18 results on '"Teixeira LV"'
Search Results
2. Impact of the Supplementation of Exogenous Protease and Carbohydrase on the Metabolizable Energy and Standardized Ileal Amino Acid Digestibility of Soybean Meals in Two Brazilian Regions
- Author
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Silva, DL, primary, Dalólio, FS, additional, Teixeira, LV, additional, Sens, RF, additional, Albino, LFT, additional, and Rostagno, HS, additional
- Published
- 2022
- Full Text
- View/download PDF
3. Protease Supplementation under Amino Acid Reduction in Diets Formulated with Different Nutritional Requirements for Broilers
- Author
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Dessimoni, GV, primary, Dalólio, FS, additional, Moreira, J, additional, Teixeira, LV, additional, Bertechini, AG, additional, and Hermes, RG, additional
- Published
- 2019
- Full Text
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4. Spontaneously Hypertensive Rats Present Exacerbated Focal Stroke Behavioral Outcomes.
- Author
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Moreira JVME, Bernardi LP, Teixeira FC, Paniago J, Teixeira LV, Bifi F, Souza DO, and Rohden F
- Abstract
This study aimed to analyze the effects of systemic arterial hypertension (SAH) in a model of permanent ischemic stroke (focal ischemia due to thermocoagulation of pial vessels) on sensorimotor function (cylinder test and patch removal test), behavioral tasks (novelty habituation memory open field task) and cerebral infarct size in adult male spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) for 42 days after the occurrence of a stroke. We observed that the stroke caused asymmetry in the front paws and delayed adhesive removal. These effects were spontaneously reduced in WKY rats, but not in SHR. Short- and long-term novelty habituation memories were abolished by stroke in WYK and SHR. On the 3rd day after stroke, the size of the focal cerebral infarct was the same in WKY and SHR. However, on the 7th day, the infarct size decreased in WKY rats, but not SHR. These results suggested that SAH impairment of sensorimotor recovery in rats subjected to cerebral ischemia could be related to augmented focal cerebral infarct size. Moreover, the behavioral tasks used in this study were unaffected by Systemic Arterial Hypertension. Our results highlight the need for animal models of comorbidities in stroke research.
- Published
- 2024
- Full Text
- View/download PDF
5. Preventive aerobic training preserves sympathovagal function and improves DNA repair capacity of peripheral blood mononuclear cells in rats with cardiomyopathy.
- Author
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Ghignatti PVDC, Russo MKB, Becker T, Guecheva TN, Teixeira LV, Lehnen AM, Schaun MI, and Leguisamo NM
- Subjects
- Animals, DNA Repair, Doxorubicin pharmacology, Leukocytes, Mononuclear, Male, Rats, Rats, Inbred WKY, Troponin T, Cardiomyopathies chemically induced, Physical Conditioning, Animal
- Abstract
To evaluate the effect of preventive aerobic exercise training on sympathovagal function, cardiac function, and DNA repair capacity in a preclinical model of doxorubicin (DOX)-induced cardiomyopathy. Forty male Wistar-Kyoto rats were allocated into four groups (n = 10/group): D (DOX-treated) and C (controls) remained sedentary, and DT (DOX-trained) and CT (control-trained) performed aerobic training 4 days/week, during 4 weeks before exposure to DOX (4 mg/kg/week during 4 weeks) or saline solution. We evaluated cardiac function (echocardiography), hemodynamic and sympathovagal modulation (artery-femoral cannulation), cardiac troponin T levels, and DNA repair capacity (comet assay). Exercise training preserved ejection fraction (D: - 14.44% vs. DT: - 1.05%, p < 0.001), fractional shortening (D: - 8.96% vs. DT: - 0.27%, p = 0.025) and troponin T levels (D: 6.4 ± 3.6 vs. DT: 2.8 ± 1.7 ng/mL, p = 0.010). DOX increased heart rate variability (C: 27.7 ± 7.9 vs. D: 7.5 ± 2.2 ms
2 , p < 0.001) and induced sympathovagal dysfunction (LF/HF, C: 0.37 ± 0.15 vs. D: 0.15 ± 0.15, p = 0.036) through exacerbation of sympathetic function (LF, C: 0.22 ± 0.01 vs. D: 0.48 ± 0.24 Hz, p = 0.019). Peripheral mononuclear blood cells of DT animals presented lower residual DNA damage (D: 43.4 ± 8.4% vs. DT: 26 ± 3.4%, p = 0.003 after 1 h). Cardioprotective effects of preventive aerobic exercise training are mediated by preservation of sympathovagal function and improvement of DNA repair capacity of peripheral blood mononuclear cells., (© 2022. The Author(s).)- Published
- 2022
- Full Text
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6. Continuous design and economic analysis of a Sargassum muticum biorefinery process.
- Author
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Caxiano IN, Mello PA, Alijó PHR, Teixeira LV, Cano RF, Maia JGSS, Bastos JBV, and Pavão MSG
- Subjects
- Biofuels, Fertilizers, Methane, Sargassum, Seaweed
- Abstract
This work assesses scale effects in designing a biorefinery from Sargassum muticum seaweed by applying a detailed process modeling methodology. Two process conversion units were simulated: one considering anaerobic digestion steps for producing biogas and generating electricity (base project), and the other with residual seaweed solids sold as fertilizer (alternative project). A comprehensive economic analysis was performed to estimate the minimum selling price of the process's main product (fucoidan extract). Results indicated that capital expenditures are up to 12.7% times higher in the base project. Minimum selling prices of the fucoidan extract product demonstrate the biorefinery's economies of scale for both projects. Seaweed's low methane potential reduces the economic attractiveness of electricity generation from biogas in the base project. Conversely, organic fertilizer price was more influential in the alternative project. Nonetheless, risk analyses show similar results for both scenarios, mainly due to fucoidan extract selling price and CAPEX estimates uncertainties., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2022
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7. Functional Recovery Caused by Human Adipose Tissue Mesenchymal Stem Cell-Derived Extracellular Vesicles Administered 24 h after Stroke in Rats.
- Author
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Rohden F, Teixeira LV, Bernardi LP, Ferreira PCL, Colombo M, Teixeira GR, de Oliveira FDS, Cirne Lima EO, Guma FCR, and Souza DO
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- Administration, Intranasal, Adult, Animals, Blood-Brain Barrier, Brain blood supply, Brain pathology, Elevated Plus Maze Test, Female, Humans, Male, Middle Aged, Neovascularization, Physiologic, Rats, Wistar, Recovery of Function, Stroke pathology, Rats, Extracellular Vesicles transplantation, Mesenchymal Stem Cells, Stem Cell Transplantation methods, Stroke therapy
- Abstract
Ischemic stroke is a major cause of death and disability, intensely demanding innovative and accessible therapeutic strategies. Approaches presenting a prolonged period for therapeutic intervention and new treatment administration routes are promising tools for stroke treatment. Here, we evaluated the potential neuroprotective properties of nasally administered human adipose tissue mesenchymal stem cell (hAT-MSC)-derived extracellular vesicles (EVs) obtained from healthy individuals who underwent liposuction. After a single intranasal EV (200 µg/kg) administered 24 h after a focal permanent ischemic stroke in rats, a higher number of EVs, improvement of the blood-brain barrier, and re-stabilization of vascularization were observed in the recoverable peri-infarct zone, as well as a significant decrease in infarct volume. In addition, EV treatment recovered long-term motor (front paws symmetry) and behavioral impairment (short- and long-term memory and anxiety-like behavior) induced by ischemic stroke. In line with these findings, our work highlights hAT-MSC-derived EVs as a promising therapeutic strategy for stroke.
- Published
- 2021
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8. Classic and Non-Classic Effects of the Duration of Supplementation of 25-Hydroxicholecalciferol in Broiler Chicken Diets.
- Author
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Prokoski K, Bittencourt LC, Teixeira LV, Bortoluzzi C, Vanroo E, Palma S, and Fernandes JIM
- Abstract
The present study aimed to determine the effect of different times of supplementation of 25-hydroxycholecalciferol (25(OH)D
3 ) in broiler chickens on the performance, carcass and cuts yield, bone resistance, plasma concentration of 25(OH)D3 , and expression of the mTOR gene. The treatments were a control diet (CD) supplemented with 3000 IU vitamin D3 /kg of feed from 1 to 46 d, or the CD + 2760 IU (69 mcg) of 25(OH)D3 /kg of feed from 1 to 21 d, from 1 to 35 d, or from 1 to 46 d. The period of supplementation of 25(OH)D3 did not affect the growth performance of broilers, but the breast meat yield was linearly increased in response to increasing days of supplementation ( p < 0.05). Birds supplemented with 25(OH)D3 at the time of the analysis showed an increase ( p < 0.05) in the plasma concentration of 25(OH)D3 when compared to non-supplemented birds. The mTOR gene expression ( p < 0.05), and breast protein deposition ( p < 0.05) presented a quadratic response related to the supplementation period of 25(OH)D3 . The fat content of the breast linearly decreased ( p < 0.05) as the period of supplementation was extended. The results also showed a positive linear correlation between mTOR expression and 25(OH)D3 plasma levels (r = 0.593; p < 0.05).- Published
- 2021
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9. High doses of phytase on growth performance, bone mineralization, diet utilization, and plasmatic myo-inositol of turkey poults.
- Author
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Bassi LS, Teixeira LV, Sens RF, Almeida L, Zavelinski VAB, and Maiorka A
- Subjects
- Animal Feed analysis, Animal Nutritional Physiological Phenomena, Animals, Calcification, Physiologic, Chickens, Diet veterinary, Dietary Supplements, Digestion, Inositol, Turkeys, 6-Phytase
- Abstract
An experiment was conducted to evaluate the growth performance, bone mineral composition, diet utilization, and plasmatic concentration of myo-inositol (MYO) in turkeys fed different phytase doses from 1 to 28 d. A total of three hundred and twenty 1-day-old turkeys were distributed in a completely randomized design with 4 treatments and 8 replicates of 10 birds each. Treatments included a basal diet without phytase; reduced diet (reduced -0.15% available P and -0.18% Ca) without phytase; reduced diet + 2,000 units of phytase (FYT)/kg; and reduced diet + 4,000 FYT/kg. From day 26 to 28, partial excreta collection was conducted, and on day 28, 7 birds per replicate were euthanized for collection of ileal content and left tibia bones were removed from 2 of the same euthanized birds. Feed, excreta, and ileal digesta samples were analyzed to determine nutrient digestibility and metabolizability, ileal digestible energy, and AME. Tibia bones were analyzed for ash, Ca, and P content, and calculation of Seedor index. On day 28, blood samples were collected from 2 turkeys per replicate to analyze plasmatic MYO concentration. Feed conversion ratio was not affected, but phytase supplementation resulted in higher feed intake and body weight gain compared to turkeys fed the reduced diet (P < 0.05), and both doses were similar to the basal diet. Increasing the phytase dose had a linear effect (P < 0.05) on ileal digestibility of P and metabolizability of DM, CP, Ca, and Na, and also on AME. P content in the tibia bone increased linearly (P < 0.05) with phytase supplementation, and the same linear increase (P < 0.05) was observed for plasmatic MYO. In conclusion, the supplementation of turkey poult's diets with high levels of phytase up to 4,000 FYT/kg improves diet utilization by increasing P digestibility and dietary metabolizability, leading to higher P content in the bone and enhancing MYO provision and absorption., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
- Full Text
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10. Different enzymatic associations in diets of broiler chickens formulated with corn dried at various temperatures.
- Author
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Giacobbo FCN, Eyng C, Nunes RV, de Souza C, Teixeira LV, Pilla R, Suchodolski JS, and Bortoluzzi C
- Subjects
- Animal Feed analysis, Animal Nutritional Physiological Phenomena, Animals, Diet veterinary, Dietary Supplements analysis, Male, Temperature, Chickens, Zea mays
- Abstract
The effect of supplementation of different enzymatic associations in the feed of broiler chickens formulated with corn dried at 80°C or 110°C on growth performance and carcass yield was evaluated. In addition, the influence of the different enzymatic associations on the cecal microbiota was studied. One-day-old male broiler chicks (1,320) were distributed in a completely randomized design in a 2 × 5 factorial arrangement (6 replicates; 22 birds/replicate). The treatments were 2 corn drying temperatures (80°C and 110°C) and 5 diets. The diets consisted of a positive control (PC), a negative control (NC) with a reduction of 100 kcal/kg of apparent metabolizable energy, and 3 enzyme combinations added to the NC diet: amylase, amylase + xylanase, and amylase + xylanase + protease. The feed conversion ratio (FCR) from 1 to 7 d of chickens fed diets formulated with corn dried at 80°C was better (P = 0.045) than that of chickens fed diets dried at 110°C. Regardless of the enzymatic association, the supplementation improved body weight gain (P = 0.01) of the NC group to the same level as the PC group. The FCR of the NC was similar to that of the PC only when the 3 enzymes were included from 1 to 21 d (P = 0.001) and regardless of the enzymatic association for the period from 1 to 42 d (P = 0.007). Regarding cecal microbiota, the alpha diversity was similar among the groups (P > 0.05). The beta-diversity analysis showed that the microbiota of the birds receiving the combination of the 3 enzymes was similar to that of birds fed the PC diet (P = 0.18; R = 0.074), with a similar effect observed for the predicted metabolic functions (Linear discriminant analysis effect size). In conclusion, chickens fed diets formulated with corn dried at 80°C had better FCR during the prestarter phase. The enzymatic supplementation improved the FCR of the birds, which may partially be explained by the modulation of the cecal microbiota., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
11. Effect of different doses of phytase and protein content of soybean meal on growth performance, nutrient digestibility, and bone characteristics of broilers.
- Author
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Sens RF, Bassi LS, Almeida LM, Rosso DF, Teixeira LV, and Maiorka A
- Subjects
- Animal Feed analysis, Animal Nutritional Physiological Phenomena, Animals, Chickens, Diet veterinary, Dietary Supplements, Digestion, Nutrients, Glycine max, 6-Phytase
- Abstract
This study evaluated the effects of high phytase doses and soybean meal (SBM) with different CP content on growth performance, ileal nutrient digestibility, digestible energy, plasmatic myo-inositol, phosphate release in vitro, and bone composition of broiler chickens. One thousand two hundred 1-day-old broilers were distributed in a 2 × 2 completely randomized factorial arrangement, with 2 phytase doses (1,000 and 2,500 phytase units [FYT]/kg of feed) and 2 SBM with different CP concentrations (45 and 47%), totaling 4 treatments with 12 replicates of 25 birds each. The chickens received feed and water ad libitum. Diets were based on corn and SBM, with different inclusions of soybean hull used to dilute the CP content of SBM according to each treatment. The inclusion of 2,500 FYT increased weight gain from 0 to 21 d (P < 0.05), whereas growth performance from 22 to 42 d was not affected, and SBM had no effect on growth performance. At day 21, ileal digestibility of dry matter, ash, and P, and digestible energy were greater in diets with 2,500 FYT/kg (P < 0.05), as well as phosphate in vitro release (P < 0.01) compared to the lower dose. At day 42, diets with SBM 47% CP and 2,500 FYT/kg promoted greater digestibility of dry matter, ash, CP, Ca, P, and digestible energy (P < 0.001), and greater phosphate release (P < 0.05) in comparison to other treatments. myo-inositol level in the plasma at 21 and 42 d was higher with the use of 2,500 FYT compared to 1,000 FYT (P < 0.05). The higher phytase dose increased tibia ash, toe ash, and Seedor Index (P < 0.05) at day 21, and the Ca content in tibia was higher with 2,500 FYT and SBM 47% CP at day 42. In conclusion, higher phytase doses for broilers improve weight gain, myo-inositol provision, and bone mineral composition. Nutrient ileal digestibility can be enhanced by higher phytase doses when in combination with SBM of greater nutritional quality., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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12. Influence of Enzyme Supplementation in the Diets of Broiler Chickens Formulated with Different Corn Hybrids Dried at Various Temperatures.
- Author
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Giacobbo FCN, Eyng C, Nunes RV, Souza C, Teixeira LV, Pilla R, Suchodolski JS, and Bortoluzzi C
- Abstract
We evaluated the influence of enzymatic supplementation on the growth performance and cecal microbiota of broilers. A total of 2160 1-day-old male chicks were used in a 3 × 2 × 2 factorial arrangement (three corn hybrids, two drying temperatures -80 and 110 °C, with or without the inclusion of an enzymatic blend (amylase, xylanase, and protease) (20 birds/pen, n = 9). For all performance and digestibility parameters, we observed, in general, isolated effects of the corn hybrids and drying temperature. Birds that received the enzymatic blend in the diet showed better weight gain from 1 to 21 days (d) and better digestibility coefficients of nutrients at 42 d. Birds fed diets with corn dried at 80 °C showed a better feed conversion ratio from 1 to 42 d. At 21 d of age, enzymatic supplementation had positive effects on jejunum morphology. Enzyme supplementation increased the abundance of the phylum Tenericutes, class Bacilli and Mollicutes, reduced Clostridia, and increased the abundances of the families Lactobacillaceae, Anaeroplasmataceae, and O_RF39;F. In conclusion, the addition of amylase, xylanase, and protease led to a better nutrient digestibility, performance, and intestinal morphology. In addition, enzyme supplementation changed the diversity, composition, and predicted function of the cecal microbiota at d 21., Competing Interests: The authors declare no conflicts of interest. The founders had no role in the design of the study, in the collection, analyses or interpretation of data, in the writing of the manuscript or in the decision to publish the result.
- Published
- 2021
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13. Neuroprotective Effects of Guanosine Administration on In Vivo Cortical Focal Ischemia in Female and Male Wistar Rats.
- Author
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Teixeira LV, Almeida RF, Rohden F, Martins LAM, Spritzer PM, and de Souza DOG
- Subjects
- Animals, Brain Ischemia pathology, Cerebral Cortex pathology, Female, Male, Maze Learning drug effects, Maze Learning physiology, Rats, Rats, Wistar, Recovery of Function drug effects, Recovery of Function physiology, Brain Ischemia prevention & control, Cerebral Cortex drug effects, Guanosine administration & dosage, Neuroprotective Agents administration & dosage, Sex Characteristics
- Abstract
Guanosine (GUO) has neuroprotective effects in experimental models of brain diseases involving glutamatergic excitotoxicity in male animals; however, its effects in female animals are poorly understood. Thus, we investigated the influence of gender and GUO treatment in adult male and female Wistar rats submitted to focal permanent cerebral ischemia in the motor cortex brain. Female rats were subdivided into non-estrogenic and estrogenic phase groups by estrous cycle verification. Immediately after surgeries, the ischemic animals were treated with GUO or a saline solution. Open field and elevated plus maze tasks were conducted with ischemic and naïve animals. Cylinder task, immunohistochemistry and infarct volume analyses were conducted only with ischemic animals. Female GUO groups achieved a full recovery of the forelimb symmetry at 28-35 days after the insult, while male GUO groups only partially recovered at 42 days, in the final evaluation. The ischemic insult affected long-term memory habituation to novelty only in female groups. Anxiety-like behavior, astrocyte morphology and infarct volume were not affected. Regardless the estrous cycle, the ischemic injury affected differently female and male animals. Thus, this study points that GUO is a potential neuroprotective compound in experimental stroke and that more studies, considering the estrous cycle, with both genders are recommended in future investigation concerning brain diseases.
- Published
- 2018
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14. A Fast and Reliable Real-Time PCR Method for Detection of Ten Animal Species in Meat Products.
- Author
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Dalsecco LS, Palhares RM, Oliveira PC, Teixeira LV, Drummond MG, and de Oliveira DAA
- Subjects
- Animals, Buffaloes, Cats, Cattle, Chickens, DNA Primers, Dogs, Goats, Horses, Limit of Detection, Reproducibility of Results, Sensitivity and Specificity, Sequence Analysis, DNA, Sheep, Domestic, Species Specificity, Sus scrofa, Turkeys, Food Contamination analysis, Meat Products analysis, Real-Time Polymerase Chain Reaction
- Abstract
Species substitution in meat products is a common problem reported worldwide. This type of food fraud is, typically, an intentional act for economic gain, using sources of low-priced meats in high-value meat products. Consequences include economic, health, and religious concerns. Highly sensitive and efficient techniques are thus required to detect meat species. This paper describes a method based on real-time PCR to detect 10 animal species (Bos taurus, Sus scrofa, Ovis aries, Capra hircus, Gallus gallus, Meleagris gallopavo, Bubalus bubalis, Equus caballus, Felis catus, and Canis familiaris) in meat product. The method combines species-specific and universal (used here as internal positive control) primers, and applies melt curve analysis for amplicon checking. Method accuracy was evaluated on 46 experimental meat mixtures and all species were correctly identified in all cases, at 1% test sensitivity. Analysis of 14 commercial meat products revealed that 6 of 14 samples had nondeclared bovine and/or chicken material. We performed an interlaboratory comparison using the reference meat mixtures and commercial samples, achieving 100% of reproducibility. The developed test proved to be effective and reliable for routine analysis of meat products., Practical Application: This paper describes a fast and reliable method for species detection in meat products based on real-time PCR. It can be applied for analysis of in natura or processed meat. The method proposed here can play an important role in controlling the origin of meat products, ensuring their quality and safety for the entire food industry-producers to consumers., (© 2018 Institute of Food Technologists®.)
- Published
- 2018
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15. Activity of glutamate dehydrogenase and protein content in the breast of broilers fed diets containing different sources and levels of glycerine.
- Author
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Bernardino VM, Rodrigues PB, de Paula Naves L, Zangeronimo MG, Alvarenga RR, Rosa PV, Santos LM, and Teixeira LV
- Subjects
- Animal Feed analysis, Animal Nutritional Physiological Phenomena, Animals, Chickens growth & development, Diet veterinary, Male, Weight Gain drug effects, Chickens metabolism, Gene Expression Regulation, Enzymologic drug effects, Glutamate Dehydrogenase metabolism, Glycerol metabolism, Muscle Proteins metabolism
- Abstract
According to scientific literature, glycerol in the diet can spare glucogenic amino acids by inhibiting the activity of enzymes, such as glutamate dehydrogenase, thereby promoting protein deposition in muscle tissues. Therefore, the objective of this study was to evaluate the effect of three sources of glycerine (crude glycerine from soybean oil--CGSO, mixed crude glycerine from frying oil and lard--MCG and a semipurified glycerine from soybean oil--SPGSO) in four concentrations in the diet (17.5, 35.0, 52.5 and 70.0 g of each type of glycerine/kg of feed) on the activity of hepatic glutamate dehydrogenase, performance and protein content in the breast of broilers, during 22-35 days of age (experiment I) and 33-43 days of age (experiment II). In both experiments, an increase in MCG induced a linear decline in glutamate dehydrogenase activity (p < 0.05). In contrast, increasing the concentration of SPGSO in the diet caused a linear increase in enzyme activity (p < 0.05). There was no (p > 0.05) isolated effect of glycerine on the enzyme activity in either evaluated phase; however, during 33-42 days of age, MCG inhibited (p < 0.05) the glutamate dehydrogenase activity by up to 34.43%. During 22-35 days of age, the diet containing SPGSO induced a higher protein content (p < 0.05) in the breast, and regardless of the source utilized, the maximum protein deposition was estimated (p < 0.05) when broilers were fed with 55.08 g glycerine/kg of diet. There was no (p > 0.05) interaction or isolated effects of the sources and levels of glycerine on the protein content in the breast of broilers at 33-42 days of age, and moreover, all diets containing glycerine promoted a similar protein deposition in the breast compared with birds that received the diet without glycerine. The bird age also showed to influence the feed intake and weight gain of broilers fed diet containing glycerine. It is concluded that for both rearing phases, an increase in glycerine in the diet did not necessarily reduce the glutamate dehydrogenase activity, and the protein deposition in the breast of broilers may not be strictly correlated with the activity of this enzyme., (Journal of Animal Physiology and Animal Nutrition © 2013 Blackwell Verlag GmbH.)
- Published
- 2014
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16. Candidate gene linkage analysis indicates genetic heterogeneity in Marfan syndrome.
- Author
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Teixeira LV, Lezirovitz K, Pereira LV, and Perez AB
- Subjects
- Chi-Square Distribution, Cohort Studies, Female, Fibrillin-1, Fibrillins, Genetic Markers, Humans, Lod Score, Male, Marfan Syndrome diagnosis, Mutation Rate, Genetic Heterogeneity, Genetic Linkage genetics, Marfan Syndrome genetics, Microfilament Proteins genetics, Transforming Growth Factor beta genetics
- Abstract
Marfan syndrome (MFS) is an autosomal dominant disease of the connective tissue that affects the ocular, skeletal and cardiovascular systems, with a wide clinical variability. Although mutations in the FBN1 gene have been recognized as the cause of the disease, more recently other loci have been associated with MFS, indicating the genetic heterogeneity of this disease. We addressed the issue of genetic heterogeneity in MFS by performing linkage analysis of the FBN1 and TGFBR2 genes in 34 families (345 subjects) who met the clinical diagnostic criteria for the disease according to Ghent. Using a total of six microsatellite markers, we found that linkage with the FBN1 gene was observed or not excluded in 70.6% (24/34) of the families, and in 1 family the MFS phenotype segregated with the TGFBR2 gene. Moreover, in 4 families linkage with the FBN1 and TGFBR2 genes was excluded, and no mutations were identified in the coding region of TGFBR1, indicating the existence of other genes involved in MFS. Our results suggest that the genetic heterogeneity of MFS may be greater that previously reported.
- Published
- 2011
- Full Text
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17. Respiratory rhythms in stingless bee workers: circadian and ultradian components throughout adult development.
- Author
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Teixeira LV, Waterhouse JM, and Marques MD
- Subjects
- Analysis of Variance, Animals, Bees classification, Bees growth & development, Exploratory Behavior, Female, Seasons, Social Behavior, Activity Cycles, Aging, Bees physiology, Behavior, Animal, Circadian Rhythm, Oxygen Consumption, Respiratory Mechanics
- Abstract
The workers of the stingless bee, Melipona quadrifasciata, assume different tasks during their adult life. Newly emerged individuals remain inside the nest, without contact with the external environment. Maturing workers go to more peripheral regions and only the oldest, the foragers, leave the nest. As this diversity of activities implies different metabolic patterns, oxygen consumption has been measured in workers of three different ages: 24-48 h (nurses), 10-15 days (builders), and older than 25 days (foragers). Oxygen consumption of individually isolated workers was determined by intermittent respirometry, under constant darkness and temperature of 25±1 °C. Sets of 24-h measurements were obtained from individuals belonging to each of the three worker groups. Rhythmicity has been assessed in the daily (24 h) and ultradian (5-14 h) domains. This experimental design allowed detection of endogenous rhythms without the influence of the social group and without inflicting stress on the individuals, as would be caused by their longer isolation from the colony. Significant 24-h rhythms in oxygen consumption were present in nurses, builders and foragers; therefore, workers are rhythmic from the age of 24-48 h. However, the amplitude of the circadian rhythm changed according to age: nurses showed the lowest values, while foragers consistently presented the largest ones, about ten times larger than the amplitude of nurses' respiratory rhythm. Ultradian frequencies were detected for all worker groups, the power and frequencies of which varied little with age. This means that the ultradian strength was relatively larger in nurses and apparently maintains some relationship with the queen's oviposition episodes., (© Springer-Verlag 2011)
- Published
- 2011
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18. Repetitive DNA alterations in human skin cancers.
- Author
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Ribeiro GR, Francisco G, Teixeira LV, Romão-Correia RF, Sanches JA Jr, Neto CF, and Ruiz IR
- Subjects
- Genomic Instability, Humans, Loss of Heterozygosity, Microsatellite Repeats, Nucleic Acid Amplification Techniques, Polymorphism, Genetic, DNA, Neoplasm genetics, Repetitive Sequences, Nucleic Acid, Skin Neoplasms genetics
- Abstract
Repetitive sequences constitute landmarks for genome regulation, evolution, and chromatin architecture. Patterns of specific and non-specific repetitive sequences change in many types and stages of tumor cells, characterized by band loss, gain, and (de) increased staining of pre-existing bands. In this work, repetitive DNA was studied in search of genome instability of skin cancers: basal and squamous cell carcinomas (BCC and SCC), malignant melanoma (MM), melanocytic nevus (MN), and actinic keratosis (AK) lesions. DNAs were extracted from blood and tumor samples from 21 BCC, 7 SCC, 11 MM and 7 lesions. Banding patterns were obtained by random amplification of polymorphic DNA (RAPD), and specific D9S50 and D9S52 microsatellites (9p21). D9S50 patterns revealed microsatellite instability (MSI) and/or loss of heterozygosity (LOH) in 36% BCC, 25% SCC, and 57% MM tumors. D9S52 microsatellite showed 28.5%; 42.8%; and 71.4% altered tumors, respectively. No microsatellite alterations were found in MN and AK. On the other hand, genomic rearrangements detected by RAPD were present in 100% tumors. In BCC, the mean number of tumor DNA alterations showed predominant gain of bands. On the contrary, MM samples presented loss, or decreased intensity signal of RAPD bands. Genome alterations in skin cancers would result from chromosomal rearrangements, aneuploidy and/or polysomies. The low-cost and quick RAPD technique may reveal unknown genes or DNA sequences associated with tumor development and progression, and may be easily implemented in clinical diagnosis.
- Published
- 2004
- Full Text
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