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1.
Sociol Ruralis ; 64(2): 180-201, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38680761

RESUMEN

This paper focuses on the relationships between people and farmed nonhuman animals, and between these animals and the farmed environments they encounter, in the enactment of interspecies endemic disease situations. It examines how the nonhuman embodied capacities, agency and subjectivities of cows and sheep on farms in the north of England make a difference to how the endemic conditions of lameness and bovine viral diarrhoea (BVD) are encountered and responded to by farmers and advisers. The paper draws on empirical research with farmers and their advisers, and explores three key, inter-related, themes: first, the importance of intersubjective relationships between people and animals on farms; second, the nonhuman components of the 'disease situations' associated with endemic diseases, including animals' embodied characteristics and behaviours and the relationships between bodies and environments on different farms; and finally the ways in which animal agency and resistance makes a difference to on-farm interventions aiming to prevent or treat lameness and BVD. The paper concludes by arguing that animals' capacities, and nonhuman difference, should be taken further into account in future policy and practice interventions in endemic disease in farmed animals.

2.
Behav Brain Res ; 356: 221-226, 2019 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-30153465

RESUMEN

Despite considerable attention, the mechanisms by which the microbiota affect brain function and host behaviour via the gut-brain axis remain undefined. Identifying microbe-specific pathways that influence neuronal function and bi-directional communication between the gut microbiota and the host central nervous system is challenging due to the extreme microbial diversity in the gut of conventionally-reared mice. Herein, we describe the use of the altered Schaedler flora (ASF) mouse model as an alternative to conventionally-reared and germ-free animals. Colonized with only 8 bacterial species, use of ASF mice greatly simplifies the examination of microbiota-host interactions. We assessed the extent to which behaviour differed between mice with a limited consortium of bacteria compared with a complex, conventional microbiota. The elevated plus maze and open-field assays were utilized to assess murine behaviour. Histological analysis of ileum and colon was performed to evaluate intestinal morphology, and 16 s rRNA gene taxonomic profiling was performed to determine host-stress induced changes in fecal microbial communities. Behavioural and serum corticosterone differences were observed between ASF and conventionally-reared mice, while no differences were found between the intestinal morphology of these two groups. The stress of the behavioural tests induced significant changes in the ASF fecal microbial community but not in that of the conventionally-reared mice. In contrast to the conventionally-reared mice, the results indicated that the ASF mice displayed a marked anxiogenic-like behaviour. These data indicate that ASF mice represent a unique model to elucidate mechanisms governing microbiota-gut-brain communication affecting behaviour.


Asunto(s)
Bacterias/patogenicidad , Encéfalo/microbiología , Microbioma Gastrointestinal/fisiología , Intestinos/microbiología , Microbiota/fisiología , Animales , Encéfalo/metabolismo , Colon/microbiología , Modelos Animales de Enfermedad , Vida Libre de Gérmenes , Ratones
3.
Vet Pathol ; 49(3): 462-9, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22002976

RESUMEN

Six ovine fetal brains were harvested 33 to 35 days postchallenge from 5 ewes, each of which was given 3000 Toxoplasma gondii oocysts on day 90 of pregnancy. Histopathologic examination of transverse sections taken at 13 levels in the fetal brains revealed the presence of toxoplasmosis-related lesions in all 6 brains. However, lesions were not randomly distributed (P = .007); they were most numerous at the level of the optic tract, the rostral margin of the pons, and 4 mm caudal to the ansate sulcus and were absent in all sections at the level of the caudal cerebellum. Lesion distribution may be due to hemodynamic factors, differences in the expression of endothelial surface receptor molecules at the level of the blood-brain barrier, or the presence of localized permissive/inhibitory factors within the brain. The results have implications for the selection of areas of brain from aborted ovine fetuses to be examined histopathologically for laboratory diagnosis.


Asunto(s)
Encéfalo/patología , Encéfalo/parasitología , Transmisión Vertical de Enfermedad Infecciosa/veterinaria , Enfermedades de las Ovejas/parasitología , Toxoplasmosis Animal/transmisión , Animales , Ensayo de Inmunoadsorción Enzimática/veterinaria , Femenino , Técnicas Histológicas/veterinaria , Embarazo , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Ovinos , Enfermedades de las Ovejas/transmisión
4.
Vet Parasitol ; 185(2-4): 91-100, 2012 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-22088616

RESUMEN

Toxoplasma gondii, an intracellular protozoan parasite, is one of the major causes of infectious abortion in sheep. To further understand the pathogenesis of toxoplasmosis, serum, amniotic and allantoic fluids and foetal stomach contents were collected from experimentally infected pregnant ewes to determine pathogen numbers and other markers of infection. Fifteen pregnant ewes (90 days of gestation) were each orally inoculated with 3000 sporulated oocysts of T. gondii. Serum samples were collected weekly following challenge. Amniotic and allantoic fluids and foetal stomach contents were collected at 21, 25, 28, 33 and 35 days post-infection. Characteristic placental lesions were detected in 1 of 4 challenged ewes at day 25, 3 of 4 challenged ewes at day 28 and in all challenged ewes at days 33 and 35 post-infection. T. gondii was detected only sporadically in amniotic and allantoic fluids before 35 days of infection, by real-time PCR, and only in ewes with placental lesions. At 35 days post-infection, high numbers of parasite were detected in both amniotic and allantoic fluids. An increase in the number of fluids from challenged animals with IgM and IgG was detected over time, except for IgG in allantoic fluid, which was detected in all samples from day 21 post-infection. IgG in amniotic and allantoic fluids was shown to be specific for T. gondii, and reacted with antigens with an apparent molecular mass of approximately 22 kDa and 30 kDa. Results suggest a maternal source of immunoglobulin in the allantoic fluid and a foetal source of immunoglobulin in the amniotic fluid early in infection but that both sources may contribute immunoglobulin to both fluids at a later stage.


Asunto(s)
Líquido Amniótico/química , Anticuerpos Antiprotozoarios/inmunología , Antígenos de Protozoos/inmunología , Complicaciones Parasitarias del Embarazo/parasitología , Enfermedades de las Ovejas/parasitología , Toxoplasmosis Animal/parasitología , Alantoides , Animales , Anticuerpos Antiprotozoarios/sangre , Anticuerpos Antiprotozoarios/química , Antígenos de Protozoos/sangre , Antígenos de Protozoos/química , Chlorocebus aethiops , Femenino , Inmunoglobulina G/sangre , Inmunoglobulina G/química , Inmunoglobulina M/sangre , Inmunoglobulina M/química , Placenta/parasitología , Placenta/patología , Embarazo , Complicaciones Parasitarias del Embarazo/inmunología , Complicaciones Parasitarias del Embarazo/patología , Ovinos , Enfermedades de las Ovejas/inmunología , Toxoplasmosis Animal/inmunología , Toxoplasmosis Animal/patología , Células Vero
6.
J Reprod Immunol ; 90(2): 214-9, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21722966

RESUMEN

Pregnant ewes were challenged with Chlamydia abortus at 91-98 days of gestation and euthanised at 14, 21 and 28 days post-challenge. IFNγ mRNA labelling appeared to be co-localised with Chlamydial lipopolysaccharide within trophoblast cells in discrete areas lining the primary villi in the limbus and hilar zone of the placentomes from challenged sheep on days 21 and 28 post-infection. The presence of IFNγ was also demonstrated by immunohistochemistry. No labelling was seen in tissues from the non-infected ewes. The presence of IFNγ in trophoblast cells from infected ewes may indicate an attempt to restrict the replication of the organism and be an important trigger for the inflammatory responses that develop on the fetal side of the placenta in enzootic abortion.


Asunto(s)
Infecciones por Chlamydophila/metabolismo , Chlamydophila , Interferón gamma/biosíntesis , Trofoblastos/metabolismo , Aborto Séptico/inmunología , Aborto Séptico/metabolismo , Aborto Séptico/microbiología , Aborto Séptico/veterinaria , Animales , Infecciones por Chlamydophila/inmunología , Infecciones por Chlamydophila/microbiología , Femenino , Interferón gamma/inmunología , Embarazo , ARN Mensajero/biosíntesis , ARN Mensajero/inmunología , Ovinos , Enfermedades de las Ovejas/inmunología , Enfermedades de las Ovejas/microbiología , Trofoblastos/inmunología , Trofoblastos/microbiología
7.
Cell Cycle ; 10(6): 963-70, 2011 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-21368575

RESUMEN

BACKGROUND: PHA-793887 is an inhibitor of multiple cyclin dependent kinases (CDK) with activity against CDK2, CDK1 and CDK4. The primary objectives of this first in man study were to determine the dose limiting toxicities (DLTs), maximum tolerated dose (MTD) and recommended phase II dose of PHA-793887. RESULTS: Although toxicity was acceptable at initial dose levels, PHA-793887 was poorly tolerated at doses ≥44 mg/m2. The most frequent events across all dose levels were gastrointestinal or nervous system events. DLTs were experienced by two of three patients at the dose level of 66 mg/m2, and by three of nine patients at the dose level of 44 mg/m2. In all but one patient the DLT was hepatotoxicity; fatal hepatorenal failure was seen in one patient treated at the 44 mg/ m2 dose level. There were no objective responses, but disease stabilization was observed in five patients. Over the dose range investigated, pharmacokinetic studies showed that systemic exposure to PHA-793887 increased with the dose and was time-independent. The study terminated after the enrolment of 19 patients due to the severe hepatic toxicity. PATIENTS AND METHODS: Cohorts of three to six patients were treated at doses of 11, 22, 44 and 66 mg/m2 of PHA-793887 administered as 1-hour intravenous infusion on days 1, 8 and 15 in a 4-week cycle. Safety and pharmacokinetics were investigated. CONCLUSION: PHA-793887 induces severe, dose-related hepatic toxicity, which was not predicted by pre-clinical models and currently precludes its further clinical development.


Asunto(s)
Antineoplásicos/efectos adversos , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Neoplasias/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/efectos adversos , Pirazoles/efectos adversos , Pirroles/efectos adversos , Adulto , Anciano , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapéutico , Proteína Quinasa CDC2/antagonistas & inhibidores , Proteína Quinasa CDC2/metabolismo , Estudios de Cohortes , Quinasa 2 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 2 Dependiente de la Ciclina/metabolismo , Quinasa 4 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 4 Dependiente de la Ciclina/metabolismo , Quinasas Ciclina-Dependientes/metabolismo , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Inhibidores de Proteínas Quinasas/farmacocinética , Inhibidores de Proteínas Quinasas/uso terapéutico , Pirazoles/farmacocinética , Pirazoles/uso terapéutico , Pirroles/farmacocinética , Pirroles/uso terapéutico
8.
Genetica ; 139(11-12): 1383-98, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22403009

RESUMEN

An association analysis on the genetic variability for silica concentration in rice hulls was performed using a "Mini-Core" set of 174 accessions representative of the germplasm diversity found in the USDA world collection of rice. Hull silica concentration was determined in replicated trials conducted in two southern states in the USA and was analyzed for its association with 164 genome-wide DNA markers. Among the accessions, the average silica concentration ranged from 120 to 251 mg g(-1). Ample variation was seen within each of the five sub-populations of rice, as well as the 14 geographic regions that the accessions originated from. There was also an effect due to location and accession × location (G × E) interaction demonstrating the importance of assessing silica concentration across multiple environments. Twelve markers on ten chromosomes were significantly associated with hull silica concentration. Six markers (RM5644, RM5371, RM1335, RM283, RM263, and RM178) corroborated quantitative trait locus for silica concentration identified in other mapping studies. Our results provide germplasm and genetic markers that will assist breeding efforts to develop cultivars that have either high or low hull silica concentration. High silica hulls are good raw material for silica based industrial compounds, while low silica hulls are more biodegradable.


Asunto(s)
Variación Genética , Oryza/genética , Oryza/metabolismo , Dióxido de Silicio/metabolismo , Mapeo Cromosómico , Cromosomas de las Plantas , Estudios de Asociación Genética , Desequilibrio de Ligamiento , Filogenia
9.
Clin Vaccine Immunol ; 17(8): 1274-81, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20554807

RESUMEN

Chlamydophila abortus is an intracellular pathogen and the etiological agent of enzootic abortion of ewes (EAE). C. abortus has a biphasic development cycle; extracellular infectious elementary bodies (EB) attach and penetrate host cells, where they give rise to intracellular, metabolically active reticulate bodies (RB). RB divide by binary fission and subsequently mature to EB, which, on rupture of infected cells, are released to infect new host cells. Pregnant ewes were challenged with 2 x 10(6) inclusion forming units (IFU) of C. abortus cultured in yolk sac (comprising both EB and RB). Serum samples were collected at 0, 7, 14, 21, 27, 30, 35, 40, and 43 days postinfection (dpi) and used to identify antigens of C. abortus expressed during disease. Additionally, sera from fetal lambs were collected at 30, 35, 40, and 43 dpi. All serum samples collected from experimentally infected pregnant ewes reacted specifically with several antigens of EB as determined by one-dimensional (1-D) and 2-D gel electrophoresis; reactive antigens identified by mass spectrometry included the major outer membrane protein (MOMP), polymorphic outer membrane protein (POMP), and macrophage infectivity potentiator (MIP) lipoprotein.


Asunto(s)
Anticuerpos Antibacterianos/sangre , Antígenos Bacterianos/inmunología , Proteínas Bacterianas/inmunología , Chlamydophila/inmunología , Feto Abortado/inmunología , Animales , Western Blotting , Infecciones por Chlamydophila/inmunología , Infecciones por Chlamydophila/veterinaria , Modelos Animales de Enfermedad , Electroforesis en Gel Bidimensional , Electroforesis en Gel de Poliacrilamida , Femenino , Espectrometría de Masas , Embarazo , Complicaciones Infecciosas del Embarazo/inmunología , Complicaciones Infecciosas del Embarazo/microbiología , Complicaciones Infecciosas del Embarazo/veterinaria , Ovinos , Enfermedades de las Ovejas/inmunología , Enfermedades de las Ovejas/microbiología
10.
Vet Parasitol ; 172(1-2): 8-15, 2010 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-20510517

RESUMEN

A real-time PCR (rt-PCR) targeting the 529-bp repeat element (RE) of Toxoplasma gondii was used to detect and quantify the parasite burden in maternal and foetal tissues in 18 seronegative ewes infected with 3000 toxoplasma oocysts on day 90 of pregnancy. The infected ewes were sacrificed in groups of 4-6 at 21, 25, 33 and 35 days post-challenge. Ten sham inoculated pregnant ewes were used as controls. T. gondii was not detected in the control ewes or their foeti. The parasite was only detected in the maternal tissues in a few of the challenged ewes on a small number of occasions where it was identified in spleen and uterine lymph nodes. T. gondii was detected in the foetal spleen and liver at the early sacrifice times but only sporadically thereafter. In the case of amniotic, allantoic and foetal aqueous humor samples T. gondii was only detected on a small number of occasions. However, it was found in the majority of the foetal lung and placentome samples throughout the study period, while placentomes and foetal brains contained high levels of the parasite during the later stages. Histopathological examination of placentome and brain tissue from the foeti in the present study revealed a strong correlation between histopathological lesions and quantities of the parasite DNA detected. These results indicate that the cotyledonary component of the foetal membranes is the sample of choice for the diagnosis of T. gondii by rt-PCR, followed by foetal lung and brain.


Asunto(s)
Enfermedades de las Ovejas/parasitología , Toxoplasma/aislamiento & purificación , Toxoplasmosis Animal/parasitología , Animales , Encéfalo/parasitología , ADN Protozoario/química , ADN Protozoario/genética , Femenino , Feto/parasitología , Inmunohistoquímica/veterinaria , Placenta/parasitología , Reacción en Cadena de la Polimerasa/veterinaria , Embarazo , Distribución Aleatoria , Ovinos , Enfermedades de las Ovejas/diagnóstico , Toxoplasma/genética , Toxoplasmosis Animal/diagnóstico
11.
Commun Agric Appl Biol Sci ; 75(1): 105-13, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20491403

RESUMEN

We are now faced with increasingly expensive motor fuels and agriculture has potential to partially relieve these pressures. The 2007 U.S. Energy Independence and Security Act calls for the U.S. to replace with renewable fuels about 36 billion gallons of its annual 150 billion gallon motor fuel consumption by 2022. This is a monumental task that can only be achieved by conducting innovative research to discover breakthrough technologies and by educating scientists and engineers around the world. Three European and three U.S. institutions have forged partnerships that have enabled 4-6 month graduate student and faculty exchanges, faculty and graduate student participation in two-week intensive courses in both the E.U. and U.S., and sharing of educational materials. With two years to go on a second grant, 23 U.S. students have been sent to the E.U. for 4-6 months and the E.U. has sent 29 students to the U.S. Another 38 U.S. students and 36 faculty have participated in two-week intensive programs in Europe; and five E.U. students and two faculty came to the U.S. to learn and teach, respectively, in our intensive program.


Asunto(s)
Conservación de los Recursos Naturales , Educación de Postgrado , Universidades , África , Disciplinas de las Ciencias Biológicas/educación , Alemania , Cooperación Internacional
12.
Epidemiol Infect ; 137(2): 270-7, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18474128

RESUMEN

Cryptosporidium is an important cause of diarrhoeal disease worldwide and, as several recent waterborne outbreaks have shown, poses a significant threat to public health in Ireland. We identified the Cryptosporidium spp. in 199 positive human stool samples by PCR-RFLP of the 18S rRNA and COWP gene loci. Subspecies were identified in 104 samples by sequence analysis of the 60 kDa glycoprotein (gp60) gene fragment. Overall C. parvum was identified in 80%, and C. hominis in 20% of cases. No other Cryptosporidium spp. were detected. C. parvum was by far the most common species in the rural, more sparsely populated west of Ireland and exhibited a pronounced spring peak coincident with a peak in the national cryptosporidiosis incidence rate. Our data indicated a trend towards higher proportions of C. hominis in older age groups. Ninety-nine per cent of all subtyped C. parvum isolates belonged to allele family IIa, of which allele IIaA18G3R1 was by far the most common (63%). According to a recent study by Thompson and colleagues [Parasitology Research (2007), 100, 619-624] this allele is also the most common in Irish cattle. Subtyping of the C. hominis isolates indicated that they belonged to a geographically widely distributed allele (IbA10G2) known to have caused several water- and foodborne outbreaks around the world. The predominance of C. parvum, its geographic and seasonal distribution and the IIaA18G3R1 subtype underlines the importance of zoonotic Cryptosporidium transmission in Ireland.


Asunto(s)
Criptosporidiosis/epidemiología , Criptosporidiosis/parasitología , Cryptosporidium/clasificación , Cryptosporidium/aislamiento & purificación , Heces/parasitología , Adolescente , Adulto , Anciano de 80 o más Años , Animales , Niño , Preescolar , Cryptosporidium/genética , Dermatoglifia del ADN , ADN Protozoario/química , ADN Protozoario/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Genotipo , Humanos , Lactante , Recién Nacido , Irlanda/epidemiología , Datos de Secuencia Molecular , Polimorfismo de Longitud del Fragmento de Restricción , Prevalencia , Proteínas Protozoarias/genética , ARN Protozoario/genética , ARN Ribosómico 18S/genética , Análisis de Secuencia de ADN , Adulto Joven
13.
J Food Sci ; 73(4): E183-92, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18460128

RESUMEN

Conjugated linoleic acid (CLA) is found naturally in dairy and beef products at levels of 0.2% to 2% of the total fat. A more concentrated source of dietary CLA, low in saturated fat, would be highly desirable to obtain optimum CLA levels of about 3 g/d. We recently reported photoisomerization of soy oil with iodine catalysis to be a simple way of producing CLA in laboratory without high-energy input or expensive enzymes and microorganisms. However, a long irradiation time of 144 h has been a limitation for this technique to be of practical value. The objectives of this study were to build a pilot plant unit to rapidly produce high-CLA soy oil by photoirradiation and optimize the processing parameters to obtain high-CLA soy oil. Degassed oil with dissolved-iodine catalyst was irradiated by UV lamps in an illuminated laminar flow unit (ILFU). The ILFU consists of 2 borosilicate glass plates in a silicone lined stainless steel frame. The static mode of operation yielded 5.7% of total CLA isomers and performed twice as well than the continuous mode with 2.5% of total CLA. Irradiating oil in a static mode with reflective surfaces increased the CLA yields 3-fold to 16.4%. About 22% of total CLA isomers can be rapidly produced from soy oil linoleic acid with 0.35% iodine catalyst in a 0.5-cm-thick oil layer maintained at 48 degrees C for 12 h. The peroxide value and GC-MS analysis did not identify any volatile compounds characteristic of lipid oxidation. This study is a definitive step toward the commercialization of large-scale production of CLA-rich soy oil.


Asunto(s)
Manipulación de Alimentos/métodos , Luz , Ácidos Linoleicos Conjugados/análisis , Aceite de Soja/química , Cromatografía de Gases y Espectrometría de Masas , Yodo/química , Peroxidación de Lípido , Oxidación-Reducción , Fotoquímica , Proyectos Piloto
14.
Meat Sci ; 75(1): 84-93, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22063415

RESUMEN

Beef strip loins (IMPS 180; n=15) were sectioned in thirds and sections (n=45) were left untreated (CNT) or injected with either a commercial powder conjugated linoleic acid (CLA) source (Powder) or a commercial oil CLA source (Oil), whose major isomers were 18:2cis-9, trans-11 and 18:2trans-10, cis-12 CLA isomers. Fresh Oil steaks had 3.20 and 3.15, Powder steaks had 4.67 and 4.62, and CNT steaks had 0.19 and 0.02mg/g muscle tissue (wet basis) of the cis-9, trans-11 and trans-10, cis-12 CLA isomers, respectively. TBARS were similar (Oil) and lower (Powder), compared to CNT. Powder steaks had similar instrumental color, and beef and off flavor characteristics as CNT. Artificial marbling was created with Oil steaks having USDA Small(79) and Powder steaks having USDA Modest(86) marbling scores, while CNT steaks had USDA Slight(94) marbling scores. Injection of CLA can be effective in significantly increasing CLA and potentially creating artificial marbling.

15.
Acute Card Care ; 8(2): 119-21, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16885081

RESUMEN

Anomalous coronary arteries are uncommon. This case illustrates an unusual result of percutaneous coronary intervention to the right coronary artery (RCA), where the circulation was also restored in the left anterior descending artery (LAD) territory via an anomalous vessel.


Asunto(s)
Angioplastia Coronaria con Balón , Enfermedad Coronaria/terapia , Anomalías de los Vasos Coronarios/terapia , Stents , Angiografía Coronaria , Enfermedad Coronaria/complicaciones , Enfermedad Coronaria/diagnóstico por imagen , Anomalías de los Vasos Coronarios/complicaciones , Anomalías de los Vasos Coronarios/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos X
16.
Respir Med ; 99(4): 403-7, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15763445

RESUMEN

Families with asthmatic children were recruited to take part in a multi-centre collaborative study into the genetics of asthma. Detailed phenotypic information was collected on all family members including: lung function, anthropomorphic measurements, response to methacholine challenge, skin prick testing, serum IgE measurements and a detailed nurse-administered questionnaire. Families were eligible for entry into the study if they had two children with a doctor-diagnosis of asthma. Bennett/Twin nebulisers were supplied to each centre from a single source and these were calibrated to determine gravimetric nebuliser output prior to use. Asthmatic probands from each centre had similar degrees of asthma severity and atopy. There was no significant difference in the sex ratios or ages of the probands or numbers of parents with a history of smoking in the families recruited at each centre. However, there was a significant difference in the number of children with airway hyperresponsiveness, with 90% of the North Staffordshire group but only 60% of the Sheffield group having a PC20 of <8 mg/ml for methacholine. This difference highlights the difficulty of using families from different centres in genetic and epidemiological studies.


Asunto(s)
Asma/genética , Hiperreactividad Bronquial/genética , Asma/epidemiología , Asma/fisiopatología , Hiperreactividad Bronquial/epidemiología , Hiperreactividad Bronquial/fisiopatología , Niño , Inglaterra/epidemiología , Femenino , Volumen Espiratorio Forzado/fisiología , Humanos , Masculino , Linaje , Fenotipo , Características de la Residencia , Capacidad Vital/fisiología
17.
Lipids ; 39(6): 577-82, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15554158

RESUMEN

Conjugated linoleic acid (CLA), an anticarcinogenic compound with numerous other health benefits, is present mainly in dairy and beef lipids. The main CLA isomer present in dairy and beef lipids is cis 9, trans 11 CLA at a 0.5% concentration. The typical minimum human dietary intake of CLA is 10 times less than the 3 g/d suggested requirement that has been extrapolated from animal and cell-line studies. The objectives of this study were to produce CLA isomers from soybean oil by photoisomerization of soybean oil linoleic acid and to study the oxidation status of the oil. Refined, bleached, and deodorized soybean oil with added iodine concentrations of 0, 0.1, 0.25, and 0.5% was exposed to a 100-W mercury lamp for 0 to 120 h. An SP-2560 fused-silica capillary GC column with FID was used to analyze the esterified CLA isomers in the photoisomerized oil. The CLA content of the individual isomers was optimized by response surface methodology. Attenuated total reflectance (ATR)-FTIR spectra in the 3400 to 3600 cm(-1) range and 1H NMR spectra in the 8 to 12 ppm range of the photoisomerized soybean oil were obtained to follow hydroperoxide formation. The largest amount of cis 9, trans 11 CLA isomer in soybean oil was 0.6%, obtained with 0.25% iodine and 84 h of photoisomerization. Lipid hydroperoxide peaks in the ATR-FTIR spectra and aldehyde peaks in the 1H NMR spectra were not observed in the photoisomerized soybean oil, and the spectra were similar to that of fresh soybean oil. This study shows that CLA isomers can be produced simply and inexpensively from soybean oil by photoisomerization.


Asunto(s)
Ácidos Linoleicos Conjugados/síntesis química , Aceite de Soja/efectos de la radiación , Peróxido de Hidrógeno/metabolismo , Isomerismo , Ácido Linoleico , Fotoquímica , Aceite de Soja/química , Análisis Espectral
18.
Food Addit Contam ; 21(8): 786-93, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15370830

RESUMEN

Aflatoxins occur naturally in many agricultural crops causing health hazards and economic losses. Despite improved handling, processing and storage, they remain a problem in the peanut industry. Therefore, new ways to detoxify contaminated products are needed to limit economic/health impacts and add value to the peanut industry. The study was conducted (1) to evaluate the effectiveness of ozonation and mild heat in breaking down aflatoxins in peanut kernels and flour, and (2) to quantify aflatoxin destruction compared with untreated samples. Peanut samples were inoculated with known concentrations of aflatoxins B1, B2, G1 and G2. Samples were subjected to gaseous ozonation and under various temperatures (25, 50, 75 degrees C) and exposure times (5, 10, 15 min). Ozonated and non-ozonated samples were extracted in acetonitrile/water, derivatized in a Kobra cell and quantified by high-performance liquid chromatography. Ozonation efficiency increased with higher temperatures and longer treatment times. Regardless of treatment combinations, aflatoxins B1 and G1 exhibited the highest degradation levels. Higher levels of toxin degradation were achieved in peanut kernels than in flour. The temperature effect lessened as the exposure time increased, suggesting that ozonation at room temperature for 10-15 min could yield degradation levels similar to those achieved at higher temperatures while being more economical.


Asunto(s)
Aflatoxinas/química , Arachis/química , Contaminación de Alimentos/prevención & control , Ozono/farmacología , Aflatoxina B1/química , Calor , Factores de Tiempo
19.
Bioresour Technol ; 85(3): 285-9, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12365496

RESUMEN

Rice hull ash (RHA) contains over 60% silica and can be an economically viable raw material for the production of silica based products. A previously published method for producing silica xerogel involved dissolving RHA silica with alkali solution to form sodium silicate solution and subsequently forming silica aquagel by adding hydrochloric acid to lower the pH from 11.8 to 7.0, followed by washing and drying aquagel to form xerogel. The silica xerogel had over 4% sodium as a contaminant. An improved method to produce silica xerogel with lower sodium is described in this study. The improved method involved production of silica aquagel by adding silicate solution to pH 1.5 hydrochloric, citric, or oxalic acid solutions until the pH 4.0 was reached. The aquagel was washed and dried to form silica xerogel. For comparison silica xerogels were also produced at pH 7.0 by the published method. X-ray photoelectron spectroscopy was used to determine the elemental content of silica xerogels. The silica, sodium, carbon and oxygen content of silica xerogels varied depending on the pH and the type of acid used for the production of these xerogels. Silica xerogels produced by the improved method using citric and oxalic acid had sodium content of 0.52% and 0.22%, respectively.


Asunto(s)
Ácidos/química , Oryza/química , Eliminación de Residuos/métodos , Semillas/química , Silicatos/química , Dióxido de Silicio/síntesis química , Agricultura/métodos , Ácido Cítrico/química , Geles/química , Ácido Clorhídrico/química , Concentración de Iones de Hidrógeno , Incineración , Minerales/química , Ácido Oxálico/química , Control de Calidad , Sensibilidad y Especificidad , Dióxido de Silicio/aislamiento & purificación
20.
Thorax ; 57(8): 701-4, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12149530

RESUMEN

BACKGROUND: The prevalence and severity of asthma is believed to increase with increasing socioeconomic deprivation. The relationship between asthma diagnosis, symptoms, diagnostic accuracy, and socioeconomic deprivation as determined by Townsend scores was determined in Sheffield schoolchildren. METHODS: All 6021 schoolchildren aged 8-9 years in one school year in Sheffield were given a parent respondent survey based on International Survey of Asthma and Allergies in Childhood (ISAAC) questions. RESULTS: 5011/6021 (83.2%) questionnaires were returned. Postcode data were available in 4131 replies (82.4%) and were used to assign a composite deprivation score (Townsend score). Scores were divided into five quintiles, with group 1 being least and group 5 being most deprived. A positive trend was observed from group 1 to group 5 for the prevalence of wheeze in the previous 12 months, wheeze attacks >or=4/year, nocturnal wheeze and cough (all p<0.001), cough and/or wheeze "most times" with exertion (p<0.03), current asthma (p<0.001), and significant asthma symptoms (p<0.001). No significant trend was observed for lifetime wheeze or attacks of speech limiting wheeze. There were no significant trends in the prevalence of current asthmatic children without significant symptoms (overdiagnosis) or children with significant asthma symptoms but no current asthma diagnosis (underdiagnosis) across the social groups. There was a significant negative trend in the ratio of asthma medication to asthma diagnosis from least to most deprived groups (p<0.001). CONCLUSIONS: Asthma morbidity and severity increase according to the level of socioeconomic deprivation. This may be due to differences in environment, asthma management, and/or symptom reporting. Diagnostic accuracy does not vary significantly across deprivation groups but children living in areas of least deprivation and taking asthma medication are less likely to be labelled as having asthma, suggesting diagnostic labelling bias.


Asunto(s)
Asma/diagnóstico , Asma/terapia , Asma/epidemiología , Niño , Enfermedad Crónica , Tos/etiología , Inglaterra/epidemiología , Humanos , Pobreza , Prevalencia , Pronóstico , Ruidos Respiratorios/diagnóstico , Sensibilidad y Especificidad , Factores Socioeconómicos
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