171 research outputs found
Custos no processo de desenvolvimento de produtos seguindo a metodologia de Pahl & Beitz
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina. Centro TecnologicoEm mercados cada vez mais competitivos, há necessidade de um maior rigor no controle e avaliação de todos os aspectos de custos no processo de desenvolvimento de produtos. Por isso, este trabalho, tomando como suporte conceitual a metodologia de Pahl & Beitz, identifica o contexto de mercado do produto e sistematiza procedimentos, métodos e técnicas para controlar as despesas com o desenvolvimento, estimar adequadamente os custos futuros do produto, bem como viabilizar uma análise custo-benefício mais precisa do produto na fase do desenvolvimento, coerente com o nível de concretização do mesmo. Neste terceiro ponto, será apenas complementado o já apresentado por Pahl & Beitz. A toda etapa e fase da metodologia de desenvolvimento de produtos de Pahl & Beitz, são associados os procedimentos, os métodos e as técnicas adequadas para os aspectos de custos citados acima. Com uma aplicação simulada no processo de desenvolvimento de um tanque de combustível, termina este trabalho
Effect of age and feeding on cholesterol 27-hydroxylase in pigs
No full textThe objective of this study was to determined the responses of hepatic mitochondrial cholesterol 27-hydroxylase to nursing in three-week-old suckling piglets and to feeding in 7-week-old weaned piglets. In feeding studies, livers were collected from 59 piglets at 0, 1, 3, and 5 hours after nursing or feeding and from ad libitum-fed piglets. In development studies, livers were collected from 21 ad libitum-fed pigs, which were fetal, suckling, 7-week-old weaned piglets and 12-week-old pigs. Cholesterol 27-hydroxylase activity was determined by incubating isolated mitochondria with 4-¹⁴C-cholesterol and by isolating the 27- hydroxycholesterol via thin-layer chromatography. Fasting for 14 hours decreased cholesterol 27-hydroxylase from 1.071 to 0.162 pmol/min.mg protein in three-week-old suckling piglets and from 1.120 to 0.273 pmol/min.mg protein in seven-week-old weaned piglets. The cholesterol 27-hydroxylase activities increased within 5 hours after fasted piglets nursed or fed, attaining the activities of the ad libitum-fed piglets. Furthermore, fasting decreased the activity of cholesterol 27-hydroxylase was determined. Additionally, the stability of the cholesterol 27-hydroxylase from fresh liver were compared with that of frozen liver and frozen mitochondria homogenates. It was found that the cholesterol 27-hydroxylase was not stable to freezing/thawing. Finally, the effect of age on the activity of cholesterol 27- hydroxylase was investigated. No significant differences in cholesterol 27-hydroxylase activities were detected among pigs of different ages
Sequence heterogeneity of bovine mitochondrial DNA
No full textThe displacement-loop (D-loop) region of bovine mitochondrial DNA (mtDNA) isolated from blood leukocytes was studied. A method was devised for the isolation of mtDNA from blood leukocytes based on detergent lysis of the plasma membrane and removal of cell nuclei by centrifugation. Nucleic acids extracted from the residual cytoplasmic fraction contained mtDNA in quantities sufficient for restriction enzyme analysis and for DNA cloning and sequencing;MtDNA was from a herd of Holstein cattle that was established 1968 from diverse genetic sources. Maternal lineages were traced by pedigree analysis to their earliest origins in the late 1800s. MtDNA was isolated from blood leukocytes and nucleotide sequences were determined for the light strand of the 910 base-pair (bp) D-loop region. Fifty-one sites of sequence variation in 38 maternal lineages were identified. Nucleotide substitutions were found at 48 sites (38 transitions and 10 transversions); one nine-bp deletion, and two variable-length poly G/poly C regions of 6-8 bp and of 11-16 bp were found. Nucleotide substitutions were distributed nonrandomly across the D-loop region with avoidance of the 5[superscript]' end (100 bp), a central GC-rich region (80 bp), and the 3[superscript]' end that contains light and heavy strand transcriptional promoters and the origin of heavy strand replication. Variation within maternal lineages was observed at two sites: One G-to-C transversion at nucleotide (nt) 363 and in the length of a poly G/poly C region that extends from nt 351 to nt 363. A cytoplasmic gene tree constructed from the sequence data revealed a bifurcation in the mtDNA of cattle into two major groups based on a transition at nt 169. Sufficient variation seems to exist in mtDNA of cattle for the assignment of animals to cytoplasmic lineages.</p
Effects of dietary CLA on fatty acid composition of egg yolks and [delta]9-, [delta]6-, and [delta]5- desaturase activities of livers of laying hens
No full textConjugated linoleic acid (CLA) alters the fatty acid composition of chicken eggs. It also decreases hepatic stearoyl-CoA desaturase mRNA in HepG2 cells. The fatty acid composition of egg yolks was investigated as a function of amount of dietary CLA for laying hens. In addition, the activities of [Delta]9-, [Delta]6-, and [Delta]5- desaturases in hen liver were investigated as a function of CLA in the diet. Forty-eight Leghorn laying hens were assigned randomly to one of four dietary treatments formulated to contain 0, 1.25, 2.5, and 5.0% CLA. The fatty acid composition of yolk lipids was altered by dietary CLA, with a decrease in unsaturated fatty acids (palmitoleyl, linolenic, and arachidonic acids). The amount of CLA in eggs increased linearly with amount of dietary CLA. [Delta]9- and [Delta]5- Desaturase activities were lower in livers from hens fed the 5% diet than in livers of hens fed the 0% diet. [Delta]6-Desaturase activity was very low in livers of hens in all groups. In summary, dietary CLA decreases the amount of unsaturated fatty acids in chicken eggs with a corresponding decrease in desaturation activity in the hen liver microsomes
Redesigning pork by type and amount of dietary fat for better human nutrition
No full textThe objective of this study was to alter the ratio of polyunsaturated to saturated fatty acids of muscular lipids in pork for better human nutrition. Pigs were fed either choice white grease or soybean oil at 10, 20, 30, or 40% of total calories. All diets, including a control diet, were based on corn and soybean meal. The study used 54 pigs with six pigs per treatment. Initial and slaughter weights were 54 and 110 kg, respectively. Skeletal muscle samples were taken from the longissimus dorsi, biceps femoris, and triceps brachii muscles. Adipose tissue sample were taken from the outer, middle, and inner layers of tenth rib backfat, perirenal adipose tissue, and an intermuscular fat deposit within the ham. Total lipids were extracted; fatty acid methyl esters were formed by transesterification and quantified by gas chromatography. Adding choice white grease or soybean oil to diets of growing swine did not alter animal growth rates. The outer layer of 10th rib backfat showed linear increases (P < .05) of polyunsaturated fatty acids when pigs were fed diets with increasing amounts of the soybean oil, whereas the backfat from pigs fed increasing amounts choice white grease resulted in a linear increase (P < .05) of monounsaturated fatty acids. The middle and inner layers of 10th rib backfat tended to contain more saturated fatty acids than did the outer layer. Addition of soybean oil to the low-fat control diet at 30 and 40% increased the ratio of polyunsaturated to saturated fatty acids to .9 and 1.26 (P < .05), respectively, in longissimus muscle. The monounsaturated fatty acids of longissimus muscle were decreased by 30% (P < .05) with the 40% soybean oil diet. Myristate, palmitate, and total saturated fatty acids in longissimus muscle decreased 27 (P < .05), 30 (P < .05), and 29% (P < .05), respectively, with the 40% soybean oil diet. Compositional changes were increasingly less dramatic with the 30, 20, and 10% soybean oil diets. The addition of choice white grease had minimal effects on the ratio of unsaturated to saturated fatty acids of muscular lipids. In conclusion, high fat diets can be used effectively to redesign pork for the health conscious consumer
Effect of stress condition, gender, and dietary dl-alpha-tocopheryl acetate on fatty acid composition and catecholamines in five selected brain regions of pigs
No full textThe broad objective of this project is to further define the physiological processes that contribute to the genetic disease in pigs known as porcine stress syndrome. Because several organs are affected by the disease, there exists a need for focus on a specific organ system; I have chosen the central nervous system. Accordingly, this project will focus specifically on certain physiological and biochemical changes that occur in the cerebellum, cortex, substantia nigra, caudate nucleus, and hypothalamus. During episodes of oxidative stress in pigs, reactive oxygen species, such as free radicals, peroxides, and super oxides, increase in concentration in several organs. Tissue damage may occur as a result of the reactive oxygen species, and, in fact, oxidative stress is suspected of being an agent in premature cell death. If this is the case, then increasing the capacity of the antioxidant system of an animal should help prevent the damage caused by reactive oxygen species, even in the central nervous system. Vitamin E is a potent antioxidant that is commercially available and can be incorporated easily in the diet for administration to animals. Absorption of vitamin E occurs efficiently. And the vitamin becomes distributed ubiquitously in tissues. Therefore, an experiment conducted to examine the protective effects of dietary vitamin E is necessary and beneficial because scientists may be able to use the information to delay onset of specific diseases, such as the PSS, by nutritional intervention
Influence of two different dietary fats on the composition of emu oil and meat
No full textThe goal of this research was to characterize the chemical composition of emu oil in order toprovide an explanation for alleged medicinal properties of the oil and to test whether two sources of dietary fat affect composition of emu oil and meat. Twenty-four emus, 12 female and 12 male,were fed two diets, one containing soybean oil and the other containing beef tallow, from the age of 8 months until slaughter at approximately 35 kilograms of body weight. The fatty acid composition and phospholipid, sterol, and DHEA/DHEAS contents of oil rendered from subcutaneous and retroperitoneal adipose tissues were determined. Adipose cellularity also was determined. Five different cuts of meat were used to determine the lipid and cholesterol contents of emu meat. Fatty acid composition of the fan cut of meat was determined. Soybean oil fed-emus had a greater percentage of linoleic and linolenic acids in their oil.
The beef tallow fed-emus had a greater percentage of palmitic acid from the retroperitoneal adipose tissue. Females had less palmitic acid in the oil from the subcutaneous adipose tissue. No phospholipids were detected. The only sterol found in the oil was cholesterol, which was present at 29.3 milligrams per 100 grams of subcutaneous adipose tissue and 41.2 milligrams per 100 grams of retroperitoneal adipose tissue. Concentrations of DHEA and DHEAS were not affected by diet, but the female emus had more DHEA. Males emus had larger adipocytes and fewer cells per gram of tissue. The retroperitoneal adipose tissue had larger cells than did the subcutaneous adipose tissue. Emu meat was relatively low in fat (2.2 percent) and cholesterol (32.2 milligrams per 100 grams tissue).
The regular cut of meat had the highest percentage of fat, and the fan cut had the most cholesterol. Diet and gender did not affect the fatty acid composition, cholesterol concentration, or percentage of lipid in the meat. In conclusion, the fatty acid composition of emu oil, but not emu meat, depends on the gender of the emu, source of dietary fat, and the anatomical site of the adipose tissue from which the oil is derived
Hypocholesterolemic effects of orally administrated Eubacterium coprostanoligenes in cynomolgus monkeys
No full textOrally administrated E. coprostanoligenes has been shown to decrease blood cholesterol concentrations in cholesterol-fed rabbits. In this study, the safety and efficacy of dietary E. coprostanoligenes to decrease blood cholesterol concentration were evaluated in cynomolgus monkeys. Nine adult male cynomolgus monkeys (Macaca fascicularis) were divided randomly into two groups: group A (five monkeys) and group B (four monkeys). Both groups were fed a hypercholesterolemic diet for 10 weeks. Then, group A received the hypercholesterolemic diet supplemented with E. coprostanoligenes (4 x 1010 cells) daily for 10 weeks and then the hypercholesterolemic diet with the same amount of heat-treated (1200C for 15 minutes) E. coprostanoligenes for another 10 weeks. Group B received the hypercholesterolemic diet with 4 x 1010 heat-treated E. coprostanoligenes daily for 10 weeks and then the same amount of live E. coprostanoligenes for another 10 weeks. No treatment-associated illness or death was observed throughout the experiment. Body weight and body temperature of individual monkeys were normal throughout the experiment. Oral administration of E. coprostanoligenes causes a significant (P < 0.05) decrease in plasma cholesterol in high-response monkeys.
Low response monkeys fed dead E. coprostanoligenes experienced no change (P > 0.05) in blood cholesterol. Feeding E. coprostanoligenes markedly increased the ratio of coprostanol to cholesterol in contents and of mucosal cells of the stomach and all sections of the small and large intestine. Weight ratios of coprostanol to cholesterol in feces also were increased because of feeding the E. coprostanoligenes. Thus, viable E. coprostanoligenes reached the small intestine where they reduced cholesterol to coprostanol, thereby potentially decreasing cholesterol absorption. We hypothesize that this probable decrease in cholesterol absorption caused the observed decrease in blood cholesterol. In general, no adverse effects were shown on animals' general health status, hematology, blood biochemistry, gut mucosal histology parameters, or the incidence of bacterial translocation. These results suggest the use of a dietary supplement of E. coprostanoligenes to decrease the cholesterol in human
Characterization and application of a novel cholesterol-reducing anaerobe, Eubacterium coprostanoligenes ATCC 51222
No full textA novel cholesterol-reducing bacterium, Eubacterium coprostanoligenes ATCC 51222, was characterized and tested for its hypocholesterolemic effects in animal models. The bacterium did not require cholesterol for growth and synthesized cholesterol reductase constitutively. Lecithin was required for growth but excess lecithin in media did not improve bacterial growth and coprostanol production. Addition of pyruvate, lactose, and most reducing agents in media increased bacterial growth and coprostanol production. The bacterium was sensitive to most antibiotics but had strong resistance to tetracycline. A resting cell assay was established to evaluate the cholesterol reductase activity. E. coprostanoligenes reduced cholesterol through an indirect pathway. Intermediates were detected in resting cell assays even though no accumulation of intermediates was observed in actively growing cultures. E. coprostanoligenes seemed to have a broad specificity for substrates. In resting cell assays, NADH or FAD increased cholesterol reductase activity, whereas EDTA inhibited the activity, and HgCl2 abolished the cholesterol reductase activity. Attempts to achieve active cell-free extracts were not successful because a great loss of activity occurred after the disruption of bacterial cells. The genomic expression library of E. coprostanoligenes was constructed in an expression vector, bacteriophage [lambda] vector [lambda]gt11. Much effort was made to develop a screening technique for cholesterol reductase-containing clones. Effects of orally administered E. coprostanoligenes on plasma cholesterol concentrations were studied in rabbits, laying hens, and germ-free and conventional mice. Oral administration of E. coprostanoligenes caused a significant hypocholesterolemic effect in dietary-induced hypercholesterolemic rabbits, and this effect can be explained by increased conversion of cholesterol to coprostanol in the intestine. In normocholesterolemic laying hens, the bacteria colonized in the intestine but did not affect plasma cholesterol concentrations. E. coprostanoligenes did not colonize in the intestine of germ-free and conventional mice after bacterial feeding. In summary, the study has shown that E. coprostanoligenes reduced cholesterol to coprostanol in vitro and in vivo. The results suggest a potential application of E. coprostanoligenes in humans to decrease plasma cholesterol concentration naturally in hypercholesterolemic individuals.</p
Modification of the animal immune system by feeding probiotics
No full textThe objective of this study was to examine immune effects of feeding novel probiotic Lactobacillus acidophilus strain NP51 to specific pathogen-free Balb/c mice challenged with Mycobacterium avium subspecies paratuberculosis (MAP), the causative agent of Johne's
disease (JD). We hypothesized that feeding the NP51 would activate the adaptive immunity and impede the development of MAP infection in murine model of JD. Thus, Balb/c mice were randomized to treatment groups in a factorial design including mice that either fed the heat-killed or viable NP51 (HNP51 or VNP51, respectively) and challenged with either a heat-killed or a viable MAP (HMAP or VMAP, respectively). Mice were fed 1 × 106 CFU of either HNP51 or
VNP51*mice-1*day-1 mixed with standard mouse chow until the end of the study. Subsequently, mice were challenged with 1 × 108 CFU of HMAP or VMAP injected intraperitonealy on day 45 of the study. Ten mice from each group were euthanized on days 45, 90, 135, and 180. Spleens were excised and used for an in vitro splenocytes cell cultures that were either stimulated with sonicated MAP antigen or concanavalin A and examined for the cytokine secretion pattern and
frequency of T lymphocyte subpopulations. Blood was withdrawn by cardiac puncture and used for examination of immunoglobulins production. HNP51 and VNP51 differentially stimulated the adaptive immunity and decrease MAP tissue burden. With VMAP as the inoculum, both VNP51 and HNP51 stimulated CD8α+ immune cell-mediated immunity and decreased the humoral immunity. When HMAP was used as the inoculum, VNP51 stimulated the CD8α+ immune cells-mediated and the humoral immunity. In contrast, HNP51 feeding induced CD8α+ immune cells-mediated immunity only as verified by the differential cytokines and immunoglobulins secretion pattern. The data provide persuasive evidence that NP51 has the potency to prevent JD infection in murine model of JD.</p
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