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1.
Diabetologia ; 56(9): 1934-43, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23797633

RESUMO

AIMS/HYPOTHESES: Despite oral hypoglycaemic medications being the most commonly used pharmacological treatments for type 2 diabetes, research is limited on their comparative safety, particularly their effects on overall mortality. We compared mortality risk with monotherapy initiation of four oral hypoglycaemic medications in a nationwide cohort of US veterans with type 2 diabetes. METHODS: We identified new users of oral hypoglycaemic medication monotherapy between 2004 and 2009 who received care for at least 1 year from the Veterans Health Administration.Patients were followed until initial monotherapy discontinuation,addition of another diabetes pharmacotherapy, death or end of follow-up. Mortality HRs were estimated using Cox regression adjusted for potential confounding factors. RESULTS: Among new users of metformin, sulfonylureas and rosiglitazone (185,360 men, 7,812 women), 4,256 (2.2%) died during follow-up. Average duration of medication use ranged from 1.4 to 1.7 years. Significantly higher mortality risk was seen for glibenclamide (known as glyburide in the USA and Canada) (HR 1.38, 95% CI 1.27, 1.50) or glipizide (HR 1.55,95% CI 1.43, 1.67) compared with metformin monotherapy,and for glipizide compared with rosiglitazone (HR 1.27, 95%CI 1.01, 1.59) or glibenclamide monotherapy (HR 1.12, 95%CI 1.02, 1.23). A significant sex­rosiglitazone interaction was seen (p=0.034) compared with metformin monotherapy, with women having a higher HR (HR 4.36, 95% CI 1.34, 14.20)than men (HR 1.19, 95% CI 0.95, 1.49). CONCLUSIONS/INTERPRETATIONS: Significantly higher mortality was associated with glibenclamide, glipizide and rosiglitazone use compared with metformin, and with glipizide use compared with rosiglitazone or glibenclamide. The potential for residual confounding by indication should be considered in interpreting these results.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Metformina/administração & dosagem , Compostos de Sulfonilureia/administração & dosagem , Tiazolidinedionas/administração & dosagem , Veteranos/estatística & dados numéricos , Diabetes Mellitus Tipo 2/mortalidade , Feminino , Seguimentos , Glipizida/administração & dosagem , Glipizida/efeitos adversos , Glibureto/administração & dosagem , Glibureto/efeitos adversos , Humanos , Hipoglicemiantes/efeitos adversos , Masculino , Metformina/efeitos adversos , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Rosiglitazona , Compostos de Sulfonilureia/efeitos adversos , Tiazolidinedionas/efeitos adversos , Fatores de Tempo , Estados Unidos/epidemiologia
2.
Transpl Infect Dis ; 13(1): 15-23, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20636480

RESUMO

BACKGROUND: Immunosuppressed patients are at increased risk for herpes zoster (HZ), but incidence in solid organ transplant (SOT) recipients has varied in multiple studies. To assess incidence of HZ, we examined patients who underwent SOT and received follow-up care within the large multicenter US Department of Veteran's Affairs healthcare system. METHODS: Incident cases of HZ were determined using ICD-9 coding from administrative databases. A multivariable Cox proportional hazards model, adjusted for a priori risk factors, was used to assess demographic factors associated with development of HZ. RESULTS: Among the 1077 eligible SOT recipients, the cohort-specific incidence rate of HZ was 22.2 per 1000 patient-years (95% confidence interval [CI], 18.1-27.4). African Americans (37.6 per 1000 [95% CI, 25.0-56.6]) and heart transplants recipients (40.0 per 1000 [95% CI, 23.2-68.9]) had the highest incidence of HZ. Patients transplanted between 2005 and 2007 had the lowest incidence (15.3 per 1000 [95% CI, 8.2-28.3]). In a multivariable model, African Americans (hazard ratio [HR] 1.88; 95% CI: 1.12, 3.17) and older transplant recipients (HR 1.13; 95% CI: 1.01, 1.27 [per 5-year increment]) had increased relative hazards of HZ. CONCLUSIONS: These data demonstrate that HZ is a common infectious complication following SOT. Future studies focused on HZ prevention are needed in this high-risk population.


Assuntos
Herpes Zoster/epidemiologia , Herpesvirus Humano 3 , Transplante de Órgãos/efeitos adversos , Negro ou Afro-Americano , Estudos de Coortes , Feminino , Transplante de Coração/efeitos adversos , Herpes Zoster/diagnóstico , Herpes Zoster/etnologia , Herpes Zoster/virologia , Humanos , Incidência , Classificação Internacional de Doenças , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Fatores de Risco
3.
Appl Environ Microbiol ; 74(4): 987-93, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18156324

RESUMO

Fibrobacter is a highly cellulolytic genus commonly found in the rumen of ruminant animals and cecum of monogastric animals. In this study, suppression subtractive hybridization was used to identify the genes present in Fibrobacter succinogenes S85 but absent from F. intestinalis DR7. A total of 1,082 subtractive clones were picked, plasmids were purified, and inserts were sequenced, and the clones lacking homology to F. intestinalis were confirmed by Southern hybridization. By comparison of the sequences of the clones to one another and to those of the F. succinogenes genome, 802 sequences or 955 putative genes, comprising approximately 409 kb of F. succinogenes genomic DNA, were identified that lack similarity to those of F. intestinalis chromosomal DNA. The functional groups of genes, including those involved in cell envelope structure and function, energy metabolism, and transport and binding, had the largest number of genes specific to F. succinogenes. Low-stringency Southern hybridization showed that at least 37 glycoside hydrolases are shared by both species. A cluster of genes responsible for heme, porphyrin, and cobalamin biosynthesis in F. succinogenes S85 was either missing from or not functional in F. intestinalis DR7, which explains the requirement of vitamin B12 for the growth of the F. intestinalis species. Two gene clusters encoding NADH-ubiquinone oxidoreductase subunits probably shared by Fibrobacter genera appear to have an important role in energy metabolism.


Assuntos
Fibrobacter/genética , Genes Bacterianos/genética , Genoma Bacteriano/genética , Southern Blotting , Biologia Computacional , Hibridização de Ácido Nucleico , Análise de Sequência de DNA , Especificidade da Espécie
4.
Nat Biotechnol ; 19(5): 429-33, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11329011

RESUMO

We have developed transgenic mouse models to determine whether endogenous expression of phytase transgenes in the digestive tract of monogastric animals can increase the bioavailability of dietary phytate, a major but indigestible form of dietary phosphorus. We constructed phytase transgenes composed of the appA phytase gene from Escherichia coli regulated for expression in salivary glands by the rat R15 proline-rich protein promoter or by the mouse parotid secretory protein promoter. Transgenic phytase is highly expressed in the parotid salivary glands and secreted in saliva as an enzymatically active 55 kDa glycosylated protein. Expression of salivary phytase reduces fecal phosphorus by 11%. These results suggest that the introduction of salivary phytase transgenes into monogastric farm animals offers a promising biological approach to relieving the requirement for dietary phosphate supplements and to reducing phosphorus pollution from animal agriculture.


Assuntos
6-Fitase/genética , Fosfatase Ácida/genética , Poluição Ambiental/prevenção & controle , Proteínas de Escherichia coli , Camundongos Transgênicos , Fósforo/metabolismo , Animais , Northern Blotting , Eletroforese em Gel de Poliacrilamida , Fezes/química , Feminino , Imuno-Histoquímica , Masculino , Esterco/análise , Camundongos , Camundongos Transgênicos/fisiologia , Glândula Parótida/enzimologia , Ratos , Glândula Submandibular/enzimologia
5.
Nat Biotechnol ; 19(8): 741-5, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11479566

RESUMO

To address the problem of manure-based environmental pollution in the pork industry, we have developed the phytase transgenic pig. The saliva of these pigs contains the enzyme phytase, which allows the pigs to digest the phosphorus in phytate, the most abundant source of phosphorus in the pig diet. Without this enzyme, phytate phosphorus passes undigested into manure to become the single most important manure pollutant of pork production. We show here that salivary phytase provides essentially complete digestion of dietary phytate phosphorus, relieves the requirement for inorganic phosphate supplements, and reduces fecal phosphorus output by up to 75%. These pigs offer a unique biological approach to the management of phosphorus nutrition and environmental pollution in the pork industry.


Assuntos
6-Fitase/química , 6-Fitase/genética , Animais Geneticamente Modificados , Fósforo/química , Saliva/enzimologia , Animais , Western Blotting , Suplementos Nutricionais , Imuno-Histoquímica , Esterco , Glândula Parótida/metabolismo , Fosfatos/farmacologia , Fósforo/metabolismo , Glândulas Salivares/metabolismo , Suínos , Transgenes
6.
Lung Cancer ; 100: 102-109, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27597288

RESUMO

OBJECTIVES: Among lung cancer patients depression symptoms are common and impact outcomes. The aims of this study were to determine risk factors that contribute to persistent or new onset depression symptoms during lung cancer treatment, and examine interactions between depression symptoms and health domains that influence mortality. MATERIALS AND METHODS: Prospective observational study in five healthcare systems and 15 Veterans Affairs medical centers. Patients in the Cancer Care Outcomes Research and Surveillance (CanCORS) Consortium with lung cancer were eligible. The 8-item Center for Epidemiologic Studies Depression (CES-D) scale was administered at baseline and follow-up. Scores ≥4 indicated elevated depressive symptoms. Health domains were measured using validated instruments. We applied logistic regression and Cox proportional hazards modeling to explore the association between depression symptoms, health domains, and mortality. RESULTS: Of 1790 participants, 38% had depression symptoms at baseline and among those still alive, 31% at follow-up. Risk factors for depression symptoms at follow-up included younger age (OR=2.81), female sex (OR=1.59), low income (OR=1.45), not being married (OR=1.74) and current smoking status (OR=1.80); high school education was associated with reduced odds of depression symptoms at follow-up, compared with lesser educational attainment (OR=0.74) (all p values <0.05). Patients with depression symptoms had worse health-related quality of life, vitality, cancer-specific symptoms, and social support than patients without depression symptoms (all p<0.001). The association between depression symptoms and increased mortality is greater among patients with more lung cancer symptoms (p=0.008) or less social support (p=0.04). CONCLUSIONS: Patient risk factors for depression symptoms at follow-up were identified and these subgroups should be targeted for enhanced surveillance. Patients with depression symptoms suffer across all health domains; however, only more lung cancer symptoms or less social support are associated with worse mortality among these patients. These potentially modifiable health domains suggest targets for possible intervention in future studies.


Assuntos
Depressão/complicações , Nível de Saúde , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Depressão/etnologia , Depressão/etiologia , Depressão/mortalidade , Estudos Epidemiológicos , Feminino , Humanos , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Qualidade de Vida , Fatores de Risco , Taxa de Sobrevida
7.
Biochim Biophys Acta ; 1357(2): 215-24, 1997 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-9223625

RESUMO

An endo (1-4)-beta-glucanase gene C6.5 from Bacillus subtilis has been expressed in Chinese hamster ovary (CHO) cells and pancreatic 266-6 cells. The fusion gene, stably transfected into CHO cells consisted of the mouse Amy-2.2 signal peptide coding sequence and the endoglucanase gene C6.5 transcribed from the early SV40 promoter/enhancer, using the dihydrofolate reductase gene as a selective marker. The gene construct transfected into pancreatic 266-6 cells consisted of the mouse Amy-2.2 promoter/enhancer and signal peptide coding sequence and the same C6.5 sequences using the xanthine-guanine phosphoribosyl transferase gene (gpt) as the selective marker. The stably transfected CHO cells synthesized endoglucanase at 1.1 U/mg cell protein in a 72 h culture, with 89% of the activity secreted into the culture fluid in a glycosylated form of 66 kDa as compared with the unglycosylated 53 kDa form expressed in E. coli. Glycosylation did not change the specific activity, protease resistance, or cellulose binding of the endoglucanase as compared to the unglycosylated form of the enzyme from E. coli. The level of expression in the stably transfected pancreatic cells was substantially lower at 0.3 mU/mg cell protein with all detectable activity present in the culture fluid. The secreted enzyme from pancreatic cells was glycosylated with a mass similar to that secreted from CHO cells.


Assuntos
Bacillus subtilis/genética , Celulase/genética , Pâncreas/enzimologia , Processamento de Proteína Pós-Traducional , Sequência de Aminoácidos , Animais , Bacillus subtilis/enzimologia , Sequência de Bases , Células CHO , Linhagem Celular , Celulase/química , Celulase/metabolismo , Cricetinae , Elementos Facilitadores Genéticos , Camundongos , Dados de Sequência Molecular , Plasmídeos , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas , Sinais Direcionadores de Proteínas , Proteínas Recombinantes de Fusão/metabolismo , Transfecção , alfa-Amilases/genética
8.
Andrology ; 3(2): 287-92, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25684636

RESUMO

Low serum testosterone (T) is common and increasingly prevalent with increased age. Recent studies report an 'epidemic' of T prescribing and concern about unnecessary T treatment. We investigated the number of men tested for T, the prevalence of low serum T levels, and initiation of T treatment among those with low T levels in men treated at Veterans Affairs (VA) facilities in the Northwest US (VISN 20). We identified male Veterans aged 40-89 years and examined yearly proportions of men tested for T, found to have low T levels (total T < 280 ng/dL, free T < 34 pg/mL, or bioavailable T < 84 ng/dL), and subsequently treated with T from 2002 to 2011. We excluded men who had T treatment in the year prior and men with diagnoses of prostate or breast cancer. Treatment initiation was defined as the first prescription for T within a year following a low T test. From 2002 to 2011, the yearly population of eligible men in VISN 20 increased from 129 247 to 163 572. The proportion of men who had serum T tests increased from 3.2% in 2002 to 5.8% in 2011. Among the tested men, the percentage of men with low T levels increased from 35.0 to 47.3%. However, the proportion of men with low T levels who were given T treatment within a year decreased from 31.0 to 28.0%. Despite large increases in T testing, and detection of men with low T levels, there was a slight decrease in the proportion of men with low T levels who were treated with T. The decrease in T treatment during this time period contrasts with other studies and may be related to higher comorbidity in Veterans and/or VA formulary restrictions on the use of transdermal T formulations.


Assuntos
Testosterona/administração & dosagem , Veteranos , Adulto , Idoso , Idoso de 80 Anos ou mais , Terapia de Reposição Hormonal , Humanos , Masculino , Pessoa de Meia-Idade , Estados Unidos
9.
J Anim Sci ; 63(1): 310-25, 1986 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-3525493

RESUMO

Recombinant DNA techniques offer a new approach to the study and eventual genetic manipulation of rumen bacteria to modify the rate and extent of nutrient digestion within the rumen. The foreign genes cloned into a rumen bacterium undoubtedly will have to enhance its ability to compete; otherwise, the new trait will be lost from the highly competitive environment within the rumen. As a general rule, the types of metabolic activities amenable to gene cloning may be those that enhance substrate versatility or eliminate a dependence of a specific rumen bacteria on cross-feeding by other rumen microorganisms. Enhanced substrate diversity and bypassing cross-feeding probably will become more important as the use of highly refined feeds and waste materials from the food and other industries are used in greater quantities to meet the dietary needs of ruminants.


Assuntos
DNA Recombinante , Fermentação , Engenharia Genética , Rúmen/microbiologia , Animais , Clonagem Molecular , Genes Bacterianos , Rúmen/metabolismo
10.
J Anim Sci ; 69(7): 3039-43, 1991 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1885412

RESUMO

Experiments were initiated to select a sterilization method(s) that minimizes alterations in the digestive properties of cereal grains and, thus, would be suitable for the study of cereal grain digestion by pure cultures of ruminal bacteria. The following five treatments were examined: unsterilized (U), autoclaving with buffer (AB), autoclaving without buffer (AD), ethylene oxide (E), and gamma irradiation (I). Solubility of DM, starch, and CP was determined by soaking grain in buffer for 1 h followed by filtration through Whatman #54 filter paper. Ground corn and wheat from each treatment were placed in vials with a 1:1 mixture of Bryant's medium and ruminal inoculum. Vials were incubated for 4, 8, 12, 24, and 48 h and analyzed for starch content. Bacterial growth was not evident in sterilized, uninoculated samples. The AD treatment decreased the disappearance of CP in wheat and corn, whereas AB caused an increase in the disappearance of DM, CP, and starch in wheat (P less than .001) compared with U. Rates of microbial starch digestion for corn were 1.3, 1.5, 3.3, 14.7, and 3.5%/h and for wheat were 1.3, 3.4, 4.6, 17.1, and 4.6%/h for AD, E, I, AB, and U, respectively. Contrasts indicated that AD and AB differed (P less than .001) from U for both corn and wheat. It is likely that gelatinization of cereal starch enhanced microbial starch digestion in AB and the formation of Maillard products reduced starch digestion in AD. Corn and wheat sterilized with E or I had digestive properties that closely resembled those of U grain, and either sterilization method was suitable for studying cereal grain digestion.


Assuntos
Bactérias/metabolismo , Digestão , Grão Comestível/microbiologia , Rúmen/microbiologia , Esterilização/métodos , Animais , Óxido de Etileno , Raios gama , Rúmen/metabolismo
11.
J Anim Sci ; 81(11): 2766-75, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14601880

RESUMO

The objectives of this study were to determine true P digestibility, the gastrointestinal endogenous P outputs associated with soybean meal (SBM), and the role of the large intestine in P digestion in growing pigs. Four Yorkshire barrows, with average initial and final BW of 40 and 58 kg, were fitted with a simple T-cannula at the distal ileum and fed four diets according to a 4 x 4 Latin square design. The diets were cornstarch-based and contained four levels of P (0.098, 0.196, 0.293, and 0.391% on a DM basis) from solvent-extracted conventional SBM. Chromic oxide (3.5 g/kg of diet, as-fed basis) was included as a digestibility marker. Each experimental period consisted of 8 d with a 4-d adaptation period and a 4-d collection of representative ileal digesta (2 d) and fecal (2 d) samples. True ileal and fecal P digestibility values and the ileal and fecal endogenous P outputs associated with SBM were determined by the regression analysis technique. There were no differences (P > 0.05) in true P digestibility values (ileal, 59.0 +/- 8.3 vs. fecal, 51.3 +/- 7.9%, n = 16) and endogenous P outputs (ileal, 0.59 +/- 0.18 vs. fecal, 0.45 +/- 0.21 g/kg of DMI, n = 16) between the ileal and the fecal levels. The endogenous fecal P loss accounted for 8.1 and 17.6% of the NRC (1998) recommended total and available P requirements in growing pigs, respectively. In conclusion, approximately 51% of the total P in conventional SBM is digested in growing pigs. The large intestine does not play an important role in the digestion of P associated with SBM in the growing pig. The fecal loss of the gastrointestinal endogenous P is an important route of P excretion in the growing pig.


Assuntos
Digestão , Glycine max , Íleo/metabolismo , Fósforo/metabolismo , Suínos/metabolismo , Animais , Compostos de Cromo/metabolismo , Relação Dose-Resposta a Droga , Fezes/química , Absorção Intestinal , Masculino , Necessidades Nutricionais , Valor Nutritivo , Distribuição Aleatória , Análise de Regressão , Suínos/crescimento & desenvolvimento
12.
Poult Sci ; 75(7): 891-9, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8966178

RESUMO

Two experiments were conducted to determine the physical, chemical, and microbial properties of turkey cecal droppings and relate them to intake of common dietary components, namely fat, fiber, and the anticoccidial, monensin. Experiment 1 involved collection and analysis of physical and chemical properties of cecal and regular droppings from commercial turkey flocks. Experiment 2 tested the effect of dietary fat, fiber, and monensin on growth performance and cecal activity in male turkeys. Compared to regular excreta, cecal droppings analyzed in Experiment 1 were higher in viscosity and fat content, and lower in dry matter, nitrogen, and fiber content (P < 0.05). High dietary fiber and fat significantly (P < 0.05) improved growth performance in Experiment 2. Prolonged feeding of monensin significantly (P < 0.05) reduced cecal evacuation. Results of chemical composition showed that higher dietary fat and fiber significantly (P < 0.01) reduced the fat percentage of cecal contents, whereas prolonged feeding of monensin increased the fat in both cecal contents and droppings. There was no significant effect of any of the treatments on pH, viscosity, and microbial counts of cecal contents. There is the need to identify and characterize the compound responsible for the high viscosity of cecal droppings.


Assuntos
Ceco/efeitos dos fármacos , Coccidiostáticos/farmacologia , Dieta/veterinária , Gorduras na Dieta/farmacologia , Fibras na Dieta/farmacologia , Monensin/farmacologia , Perus/fisiologia , Animais , Peso Corporal/efeitos dos fármacos , Peso Corporal/fisiologia , Ceco/metabolismo , Ceco/fisiologia , Coccidiostáticos/análise , Gorduras na Dieta/análise , Fibras na Dieta/análise , Fezes/química , Fezes/microbiologia , Concentração de Íons de Hidrogênio , Lipídeos/análise , Masculino , Monensin/análise , Nitrogênio/análise , Distribuição Aleatória , Perus/crescimento & desenvolvimento , Viscosidade , Aumento de Peso/efeitos dos fármacos , Aumento de Peso/fisiologia
13.
J Anim Sci ; 92(10): 4417-39, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25085399

RESUMO

A transgenic line of Yorkshire (YK) pigs named the Cassie (CA) line was produced with a low copy number phytase transgene inserted in the genome. The transgenic line efficiently digests P, Ca, and other major minerals of plant dietary origin. The objectives of this study were to 1) compare carcass and tissue nutrient composition and meat quality traits for third generation hemizygous CA line market BW finisher pigs (n = 24) with age-matched conventional YK finisher pigs (n = 24) and 2) examine effects of outbreeding with high-index conventional YK boars on modifying carcass leanness from the third to sixth generations in CA line finisher boars (n = 73) and gilts (n = 103). Cassie boars (n = 12) and CA gilts (n = 12) were fed diets without supplemental P and comparable numbers of age-matched YK boars and gilts fed diets containing supplement P were raised throughout the finisher phase. The pigs were slaughtered and then fabricated into commercial pork primals before meat composition and quality evaluation. Proximate and major micronutrient composition was determined on tissues including fat, kidney, lean, liver, and skin. The main difference observed was greater (P = 0.033) crude fat content in CA boar carcasses and increased (P < 0.04) leaf lard in both CA boars and gilts but no differences were observed (P = 0.895 and P = 0.223, respectively) in carcass backfat thickness as compared with YK pigs. There were no substantive differences in tissue composition, except for CA boar kidneys. Numerous changes in the mineral, fatty acid, and indispensable AA composition for CA boar kidneys were not apparent in CA gilts. These changes may point to adaptive physiological changes in the boar kidney necessary for homeostatic regulation of mineral retention related to phytase action rather than to insertion of the transgene. However, from a meat composition perspective, transgenic expression of phytase in the CA line of YK pigs had little overall effect on meat composition. Outbreeding of high-index CA gilts with high-index commercial YK boars linearly reduced (P = 0.002) back fat thickness with a corresponding linear increase (P = 0.001) in lean yield in finisher CA gilts, although no change in these parameters was observed in CA finisher boars. The increase in lean yield in CA gilts by selective breeding without affecting the level of salivary phytase activity documents the value of conventional genetic selection in conjunction with genetic modification.


Assuntos
6-Fitase/metabolismo , Animais Geneticamente Modificados/fisiologia , Composição Corporal/fisiologia , Rim/fisiologia , Carne , Saliva/metabolismo , Sus scrofa/fisiologia , 6-Fitase/genética , Fatores Etários , Animais , Animais Geneticamente Modificados/genética , Cruzamento/métodos , Suplementos Nutricionais , Técnicas de Transferência de Genes/veterinária , Fósforo/metabolismo , Sus scrofa/genética , Suínos
14.
J Anim Sci ; 92(8): 3375-87, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24902597

RESUMO

A transgenic Cassie (CA) line of Yorkshire (YK) pigs was developed using a transgene composed of the mouse parotid secretory protein promoter linked to the Escherichia coli phytase gene integrated in chromosome 4. Previous studies documented that salivary secretion of phytase was sufficient to enable efficient digestion of plant feed phytate P. In the present study the catalytic properties and tissue distribution of the phytase in CA pigs were determined by a combination of enzymatic assays, immunohistochemistry, and immunoblots of tissue samples. The E. coli phytase had a mass of 44.82 kDa whereas the phytase secreted in CA saliva had a mass of 52.42 kDa as a result of glycosylation of the enzyme in the parotid gland. Despite the difference in size, the 2 enzymes exhibited similar substrate specificities, and substrate affinity ( K: m) and maximum hydrolytic activity ( V: max) catalytic properties. Phytase assays showed that the enzyme was present at high specific activity in the salivary glands with low activity in the soft palate and essentially none in the kidney, lean (muscle), liver, or skin of CA pigs and none in YK pigs. This conclusion was supported by immunoblot analysis using a polyclonal anti-phytase antibody. Immunohistochemical analysis of 83 different tissue locations of CA and YK pigs confirmed the ubiquitous presence of phytase in serous cells of the salivary glands and the localized presence of phytase in both serous and mixed cell types in the submucosal glands of the oropharynx; in the pharynx, tonsils, and esophagus; in some Bowman's glands in the nasal mucosa and eustachian tube; and in the prostate gland of CA boars. Furthermore, it showed the absence of phytase from the kidney, lean, liver, and skin of CA pigs. Phytase was not detected in any of the conventional YK tissues tested. The phytase was found to be glycosylated with the allergenic galactose-α-1,3-galactose (α-gal) epitope by immunoblotting using α-gal specific monoclonal antibodies. Galactose-α-1,3-galactose glycosylation of proteins is a common feature of pork and other red meats. The α-gal epitope was shown to be associated with a few proteins in muscle and skin but with the greatest number of proteins in kidney and parotid tissues of CA and YK pigs. The absence of phytase from the major food tissues and the displacement of other α-gal glycosylated proteins in the parotid glands by α-gal glycosylated phytase in conjunction with previously published data support the contention that expression of the novel phytase has minimal influence on pork quality and safety.


Assuntos
6-Fitase/metabolismo , Animais Geneticamente Modificados/metabolismo , Palato/metabolismo , Glândula Parótida/metabolismo , Saliva/metabolismo , Glândulas Salivares/metabolismo , Suínos/metabolismo , Animais , Animais Geneticamente Modificados/genética , Encéfalo/metabolismo , Escherichia coli/enzimologia , Feminino , Concentração de Íons de Hidrogênio , Mucosa Intestinal/metabolismo , Masculino , Músculo Esquelético/metabolismo , Suínos/genética , Distribuição Tecidual
15.
J Anim Sci ; 91(3): 1307-20, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23296825

RESUMO

A line of transgenic Yorkshire pigs referred to as the Cassie (CA) line was generated, which possessed a stable, low copy number phytase transgene insertion that enabled phytase secretion in the saliva. This study was conducted to assess growth and efficacy for improving P, Ca, and other macromineral utilization in the CA pigs receiving diets typical of those used for commercial swine production. In Exp. 1, 12 CA boars and 12 CA gilts fed diets without supplemental P gained weight and exhibited feed efficiency similar to conventional age-matched 12 Yorkshire boars and 12 Yorkshire gilts raised on similar diets with supplemental P. Serum concentrations of P and Ca were similar for CA and Yorkshire pigs during the growing and finishing phases, indicating that the CA pigs were not P limited. In Exp. 2, 6 CA (13.1 kg BW) and 6 Yorkshire barrows (8.8 kg BW) were fed 3 diets (control; low in Ca and P; and low in Ca, P, and CP) over 3 phases. The CA barrows fed the diet without supplemental P retained 25 to 40% (P < 0.001), 77 to 91% (P < 0.001), and 27 to 56% (P < 0.001) more P during the weaning, growing, and finishing phases, respectively, than conventional Yorkshire barrows fed similar diets without supplemental P. In Exp. 3, CA and Yorkshire barrows of similar ages weighing 66.2 ± 1.7 kg (n = 10) and 50.0 ± 1.0 kg (n = 10), respectively, were used. The P retention of CA finisher barrows fed a diet without supplemental P was 34% greater (P < 0.001) than conventional Yorkshire barrows fed the same diet with 750 units of exogenous phytase/kg diet. Urinary Ca to P ratio in the CA pigs was 0.27, whereas that for the Yorkshire barrows was 30, thereby, indicating that the Yorkshire barrows suffered a P deficiency. Furthermore, digestive utilization of major electrolyte macrominerals, K and Na, was improved (P < 0.05) by 18 and 16%, respectively, in the CA finisher pigs compared with the conventional Yorkshire finisher pigs fed phytase; however, only K exhibited enhanced retention. In conclusion, the CA line pigs secrete sufficient phytase from the salivary glands to enable efficient digestion of plant P, Ca, and major electrolyte macrominerals.


Assuntos
6-Fitase/administração & dosagem , 6-Fitase/metabolismo , Digestão , Eletrólitos/metabolismo , Fósforo na Dieta/metabolismo , Sus scrofa/fisiologia , 6-Fitase/genética , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/crescimento & desenvolvimento , Animais Geneticamente Modificados/fisiologia , Análise Química do Sangue/veterinária , Cálcio/sangue , Cálcio/metabolismo , Cálcio/urina , Suplementos Nutricionais/análise , Eletrólitos/sangue , Eletrólitos/urina , Fezes/química , Masculino , Minerais/sangue , Minerais/metabolismo , Minerais/urina , Fósforo na Dieta/sangue , Fósforo na Dieta/urina , Espectrofotometria Atômica/veterinária , Sus scrofa/genética , Sus scrofa/crescimento & desenvolvimento
16.
Appl Environ Microbiol ; 53(4): 639-43, 1987 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16347311

RESUMO

Glycerol was fermented with the production of 1,3-propanediol as the major fermentation product by four strains of Clostridium acetobutylicum, six of C. butylicum, two of C. beijerinckii, one of C. kainantoi, and three of C. butyricum. 1,3-Propanediol was identified by its retention times in gas chromatography and high-pressure liquid chromatography and by its mass spectrum. During growth of C. butylicum B593 in a chemostat culture at pH 6.5, 61% of the glycerol fermented was converted to 1,3-propanediol. When the pH was decreased to 4.9, growth and 1,3-propanediol production were substantially reduced.

17.
Can J Microbiol ; 24(1): 36-44, 1978 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-754875

RESUMO

The rate of fermentation of the rumen microflora was inhibited almost 30% by 5 micrograms/ml of arsenic added in the form of arsenite, although 304 micrograms/ml was required to cause 50% inhibition. Arsenate was less inhibitory. The rate of fermentation of a separated bacterial fraction was inhibited 37% by 1 microgram of arsenite per millilitre, whereas 100 micrograms/ml had little effect on the fermentation of a separated protozoal fraction. Similar results were obtained for arsenate. Both fractions had the capacity to take up arsenate, but the protozoa took it up more readily to a higher intracellular concentration. Both arsenate and arsenite inhibited the growth of a number of rumen bacteria in pure culture at concentrations as low as 5 micrograms of arsenic per millilitre. The greater resistance of Megasphaera elsdenii to arsenate as compared with that of Bacteroides succinogenes was not related to the inability to take up the element. In conclusion, the concentrations of arsenic causing a significant inhibitory effect on the fermentative activity and growth of some rumen bacteria are less than that reported to be toxic to ruminant animals.


Assuntos
Arseniatos/farmacologia , Arsênio/farmacologia , Bactérias/efeitos dos fármacos , Eucariotos/efeitos dos fármacos , Rúmen/microbiologia , Anaerobiose , Animais , Arseniatos/metabolismo , Arsênio/metabolismo , Bactérias/metabolismo , Eucariotos/metabolismo , Fermentação , Especificidade da Espécie
18.
Can J Microbiol ; 24(3): 298-306, 1978 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-565671

RESUMO

The inhibitory effects of high concentrations of essential and non-essential trace elements were tested on the rumen microflora using the rate of fermentation in vitro as the assay. The elements (and the concentration causing 50% inhibition) in decreasing order of toxicity were Hg2+ (20 microgram/ml), Cu2+ (21 microgram/ml), Cr6+ (70 microgram/ml), Se4+ (73 microgram/ml), Ni2+ (160 microgram/ml), Cd2+ (175 microgram/ml), As3+ (304 microgram/ml) and As5+ (1610 microgram/ml). The elements tested that were either weak or noninhibitory at concentrations greater than 400 microgram/ml included Zn2+, Cr2+, Fe2+, Mn2+, Pb2+, and Co2+. Methylmercury was as inhibitory as mercuric chloride to the fermentation. When the inhibitory effect of Cd2+ was tested on separated bacterial and protozoal fractions, it was more inhibitory to the bacteria. The inhibitory effects of trace elements were also determined for a number of axenic cultures of rumen bacteria. The bacteria which most frequently exhibited the greatest sensitivity were Bacteroides succinogenses, Ruminococcus albus, Bacteroides amylophilus, and Eubacterium ruminantium. Those often exhibiting intermediate sensitivities included Butyrivibrio fibrisolvens, Selenomonas ruminantium, and Megasphera elsdenii, while Streptococcus bovis was very refractory to all elements tested. Rumen fluid provided a modest protective effect for the bacteria.


Assuntos
Bactérias/efeitos dos fármacos , Metais/farmacologia , Rúmen/microbiologia , Oligoelementos/farmacologia , Animais , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Fermentação/efeitos dos fármacos , Especificidade da Espécie , Sulfetos/farmacologia
19.
Appl Environ Microbiol ; 39(2): 453-5, 1980 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16345519

RESUMO

Two rumen nitrate-reducing isolates of Desulfovibrio desulfuricans were found to hydrolyze cysteine with the production of sulfide and pyruvate. When cultured on agar medium containing yeast extract with nitrate as the primary electron acceptor and ferrous chloride as the indicator, blackening of colonies occurred. The blackening of colonies appeared sooner and was more intense when either cysteine or sulfate was added to the culture medium with nitrate present.

20.
Can J Microbiol ; 24(8): 981-5, 1978 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-688105

RESUMO

Megasphaera elsdenii B159 (formerly Peptostreptococcus elsdenii; Rogosa 1971) is able to grow in a chemically defined medium containing minerals, NH4+ as the sole nitrogen source, sulfate as the source of sulfur, acetate and glucose as the carbon and energy sources, and the vitamins biotin, pyridoxine, and calcium pantothenate. When lactate serves as the carbon source, with cysteine present as the reducing agent, acetate is not required. Valine and threonine appeared to be required although direct inoculation of unwashed cells into media lacking these amino acids permitted growth in their absence after an extended incubation period. Sulfur sources utilized included sulfate, sulfide, thiosulfate, cysteine, and glutathionine; methionine was utilized less readily. When glucose was autoclaved in the medium, the generation time of M. elsdenii was 170--200 min, but increased to more than 400 min when glucose was autoclaved separately and added to the cooled sterile medium. When fructose, which had been sterilized separately, was utilized as the carbon and energy source, the generation time was 200 min.


Assuntos
Peptostreptococcus/crescimento & desenvolvimento , Acetatos/metabolismo , Aminoácidos/metabolismo , Biotina/metabolismo , Carbono/metabolismo , Meios de Cultura , Metabolismo Energético , Glucose/metabolismo , Nitrogênio/metabolismo , Peptostreptococcus/metabolismo , Piridoxina/metabolismo , Sulfatos/metabolismo , Enxofre/metabolismo
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