Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
Más filtros

País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
J Anim Physiol Anim Nutr (Berl) ; 97(5): 838-45, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22853431

RESUMEN

Sulphur-induced polioencephalomalacia (sPEM), a neurological disorder affecting ruminants, is frequently associated with the consumption of high-sulphur (S) water and subsequent poor performance. Currently, there is no economical method for S removal from surface water sources, and alternative water sources are typically neither readily available nor cost-effective. Determination of genes differentially expressed in response to high-S water consumption may provide a better understanding of the physiology corresponding to high dietary S and ultimately lead to the development of treatment and prevention strategies. The objective of this study was to determine changes in gene expression in the liver, an organ important for S metabolism, of fibre-fed steers consuming high-S water. For this study, liver tissues were collected on the final day of a trial from yearling steers randomly assigned to low-S water control (566 mg/kg SO4 ; n = 24), high-S water (3651 mg/kg SO4 ; n = 24) or high-S water plus clinoptilolite supplemented at either 2.5% (n = 24) or 5.0% (n = 24) of diet dry matter (DM). Microarray analyses on randomly selected healthy low-S control (n = 4) and high-S (n = 4; no clinoptilolite) steers using the Affymetrix GeneChip Bovine Genome Array revealed 488 genes upregulated (p < 0.05) and 154 genes downregulated (p < 0.05) in response to the high- vs. low-S water consumption. Real-time RT-PCR confirmed the upregulation (p < 0.10) of seven genes involved in inflammatory response and immune functions. Changes in such genes suggest that ruminant animals administered high-S water may be undergoing an inflammation or immune response, even if signs of sPEM or compromised health are not readily observed. Further study of these, and other affected genes, may deliver new insights into the physiology underlying the response to high dietary S, ultimately leading to the development of treatments for high S-affected ruminant livestock.


Asunto(s)
Bovinos/fisiología , Fibras de la Dieta/farmacología , Hígado/efectos de los fármacos , Azufre/toxicidad , Agua/química , Alimentación Animal , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Dieta/veterinaria , Regulación de la Expresión Génica/efectos de los fármacos , Péptidos y Proteínas de Señalización Intracelular , Hígado/metabolismo , Masculino , Oxidación-Reducción , Azufre/química , Transcriptoma , Regulación hacia Arriba
2.
Diam Relat Mater ; 17(4-5): 419-427, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19112519

RESUMEN

Ultra smooth nanostructured diamond (USND) coatings were deposited by microwave plasma chemical vapor deposition (MPCVD) technique using He/H(2)/CH(4)/N(2) gas mixture. The RMS surface roughness as low as 4 nm (2 micron square area) and grain size of 5-6 nm diamond coatings were achieved on medical grade titanium alloy. Previously it was demonstrated that the C(2) species in the plasma is responsible for the production of nanocrystalline diamond coatings in the Ar/H(2)/CH(4) gas mixture. In this work we have found that CN species is responsible for the production of USND coatings in He/H(2)/CH(4)/N(2) plasma. It was found that diamond coatings deposited with higher CN species concentration (normalized by Balmer H(α) line) in the plasma produced smoother and highly nanostructured diamond coatings. The correlation between CN/H(α) ratios with the coating roughness and grain size were also confirmed with different set of gas flows/plasma parameters. It is suggested that the presence of CN species could be responsible for producing nanocrystallinity in the growth of USND coatings using He/H(2)/CH(4)/N(2) gas mixture. The RMS roughness of 4 nm and grain size of 5-6 nm were calculated from the deposited diamond coatings using the gas mixture which produced the highest CN/H(α) species in the plasma. Wear tests were performed on the OrthoPOD(®), a six station pin-on-disk apparatus with ultra-high molecular weight polyethylene (UHMWPE) pins articulating on USND disks and CoCrMo alloy disk. Wear of the UHMWPE was found to be lower for the polyethylene on USND than that of polyethylene on CoCrMo alloy.

3.
J Natl Cancer Inst ; 82(13): 1127-32, 1990 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-2193166

RESUMEN

Preliminary information has suggested that megestrol acetate leads to appetite stimulation and nonfluid weight gain in patients with breast cancer, other cancers, and AIDS. Pursuant to this, we developed a randomized, double-blind, placebo-controlled trial of megestrol acetate in patients with cancer-associated anorexia and cachexia. We randomly assigned 133 eligible patients to receive 800 mg of megestrol acetate per day or a placebo. Patients assigned to megestrol acetate more frequently reported improved appetite (P = .003) and food intake (P = .009) when compared with patients receiving the placebo. A weight gain of 15 lb or more over baseline was seen in 11 of 67 (16%) patients receiving megestrol acetate compared with one of 66 (2%) given the placebo (P = .003). Patients receiving megestrol acetate reported significantly less nausea (13% vs. 38%; P = .001) and emesis (8% vs. 25%, P = .009). No clinically or statistically significant toxic reactions were ascribed to megestrol acetate, with the exception of mild edema. This study convincingly demonstrated that megestrol acetate can stimulate appetite and food intake in patients with anorexia and cachexia associated with cancer, leading to significant weight gain in a proportion of such patients.


Asunto(s)
Anorexia/tratamiento farmacológico , Caquexia/tratamiento farmacológico , Trastornos de Alimentación y de la Ingestión de Alimentos/tratamiento farmacológico , Megestrol/análogos & derivados , Neoplasias/complicaciones , Adulto , Anciano , Anciano de 80 o más Años , Anorexia/etiología , Antineoplásicos/uso terapéutico , Apetito/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Caquexia/etiología , Ingestión de Alimentos/efectos de los fármacos , Femenino , Estudios de Seguimiento , Neoplasias Gastrointestinales/complicaciones , Neoplasias Gastrointestinales/tratamiento farmacológico , Humanos , Neoplasias Pulmonares/complicaciones , Neoplasias Pulmonares/tratamiento farmacológico , Masculino , Megestrol/uso terapéutico , Megestrol/toxicidad , Acetato de Megestrol , Persona de Mediana Edad , Neoplasias/tratamiento farmacológico , Ensayos Clínicos Controlados Aleatorios como Asunto
4.
J Natl Cancer Inst ; 82(24): 1899-903, 1990 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-2174464

RESUMEN

In an effort to test clinically the hypothesis that the duration of cellular exposure to etoposide (VP-16) and cisplatin (CDDP) is an important determinant of cytotoxicity, we performed a phase III randomized trial comparing an outpatient bolus regimen of combined VP-16 and CDDP with a sequential infusion over 72 hours of these same two drugs. All patients had stage IV non-small cell lung cancer, and survival was the primary end point. Of 113 patients randomly allocated to the study, 108 were assessable for response, survival, and toxicity. A major response was observed in 20 (37%) of 54 patients on the bolus regimen and in 16 (30%) of 54 patients receiving infusion therapy. The median time to progression was 61 and 88 days for bolus and infusion therapy, respectively. The median survival time was 148 and 157 days, respectively (P = .71). Study results were not consistent with the possibility that infusion therapy could be associated with a 50% improvement in median survival, i.e. from 5 months to 7 1/2 months. Toxicity was primarily myelosuppression and was significantly greater with the infusion regimen. We conclude that infusion therapy as tested in this protocol with VP-16 and CDDP does not offer any advantage in response rate, time to disease progression, or survival as compared with bolus therapy. In addition, infusion therapy is associated with a greater degree of neutropenia and more treatment-related deaths.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Adulto , Anciano , Supervivencia Celular/efectos de los fármacos , Cisplatino/administración & dosificación , Esquema de Medicación , Sinergismo Farmacológico , Etopósido/administración & dosificación , Femenino , Humanos , Infusiones Intravenosas , Inyecciones Intravenosas , Masculino , Persona de Mediana Edad
5.
J Clin Oncol ; 4(2): 160-4, 1986 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2418167

RESUMEN

Fifty-one patients with diffuse large-cell lymphoma (DLCL) were treated with a six-drug combination chemotherapy regimen including cyclophosphamide, doxorubicin, procarbazine, bleomycin, vincristine, and prednisone. The patients were restaged after three cycles of therapy, and restaging was repeated at 2-month intervals in patients who had persistent disease. Responding patients received two cycles of therapy after documentation of complete remission (CR). With all patients considered evaluable, 73% of the patients achieved a CR. Twenty-six of the 37 CRs (70%) achieved remission in the first three treatment cycles. The durability of remission in the rapidly responding patients was significantly better than for patients who required five cycles to achieve CR (80% v 40% at 2 years, P = .02) despite the latter patients having received two more cycles of therapy. Rapidly responding patients with DLCL do not require prolonged therapy and have a better prognosis than patients achieving a CR more slowly.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Linfoma/tratamiento farmacológico , Análisis Actuarial , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Bleomicina/administración & dosificación , Ciclofosfamida/administración & dosificación , Doxorrubicina/administración & dosificación , Esquema de Medicación , Femenino , Humanos , Linfoma/patología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Prednisona/administración & dosificación , Procarbazina/administración & dosificación , Vincristina/administración & dosificación
6.
J Clin Oncol ; 9(12): 2104-9, 1991 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1960551

RESUMEN

We performed a prospective, controlled trial of recombinant leukocyte A interferon (IFN-alpha 2A) with or without aspirin (ASA) in 176 patients with assessable advanced renal cell cancer in light of a 34% response rate (10 of 29 patients) from the two-agent regimen in an earlier nonrandomized trial. This encouraging result was substantially higher than the 15% response rate typically achieved with IFN therapy alone. Eighty-seven patients received IFN-alpha 2A 20 x 10(6) U/m2 intramuscularly three times a week, and 89 received the same IFN therapy with ASA 600 mg orally four times each day. Each group was balanced as to relevant prognostic discriminants. Response rates were 8% for the group receiving ASA in addition to IFN, and 13% for the group receiving IFN alone (P = .30). The median times to progression were 1.9 months for the group receiving IFN with ASA and 2.7 months for the group receiving IFN alone (log-rank P = .36). The median survival durations were 8.8 months for the IFN and ASA group and 8.0 months for the IFN-only group (log-rank P = .60). These figures are also inferior to those typically reported from other studies. Our findings reemphasize the crucial role of randomized trials, admittedly cumbersome and time-consuming, to determine accurately the value of apparently promising therapies. Although some patients may derive benefit from IFN therapy, our findings raise disturbing questions regarding the potential IFN-alpha 2A according to the dose and schedule used in this trial to have any substantive impact on the ultimate outcome of disseminated renal cell cancer.


Asunto(s)
Aspirina/uso terapéutico , Carcinoma de Células Renales/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Neoplasias Renales/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Aspirina/efectos adversos , Evaluación de Medicamentos , Femenino , Humanos , Interferón alfa-2 , Interferón-alfa/efectos adversos , Interferón-alfa/antagonistas & inhibidores , Masculino , Persona de Mediana Edad , Proteínas Recombinantes , Análisis de Supervivencia
7.
FEBS Lett ; 348(1): 75-9, 1994 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-8026588

RESUMEN

Radioligand binding and cDNA homology studies have suggested the existence of opiate receptors distinct from the recently-cloned mu, delta and kappa receptors. XOR1S, a rat brain cDNA whose predicted translation product displays 67-72% homology with those encoded by mu 1, delta 1 and kappa 1 opiate receptor cDNAs, was constructed from two partial cDNAs identified through cDNA homology approaches. A longer XOR1L variant of this cDNA was also identified by polymerase chain reaction studies using genomic DNA and cDNA from brain and peripheral tissues. XOR1 mRNA is most highly expressed in hypothalamus. COS cell expression of both clones confers neither robust binding of opiate ligands nor reproducible opiate inhibition of forskolin-stimulated adenylate cyclase. These studies identify an orphan clone that helps to define features of the opiate receptor gene family, including apparent differential splicing and expression in peripheral tissues.


Asunto(s)
Empalme Alternativo , Familia de Multigenes , Receptores Opioides/genética , Adolescente , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Línea Celular , Corteza Cerebral/metabolismo , Clonación Molecular , Cartilla de ADN , ADN Complementario , Cobayas , Humanos , Datos de Secuencia Molecular , Ratas , Receptores Opioides/metabolismo
8.
FEBS Lett ; 338(2): 217-22, 1994 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-7905839

RESUMEN

A human mu opiate receptor cDNA has been identified from a cerebral cortical cDNA library using sequences from the rat mu opiate receptor cDNA. The human mu opiate receptor (h mu OR1) shares 95% amino acid identity with the rat sequence. The expressed mu OR1 recognized tested opiate drugs and opioid peptides in a sodium- and GTP-sensitive fashion with affinities virtually identical to those displayed by the rat mu opiate receptor. Effects on cyclic AMP are similar to those noted for the rat mu opiate receptor. An 18 kb genomic clone hybridizing with the h mu OR1 cDNA contains 63 and 489 bp exonic sequences flanked by splice donor/acceptor sequences. Analysis of hybridization to DNA prepared from human rodent hybrid cell lines and chromosomal in situ hybridization studies indicate localization to 6q24-25. An MspI polymorphism, producing a 3.7 kb band, may prove useful in assessing this gene's involvement in neuropsychiatric disorders involving opiatergic systems.


Asunto(s)
Mapeo Cromosómico , Clonación Molecular , ADN Complementario/química , Receptores Opioides mu/genética , Secuencia de Aminoácidos , Animales , Corteza Cerebral/química , Cromosomas Humanos Par 6 , Enzimas de Restricción del ADN/metabolismo , Encefalina Ala(2)-MeFe(4)-Gli(5) , Encefalinas/metabolismo , Humanos , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Polimorfismo de Longitud del Fragmento de Restricción , Ratas , Receptores Opioides mu/química , Receptores Opioides mu/fisiología , Homología de Secuencia
9.
Brain Res Mol Brain Res ; 79(1-2): 159-62, 2000 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-10925154

RESUMEN

Removal of a 712 base pair (bp) sequence following the coding region of a human micro opioid receptor (hmuOR) cDNA unexpectedly increased expression of the receptor protein. A series of 3'-noncoding region deletion mutants revealed that at least three discrete regions following the stop codon influenced receptor expression levels. Deletion of the 205-bp 5'-noncoding region immediately preceding the Kozak sequence doubled receptor expression relative to wild type, and simultaneous deletion of 5'- and 3'-noncoding regions increased expression several fold. The hmuOR noncoding regions may participate in a regulatory mechanism that controls the number of cell surface receptors.


Asunto(s)
Receptores Opioides mu/genética , Regiones no Traducidas 3'/genética , Regiones no Traducidas 5'/genética , Animales , Células COS , ADN Complementario , Encefalina Ala(2)-MeFe(4)-Gli(5)/farmacocinética , Regulación de la Expresión Génica , Humanos , Receptores Opioides mu/metabolismo , Proteínas Recombinantes/metabolismo , Eliminación de Secuencia , Transfección
10.
Brain Res Mol Brain Res ; 72(2): 195-204, 1999 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-10529478

RESUMEN

The mu opioid receptor, a primary site of action in the brain for opioid neuropeptides and opiate drugs of abuse, is a member of the seven transmembrane, G protein-coupled receptor (GPCR) superfamily. Two cysteine residues, one in each of the first two of three extracellular loops (ECLs), are highly conserved among GPCRs, and there is direct or circumstantial evidence that the residues form a disulfide bond in many of these receptors. Such a bond would dramatically govern the topology of the ECLs, and possibly affect the position of the membrane-spanning domains. Recent findings from several laboratories indicate the importance of the ECLs for opioid ligand selectivity. These conserved cysteine residues in the mu opioid receptor were studied using site-directed mutagenesis. Little or no specific binding of radiolabled opiate alkaloid or opioid peptide agonists or antagonists was observed for receptors mutated at either "disulfide cysteine" residue. Each mutant mu opioid receptor was expressed in both transiently- and stably-transfected cells, in some cases at levels comparable to the wild type receptor. The two point mutants possessing serine-for-cysteine substitutions were also observed to successfully reach the cell plasma membrane, as evidenced by electron microscopy. Consistent with related work with other GPCRs, the mu opioid receptor apparently also employs the extracellular disulfide bond. This information now permits accurate molecular modeling of extracellular aspects of the receptor, including plausible scenarios of mu receptor docking of opioid ligands known to require specific extracellular loop features for high affinity binding.


Asunto(s)
Cisteína/química , Proteínas del Tejido Nervioso/genética , Receptores Opioides mu/genética , Sustitución de Aminoácidos , Animales , Células CHO , Células COS , Chlorocebus aethiops , Cricetinae , Cricetulus , Cistina/química , Encefalina Ala(2)-MeFe(4)-Gli(5)/metabolismo , Humanos , Ligandos , Morfina/metabolismo , Mutagénesis Sitio-Dirigida , Naloxona/metabolismo , Antagonistas de Narcóticos/metabolismo , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/metabolismo , Péptidos/metabolismo , Mutación Puntual , Unión Proteica , Estructura Terciaria de Proteína , Ensayo de Unión Radioligante , Receptores Opioides mu/química , Receptores Opioides mu/metabolismo , Relación Estructura-Actividad , Transfección
11.
Neuroreport ; 5(4): 507-9, 1994 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-8003685

RESUMEN

The recently cloned rat mu opiate receptor cDNA has been expressed in COS and Chinese hamster ovary (CHO) cells to examine the coupling of this receptor to G-protein linked second messenger systems and examine possible coupling to multiple second messenger systems. Morphine (1 microM) reduced both forskolin-stimulated cAMP levels and IP3 levels by 20 +/- 5 and 34 +/- 8% respectively in COS and CHO cell cultures expressing the cloned rat mu receptor cDNA. Both effects could be blocked by naloxone and Gpp(NH)p. These results represent the first clear representation of the second messenger system promiscuity possible with a single cloned opiate receptor.


Asunto(s)
Adenilil Ciclasas/metabolismo , Fosfatidilinositoles/metabolismo , Receptores Opioides mu/biosíntesis , Sistemas de Mensajero Secundario/fisiología , Animales , Células CHO , Línea Celular , Clonación Molecular , Colforsina/farmacología , Cricetinae , ADN Complementario/biosíntesis , Guanilil Imidodifosfato/farmacología , Morfina/farmacología , Naloxona/farmacología , Ratas , Receptores Opioides mu/genética , Proteínas Recombinantes/biosíntesis
12.
Arch Surg ; 122(11): 1280-3, 1987 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-3675192

RESUMEN

We reviewed complications requiring removal of Hickman catheters (HCs) and implantable central venous access devices (ICVADs) in patients with cancer over a 30-month period. The study was unique in the sense that patients chose which system would be inserted, unless continuous infusion was anticipated. A total of 115 systems were inserted in 102 patients. Forty-four HCs were inserted in 34 patients (total system days, 8533 [mean, 194 days]); 71 ICVADs were inserted in 68 patients (total system days, 18,681 [mean, 263 days]). Complications required removal in 38.6% of HCs and 18.3% of ICVADs. Complication rates were one in 501 days in the HC group and one in 1450 days in the ICVAD group. Although 15 systems were removed for suspected infection, closer analysis revealed that bacteremia ultimately found to be unrelated to the catheter resulted in premature removal in many cases. The catheter tip was located high in the superior vena cava or in the subclavian vein in all systems removed due to thrombosis. Miscellaneous complications in HCs included dislodgment and catheter embolism. The increased longevity, lower complication rate, and decreased maintenance requirements in the use of ICVADs support their superiority over HCs in the treatment of patients with cancer.


Asunto(s)
Cateterismo Venoso Central/instrumentación , Neoplasias/terapia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Cateterismo Venoso Central/efectos adversos , Niño , Preescolar , Falla de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad
13.
Am J Prev Med ; 8(3): 186-92, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1385968

RESUMEN

The efficacy of fish oil in decreasing restenosis following percutaneous transluminal coronary angioplasty (PTCA) remains controversial despite seven published reports of randomized trials involving 951 patients. We performed a meta-analysis to determine whether these trials, viewed in aggregate, demonstrate a significant benefit. We evaluated rates of restenosis two to 12 months after PTCA and calculated an estimate of the overall effect and 95% confidence interval (CI). The typical odds ratio (treatment versus control) was 0.71 (95% CI 0.54, 0.94), P = 0.016 (two-tailed). The data show a strong and highly significant (P less than .0001) relationship between daily fish oil dose and gastrointestinal side effects. While compatible with a small to moderate benefit of fish oil on rates of restenosis, these results require confirmation in a randomized clinical trial large enough to distinguish reliably between a clinically meaningful benefit and a null result.


Asunto(s)
Angioplastia Coronaria con Balón , Enfermedad Coronaria/prevención & control , Aceites de Pescado/uso terapéutico , Enfermedad Coronaria/terapia , Femenino , Humanos , Masculino , Metaanálisis como Asunto , Persona de Mediana Edad , Ensayos Clínicos Controlados Aleatorios como Asunto , Recurrencia
14.
Am J Clin Oncol ; 11(2): 149-51, 1988 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-2451883

RESUMEN

In a randomized phase II trial of two cisplatin-based chemotherapy regimens, 45 patients with advanced cervical carcinoma received a combination of bleomycin, cyclophosphamide, doxorubicin, and cisplatin (BCAP), and 45 others received bleomycin plus cisplatin (BP). BCAP was repeated every 4 weeks, and BP was given at 3-week intervals. Although 19 of 43 (44%) evaluable patients receiving BCAP and 16 of 42 (38%) evaluable patients receiving BP experienced tumor regression, only 22% of those receiving BCAP and 21% of those on BP survived 1 year after beginning treatment. Among bidimensionally measurable patients, 15 of 27 (56%) and 8 of 25 (32%) receiving BCAP and BP, respectively, achieved tumor regression. One patient died of bleeding resulting from severe myelosuppression on BCAP, and two others succumbed to pulmonary toxicity of bleomycin on the BP regimen. Although active against cervical carcinoma, these regimens have limited therapeutic value at this advanced stage of the disease.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias del Cuello Uterino/tratamiento farmacológico , Adulto , Anciano , Bleomicina/administración & dosificación , Cisplatino/administración & dosificación , Ciclofosfamida/administración & dosificación , Doxorrubicina/administración & dosificación , Evaluación de Medicamentos , Femenino , Humanos , Persona de Mediana Edad , Distribución Aleatoria
15.
J Anim Sci ; 71(2): 515-21, 1993 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8440672

RESUMEN

A digestibility trial involving 20 Hampshire ram lambs and a 2-yr grazing study using 103 mature crossbred cows were conducted to determine the effects of methionine addition to a urea-grain supplement on intake and digestibility of dormant range grasses and on cow performance. In each trial, four treatment groups were supplemented with either a urea-grain control (CON), urea-grain plus methionine (MET, 3.3% DL-methionine), urea-grain plus inorganic sulfur (SUL, 3.0% sodium sulfate), or soybean meal (SBM). Supplements were designed to provide 45 and 360 g of CP.animal-1.d-1 (lambs and cows, respectively) and were balanced for ME, Ca, P, and K. Lambs had ad libitum access to mature prairie hay, whereas cows grazed dormant winter range from mid-November until mid-February. For the grazing study, forage OM intake (OMI) was determined in late November and in late January by the fecal output/indigestibility ratio technique. Controlled-release chromic oxide boluses were used as an external marker to estimate fecal output, and acid insoluble ash was used as an internal marker to predict OM digestibility (OMD). Mean daily DMI of mature prairie hay was 1,057 g/lamb and was not affected by supplementation. Apparent DM, NDF, and ADF digestibilities and N biological value did not differ (P > .10) among treatments. Nitrogen digestibility was increased (P = .06) for lambs fed the MET or SUL compared with CON.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Alimentación Animal , Bovinos/fisiología , Digestión , Ingestión de Alimentos , Metionina/administración & dosificación , Animales , Bovinos/crecimiento & desarrollo , Grano Comestible , Femenino , Alimentos Fortificados , Masculino , Poaceae , Embarazo , Ovinos/fisiología , Urea , Aumento de Peso
16.
J Anim Sci ; 76(2): 378-87, 1998 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9498342

RESUMEN

We conducted two studies to compare wheat middlings as a low-protein, highly digestible fiber supplement to soybean meal and corn-soybean meal supplement for cows grazing winter range. In two 60-d winter grazing trials (December to February) cows (BW 500 kg) were allotted by age and weight to a 2 x 4 factorial with two forage availabilities and four supplements. Cows received either soybean meal (SBM), corn-soybean meal (CS), low wheat middlings (LWM), or high wheat middlings (HWM). The SBM and LWM supplements were formulated to provide the same daily CP, and CS and HWM provided the same daily CP and ME. In a 4 x 4 Latin square, four ruminally fistulated steers (BW 765 kg) received the same supplements and had free access to mature prairie hay. Cows grazing the high forage pasture gained more (P < .01) weight than cows grazing the low forage pasture. Cows supplemented with HWM gained less weight (P = .05) than cows supplemented with a similar amount of CP and ME from CS. Weight change of cows receiving SBM or LWM was similar. Increasing the amount of wheat middlings from LWM to HWM increased weight change (P = .04). In Exp. 2, SBM and LWM had similar total digestible DMI (DDMI). Steers supplemented with CS had higher total (P = .08) DDMI than HWM. Supplementation with HWM resulted in lower total (P = .02) DDMI than LWM. Response to SBM and LWM was similar. The CS and HWM resulted in beneficial performance responses as well as increasing the level of wheat middlings from low to high.


Asunto(s)
Alimentación Animal , Digestión , Alimentos Fortificados , Triticum , Animales , Bovinos , Fibras de la Dieta , Femenino , Carne , Poaceae , Estaciones del Año
17.
J Anim Sci ; 90(13): 5005-12, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22871931

RESUMEN

Poor performance and S-induced polioencephalomalacia (sPEM) have been observed in ruminant livestock in high-S drinking water regions. No gainful method of removing S from drinking water is available and therefore a feed supplement that negates the effects of high-S water is needed. Our objective was to determine if supplementing Mo improves health and performance of steers administered a high-fiber diet and high-S drinking water. We hypothesized that if the supplemental Mo adequately bound excess S in the rumen, it would not be available at toxic concentrations. Yearling steers (n = 96; 260.0 ± 1.3 kg BW) were stratified by pretrial BW into 12 feedlot pens (n = 8 steers per pen). One of 3 treatments, low-S water (LS; 375 mg SO(4)/L), high-S water (HS; 2,218 mg SO(4)/L), or high-S water plus Mo (HSMO; 2,218 mg SO(4)/L; 187.5 mg Mo/kg DM), were randomly assigned to pens within 4 blocks for a 56-d trial. Body weights were recorded on d -2, -1, 29, 56, and 57, ruminal H(2)S concentrations were measured by rumenocentesis on d -1, 29, and 57, and liver biopsies were performed on d -1 and 57. Performance data were analyzed over the 56-d trial period (overall) as well as over 2 periods: Period 1 (d 0 to d 28) and Period 2 (d 29 to d 56). One case of sPEM was confirmed by the presence of cortical lesions in the HS treatment group. Daily DMI and ADG were affected by treatment and period (P < 0.001) main effects. The LS steers had the greatest (P < 0.05) DMI followed by HS and HSMO steers, respectively. Similar results were observed for ADG. Daily water intake was affected (P < 0.001) by period only, with greater daily water intake in Period 2 than Period 1. Change in hepatic concentrations of Cu, Fe, and Mo over the course of the trial were all affected (P < 0.001) by treatment. Hepatic Cu increased from d 1 to 57 in LS and HS steers but was depleted in HSMO steers. Hepatic Fe and Mo increased in HSMO steers only. Ruminal H(2)S concentrations were affected by treatment (P < 0.021), with greater H(2)S concentrations in HSMO compared with LS and HS steers. Signs of Mo toxicity such as severe diarrhea, loss of body condition, anorexia, changes in hair color, and stiffness in joints were observed in the Mo supplemented steers. These results indicate that added dietary Mo does not adequately bind excess S in the rumen, causing aggravated toxic effects from potentially both the high dietary S and Mo.


Asunto(s)
Bovinos/crecimiento & desarrollo , Bovinos/metabolismo , Suplementos Dietéticos/análisis , Sulfuro de Hidrógeno/metabolismo , Molibdeno/administración & dosificación , Azufre/metabolismo , Alimentación Animal/análisis , Animales , Cobre/metabolismo , Fibras de la Dieta/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Espectrometría de Masas/veterinaria , Rumen/metabolismo
18.
J Anim Sci ; 88(5): 1777-85, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20081088

RESUMEN

Sulfur-induced polioencephalomalacia (sPEM), a neurological disorder affecting ruminants, is associated with consumption of diets with increased S (high-S). High-S water is commonly found in many western states and is a major source of dietary S for grazing cattle. Consumption of high-S water has been associated with sPEM and decreased performance. Identification of a feed supplement that would counteract the negative effects of high-S water would decrease the incidence of sPEM and prevent performance reductions in regions with problematic water sources. The objectives of this study were to 1) determine the effects of administering high-S drinking water to forage-fed feedlot steers on health and performance, and 2) determine the effectiveness of clinoptilolite, a clay mineral with increased cation-exchange capacity, in negating the effects of high-S drinking water. Yearling steers (n = 96; 318.2 +/- 2.1 kg of BW) were randomly assigned to 1 of 4 treatments for a 77-d trial period: control with low-S water (566 mg of SO(4)/L), high-S water (3,651 mg of SO(4)/L), or high-S water plus clinoptilolite supplemented at 2.5 or 5.0% of the diet DM. Feed and water consumption were measured daily, and all steers were weighed on d -2, -1, 29, 53, 76, and 77. Plasma samples were collected on d 0, 58, and 77, and liver samples on d 0 and 77. There was a greater (P or= 0.546) in ADG or G:F were observed. Plasma Cu decreased (P = 0.029) to a greater magnitude in high-S water steers than the control steers over the 77-d trial period. Mineral analyses of hepatic tissue from randomly selected healthy steers from each treatment group (n = 10 per treatment) showed an interaction (P

Asunto(s)
Alimentación Animal/análisis , Enfermedades de los Bovinos/prevención & control , Encefalomalacia/veterinaria , Azufre/efectos adversos , Agua/química , Zeolitas/farmacología , Animales , Antiinflamatorios/uso terapéutico , Bovinos , Enfermedades de los Bovinos/inducido químicamente , Enfermedades de los Bovinos/tratamiento farmacológico , Dexametasona/uso terapéutico , Dieta/veterinaria , Suplementos Dietéticos , Relación Dosis-Respuesta a Droga , Encefalomalacia/inducido químicamente , Encefalomalacia/tratamiento farmacológico , Encefalomalacia/prevención & control , Masculino , Azufre/química , Tiamina/uso terapéutico
20.
J Exp Biol ; 196: 229-36, 1994 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7823024

RESUMEN

Three distinct gene families encode transporter proteins that aid in temporal and spatial buffering of neurotransmitter and neurotransmitter metabolite concentrations and allow neurons to cycle and recycle transmitter molecules. Analyses of these gene families and their products are likely to enhance understanding of the molecular neurobiology of neuronal function and may elucidate contributors to the genetic etiologies of neurological and psychiatric disease.


Asunto(s)
Proteínas Portadoras/biosíntesis , Proteínas Portadoras/genética , Glicoproteínas/biosíntesis , Glicoproteínas/genética , Familia de Multigenes , Neuronas/fisiología , Neurotransmisores/metabolismo , Secuencia de Aminoácidos , Sistema de Transporte de Aminoácidos X-AG , Animales , Transporte Biológico , Proteínas Portadoras/química , Cloruros/metabolismo , Glicoproteínas/química , Humanos , Datos de Secuencia Molecular , Estructura Secundaria de Proteína , Sodio/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA