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1.
Appl Environ Microbiol ; 87(23): e0106021, 2021 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-34550767

RESUMO

Campylobacter from contaminated poultry meat is a major source of human gastroenteritis worldwide. To date, attempts to control this zoonotic infection with on-farm biosecurity measures have been inconsistent in outcome. A cornerstone of these efforts has been the detection of chicken infection with microbiological culture, where Campylobacter is generally not detectable until birds are at least 21 days old. Using parallel sequence-based bacterial 16S profiling analysis and targeted sequencing of the porA gene, Campylobacter was identified at very low levels in all commercial flocks at less than 8 days old that were tested from the United Kingdom, Switzerland, and France. These young chicks exhibited a much greater diversity of porA types than older birds testing positive for Campylobacter by culture or quantitative PCR (qPCR). This suggests that as the bacteria multiply sufficiently to be detected by culture methods, one or two variants, as indicated by porA type, dominate the infection. The findings that (i) most young chicks carry some Campylobacter and (ii) not all flocks become Campylobacter positive by culture suggest that efforts to control infection, and therefore avoid contamination of poultry meat, should concentrate on how to limit Campylobacter to low levels by the prevention of the overgrowth of single strains. IMPORTANCE Our results demonstrate the presence of Campylobacter DNA among fecal samples from a range of commercially reared meat chicks that are less than 8 days of age, consistent across 3 European countries. The recently developed, sensitive detection method indicates that infection occurs on commercial farms much earlier and more widely than previously thought, which opens up new opportunities to control Campylobacter contamination at the start of the food chain and reduce the unacceptably high levels of human disease.


Assuntos
Infecções por Campylobacter/veterinária , Campylobacter , Galinhas , Animais , Campylobacter/genética , Campylobacter/isolamento & purificação , Galinhas/microbiologia , DNA Bacteriano/genética , França , RNA Ribossômico 16S/genética , Suíça , Reino Unido
2.
Phys Chem Chem Phys ; 23(18): 11091-11103, 2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-33949518

RESUMO

The short-range structures of LiF-ThF4, NaF-AnF4, KF-AnF4, and Cs-AnF4 (An = Th, U), were probed using in situ high temperature Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy. Signally, the EXAFS spectra of pure molten ThF4 and UF4 were measured for the first time. The data were interpreted with the aid of Molecular Dynamics (MD) and standard fitting of the EXAFS equation. As in related studies, a speciation distribution dominated by [AnFx]4-x (x = 7, 8, 9) coordination complexes was observed. The average coordination number was found to decrease with the increasing size of the alkali cation, and increase with AnF4 content. An average coordination number close to 6, which had not been detected before in melts of alkali actinide fluorides, was seen when CsF was used as solvent.

3.
Parasite Immunol ; 38(7): 419-30, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27136454

RESUMO

Cytotoxic cells of the immune system may kill infected or transformed host cells via the perforin/granzyme or the Fas ligand (FasL) pathways. The purpose of this study was to determine mRNA expression of perforin, granzyme A and FasL in Eimeria tenella-infected tissues at primary infection and infection of immune chickens as an indirect measure of cytotoxic cell activity. Chickens were rendered immune by repeated E. tenella infections, which were manifested as an absence of clinical signs or pathological lesions and significantly reduced oocyst production upon challenge infection. During primary E. tenella infection, perforin, granzyme A and FasL mRNA expression in caecal tissue was significantly increased at 10 days after infection, compared to uninfected birds. In contrast, at infection of immune birds, perforin and granzyme A mRNA expression in caecal tissue was significantly increased during the early stages of E. tenella challenge infection, days 1-4, which coincided with a substantial reduction of parasite replication in these birds. These results indicate the activation of cytotoxic pathways in immune birds and support a role for cytotoxic T cells in the protection against Eimeria infections.


Assuntos
Ceco/parasitologia , Coccidiose/veterinária , Eimeria tenella/fisiologia , Proteína Ligante Fas/genética , Granzimas/genética , Perforina/genética , Doenças das Aves Domésticas/genética , Doenças das Aves Domésticas/parasitologia , Animais , Ceco/imunologia , Galinhas/genética , Galinhas/imunologia , Galinhas/parasitologia , Coccidiose/genética , Coccidiose/imunologia , Coccidiose/parasitologia , Eimeria tenella/genética , Eimeria tenella/crescimento & desenvolvimento , Proteína Ligante Fas/imunologia , Granzimas/imunologia , Perforina/imunologia , Doenças das Aves Domésticas/imunologia , RNA Mensageiro/genética , RNA Mensageiro/imunologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/parasitologia
4.
Philos Trans A Math Phys Eng Sci ; 373(2042)2015 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-25897088

RESUMO

In a number of papers dating back to the 1970s, Parker has hypothesized that, in a perfectly ideal environment, complex photospheric motions acting on a continuous magnetic field will result in the formation of tangential discontinuities corresponding to singular currents. I review direct numerical simulations of the problem and find that the evidence points to a tendency for thin but finite-thickness current layers to form, with thickness exponentially decreasing in time. Given a finite resistivity, these layers will eventually become important and cause the dynamical process of energy release. Accordingly, a body of work focuses on evolution under continual boundary driving. The coronal volume evolves into a highly dynamic but statistically steady state where quantities have a temporally and spatially intermittent nature and where the Poynting flux and dissipation are decoupled on short time scales. Although magnetic braiding is found to be a promising coronal heating mechanism, much work remains to determine its true viability. Some suggestions for future study are offered.

5.
Curr Oncol ; 22(2): 113-21, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25908910

RESUMO

BACKGROUND: Enrolling patients in studies of pancreatic ductal adenocarcinoma (pdac) is challenging because of the high fatality of the disease. We hypothesized that a prospective clinic-based study with rapid ascertainment would result in high participation rates. Using that strategy, we established the Quebec Pancreas Cancer Study (qpcs) to investigate the genetics and causes of pdac and other periampullary tumours (pats) that are also rare and underrepresented in research studies. METHODS: Patients diagnosed with pdac or pat were introduced to the study at their initial clinical encounter, with a strategy to enrol participants within 2 weeks of diagnosis. Patient self-referrals and referrals of unaffected individuals with an increased risk of pdac were also accepted. Family histories, epidemiologic and clinical data, and biospecimens were collected. Additional relatives were enrolled in families at increased genetic risk. RESULTS: The first 346 completed referrals led to 306 probands being enrolled, including 190 probands affected with pdac, who represent the population focus of the qpcs. Participation rates were 88.4% for all referrals and 89.2% for pdac referrals. Family history, epidemiologic and clinical data, and biospecimens were ascertained from 91.9%, 54.6%, and 97.5% respectively of patients with pdac. Although demographics and trends in risk factors in our patients were consistent with published statistics for patients with pdac, the qpcs is enriched for families with French-Canadian ancestry (37.4%), a population with recurrent germ-line mutations in hereditary diseases. CONCLUSIONS: Using rapid ascertainment, a pdac and pat research registry with high participation rates can be established. The qpcs is a valuable research resource and its enrichment with patients of French-Canadian ancestry provides a unique opportunity for studies of heredity in these diseases.

6.
Inorg Chem ; 53(1): 375-82, 2014 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-24350659

RESUMO

The valence state of uranium has been confirmed for the three sodium uranates NaU(V)O3/[Rn](5f(1)), Na4U(VI)O5/[Rn](5f(0)), and Na2U(VI)2O7/[Rn](5f(0)), using X-ray absorption near-edge structure (XANES) spectroscopy. Solid-state (23)Na magic angle spinning nuclear magnetic resonance (MAS NMR) measurements have been performed for the first time, yielding chemical shifts at -29.1 (NaUO3), 15.1 (Na4UO5), and -14.1 and -19 ppm (Na1 8-fold coordinated and Na2 7-fold coordinated in Na2U2O7), respectively. The [Rn]5f(1) electronic structure of uranium in NaUO3 causes a paramagnetic shift in comparison to Na4UO5 and Na2U2O7, where the electronic structure is [Rn]5f(0). A (23)Na multi quantum magic angle spinning (MQMAS) study on Na2U2O7 has confirmed a monoclinic rather than rhombohedral structure with evidence for two distinct Na sites. DFT calculations of the NMR parameters on the nonmagnetic compounds Na4UO5 and Na2U2O7 have permitted the differentiation between the two Na sites of the Na2U2O7 structure. The linear thermal expansion coefficients of all three compounds have been determined using high-temperature X-ray diffraction: αa = 22.7 × 10(-6) K(-1), αb = 12.9 × 10(-6) K(-1), αc = 16.2 × 10(-6) K(-1), and αvol = 52.8 × 10(-6) K(-1) for NaUO3 in the range 298-1273 K; αa = 37.1 × 10(-6) K(-1), αc = 6.2 × 10(-6) K(-1), and αvol = 81.8 × 10(-6) K(-1) for Na4UO5 in the range 298-1073 K; αa = 6.7 × 10(-6) K(-1), αb = 14.4 × 10(-6) K(-1), αc = 26.8 × 10(-6) K(-1), αß = -7.8 × 10(-6) K(-1), and αvol = -217.6 × 10(-6) K(-1) for Na2U2O7 in the range 298-573 K. The α to ß phase transition reported for the last compound above about 600 K was not observed in the present studies, either by high-temperature X-ray diffraction or by differential scanning calorimetry.

7.
J Fish Dis ; 37(8): 729-37, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23962351

RESUMO

Juvenile edible crabs, Cancer pagurus L., were surveyed from Mumbles Head and Oxwich Bay in South Wales, UK, and the number of heterotrophic bacteria and vibrios in the hemolymph was determined. The percentage of crabs with hemolymph containing bacteria was variable over the survey with higher numbers of animals affected in summer than in winter. Post-moult crabs contained significantly higher numbers of heterotrophic bacteria in the hemolymph than pre- and intermoult animals. Crabs with cuticular damage to the gills also had significantly higher numbers of bacteria in the hemolymph. Crabs were found to have a high prevalence of infection by the dinoflagellate, Hematodinium. Such animals had significantly fewer bacteria in the blood in comparison with Hematodinium-free animals. Of the 463 crabs surveyed, only 3 individuals had hemolymph containing 2000 + CFU mL(-1). Based on 16S rRNA gene sequences, two of these crabs contained a Vibrio pectenicida-like isolate, while the other had a mixed assemblage of vibrios. Although 59% of the crabs surveyed had culturable bacteria in the hemolymph, the majority only had small numbers (<2000 CFU mL(-1) ), suggesting that such infections may be of limited importance to the sustainability of the crab fishery in this region.


Assuntos
Braquiúros/microbiologia , Hemolinfa/microbiologia , Vibrio/isolamento & purificação , Animais , Dinoflagellida/isolamento & purificação , Feminino , Brânquias/microbiologia , Interações Hospedeiro-Patógeno , Masculino , Fatores de Tempo
8.
Cancer Med ; 13(2): e6976, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38379327

RESUMO

BACKGROUND: International bodies recommend that melanoma risk assessment should be integrated into skin cancer care provision, but evidence to support implementation is lacking. AIM: To explore the acceptability and feasibility of implementing personalised melanoma risk assessment and tailored patient education and skin surveillance within routine clinical care. METHODS: This prospective qualitative implementation study was informed by the Theoretical Framework of Acceptability (TFA). Personalised, systematic melanoma risk assessment was implemented in the dermatology clinic at the Melanoma Institute Australia, Sydney, Australia February-May 2021. Pre- and post-implementation observations and semi-structured interviews with patients and staff were conducted (September 2020-March 2021). Observational notes and interview transcript data were analysed thematically using the TFA as a classifying framework. RESULTS: A total of 37 h of observations were made, and 29 patients and 12 clinic staff were interviewed. We found that the delivery of personalised melanoma risk estimates did not impact on patient flow through the clinic. Dermatologists reported that the personalised risk information enhanced their confidence in assessing patient risk and recommending tailored surveillance schedules. Most patients reported that the risk assessment and tailored information were a beneficial addition to their care. Among patients whose risk deviated from their expectations, some reported feeling worried, confused or mistrust in the risk information, including those at lower risk who were recommended to decrease surveillance frequency. CONCLUSIONS: It is feasible and acceptable to patients and clinic staff to calculate and deliver personalised melanoma risk information and tailored surveillance as part of routine clinical care within dermatology clinics.


Assuntos
Dermatologia , Melanoma , Neoplasias Cutâneas , Humanos , Melanoma/diagnóstico , Melanoma/epidemiologia , Estudos de Viabilidade , Estudos Prospectivos , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/epidemiologia , Medição de Risco
9.
Avian Pathol ; 41(5): 413-20, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23025669

RESUMO

As a part of the 40th anniversary celebrations of Avian Pathology we review the last four decades of Salmonella research which has led to major progress in our understanding of the bacteriology and infection biology of the organism through the huge advances in molecular biology and immunology that have accompanied technical advances in biology generally. In many countries combinations of improvements in management, sometimes under legislative pressure and supported by a number of basic biological interventions, have resulted in reductions in incidence in the Salmonella serovars that are commonly associated with food-poisoning to unprecedented low levels in parent flocks, broilers and layers. Utilisation of the information generated during the past few decades should improve the efficacy of surveillance and biological interventions both for the intestinal carriage that is associated most frequently with human infection and also for systemic diseases, including fowl typhoid and pullorum disease. These two diseases continue to be major economic problems in many countries where the possibilities for improvements in hygiene may be limited but which, nevertheless, are increasingly a significant part of the global economy in poultry meat.


Assuntos
Doenças das Aves Domésticas/microbiologia , Infecções por Salmonella/microbiologia , Salmonella/patogenicidade , Animais , Humanos , Aves Domésticas , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/imunologia , Salmonella/classificação , Salmonella/isolamento & purificação , Infecções por Salmonella/epidemiologia , Infecções por Salmonella/imunologia
10.
J Pediatr Urol ; 18(4): 493-498, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35817657

RESUMO

In this focused narrative review we set out to review the current literature addressing the utilization of UDS in patients with spina bifida (SB). We specifically analyzed 6 urodynamic parameters and their roles as predictors of upper tract deterioration in pediatric SB patients. The material available did not allow a systematic analysis or the usage of metanalysis methodology, due to the predominance of small retrospective cohorts, and high heterogeneity. We identified 10 retrospective chart reviews that met our study criteria. The results of each of these papers, as well as other studies deemed relevant to the discussion, are included in our narrative review of the literature. We summarize the current literature, offer explanations for divergences in opinion, and identify future research directions and emerging solutions with a focus on machine learning.


Assuntos
Disrafismo Espinal , Bexiga Urinaria Neurogênica , Criança , Humanos , Urodinâmica , Urologistas , Estudos Retrospectivos , Disrafismo Espinal/complicações , Disrafismo Espinal/diagnóstico
11.
Curr Bladder Dysfunct Rep ; 17(3): 188-195, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37206992

RESUMO

Purpose of Review: The goal of this manuscript is to review the current literature on bladder health education, summarize Prevention of Lower Urinary Tract Symptoms (PLUS) [50] findings on environmental factors that influence knowledge and beliefs about toileting and bladder function, and describe how PLUS work will contribute to improved understanding of women's bladder-related knowledge and inform prevention intervention strategies. Recent Findings: Analysis of focus group transcripts revealed the various ways women view, experience, and describe bladder function. In the absence of formal bladder health educational platforms, women appear to develop knowledge of normal and abnormal bladder function from a variety of social processes including environmental cues and interpersonal sources. Importantly, focus group participants expressed frustration with the absence of structured bladder education to inform knowledge and practices. Summary: There is a lack of bladder health educational programming in the USA, and it is unknown to what degree women's knowledge, attitudes, and beliefs influence their risk of developing lower urinary tract symptoms (LUTS). The PLUS Consortium RISE FOR HEALTH study will estimate the prevalence of bladder health in adult women and assess risk and protective factors. A Knowledge, Attitudes, and Beliefs (KAB) questionnaire will be administered to determine KAB around bladder function, toileting, and bladder-related behaviors, and examine the relationship of KAB to bladder health and LUTS. The data generated from PLUS studies will identify opportunities for educational strategies to improve bladder health promotion and well-being across the life course.

12.
J Frailty Aging ; 10(3): 219-225, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34105704

RESUMO

BACKGROUND: Muscle provides a reservoir for water to maintain fluid volume and blood pressure, so older adults may be at risk for orthostatic hypotension due to muscle loss with age. OBJECTIVES: To evaluate the association between muscle loss with age and postural blood pressure. DESIGN: Longitudinal comparison of overnight changes in hydration, postural blood pressure, and strength. SETTING: Community field study. PARTICIPANTS: Sixty-nine men and women (76.0 ± 0.8 years) with low (Low) or normal (Normal) muscle based on the Lean Mass Index. MEASUREMENTS: Body composition was measured with bioelectrical impedance analysis. Postural blood pressure was measured sequentially (lying, sitting, standing). Strength was measured with a handgrip dynamometer, Arm Curl test, and Chair Stand test. RESULTS: On Day 1, Low had less hydration and a significant drop in postural systolic blood pressure compared to Normal (lying to standing: -11.06 ± 2.36 vs. +1.14 ± 2.20 mmHg, p < 0.001). Overnight, both groups lost significant total body water, while fluid volume was unchanged. On Day 2, both groups experienced significant drops in postural systolic blood pressure, although the drop in Low was more profound and significantly greater than Normal (lying to standing: -16.85 ± 2.50 vs. -3.89 ± 2.52 mmHg, p = 0.001). On both days, Normal compensated for postural changes with increases in postural diastolic blood pressure not observed in Low. Only Low experienced significant overnight decreases in all strength measures. CONCLUSIONS: In older men and women, muscle loss with age is accompanied by loss of hydration and less stable early morning postural systolic blood pressure that increase risk for orthostatic hypotension and can also increase risk for falls.


Assuntos
Hipotensão Ortostática , Idoso , Pressão Sanguínea , Feminino , Força da Mão , Humanos , Hipotensão Ortostática/epidemiologia , Masculino , Músculos , Postura
13.
J Exp Med ; 189(3): 593-8, 1999 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-9927521

RESUMO

Two subsets of murine splenic dendritic cells, derived from distinct precursors, can be distinguished by surface expression of CD8alpha homodimers. The functions of the two subsets remain controversial, although it has been suggested that the lymphoid-derived (CD8alpha+) subset induces tolerance, whereas the myeloid-derived (CD8alpha-) subset has been shown to prime naive T cells and to generate memory responses. To study their capacity to prime or tolerize naive CD4(+) T cells in vivo, purified CD8alpha+ or CD8alpha- dendritic cells were injected subcutaneously into normal mice. In contrast to CD8alpha- dendritic cells, the CD8alpha+ fraction failed to traffic to the draining lymph node and did not generate responses to intravenous peptide. However, after in vitro pulsing with peptide, strong in vivo T cell responses to purified CD8alpha+ dendritic cells could be detected. Such responses may have been initiated via transfer of peptide-major histocompatibility complex complexes to migratory host CD8alpha- dendritic cells after injection. These data suggest that correlation of T helper cell type 1 (Th1) and Th2 priming with injection of CD8alpha+ and CD8alpha- dendritic cells, respectively, may not result from direct T cell activation by lymphoid versus myeloid dendritic cells, but rather from indirect modification of the response to immunogenic CD8alpha- dendritic cells by CD8alpha+ dendritic cells.


Assuntos
Apresentação de Antígeno , Antígenos CD8/imunologia , Células Dendríticas/imunologia , Linfonodos/imunologia , Proteínas Supressoras de Tumor , Animais , Antígenos/imunologia , Movimento Celular , Tolerância Imunológica , Injeções Subcutâneas , Ativação Linfocitária , Camundongos , Camundongos Transgênicos , Proteínas/imunologia , Pele/imunologia , Células Th1/imunologia , Células Th2/imunologia
14.
J Exp Med ; 177(4): 1193-8, 1993 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-8459214

RESUMO

Mice homozygous for the mutant allele scid (severe combined immunodeficiency) have been described as excellent models for Pneumocystis carinii (Pc) pneumonia (PCP), a major health problem in patients with acquired immune deficiency syndrome (AIDS) and other immunodeficiency states. Other microorganisms have been shown to infect AIDS patients simultaneously with Pc, but whether one opportunist is able to directly influence the pathogenicity of another has not been determined previously. We have deliberately coinfected scid mice (with extent Pc infection) with a variety of primarily pneumotropic viruses and bacteria and have identified pneumonia virus of mice as causing a dramatic increase in the density of Pc organisms and the morbidity due to PCP in immunodeficient scid mice. This finding has clinical significance in the management of PCP, in that the identification and treatment of coinfecting pneumotropic pathogens may be as important as treatment targeted at Pc. A search for other synergistic (or antagonistic) microorganisms and determination of their mechanism(s) of action in altering the progression of PCP is indicated.


Assuntos
Pneumonia por Pneumocystis/complicações , Pneumonia Viral/complicações , Imunodeficiência Combinada Severa/complicações , Animais , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos SCID , Pneumonia Viral/microbiologia
15.
Phys Rev Lett ; 105(8): 085002, 2010 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-20868104

RESUMO

The final state of turbulent magnetic relaxation in a reversed field pinch is well explained by Taylor's hypothesis. However, recent resistive-magnetohydrodynamic simulations of the relaxation of braided solar coronal loops have led to relaxed fields far from the Taylor state, despite the conservation of helicity. We point out the existence of an additional topological invariant in any flux tube with a nonzero field: the topological degree of the field line mapping. We conjecture that this constrains the relaxation, explaining why only one of three example simulations reaches the Taylor state.

16.
Proc Natl Acad Sci U S A ; 104(47): 18589-94, 2007 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-18006662

RESUMO

The importance of sympatric speciation (the evolution of reproductive isolation between codistributed populations) in generating biodiversity is highly controversial. Whereas potential examples of sympatric speciation exist for plants, insects, and fishes, most theoretical models suggest that it requires conditions that are probably not common in nature, and only two possible cases have been described for tetrapods. One mechanism by which it could occur is through allochronic isolation-separation of populations by breeding time. Oceanodroma castro (the Madeiran or band-rumped storm-petrel) is a small seabird that nests on tropical and subtropical islands throughout the Atlantic and Pacific Oceans. In at least five archipelagos, different individuals breed on the same islands in different seasons. We compared variation in five microsatellite loci and the mitochondrial control region among 562 O. castro from throughout the species' range. We found that sympatric seasonal populations differ genetically within all five archipelagos and have ceased to exchange genes in two. Population and gene trees all indicate that seasonal populations within four of the archipelagos are more closely related to each other than to populations from the same season from other archipelagos; divergence of the fifth sympatric pair is too ancient for reliable inference. Thus, seasonal populations appear to have arisen sympatrically at least four times. This is the first evidence for sympatric speciation by allochrony in a tetrapod, and adds to growing indications that population differentiation and speciation can occur without geographic barriers to gene flow.


Assuntos
Aves/classificação , Aves/fisiologia , Especiação Genética , Geografia , Animais , Comportamento Animal/fisiologia , Biodiversidade , Aves/genética , Feminino , Dados de Sequência Molecular , Oceanos e Mares , Filogenia , Dinâmica Populacional , Reprodução/fisiologia , Estações do Ano
17.
Br Poult Sci ; 51(6): 703-13, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21161776

RESUMO

1. Much evidence exists detailing how animals respond to pathogen challenge, yet information explaining how the various behavioural, immunological, and physiological systems in chickens interplay during such challenges remains limited. 2. To gain an understanding of this interplay while controlling for genetic variation, the current study collected a variety of behavioural, physiological and immunological measures from three inbred lines (P, O and N) of laying hens before and after a sub-clinical infection with Salmonella enterica Typhimurium at 56 d of age. For comparison, an equal number of control birds were inoculated with a Salmonella-free broth. To identify an underlying profile, which might result in reduced susceptibility to infection, data were also collected in the pre-infection period. Post-infection blood and faeces were collected at 1-d post infection (dpi) and faeces again at 8 dpi. Animals were killed 15 d after infection and faeces, caecal contents, and spleen were examined for the presence of Salmonella. 3. Statistical analysis was performed to identify pre- and post-infection differences between genetic lines, changes in bird behavioural patterns between the two periods, and associations between a positive test for Salmonella and the various response measures. 4. Tissues from Line P birds were more often negative for Salmonella than those from birds of other lines, though this was inconsistent and tissue-dependent. The P line was also characterised by relatively greater serum concentrations of immunoglobulins at 1 dpi and α(1)-acid glycoprotein at 15 dpi. In addition, P line birds were more timid and their growth was reduced during the pre-infection period suggesting the possibility of a profile with reduced susceptibility to the bacterial challenge. 5. The current work has identified correlations between attributes of chicken strains and improved clearance. Future work using hypothesis-based testing will be required to determine whether the identified correlations are causally related.


Assuntos
Comportamento Animal , Doenças das Aves/microbiologia , Galinhas/microbiologia , Salmonelose Animal/imunologia , Bem-Estar do Animal , Animais , Doenças das Aves/imunologia , Peso Corporal , Galinhas/imunologia , Galinhas/fisiologia , Suscetibilidade a Doenças , Feminino , Glucocorticoides/metabolismo , Imunoglobulina M/sangue , Imunoglobulinas/sangue , Masculino , Orosomucoide/metabolismo
18.
J Cell Biol ; 41(2): 477-93, 1969 May.
Artigo em Inglês | MEDLINE | ID: mdl-5783869

RESUMO

Mice which had been on a riboflavin-free diet for 6-8 wk were given daily intraperitoneal injections of riboflavin. The hepatic mitochondria, which in the deficient animals were greatly enlarged, were restored to normal dimensions within 3 days. Normalization of the mitochondrial population was brought about by division of the giant organelles. Dividing mitochondria were characterized by a membranous partition separating the inner compartment into two distinct chambers. Such organelles showed varying degrees of pinching at the level of the partition. The most common site of partition formation was at the base of a small mitochondrial bud. During the 1st day of recovery, dividing mitochondria were so common that they could be easily found in mitochondrial pellets. Injection of riboflavin into normally nourished mice also produced an apparent increase in the frequency of dividing mitochondria in the liver cells.


Assuntos
Fígado/patologia , Mitocôndrias Hepáticas/crescimento & desenvolvimento , Deficiência de Riboflavina/patologia , Animais , Fígado/citologia , Camundongos , Microscopia Eletrônica , Mitocôndrias Hepáticas/efeitos dos fármacos , Riboflavina/farmacologia , Riboflavina/uso terapêutico , Deficiência de Riboflavina/tratamento farmacológico
19.
Science ; 163(3862): 79-81, 1969 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-4975341

RESUMO

D(m)-beta-hydroxybutyrate dehydrogenase activity is very low in normal adult rat brain; but during fasting it increases severalfold in parallel with the ketosis. The increase may represent part of a mechanism by which the brain adapts to changing patterns of substrate supply during starvation.


Assuntos
Encéfalo/enzimologia , Indução Enzimática , Jejum , Hidroxibutirato Desidrogenase/biossíntese , Acetoacetatos/sangue , Acidose , Animais , Peso Corporal , Encéfalo/citologia , Ácido Edético , Hidroxibutiratos/sangue , Masculino , Mitocôndrias/enzimologia , Tamanho do Órgão , Fosfatidilcolinas/metabolismo , Ratos
20.
Science ; 215(4529): 182-4, 1982 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-7053569

RESUMO

Rabies virus was found on mouse diaphragms and on cultured chick myotubes in a distribution coinciding with that of the acetylcholine receptor. Treatment of the myotubes with alpha-bungarotoxin and d-tubocurarine before the addition of the virus reduced the number of myotubes that became infected with rabies virus. These findings together suggest that acetylcholine receptors may serve as receptors for rabies virus. The binding of virus to acetylcholine receptors, which are present in high density at the neuromuscular junction, would provide a mechanism whereby the virus could be locally concentrated at sites in proximity to peripheral nerves facilitating subsequent uptake and transfer to the central nervous system.


Assuntos
Junção Neuromuscular/metabolismo , Vírus da Raiva/metabolismo , Receptores Colinérgicos/metabolismo , Receptores Virais/metabolismo , Acetilcolina/metabolismo , Acetilcolinesterase/metabolismo , Animais , Ligação Competitiva , Bungarotoxinas/metabolismo , Células Cultivadas , Embrião de Galinha , Diafragma , Camundongos , Microscopia Eletrônica , Tubocurarina/metabolismo
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