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The rate of the final step in the astrophysical αp process, the ^{34}Ar(α,p)^{37}K reaction, suffers from large uncertainties due to a lack of experimental data, despite having a considerable impact on the observable light curves of x-ray bursts and the composition of the ashes of hydrogen and helium burning on accreting neutron stars. We present the first direct measurement constraining the ^{34}Ar(α,p)^{37}K reaction cross section, using the Jet Experiments in Nuclear Structure and Astrophysics gas jet target. The combined cross section for the ^{34}Ar,Cl(α,p)^{37}K,Ar reaction is found to agree well with Hauser-Feshbach predictions. The ^{34}Ar(α,2p)^{36}Ar cross section, which can be exclusively attributed to the ^{34}Ar beam component, also agrees to within the typical uncertainties quoted for statistical models. This indicates the applicability of the statistical model for predicting astrophysical (α,p) reaction rates in this part of the αp process, in contrast to earlier findings from indirect reaction studies indicating orders-of-magnitude discrepancies. This removes a significant uncertainty in models of hydrogen and helium burning on accreting neutron stars.
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Helio , Hidrógeno , Modelos Estadísticos , NeutronesRESUMEN
Absolute cross sections for the addition of s- and d-wave neutrons to ^{14}C and ^{14}N have been determined simultaneously via the (d,p) reaction at 10 MeV/u. The difference between the neutron and proton separation energies, ΔS, is around -20 MeV for the ^{14}C+n system and +8 MeV for ^{14}N+n. The population of the 1s_{1/2} and 0d_{5/2} orbitals for both systems is reduced by a factor of approximately 0.5 compared with the independent single-particle model, or about 0.6 when compared with the shell model. This finding strongly contrasts with results deduced from intermediate-energy knockout reactions between similar nuclei on targets of ^{9}Be and ^{12}C. The simultaneous technique used removes many systematic uncertainties.
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The ^{30}P(p,γ)^{31}S reaction plays an important role in understanding the nucleosynthesis of A≥30 nuclides in oxygen-neon novae. The Gaseous Detector with Germanium Tagging was used to measure ^{31}Cl ß-delayed proton decay through the key J^{π}=3/2^{+}, 260-keV resonance. The intensity I_{ßp}^{260}=8.3_{-0.9}^{+1.2}×10^{-6} represents the weakest ß-delayed, charged-particle emission ever measured below 400 keV, resulting in a proton branching ratio of Γ_{p}/Γ=2.5_{-0.3}^{+0.4}×10^{-4}. By combining this measurement with shell-model calculations for Γ_{γ} and past work on other resonances, the total ^{30}P(p,γ)^{31}S rate has been determined with reduced uncertainty. The new rate has been used in hydrodynamic simulations to model the composition of nova ejecta, leading to a concrete prediction of ^{30}Si:^{28}Si excesses in presolar nova grains and the calibration of nuclear thermometers.
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Proton capture on the excited isomeric state of ^{26}Al strongly influences the abundance of ^{26}Mg ejected in explosive astronomical events and, as such, plays a critical role in determining the initial content of radiogenic ^{26}Al in presolar grains. This reaction also affects the temperature range for thermal equilibrium between the ground and isomeric levels. We present a novel technique, which exploits the isospin symmetry of the nuclear force, to address the long-standing challenge of determining proton-capture rates on excited nuclear levels. Such a technique has in-built tests that strongly support its veracity and, for the first time, we have experimentally constrained the strengths of resonances that dominate the astrophysical ^{26m}Al(p,γ)^{27}Si reaction. These constraints demonstrate that the rate is at least a factor â¼8 lower than previously expected, indicating an increase in the stellar production of ^{26}Mg and a possible need to reinvestigate sensitivity studies involving the thermal equilibration of ^{26}Al.
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BACKGROUND: We investigated the safety and efficacy of a combination of the oral tyrosine kinase inhibitor, nintedanib (BIBF 1120) with oral cyclophosphamide in patients with relapsed ovarian cancer. PATIENTS AND METHODS: Patients with relapsed ovarian, fallopian tube or primary peritoneal cancer received oral cyclophosphamide (100 mg o.d.) and were randomised (1,1) to also have either oral nintedanib or placebo. The primary endpoint was overall survival (OS). Secondary endpoints included progression free survival (PFS), response rate, toxicity, and quality of life. RESULTS: 117 patients were randomised, 3 did not start trial treatment, median age 64 years. Forty-five (39%) had received ≥5 lines chemotherapy. 30% had received prior bevacizumab. The median OS was 6.8 (nintedanib) versus 6.4 (placebo) months (hazard ratio 1.08; 95% confidence interval 0.72-1.62; P = 0.72). The 6-month PFS rate was 29.6% versus 22.8% (P = 0.57). Grade 3/4 adverse events occurred in 64% (nintedanib) versus 54% (placebo) of patients (P = 0.28); the most frequent G3/4 toxicities were lymphopenia (18.6% nintedanib versus 16.4% placebo), diarrhoea (13.6% versus 0%), neutropenia (11.9% versus 0%), fatigue (10.2% versus 9.1%), and vomiting (10.2% versus 7.3%). Patients who had received prior bevacizumab treatment had 52 days less time on treatment (P < 0.01). 26 patients (23%) took oral cyclophosphamide for ≥6 months. There were no differences in quality of life between treatment arms. CONCLUSIONS: This is the largest reported cohort of patients with relapsed ovarian cancer treated with oral cyclophosphamide. Nintedanib did not improve outcomes when added to oral cyclophosphamide. Although not significant, more patients than expected remained on treatment for ≥6 months. This may reflect a higher proportion of patients with more indolent disease or the higher dose of cyclophosphamide used. CLINICAL TRIAL REGISTRATION: Clinicaltrials.govNCT01610869.
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Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Ciclofosfamida/efectos adversos , Neoplasias de las Trompas Uterinas/tratamiento farmacológico , Indoles/efectos adversos , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Peritoneales/tratamiento farmacológico , Administración Metronómica , Administración Oral , Anciano , Inhibidores de la Angiogénesis/administración & dosificación , Inhibidores de la Angiogénesis/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Ciclofosfamida/administración & dosificación , Neoplasias de las Trompas Uterinas/diagnóstico , Neoplasias de las Trompas Uterinas/mortalidad , Neoplasias de las Trompas Uterinas/patología , Femenino , Humanos , Indoles/administración & dosificación , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias Ováricas/diagnóstico , Neoplasias Ováricas/mortalidad , Neoplasias Ováricas/patología , Neoplasias Peritoneales/diagnóstico , Neoplasias Peritoneales/mortalidad , Neoplasias Peritoneales/patología , Supervivencia sin Progresión , Calidad de VidaRESUMEN
Detection of nuclear-decay γ rays provides a sensitive thermometer of nova nucleosynthesis. The most intense γ-ray flux is thought to be annihilation radiation from the ß^{+} decay of ^{18}F, which is destroyed prior to decay by the ^{18}F(p,α)^{15}O reaction. Estimates of ^{18}F production had been uncertain, however, because key near-threshold levels in the compound nucleus, ^{19}Ne, had yet to be identified. We report the first measurement of the ^{19}F(^{3}He,tγ)^{19}Ne reaction, in which the placement of two long-sought 3/2^{+} levels is suggested via triton-γ-γ coincidences. The precise determination of their resonance energies reduces the upper limit of the rate by a factor of 1.5-17 at nova temperatures and reduces the average uncertainty on the nova detection probability by a factor of 2.1.
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BACKGROUND: Chemoradiation (CRT) or short-course radiotherapy (SCRT) are standard treatments for locally advanced rectal cancer (LARC). We evaluated the efficacy/safety of two neoadjuvant chemotherapy (NACT) regimens as an alternative prior to total mesorectal excision (TME). METHODS/DESIGN: This multi-centre, phase II trial in patients with magnetic resonance imaging (MRI) defined high-risk LARC (>cT3b, cN2+ or extramural venous invasion) randomised patients (1:1) to FOLFOX + Bevacizumab (Arm 1) or FOLFOXIRI + bevacizumab (Arm 2) every 14 days for 6 cycles prior to surgery. Patients were withdrawn if positron emission tomography (PET) standardised uptake value (SUV) after 3 cycles failed to decrease by >30% or increased compared to baseline. Primary endpoint was pathological complete response rate (pCR). Secondary endpoints included adverse events (AE) and toxicity. Neoadjuvant rectal (NAR) scores based on "T" and "N" downstaging were calculated. FINDINGS: Twenty patients aged 18-75 years were randomised. The trial stopped early because of poor accrual. Seventeen patients completed all 6 cycles of NACT. One stopped due to myocardial infarction, 1 poor response on PET (both received CRT) and 1 committed suicide. 11 patients had G3 AE, 1 G4 AE (neutropenia), and 1 G5 (suicide). pCR (the primary endpoint) was 0/10 for Arm 1 and 2/10 for Arm 2 i.e. 2/20 (10%) overall. Median NAR score was 14·9 with 5 (28%), 7 (39%), and 6 (33%) having low, intermediate, or high scores. Surgical morbidity was acceptable (1/18 wound infection, no anastomotic leak/pelvic sepsis/fistulae). The 24-month progression-free survival rate was 75% (95% CI: 60%-85%). INTERPRETATION: The primary endpoint (pCR rate) was not met. However, FOLFOXIRI and bevacizumab achieved promising pCR rates, low NAR scores and was well-tolerated. This regimen is suitable for testing as the novel arm against current standards of SCRT and/or CRT in a future trial.
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The giant triton snail (Charonia tritonis) is one of the few natural predators of the adult Crown-of-Thorns starfish (COTS), a corallivore that has been damaging to many reefs in the Indo-Pacific. Charonia species have large salivary glands (SGs) that are suspected to produce either a venom and/or sulphuric acid which can immobilize their prey and neutralize the intrinsic toxic properties of COTS. To date, there is little information on the types of toxins produced by tritons. In this paper, the predatory behaviour of the C. tritonis is described. Then, the C. tritonis SG, which itself is made up of an anterior lobe (AL) and posterior lobe (PL), was analyzed using an integrated transcriptomics and proteomics approach, to identify putative toxin- and feeding-related proteins. A de novo transcriptome database and in silico protein analysis predicts that ~3800 proteins have features consistent with being secreted. A gland-specific proteomics analysis confirmed the presence of numerous SG-AL and SG-PL proteins, including those with similarity to cysteine-rich venom proteins. Sulfuric acid biosynthesis enzymes were identified, specific to the SG-PL. Our analysis of the C. tritonis SG (AL and PL) has provided a deeper insight into the biomolecular toolkit used for predation and feeding by C. tritonis.
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Genómica/métodos , Conducta Predatoria , Glándulas Salivales/metabolismo , Caracoles/genética , Estrellas de Mar/fisiología , Secuencia de Aminoácidos , Animales , Proteínas/química , Proteínas/genética , Proteómica , Glándulas Salivales/anatomía & histología , Ácidos Sulfúricos/metabolismo , TranscriptomaRESUMEN
Neuropeptides represent a diverse class of signaling molecules originating from neural tissues. These chemical modulators orchestrate complex physiological events including those associated with growth and reproduction. De novo transcriptome sequencing of a cerebral ganglion library of the endangered giant triton snail (Charonia tritonis) was undertaken in an effort to identify key neuropeptides that control or influence its physiology. The giant triton snail is considered a primary predator of the corallivore Acanthaster planci (Crown-of-Thorns Starfish) that is responsible for a significant loss in coral cover on reefs in the Indo-Pacific. The transcriptome library was assembled into contigs, and then bioinformatic analysis was used to identify a repertoire of 38 giant triton snail neuropeptide precursor genes, and various isoforms, that encode conserved molluscan neuropeptides. C. tritonis neuropeptides show overall precursor organisation consistent with those of other molluscs. These include those neuropeptides associated with mollusc reproduction such as the APGWamide, buccalin, conopressin, gonadotropin-releasing hormone (GnRH), NKY and egg-laying hormone. These data provide a foundation for further studies targeted towards the functional characterisation of neuropeptides to further understand aspects of the biology of the giant triton snail, such as elucidating its reproductive neuroendocrine pathway to allow the development of knowledge based captive breeding programs.
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Neuropéptidos/genética , Caracoles/crecimiento & desarrollo , Caracoles/genética , Transcriptoma/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Simulación por Computador , Ganglios de Invertebrados/metabolismo , Estudios de Asociación Genética , Hormonas de Invertebrados/genética , Reproducción , Estrellas de MarRESUMEN
We present a strong relationship between the microstructural characteristics of, and the fluid velocity fields confined to, three-dimensional random porous materials. The relationship is revealed through simultaneously extracting correlation functions R_{uu}(r) of the spatial (Eulerian) velocity fields and microstructural two-point correlation functions S_{2}(r) of the random porous heterogeneous materials. This demonstrates that the effective physical transport properties depend on the characteristics of complex pore structure owing to the relationship between R_{uu}(r) and S_{2}(r) revealed in this study. Further, the mean excess plot was used to investigate the right tail of the streamwise velocity component that was found to obey light-tail distributions. Based on the mean excess plot, a generalized Pareto distribution can be used to approximate the positive streamwise velocity distribution.
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BACKGROUND: Although cholecystectomy is the standard therapy for acute cholecystitis (AC), operative morbidity in the elderly may be high owing to medical co-morbidities and decreased physiological reserve. Outcomes of AC in the elderly have not been fully defined with regard to operative and long-term non-operative management. METHODS: Patients aged 65 years or over admitted to a tertiary care centre with a diagnosis of AC between January 2000 and December 2009 were reviewed retrospectively. Patient data, operative and postoperative details were obtained. To determine cholecystectomy rates in the non-operative group, medical records were reviewed, and patients and families were interviewed. RESULTS: A total of 290 patients underwent cholecystectomy during the index admission, of whom 59 (20·3 per cent) required conversion to open operation. Fifty-eight of these patients experienced 98 complications, including acute respiratory failure (27), pneumonia (18), myocardial infarction (16) and sepsis (15). Some 185 patients had non-operative treatment, of whom 67 underwent percutaneous cholecystostomy. Forty-four patients subsequently had elective cholecystectomy, with a complication rate of 23 per cent. One hundred and twenty-six patients were discharged without a plan for cholecystectomy; the rate of recurrent AC was 4 per cent among the two-thirds of patients followed to within 15 months of death. No deaths or major complications occurred among those with recurrent AC. CONCLUSION: Despite selection of the best elderly candidates for cholecystectomy, postoperative morbidity was significant. Medical management, with interval cholecystectomy only for recurrent AC, may be appropriate in selected patients.
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Antibacterianos/administración & dosificación , Colecistectomía Laparoscópica/estadística & datos numéricos , Colecistitis Aguda/tratamiento farmacológico , Anciano , Antibacterianos/uso terapéutico , Colecistitis Aguda/cirugía , Femenino , Humanos , Infusiones Parenterales , Masculino , Complicaciones Posoperatorias/etiología , Recurrencia , Estudios Retrospectivos , Factores de Riesgo , Resultado del TratamientoRESUMEN
AIMS: The isolation of lytic bacteriophage of Vibrio harveyi with potential for phage therapy of bacterial pathogens of phyllosoma larvae from the tropical rock lobster Panulirus ornatus. METHODS AND RESULTS: Water samples from discharge channels and grow-out ponds of a prawn farm in northeastern Australia were enriched for 24 h in a broth containing four V. harveyi strains. The bacteriophage-enriched filtrates were spotted onto bacterial lawns demonstrating that the bacteriophage host range for the samples included strains of V. harveyi, Vibrio campbellii, Vibrio rotiferianus, Vibrio parahaemolyticus and Vibrio proteolyticus. Bacteriophage were isolated from eight enriched samples through triple plaque purification. The host range of purified phage included V. harveyi, V. campbellii, V. rotiferianus and V. parahaemolyticus. Transmission electron microscope examination revealed that six purified phage belonged to the family Siphoviridae, whilst two belonged to the family Myoviridae. The Myoviridae appeared to induce bacteriocin production in a limited number of host bacterial strains, suggesting that they were lysogenic rather than lytic. A purified Siphoviridae phage could delay the entry of a broth culture of V. harveyi strain 12 into exponential growth, but could not prevent the overall growth of the bacterial strain. CONCLUSIONS: Bacteriophage with lytic activity against V. harveyi were isolated from prawn farm samples. Purified phage of the family Siphoviridae had a clear lytic ability and no apparent transducing properties, indicating they are appropriate for phage therapy. Phage resistance is potentially a major constraint to the use of phage therapy in aquaculture as bacteria are not completely eliminated. SIGNIFICANCE AND IMPACT OF THE STUDY: Phage therapy is emerging as a potential antibacterial agent that can be used to control pathogenic bacteria in aquaculture systems. The development of phage therapy for aquaculture requires initial isolation and determination of the bacteriophage host range, with subsequent creation of suitable phage cocktails.
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Bacteriófagos/fisiología , Vibrio/virología , Animales , Acuicultura , Australia , Bacteriófagos/aislamiento & purificación , Bacteriófagos/ultraestructura , Especificidad del Huésped , Myoviridae/fisiología , Myoviridae/ultraestructuraRESUMEN
AIMS: This study aimed to determine the bacterial community associated with wild-caught, mid-stage larvae of spiny lobsters (Palinuridae) in their native oligotrophic marine environment, and to compare their diversity and composition with communities associated with aquaculture-reared larvae of the tropical rock lobster Panulirus ornatus. METHODS AND RESULTS: Bacterial clone libraries constructed from wild P. ornatus (two libraries) and Panulirus penicillatus (one library) larvae (phyllosoma) revealed a dominance of alpha-proteobacterial sequences, with Sulfitobacter spp.-affiliated sequences dominating both P. ornatus libraries and constituting a major portion of the P. penicillatus library. Vibrio-related sequences were rarely detected from wild phyllosoma clone libraries in contrast to similar studies of aquaculture-reared animals. Scanning electron microscopy analysis revealed low levels of bacterial colonization on the external carapace of wild phyllosoma, again in contrast to aquaculture-reared animals, which are often colonized with filamentous bacteria (mainly Thiothrix sp.) that compromise their health. Fluorescence in situ hybridization of sectioned wild phyllosoma tissue displayed low overall abundance of bacteria within the tissue and on external surfaces, with alpha-, beta-, and gamma-Proteobacteria being confirmed as members of this bacterial community. CONCLUSIONS: The consistency in predominant clone sequences retrieved from the three libraries indicated a conserved microbiota associated with wild phyllosoma. In addition, the observed differences in the microbial composition and load of reared and wild phyllosoma are indicative of the different environments in which the animals live. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacterial disease during early larval stages is a major constraint currently hindering the development of an aquaculture industry for the ornate rock lobster P. ornatus. Knowledge of the microbial community associated with wild animals will be advantageous for the identification of bacteria that may promote animal health.
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Bacterias/aislamiento & purificación , Palinuridae/microbiología , Microbiología del Agua , Animales , Acuicultura , Australia , Bacterias/ultraestructura , Biodiversidad , Biblioteca de Genes , Hibridación Fluorescente in Situ/métodos , Larva/microbiología , Microscopía Electrónica de Rastreo , Sondas de Oligonucleótidos/genética , Palinuridae/ultraestructura , Filogenia , ARN Ribosómico 16S/genética , Agua de MarRESUMEN
Epizootic bovine abortion (EBA), a tick-transmitted disease of pregnant cattle grazing foothill pastures, is a major cause of reproductive failure in California and adjacent states. Affected fetuses develop a chronic disease, resulting in late-term abortion or premature calving. Despite investigations spanning 50 years, to the authors' knowledge, the etiologic agent of EBA has not yet been isolated from affected fetuses or the tick vector. The diagnosis of EBA is based on gross and microscopic lesions. Recently, documentation that the etiologic agent is susceptible to antibiotics and identification of a unique 16S deltaproteobacterial rDNA gene sequence in 90% of thymus tissues from aborted fetuses have supported the role of a bacterial infection as the cause of EBA. To determine whether bacteria could be detected in the tissues, histochemical staining and immunohistochemical procedures were used on formalin-fixed, paraffin-embedded tissues. Use of a modified Steiner silver stain revealed small numbers of intracytoplasmic bacterial rods in 37 of 42 thymic samples from EBA-affected fetuses. Improved detection was achieved by use of immunohistochemical staining with serum from EBA-affected fetuses that resulted in detection of numerous bacterial rods in the cytoplasm of histiocytic cells in the thymus from all 42 EBA-affected fetuses. Immunohistochemical examination of additional tissues from 21 field and experimental EBA cases revealed positively stained intracytoplasmic bacterial rods in many organs with inflammatory lesions. Use of the modified Steiner stain and immunohistochemical staining of tissues from negative-control fetuses failed to reveal organisms. To the authors' knowledge, this is the first report to document morphologic evidence of a bacterium associated with the lesions of EBA.
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Aborto Veterinario/patología , Enfermedades de los Bovinos/patología , Infecciones por Bacterias Grampositivas/veterinaria , Bacilos Grampositivos/aislamiento & purificación , Histocitoquímica/veterinaria , Inmunohistoquímica/veterinaria , Aborto Veterinario/microbiología , Animales , Bovinos , Enfermedades de los Bovinos/microbiología , Enfermedades de los Bovinos/transmisión , Deltaproteobacteria/aislamiento & purificación , Femenino , Feto/microbiología , Infecciones por Bacterias Grampositivas/complicaciones , Infecciones por Bacterias Grampositivas/transmisión , Histocitoquímica/métodos , Inmunohistoquímica/métodos , Embarazo , Estudios Retrospectivos , Timo/embriología , Timo/microbiología , Infestaciones por Garrapatas/complicaciones , Infestaciones por Garrapatas/veterinariaRESUMEN
Shiga toxin-producing Escherichia coli (STEC) produce toxins that have been associated with several human illnesses. E. coli O157:H7 is the most well-studied STEC and was first associated with consumption of improperly cooked ground beef in 1982. E. coli O157:H7 is not the only foodborne STEC because other STEC serotypes are also associated with human illnesses. The objective of this study was to assess prevalence of STEC in 23 yearling beef (Angus) heifers grazing an irrigated grass pasture in spring (April), summer (July), fall (October), and winter (December) of 1999. A total of 86 fecal samples were rectally collected and were subjected to microbiological testing for the presence of STEC. Nine E. coli isolates from five heifers (one in spring and fall and three in winter) were toxic to Vero cells. Of these isolates, four were E. coli O157:H7, two belonged to the serogroup O6, one O39:NM, one O113:H-, and the final isolate was untypable. The STEC prevalence rate in our herd ranged from 4% (spring) to 15% (winter). Based on detecting both O157:H7 and non-O157:H7 STEC in our heifers, it is clear that screening fecal samples should not be limited to E. coli O157:H7. Identification of STEC-positive cattle prior to slaughter should help in reducing the risk of beef contamination with such foodborne pathogens if pre- and/or postharvest control measures are applied to such animals.
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Bovinos/microbiología , Escherichia coli O157/aislamiento & purificación , Toxinas Shiga/análisis , Animales , Toxinas Bacterianas , Técnicas de Tipificación Bacteriana , Escherichia coli O157/clasificación , Escherichia coli O157/metabolismo , Heces/microbiología , Femenino , Prevalencia , Estaciones del AñoRESUMEN
Verotoxin-producing Escherichia coli (VTEC) produce one or two toxins known as VT1 and VT2. These toxins have been associated with several human illnesses. Dairy cattle harboring VTEC represent a potential health hazard because they enter the food chain as ground beef. The objective of this study was to assess the occurrence of VTEC in dairy heifers. A total of 91 fecal samples were rectally collected during four periods (spring, summer, fall, and winter of 1999) from 23 heifers. A random sample (n=530) of potential VTEC isolates were tested for verotoxicity and were screened by the polymerase chain reaction (PCR) for presence or absence of VT1 and/or VT2 genes. Thirteen isolates from two heifers (from the winter collection) were verotoxic and were confirmed as E. coli. VTEC were only detected during winter with an occurrence rate of 9.5%. Using PCR, five isolates had the VT1 gene while the remaining eight had the VT2 gene. The sequence and expression of VT1 and VT2 genes were confirmed. No E. coli O157:H7 was detected, but serotyping revealed that the five VT1-positive isolates were O26:NM (a non-motile strain of O26). The remaining eight isolates were untypeable. Identification of VTEC-positive cattle before slaughter is a critical step in any on-farm strategy to minimize the risk of beef contamination with such pathogens.
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Enfermedades de los Bovinos/microbiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli O157/aislamiento & purificación , Toxina Shiga I/biosíntesis , Toxina Shiga II/biosíntesis , Animales , Bovinos , Chlorocebus aethiops , Cartilla de ADN/química , ADN Bacteriano/análisis , Infecciones por Escherichia coli/diagnóstico , Infecciones por Escherichia coli/microbiología , Escherichia coli O157/clasificación , Escherichia coli O157/genética , Escherichia coli O157/metabolismo , Heces/microbiología , Femenino , Nevada , Reacción en Cadena de la Polimerasa , Serotipificación , Toxina Shiga I/genética , Toxina Shiga II/genética , Células Vero/citología , Células Vero/efectos de los fármacosRESUMEN
A reversed-phase HPLC method using a C18 column and a two-mobile-phase gradient elution system containing only volatile components has been developed for separation of norepinephrine, octopamine, epinephrine, dopamine, dihydroxyphenylalanine, tyramine, tyrosine, serotonin, 5-hydroxytryptophan, N-acetyl-serotonin and tryptophan. Mobile phase A contains 0.05% aqueous trifluoroacetic acid and methanol (97.5:2.5, v/v) and mobile phase B contains 0.05% aqueous trifluoracetic acid and methanol (40:60, v/v). This method has the advantage that the mobile phase can be removed completely, without salt residues, from the eluted fractions thus simplifying further analytical procedures on isolated fractions. The elution profile of standards is related to structural characteristics allowing prediction of retention times of known compounds and insight into possible structural characteristics of unknown components in a mixture. Detection is via native fluorescence using excitation at 220 nm and emission at 320 nm and under the conditions described has a sensitivity range from 2.5 to 25 pmol, although the sensitivity range can be extended depending on the emission wavelength used.
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Aminas/análisis , Catecolaminas/análisis , Cromatografía Líquida de Alta Presión/métodos , Indoles/análisis , Animales , Crustáceos , Estándares de Referencia , Solventes/química , Espectrometría de Fluorescencia/métodosRESUMEN
BACKGROUND AND OBJECTIVES: Solid tumors evade the host immunologic responses they initiate by unknown mechanisms. The authors investigated patterns of cytokine content in human colon carcinomas, colon cancer cell lines in vitro, and nude mouse xenografts from those lines in order to clarify those mechanisms. METHODS: Epithelial tumor cell lines were developed from specimens of human colon adenocarcinoma. Aliquots of these cells were then xenografted into female heterozygous BALB/c nu/+ immunologically deficient mice and serially passaged. Original tumors, cell lines, and resultant xenografts were then analyzed for histology/cytology and for levels of TGF-beta and TNF-alpha by enzyme linked immunoassay. RESULTS: Cytokine levels were elevated beyond baseline mucosal levels in original tumors and xenograft mouse tumors but not detectable in extracts from epithelial cultures. CONCLUSIONS: While the precise source of cytokine production remains unclear, these data suggest tumor/host interactions not found in pure epithelial cancer cells in culture.
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Adenocarcinoma/metabolismo , Neoplasias del Colon/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Adenocarcinoma/patología , Animales , Neoplasias del Colon/patología , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Trasplante de Neoplasias , Células Tumorales Cultivadas/metabolismo , Células Tumorales Cultivadas/patologíaRESUMEN
Ovary tissue fragments of the giant tiger prawn Penaeus monodon were incubated in vitro with L-methionine[35S] plus L-cysteine[35S] as a metabolic labeling reagent. The labeled cytoplasmic and secreted proteins synthesized in vitro during incubations under various conditions were subjected to SDS polyacrylamide electrophoresis and visualized by autoradiography. Vitellogenin (Vg) was immunologically identified and shown to be actively synthesized and released into the incubation medium. The synthesis and release of Vg into the incubation medium was optimized and shown to be linear over a 16-h period. Comparisons between different ovarian regions and different stages of development revealed that the level of Vg synthesis and accumulation in the incubation media was variable depending on stage of development and region within the ovary. Coincubation of ovarian fragments with sinus gland extracts showed a dose-related inhibition of total protein and Vg synthesis. The in vitro ovarian bioassay is suitable for examining the effect of hormonal inputs of P. monodon.