1): 681-7, 2016 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-26675987

RESUMEN

We report intense, narrow line-width, surface chemisorption-activated and reversible ultraviolet (UV) photoluminescence from radiative recombination of the two-dimensional electron gas (2DEG) with photoexcited holes at LaAlO3/SrTiO3. The switchable luminescence arises from an electron transfer-driven modification of the electronic structure via H-chemisorption onto the AlO2-terminated surface of LaAlO3, at least 2 nm away from the interface. The control of the onset of emission and its intensity are functionalities that go beyond the luminescence of compound semiconductor quantum wells. Connections between reversible chemisorption, fast electron transfer, and quantum-well luminescence suggest a new model for surface chemically reconfigurable solid-state UV optoelectronics and molecular sensing.


Asunto(s)
Óxido de Aluminio/química , Técnicas Biosensibles , Electrones , Gases/química , Luminiscencia , Óxidos/química , Estroncio/química , Propiedades de Superficie , Titanio/química , Rayos Ultravioleta
11.
J Phys Condens Matter ; 27(15): 155401, 2015 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-25812551

RESUMEN

Raman scattering in thin film La0.2Sr0.8FeO3-δ on MgO(0 0 1) collected at 300 K after different stages of annealing at selected temperatures T (300 K < T < 543 K, to 10 h) and analysis reveal changes in spectral characteristics due to a loss of oxygen, onset of oxygen vacancy-induced disorder, and activation of Raman-inactive modes that are attributed to symmetry lowering. The interpretation is further supported by carrier transport measurements under identical conditions showing orders of magnitude increase in the resistivity induced by oxygen loss. After prolonged annealing in air, evolution of the spectrum signals the appearance of a possible topotactic transformation of the crystal structure from that of the rhombohedral ABO3 perovskites to that of Brownmillerite-like structure consisting of octahedrally and tetrahedrally coordinated Fe atoms.

12.
Int Health ; 6(3): 225-31, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24938278

RESUMEN

BACKGROUND: BRAC (formerly Bangladesh Rural Advancement Committee), in collaboration with the National Tuberculosis Control Programme, provides one full-day training on TB to make informal allopathic providers knowledgeable for managing TB in rural Bangladesh. This study explored the knowledge and practices of the providers receiving the above training in the control and prevention of TB. METHODS: The study was conducted in 30 subdistricts, with 30 trained and 30 untrained providers randomly selected from each subdistrict. Approximately 3% (49/1800) did not provide complete information. Pre-tested structured and semi-structured questionnaires were used. RESULTS: TB was commonly perceived as a disease of only males (66.1%, 1157/1751). Only one-quarter knew about the bacterial cause of TB. Very few providers (2.1%, 36) had adequate knowledge regarding prevention of TB. They also lacked knowledge about TB treatment duration (71.6%, 1253), the meaning of DOTS (directly observed treatment, short course) (26.0%, 455) and multidrug resistance (20.6%, 360). Antibiotics (79.7%, 1396) and cough syrup (75.0%, 1313) were commonly prescribed by providers despite symptoms suggestive of TB. However, 70.2% (613) and 74.5% (650) of trained providers' knowledge and practice scores were equal to or more than the mean scores (≥6.97 and ≥6.6, respectively), whereas they were only 49.5% (435) and 64.2% (563), respectively, among untrained providers (p<0.0001). CONCLUSIONS: Misperception, lack of knowledge and irrational use of antibiotics are challenges that need to be addressed for controlling and preventing TB efficiently.


Asunto(s)
Terapias Complementarias , Conocimientos, Actitudes y Práctica en Salud , Personal de Salud/normas , Servicios de Salud Rural/organización & administración , Tuberculosis/prevención & control , Adulto , Bangladesh , Femenino , Personal de Salud/educación , Humanos , Masculino , Persona de Mediana Edad , Población Rural , Factores Socioeconómicos , Encuestas y Cuestionarios
13.
J Phys Condens Matter ; 25(17): 175902, 2013 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-23567868

RESUMEN

Nuclear site analysis methods are used to enumerate the normal modes of ABX3 perovskite polymorphs with octahedral rotations. We provide the modes of the 14 subgroups of the cubic aristotype describing the Glazer octahedral tilt patterns, which are obtained from rotations of the BX6 octahedra with different sense and amplitude about high-symmetry axes. We tabulate all normal modes of each tilt system and specify the contribution of each atomic species to the mode displacement pattern, elucidating the physical meaning of the symmetry unique modes. We have systematically generated 705 schematic atomic displacement patterns for the normal modes of all 15 (14 rotated + 1 unrotated) Glazer tilt systems. We show through some illustrative examples how to use these tables to identify the octahedral rotations, symmetric breathing, and first-order Jahn-Teller anti-symmetric breathing distortions of the BX6 octahedra, and the associated Raman selection rules. We anticipate that these tables and schematics will be useful in understanding the lattice dynamics of bulk perovskites and could serve as a reference point in elucidating the atomic origins of a wide range of physical properties of synthetic perovskite thin films and superlattices.

14.
Ars pharm ; 53(4): 21-27[4], oct.-dic. 2012. tab, graf
Artículo en Inglés | IBECS | ID: ibc-107845

RESUMEN

Objetivo: Unir atenolol, antagonista selectivo de los receptores beta1, y desloratadina, antagonista de los receptores H1, a albúmina sérica bovina. Método: El análisis de la unión se analizó mediante diálisis de equilibrio utilizando ranitidina y diazepam como sondas específicas para el sitio I y sitio II respectivamente. Resultados: Los resultados sugirieron dos conjuntos de constantes de asociación. Para el atenolol: constante de asociación con afinidad elevada (k1 = 5 x 10-5 M-1) con baja capacidad (n1 = 2) y constante de asociación con afinidad baja (k2 = 5 x 10-5 M-1) con alta capacidad (n2 = 5), mientras que para la desloratadina: constante de afinidad de asociación elevada (k1 = 45 x 10-5 M-1) con baja capacidad (n1 = 1,3) y constante de afinidad de asociación baja (k2= 5 x 10-5 M-1) con alta capacidad (n2 = 2,5), a un pH 7,4 y 27 °C. Tras la administración conjunta de atenolol y desloratadina en presencia o ausencia de ranitidina o diazepam, la desloratadina provocó la liberación del atenolol de su sitio de unión a la albúmina sérica bovina, provocando una disminución de la unión del atenolol a la albúmina sérica bovina. La fracción libre de atenolol incrementó del 84,1% al 99% y la concentración de la desloratadina de 0 x 10-5 M a 14 x 10-5 M. En presencia de diazepam como sonda específica para el sitio II, la desloratadina incrementó la fracción libre de atenolol del 0,45% to 14,3%. Conclusión: Los datos obtenidos indican la interacción de concentraciones elevadas de desloratadina a los sitios de unión de la albúmina sérica bovina modificando las propiedades farmacocinéticas del atenolol(AU)


Aims: The binding of atenolol a selective beta1 receptor antagonist and desloratadine, an H1 receptor antagonist, to bovine serum albumin. Methods: The analysis of binding was studied by equilibrium dialysis method (ED) using ranitidine and diazepam as site-1 and site-2 specific probe, respectively. Results: The study suggested two sets of association constants, for atenolol: high affinity association constant (k1 = 5 x 10-5 M-1) with low capacity (n1 = 2) and low affinity association constant (k2 = 2.5 x 10-5 M-1) with high capacity (n2 = 5), while for desloratadine: high affinity association constant (k1 = 45 x 10-5 M-1) with low capacity (n1 = 1.3) and low affinity association constant (k2 = 5 x 10-5 M-1) with high capacity (n2 = 2.5) at pH 7.4 and 27 ºC. During concurrent administration of atenolol and desloratadine in presence or absence of ranitidine or diazepam, desloratadine causes the release of atenolol from its binding site on BSA resulting reduced binding of atenolol to BSA. The increment in free fraction of atenolol was from 84.01% to 99 % upon the addition of increased concentration of only desloratadine at a concentration of 0 x 10-5 M to 14 x 10-5 M. In presence of diazepam as site-II specific probes, desloratadine further increases the free fraction of atenolol was from 0.45% to 14.3%. Conclusion: These data were indicative for the interaction of higher concentration of desloratadine at the binding sites on BSA changing the pharmacokinetics properties of atenolol (AU)


Asunto(s)
Atenolol/farmacología , Albúmina Sérica Bovina/farmacología , Loratadina/farmacología , Atenolol/administración & dosificación , Albúmina Sérica Bovina/administración & dosificación , Loratadina/administración & dosificación , Interacciones Farmacológicas
15.
Nano Lett ; 12(10): 5122-30, 2012 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-22963404

RESUMEN

In this work, we have developed a new fabrication method for nanoparticle (NP) assemblies for Li-ion battery electrodes that require no additional support or conductive materials such as polymeric binders or carbon black. By eliminating these additives, we are able to improve the battery capacity/weight ratio. The NP film is formed by using electrophoretic deposition (EPD) of colloidally synthesized, monodisperse cobalt NPs that are transformed through the nanoscale Kirkendall effect into hollow Co(3)O(4). EPD forms a network of NPs that are mechanically very robust and electrically connected, enabling them to act as the Li-ion battery anode. The morphology change through cycles indicates stable 5-10 nm NPs form after the first lithiation remained throughout the cycling process. This NP-film battery made without binders and conductive additives shows high gravimetric (>830 mAh/g) and volumetric capacities (>2100 mAh/cm(3)) even after 50 cycles. Because similar films made from drop-casting do not perform well under equal conditions, EPD is seen as the critical step to create good contacts between the particles and electrodes resulting in this significant improvement in battery electrode assembly. This is a promising system for colloidal nanoparticles and a template for investigating the mechanism of lithiation and delithiation of NPs.

16.
Foodborne Pathog Dis ; 7(11): 1381-5, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20704491

RESUMEN

The major objective of this study was to investigate the prevalence of Shiga toxin (Stx)-producing Escherichia coli (STEC) in different types of food samples and to compare their genetic relatedness with STEC strains previously isolated from animal sources in Bangladesh. We investigated a total of 213 food samples, including 90 raw meat samples collected from retail butcher shops, 20 raw milk samples from domestic cattle, and 103 fresh juice samples from street vendors in Dhaka city. We found that more than 68% (n = 62) of the raw meat samples were positive for the stx gene(s); 34% (n = 21) of buffalo meats and 66% (n = 41) of beef. Approximately 10% (n = 2) of the raw milk and 8% (n = 8) of the fresh juice samples were positive for stx. We isolated STEC O157 from seven meat samples (7.8%), of which two were from buffalo meats and five from beef; and no other STEC serotypes could be isolated. We could not isolate STEC from any of the stx-positive raw milk and juice samples. The STEC O157 isolates from raw meats were positive for the stx(2), eae, katP, etpD, and enterohemorrhagic E. coli hly virulence genes, and they belonged to three different phage types: 8 (14.3%), 31 (42.8%), and 32 (42.8%). Pulsed-field gel electrophoresis (PFGE) typing revealed six distinct patterns among seven isolates of STEC O157, suggesting a heterogeneous clonal diversity. Of the six PFGE patterns, one was identical and the other two were ≥90% related to PFGE patterns of STEC O157 strains previously isolated from animal feces, indicating that raw meats are readily contaminated with fecal materials. This study represents the first survey of STEC in the food chain in Bangladesh.


Asunto(s)
Bebidas/microbiología , Microbiología de Alimentos/métodos , Carne/microbiología , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Animales , Bangladesh , Búfalos , Bovinos , ADN Bacteriano/análisis , Electroforesis en Gel de Campo Pulsado , Escherichia coli O157/aislamiento & purificación , Heces/microbiología , Manipulación de Alimentos/métodos , Leche/microbiología , Reacción en Cadena de la Polimerasa , Serotipificación , Toxina Shiga/genética , Escherichia coli Shiga-Toxigénica/clasificación
17.
J Agric Food Chem ; 58(9): 5670-8, 2010 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-20373764

RESUMEN

The anticarcinogenic activity of a mixture of trans,trans-conjugated linoleic acid (trans,trans-CLA) was investigated in rat mammary tumorigenesis induced by N-methyl-N-nitrosourea (MNU), with references to cis-9,trans-11-CLA and trans-10,cis-12-CLA isomers. Female, 7-week-old Sprague-Dawley rats were intraperitoneally injected with MNU (50 mg/kg of body weight) and then subjected to one of five diets (control, 1% trans,trans-CLA, 1% cis-9,trans-11-CLA, 1% trans-10,cis-12-CLA, and 1% linoleic acid; 8 rats/group) for 16 weeks. Food and water were made available ad libitum. trans,trans-CLA significantly (p < 0.05) reduced tumor incidence, number, multiplicity, and size and significantly (p < 0.05) increased apoptosis, relative to cis-9,trans-11-CLA and trans-10,cis-12-CLA. The molecular mechanism of trans,trans-CLA was elucidated by measuring apoptosis-related gene products and fatty acid composition in tumors. trans,trans-CLA led to increases in the p53 protein and Bax protein levels but suppressed the expression of Bcl-2 protein. The activation of caspase-3 led to the cleavage of poly(ADP-ribose) polymerase, which resulted in the execution of apoptosis. In addition, trans,trans-CLA reduced cytosolic phospholipase A2, cyclooxygenease-2, and peroxisome proliferator-activated receptor gamma protein levels. These results suggest that the trans,trans-CLA inhibits MNU-induced rat mammary tumorigenesis through the induction of apoptosis in conjunction with the reduction of arachidonic acid metabolites and that the efficacy of trans,trans-CLA is superior to cis-9,trans-11-CLA and trans-10,cis-12-CLA.


Asunto(s)
Anticarcinógenos/farmacología , Carcinógenos/toxicidad , Ácidos Linoleicos Conjugados/farmacología , Neoplasias Mamarias Experimentales/inducido químicamente , Metilnitrosourea/toxicidad , Animales , Femenino , Ratas , Ratas Sprague-Dawley
18.
J Phys Condens Matter ; 21(28): 285301, 2009 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-21828514

RESUMEN

We applied a DC electric field between two flat electrodes to attract thermally charged maghemite (γ-Fe(2)O(3)) nanocrystalline quantum dots dissolved in hexane to form smooth, robust, large area and apparently identical films of equal thickness on both electrodes. Visible microscopy, scanning electron microscopy, atomic force microscopy and profilometry showed that the electrophoretically deposited dot films were very smooth with an rms roughness of ∼10 nm for ∼0.2 µm thick films. The films were of high quality. They did not re-dissolve in hexane (as do those formed by dry casting), which is a good solvent for these dots, or in common cleaning solvents such as water, alcohols and acetone. The deposition on both electrodes implies there are both positively and negatively thermally charged dots, unlike conventional electrophoretic deposition. We used simple thermodynamics to explain the results of electrophoretic deposition macroscopically. To connect the macroscopic nature of the deposition to the microscopic nature of the dots we performed electrophoretic mobility measurements of the dots and the results seem to complement the thermodynamic treatment.

19.
Appl Environ Microbiol ; 74(17): 5414-21, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18641151

RESUMEN

To determine the prevalence of Shiga toxin (Stx)-producing Escherichia coli (STEC) in slaughter animals in Dhaka, Bangladesh, we collected rectal contents immediately after animals were slaughtered. Of the samples collected from buffalo (n = 174), cows (n = 139), and goats (n = 110), 82.2%, 72.7%, and 11.8% tested positive for stx(1) and/or stx(2), respectively. STEC could be isolated from 37.9%, 20.1%, and 10.0% of the buffalo, cows, and goats, respectively. STEC O157 samples were isolated from 14.4% of the buffalo, 7.2% of the cows, and 9.1% of the goats. More than 93% (n = 42) of the STEC O157 isolates were positive for the stx(2), eae, katP, etpD, and enterohemorrhagic E. coli hly (hly(EHEC)) virulence genes. STEC O157 isolates were characterized by seven recognized phage types, of which types 14 (24.4%) and 31 (24.4%) were predominant. Subtyping of the 45 STEC O157 isolates by pulsed-field gel electrophoresis showed 37 distinct restriction patterns, suggesting a heterogeneous clonal diversity. In addition to STEC O157, 71 STEC non-O157 strains were isolated from 60 stx-positive samples from 23.6% of the buffalo, 12.9% of the cows, and 0.9% of the goats. The STEC non-O157 isolates belonged to 36 different O groups and 52 O:H serotypes. Unlike STEC O157, most of the STEC non-O157 isolates (78.9%) were positive for stx(1). Only 7.0% (n = 5) of the isolates were positive for hly(EHEC), and none was positive for eae, katP, and etpD. None of the isolates was positive for the iha, toxB, and efa1 putative adhesion genes. However, 35.2% (n = 25), 11.3% (n = 8), 12.7% (n = 9), and 12.7% (n = 9) of the isolates were positive for the lpf(O113), saa, lpfA(O157/01-141), and lpfA(O157/OI-154) genes, respectively. The results of this study provide the first evidence that slaughtered animals like buffalo, cows, and goats in Bangladesh are reservoirs for STEC, including the potentially virulent STEC strain O157.


Asunto(s)
Enfermedades de los Bovinos/epidemiología , Infecciones por Escherichia coli/epidemiología , Enfermedades de las Cabras/epidemiología , Escherichia coli Shiga-Toxigénica/genética , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Mataderos , Animales , Tipificación de Bacteriófagos , Bangladesh/epidemiología , Búfalos/microbiología , Bovinos/microbiología , Enfermedades de los Bovinos/microbiología , ADN Bacteriano/genética , Reservorios de Enfermedades/microbiología , Electroforesis en Gel de Campo Pulsado , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/veterinaria , Heces/microbiología , Microbiología de Alimentos , Genes Bacterianos , Enfermedades de las Cabras/microbiología , Cabras/microbiología , Carne/microbiología , Prevalencia , Serotipificación , Toxina Shiga I/genética , Toxina Shiga II/genética , Escherichia coli Shiga-Toxigénica/clasificación , Factores de Virulencia/genética
20.
J Agric Food Chem ; 56(14): 5970-6, 2008 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-18570428

RESUMEN

The growth inhibitory effect of a mixture of trans, trans conjugated linoleic acid isomers (t, t CLA) was investigated in a human breast cancer cell line, MCF-7, with references to c9, t11 CLA, t10, c12 CLA, and linoleic acid. The t, t CLA treatment effectively induced a cytotoxic effect in a time-dependent (0-6 days) and concentration-dependent (0-40 microM) manner, as compared to the reference and control treatments. The apoptotic parameters were measured on cells treated with 40 microM t, t CLA for 4 days. The occurrence of the characteristic morphological changes and DNA fragmentation confirmed apoptosis. The t, t CLA treatment led to an increase in the level of p53 tumor suppressor protein and Bax protein, but suppressed the expression of Bcl-2 protein. In addition, cytochrome c was released from the mitochondria into the cytosol, and the activation of caspase-3 led to the cleavage of poly(ADP-ribose) polymerase (PARP). Moreover, the composition of the linoleic and arachidonic acids was decreased in cellular membranes. These findings suggest that incorporation of t, t CLA in the membrane induces a mitochondria-mediated apoptosis that can enhance the antiproliferative effect of t, t CLA in MCF-7 cells.


Asunto(s)
Apoptosis/efectos de los fármacos , Ácidos Linoleicos Conjugados/farmacología , Proteínas Proto-Oncogénicas c-bcl-2/análisis , Proteína X Asociada a bcl-2/análisis , Neoplasias de la Mama , Línea Celular Tumoral , Citocromos c/metabolismo , Fragmentación del ADN , Humanos , Mitocondrias/metabolismo
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