The objective of part one of this study was to determine if the presence of porcine growth hormone (pGH) during oocycte in vitro maturation (IVM) affected subsequent embryo development. Pig cumulus-oocyte complexes (COC) (n=987) were aspirated from slaughterhouse derived ovaries and cultured in BSA-free NCSU 23 medium containing porcine follicular fluid (10% v/v), cysteine (0.1 mg/ml) and hormonal supplements (eCG and hCG, 10 IU/ml each), 10 ng/ml EGF, and with or without pGH (100 ng/ml) for 22 h. The COC were then cultured in the same medium with or without 100 ng/ml pGH, but without hormonal supplements for an additional 22 h. After the completion of maturation culture, cumulus cells were removed and oocytes were co-incubated with frozen-thawed spermatozoa for 8 h. Putative embryos were transferred to NCSU 23 containing 0.4% BSA and cultured for 144 h. Embryo development was assessed on d 6 of culture. The treatment groups were as follows: treatment 1 = control group cultured in IVM medium alone; treatment 2 = 100 ng/ml pGH present of the first 22 h of maturation culture and absent for the second 22 h of maturation culture; treatment 3 = 100 ng/ml pGH absent for the first 22 h of maturation culture, but present for the second 22 h of maturation culture; and treatment 4 = 100 ng/ml pGH present throughout the entire IVM period. Embryos were visually scored for developmental stage at 144 h following fertilization. Each oocyte in the study received a developmental score, based on a scale of 1 = uncleaved, 2 = 2-cell embryo, 3 = 4- to 8-cell embryo, 4 = 9- to 16-cell embryo, 5 = morula, and 6 = blastocyst. The addition of pGH did not affect porcine embryo development as compared to the control (1.57 ± .08, 1.67 ± .08, 1.47 ± .08, and 1.60 ± .08, respectively; P > .10). Replicates within the study differed significantly from each other (P < .01) primarily because the development in replicate 6 was greater than for all others. There was a significant treatment by replicate interaction (P < .05); pGH added during the first 22 h of IVM and pGH added during the second 22 h of IVM in replicate 6 resulted in higher development scores than for controls and continuous pGH addition. However, in replicate 2, continuous pGH resulted in the greatest development. These results suggest that pGH may exert a stimulatory effect on embryo development when present in the IVM media; however, further studies using pGH in IVM culture are necessary. The objectives of the second part of the study were to examine aspects of intracytoplasmic sperm injection (ICSI) using membrane-disrupted spermatozoa, in vitro fertilization (IVF), and sperm-mediated gene transfer in the pig. Porcine oocytes were shipped overnight in maturation media at 39°C in a portable incubator. After 22 h of maturation culture, oocytes were washed in maturation medium without gonadotropins and cultured for an additional 22 h. Cumulus cells were removed and oocytes were divided into four treatment groups: treatment 1 = ICSI using membrane-damaged spermatozoa coincubated with linear green fluorescent protein (GFP) DNA; treatment 2 = ICSI using membrane damaged spermatozoa; treatment 3 = IVF with frozen-thawed spermatozoa coincubated with linear GFP DNA prior to IVF; treatment 4 = IVF with frozen-thawed spermatozoa with no DNA coincubation. Embryos were scored for developmental stage at 144 h following fertilization. Each oocyte in the study received a developmental score, based on a scale of 1 = uncleaved, 2 = 2-cell embryo, 3 = 4-cell embryo, 4 = 5- to 8-cell embryo, 5 = 9- to 16-cell embryo, 6 = morula, and 7 = blastocyst. Although no overall difference in development score was observed following the four different treatments, a treatment difference among cleaved oocytes was observed when comparing only the two ICSI treatments (P < .05); development scores were greater in the ICSI treatment in which sperm were not coincubated with linear GFP DNA prior to injection than when the coincubation was performed (3.76 ± .21 vs. 3.13 ± .17, respectively). No differences in development score were observed in the two IVF treatments. The percentage of embryos expressing the GFP transgene on d 6 of culture following fertilization was 7.3% in the ICSI+GFP group and 0% in all other treatment groups. Thus, sperm-mediated gene transfer using ICSI in the pig has been demonstrated, although success rates were low. / Master of Science

With the absence of gut microbiota, gnotobiotic (Gn) pigs are a unique animal model for studying infection and immunity, and evaluating vaccine and therapeutics for human enteric pathogens. Here, we demonstrate Gn pigs as effective large animal models for human enteric viruses, through evaluating human enterovirus 71 (EV71) infection and immunity, and vaccine and therapeutics for human rotavirus (HRV). Gn pigs could be infected via oral or oronasal route, the natural route of infection. Infected pigs developed clinical signs including fever, neurological and respiratory signs, similar to those seen in human patients. Fecal shedding up to 18 days post infection and virus distribution in intestinal, respiratory and central nervous system tissues were observed. Strong mucosal and systemic T cell responses (IFN-γ producing CD4+ and CD8+ T cells) and systemic B cell responses (serum neutralizing antibodies) were also detected. The study demonstrates a novel large animal model for EV71 to investigate viral pathogenesis, immunity, and to evaluate vaccine and antiviral drugs. Using the well-established Gn pig model for HRV, the adjuvant and therapeutic effects of prebiotics rice bran (RB) and probiotics were evaluated. RB alone or RB plus probiotic Lactobacillus rhamnosus GG (LGG) and probiotic E. coli Nissle 1917 (EcN), were shown to protect against rotavirus diarrhea (80%-100% reduction in the incidence rate) significantly and display strong immune - stimulatory effects on the immunogenicity of an oral attenuated HRV (AttHRV) vaccine. Mechanisms for the adjuvant effect include stimulating the production of intestinal and systemic IFN-γ] producing T cells and promoting mucosal IgA antibody responses. The mechanisms for reducing rotavirus diarrhea include promoting LGG and EcN growth and colonization and host gut health, and maintaining gut integrity and permeability during rotavirus infection. We showed that RB plus LGG and EcN is a highly effective therapeutic regimen against HRV diarrhea. Together, these results indicated that Gn pigs may serve as an excellent animal model for the study of infection, immunity, vaccine and therapeutics for human enteric viruses. / Ph. D.

The neonatal period in mammals is characterized by high growth rates and is dominated by skeletal muscle hypertrophy. Low birth weight (LBWT) neonates experience restricted growth and development of skeletal muscle, leading to metabolic perturbations later in life. The overall hypothesis of this dissertation was that in utero disturbances in glucose metabolism and increased energy requirements predisposes LBWT neonatal pigs to metabolic disturbances after birth. We sought to increase growth of skeletal muscle and improve glucose production through increasing dietary energy and to determine the changes in glucose catabolism and metabolic flexibility in different skeletal muscle fiber types in LBWT neonates. Piglets were considered normal birth weight (NBWT) and LBWT when birth weight was within 0.5 SD and below 2 SD of the litter average, respectively. Increasing dietary energy increased lean deposition in the longissimus dorsi (LD) in both NBWT and LBWT neonates. Although glucose rate of appearance was greater in LBWT compared to their NBWT sibling, glucose concentrations were reduced in LBWT compared to NBWT pigs, regardless of diet fed. Postprandial glucose concentrations were lower in LBWT compared to NBWT pigs, regardless of diet fed, although rate of appearance did not differ between them. This would suggest that glucose is being absorbed in the peripheral tissues to be utilized. However, expression of enzymes related to glycolysis were downregulated in both the soleus and LD of LBWT compared to NBWT neonatal pigs. In addition, expression of enzymes related to the catabolism of glucose in the serine biosynthetic pathway were decreased in both the soleus and LD muscles of LBWT compared to NBWT neonatal pigs. Expression of the pentose phosphate pathway was slightly increased in LBWT compared to NBWT siblings in both muscle types. Increased expression of pyruvate dehydrogenase 4 was exhibited in both the soleus and LD of LBWT pigs compared to NBWT siblings. This would indicate a switch in fuel utilization to more fatty acid oxidation. By contrast, CO2 production from the oxidation of palmitate was reduced in LBWT compared with NBWT pigs along with reduced oxidation of glucose and pyruvate. In conclusion, lipid supplementation increased growth at the expense of fat deposition in the liver of NBWT and LBWT pigs. However, supplementing with fat did not increase glucose production due to the contribution of glycerol remaining constant. Hypoglycemia cannot be attributed to greater catabolism in skeletal muscle due to decreased expression of glycolytic genes and the addition of fatty acids did not spare glucose oxidation in skeletal muscle of LBWT pigs. / PHD / During the neonatal period animals display the fastest growth rates, especially pertaining to muscle growth. Muscle development in low birth weight (LBWT) is restricted, leading not only to impaired postnatal growth but increases the risk for developing metabolic diseases later in life such as obesity and type 2 diabetes. LBWT is also characterized by decreased glucose concentrations and decreased body fat content at birth. In the present studies we sought to increase growth and improve glucose production by supplementing with a high energy diet and to compare the changes in glucose catabolism in different skeletal muscle fiber types along with analyzing the ability to switch fuel substrates in LBWT and NBWT neonatal pigs. Increasing dietary energy increased longissimus dorsi (LD) weight as a percentage of bodyweight, regardless of growth status. In addition, during fasting glucose production was higher in LBWT compared to their NBWT siblings, regardless of diet. However, glucose concentration in LBWT were lower compared to NBWT neonatal pigs. Although glucose concentrations were lower in LBWT compared to NBWT pigs after a meal, glucose production rate was unchanged among LBWT and NBWT siblings fed either a high or low energy diet. This suggests that glucose uptake is increased in peripheral tissues of LBWT pigs. However, enzymes related to glycolysis in the LD and soleus of LBWT pigs had lower expression than their NBWT sibling. In addition, the enzyme responsible for the shift in fuel selection, pyruvate dehydrogenase kinase 4 (PDK4) was highly expressed in LBWT compared to NBWT neonatal pigs in both the LD and soleus. This would suggest a switch in glucose oxidation to fatty acid oxidation in the skeletal muscle of LBWT neonatal pigs. However, oxidation of fatty acids in both the soleus and LD of LBWT was reduced compared to NBWT neonatal pigs. In conclusion, lipid supplementation increased growth at the expense of lipid deposition in the liver and did not increase glucose production. Reduced glucose concentrations are not due to greater catabolism in skeletal muscle due to decreased expression of glycolytic genes and the addition of fatty acids did not spare glucose oxidation in the skeletal muscle of LBWT pigs.

The neonatal period in mammals is characterized by high rates of growth, attributed to rapid myonuclear accretion and protein deposition in muscle. Low-birth-weight (LBWT) neonates experience restricted muscle development, which leads to impaired postnatal growth and metabolic disorders later in life. The overall hypothesis of this dissertation was that dysfunction of myogenic satellite cells and aberrant regulation of protein synthesis and degradation signaling predispose LBWT neonatal pigs to slower postnatal growth. We sought to determine the proliferation and differentiation of satellite cells (SCs) derived from skeletal muscle of LBWT neonatal pigs and to elucidate the cellular mechanisms that regulate protein synthesis and degradation in LBWT pig muscles. Newborn pigs were considered as normal-birth-weight (NBWT) or LBWT when weight at birth was within 0.5 SD and below 2 SD of litter average respectively. SCs isolated from longissimus dorsi (LD) muscle of NBWT and LBWT neonatal pigs displayed similar proliferation rates. Fusion was modestly diminished in SCs from muscle of LBWT pigs compared with their NBWT siblings, suggesting SCs were not intrinsically different between the two groups and were unlikely a major contributor to the impaired muscle growth of LBWT pigs. Plasma and muscle insulin-like growth factor (IGF)-I was diminished in LBWT compared with NBWT pigs. In addition, reduced activation of key components of IGF-I downstream signaling pathway in LBWT pigs muscle may lead to diminished translation initiation signaling and thus decreased protein synthesis in these animals. However, IGF-I receptor expression and myostatin signaling inversely correlated to LBWT, indicating they may participate in compensatory responses for the reduction in protein synthesis signaling. Expression of eukaryotic initiation factor (eIF) 4F complex subunits, eIF4E, eIF4G, and eIF4A was reduced in LBWT compared with NBWT pigs. This would suggest that diminished translation initiation signaling in skeletal muscle of LBWT pigs is the main factor that predisposes LBWT pigs to slower growth rates in the neonatal period. In contrast, changes in protein degradation signaling do not appear to affect protein turnover in LBWT neonatal pigs. / PHD / Animals display the fastest growth during their neonatal age, especially the rapid muscle growth. Postnatal muscle growth is driven by satellite cell-mediated myonuclear accretion and muscle fiber hypertrophy, which happens when muscle protein synthesis rates surpass protein degradation rates. However, muscle development is restricted in low-birth-weight (LBWT) neonates, leading to their impaired postnatal growth. In the presented studies, we sought to characterize the functions of satellite cells (SCs) derived from skeletal muscle of LBWT neonatal pigs and to elucidate the cellular mechanisms that regulate protein synthesis and degradation in LBWT pig muscles, comparing with normal-birth-weight (NBWT) piglets. SCs isolated from longissimus dorsi (LD) muscle of NBWT and LBWT neonatal pigs displayed similar activities, suggesting SCs were not intrinsically different between the NBWT and LBWT pigs. Plasma and muscle insulin-like growth factor (IGF)-I was diminished in LBWT compared with NBWT pigs. In addition, reduced activation of key components of IGF-I downstream signaling pathway in LBWT pigs muscle may lead to diminished translation initiation signaling and thus decreased protein synthesis in these animals. Indeed, protein abundance of eukaryotic initiation factor (eIF) 4F complex subunits was reduced in LBWT compared with NBWT pigs. This would suggest that diminished translation initiation signaling in skeletal muscle of LBWT pigs is the main factor that predisposes LBWT pigs to slower growth rates in the neonatal period. In contrast, changes in protein degradation signaling do not appear to affect protein turnover in LBWT neonatal pigs.

No

No / Despite an increasing literature on the decomposition of buried and exposed human remains it is important to recognise that specific microenviron-ments will either trigger, or delay the rate of decomposition. Recent casework in arid regions of the world has indicated a need for a more detailed understanding of the effects of burial over relatively short timescales. The decomposition of buried human remains in the coastal desert of Peru was investigated using pig cadavers (Sus scrofa) as body analogues. The project aims were to specifically examine the early phases of natural mummification and contrast the effects of direct burial in ground with burial in a tomb structure (i.e. with an air void). Temperature was logged at hourly intervals from both the surface, grave fill and core body throughout the experiment. In addition, air temperature and humidity were measured within the air void of the tomb. After two years all three pig graves were excavated, the temperature and humidity data downloaded and the pig carcasses dissected on site to evaluate condition. The results demonstrate that: (1) there were distinct differences in the nature/rate of decomposition according to burial mode; (2) after two years burial the carcasses had been subject to considerable desiccation of the outer tissues while remaining moist in the core; (3) the body had undergone putrefactive change and collapsed leading to slumping of soil within the grave fill following the curvature of the pig's back, although this was not evident from the surface; (4) there was a specific plume of body decomposition products that wicked both horizontally and also vertically from the head wounds in the sandy desert soil. These observations have widespread application for prospection techniques, investigation of clandestine burial, time since deposition and in understanding changes within the burial microenvironment under arid conditions.

No / Introduction: Potential-sensitive dyes have primarily been used to optically record action potentials (APs) in whole heart tissue. Using these dyes to record drug-induced changes in AP morphology of isolated cardiac myocytes could provide an opportunity to develop medium throughout assays for the pharmaceutical industry. Ideally, this requires that the dye has a consistent and rapid response to membrane potential, is insensitive to movement, and does not itself affect AP morphology. Materials and methods: We recorded the AP from isolated adult guinea-pig ventricular myocytes optically using di-8-ANEPPS in a single-excitation dual-emission ratiometric system, either separately in electrically field stimulated myocytes, or simultaneously with an electrical AP recorded with a patch electrode in the whole-cell bridge mode. The ratio of di-8-ANEPPS fluorescence signal was calibrated against membrane potential using a switch-clamp to voltage clamp the myocyte. Results: Our data show that the ratio of the optical signals emitted at 560/620 nm is linearly related to voltage over the voltage range of an AP, producing a change in ratio of 7.5% per 100mV, is unaffected by cell movement and is identical to the AP recorded simultaneously with a patch electrode. However, the APD90 recorded optically in myocytes loaded with di-8-ANEPPS was significantly longer than in unloaded myocytes recorded with a patch electrode (355.6 ± 13.5 vs. 296.2 ± 16.2ms; p< 0.01). Despite this effect, the apparent IC50 for cisapride, which prolongs the AP by blocking IKr, was not significantly different whether determined optically or with a patch electrode (91 ± 46 vs. 81 ± 20 nM). Discussion: These data show that the optical AP recorded ratiometrically using di-8- ANEPPS from a single ventricular myocyte accurately follows the action potential morphology. This technique can be used to estimate the AP prolonging effects of a compound, although di-8-ANEPPS itself prolongs APD90. Optical dyes require less technical skills and are less invasive than conventional electrophysiological techniques and, when coupled to ventricular myocytes, decreases animal usage and facilitates higher throughput assays.

<p dir="ltr">Maximizing growth performance in swine production, in the face of larger litter sizes and potential milk limitations, is crucial. This thesis explores the impact of various nutritional strategies, including creep feeding, dietary sweeteners, glutamine supplementation, sensory additives, and low crude protein diets on piglet lactation and nursery growth performance. Data in this thesis were analyzed using the GLM procedure in SAS 9.4. In the first study (Chapter 2), fifty-one sows and their litters (17/creep treatment) were used to evaluate the effects of creep feeding and nursery diets on piglet growth. Ten days prior to weaning, litters were assigned to three treatments: control creep feed (CF-CON), CON + garlic-based flavoring (50 ppm Allium XL; CF-ALL-XL), and no creep feed (NO-CF). Post-weaning, 506 pigs were allotted to either control (CON) or flavored (ALL-XL) nursery diets in a 3x2 factorial design with 10 pens/treatment, each containing 7 or 8 pigs. Nursery dietary treatments were fed in phases 1 and 2, followed by common phase 3 and 4 diets. Weekly body weights (BW) and feed intake were recorded to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). Creep feeding treatment during lactation did not affect litter or piglet BW gain pre-weaning. ALL-XL did not affect total creep feed intake (CON=114 g/pig vs. ALL-XL=110 g/pig). Providing CF-CON or CF-ALL-XL during lactation increased ADFI on d 2, 3, and 4 post-weaning (P<0.013). Pigs fed either CF-CON or CF-ALL-XL increased week 1 nursery ADFI (8.8%; P<0.02), numerically increased ADG (5.2%), and greater d7 BW (P=0.055). Overall (d0-35), pigs fed CF-CON had greater ADG (P<0.05) and ADFI (P<0.05) than CF-ALL-XL with No-CF pigs being intermediate in ADG and greater ADFI (P<0.05) than CF-ALL-XL fed pigs. Final BW (P<0.05) was greater for CF-CON fed pigs than CF-ALL-XL fed pigs with No-CF pigs being intermediate (23.5 kg, 23.0 kg, 23.3 kg, respectively). Nursery dietary flavoring treatment (CON vs ALL-XL) did not affect post-weaning ADG, ADFI, or G:F at any point during the study (P>0.12). In the second study (Chapter 3), fifty-seven sows and their litters were used to test the effects of creep feed and a dietary sweetener (Taktik) on piglet lactation and nursery performance in low lactose diets. Six days prior to weaning, litters were assigned to either control creep feed (CF-CON), control + sweetener (50 ppm Taktik; CF-TAK), or no creep (No-CF). Post-weaning, 550 pigs were assigned to control (CON) or sweetened (Taktik, 50 ppm; TAK) nursery diets in a 3x2 factorial design with 10 nursery pens per treatment, each containing 9 or 10 pigs. There were no significant differences in litter weight, weight gain, or piglet weight during lactation due to CF treatment. However, CF-CON pigs tended to have higher litter feed intake (P=0.060) and ADFI per pig (P=0.059) during lactation. During the first week post-weaning, CF-CON pigs had higher ADFI (P<0.05), ADG (P<0.05), and d7 BW compared to CF-Tak pigs and No-CF pigs. During d 6-14 CF-CON pigs had greater ADG (P<0.05) and ADFI (P<0.05) than CF-Tak pigs and the No-CF pigs tended (P<0.10) to also have greater ADFI than CF-Tak pigs. Overall (d0-34), CF-CON pigs had higher ADG and ADFI compared to CF-Tak pigs (P<0.05) and No-CF pigs tended (P<0.10) to have greater ADG than CF-Tak pigs. There were no significant differences (P>0.15) in ADG, ADFI, or G:F between CON and TAK nursery diet treatments. In the third study (chapter 4), thirty-one sows and their litters were utilized to test the effects creep feed and nursery diets supplemented with or without glutamine on lactation and nursery performance as well as creep feeder type impacts. During lactation there were three dietary treatments: control creep feed (CF-CON), control creep feed + glutamine (0.40%; CF-GLUT), or no creep feed (No-CF). There were two creep feeder types: plastic (PLAST) or stainless steel (SS), that were evenly distributed between the creep feed treatments. Post-weaning 270 pigs were allotted to either control (CON) or control + glutamine (0.40%; GLUT) nursery diets with pigs previously given or not glutamine creep feed continuing to receive similar glutamine treatment in the nursery period and the No-CF pigs being evenly split to CON and GLUT nursery diets. Litter weights and creep feed intake were recorded on d -7 and 0 (weaning). During nursery there were 7 pens/treatment with 6 or 7 pigs/pen, blocked by initial BW within creep treatment. Neither glutamine creep feeding treatments affected litter or piglet weaning weights (P>0.24). Pigs given creep feed during lactation had increased ADFI during the first week post-weaning (P<0.03) but did not result in greater overall nursery growth performance. The inclusion of glutamine in creep feed or nursery diets did not improve growth performance at any point during the study. In the fourth study (chapter 5), 416 weanling pigs were used to test the effects of a sensory feed additive (SA; Luctamax) on control (CON) and low crude protein (LCP) nursery diets in a 2x2 factorial design (CON, CON+SA, LCP, LCP+SA) with 15 replicate pens of 6 or 7 pigs/pen. Decreased dietary CP (4%) was achieved by removing or decreasing fish meal and soy concentrate in phases 1 and 2 and reducing soybean meal in phase 3 and adding synthetic amino acids to maintain amino acid ratios (NRC 2012). The SA was included at 0.1% in Phase 1 and 2 diets and 0.05% in Phase 3 diets. During PH1 (d 0-7) pigs receiving the CON diets tended (P=0.065) to have a higher G:F compared to pigs receiving LCP diets. For the remainder of this study there were consistent interactions between dietary CP and SA. When SA was added to the LCP diet ADFI slightly increased but when SA was added to CON diet ADFI decreased and these changes in feed intake often led to similar dietary interactions in ADG. During PH2 (d 7-21), pigs fed CON or LCP+SA diets had higher ADFI (P=0.032) and tended to have a higher ADG (P=0.094) but reduced G:F (P=0.100) compared to pigs fed CON+SA or LCP diets. In PH3 (d 21-36), pigs fed CON or LCP+SA diets had a higher ADG (P=0.027) and ADFI (P=0.011) compared to CON+SA or LCP diets. During PH3 pigs fed LCP diets had higher ADFI (P<0.001) but reduced G:F (P<0.0001) than pigs fed CON diets. Overall (d0-36), pigs fed CON or LCP+SA diets had higher ADFI (P=0.016) and tended to have a higher ADG (P=0.059) but reduced G:F (P=0.067) compared to pigs fed CON+SA or LCP diets. For the entire nursery period, pigs fed CON diets had a higher G:F (P<0.001) compared to pigs fed LCP diets, while LCP pigs tended to have a higher ADFI (P=0.054) compared to CON pigs. Feeding LCP diets during PH2 decreased feed costs/kg of gain but feed cost were increased (P<0.0001) during PH3 when LCP diets were fed compared to CON diets. These studies highlight the potential benefits and limitations of various nutritional strategies in enhancing piglet growth performance. Creep feeding, dietary sweeteners, glutamine supplementation, sensory additives, and low crude protein diets can potentially influence post-weaning performance, but their effectiveness depends on specific conditions and formulations. Further research is needed to optimize these strategies for improved swine production efficiency.</p>

This work is concerned with an attempt to clarify the role of cortisone in both the immune complement response and the progression of mouse leukemic tumor.

Este trabalho descreve o desenvolvimento de um algoritmo para avaliar o grau de corrosão em paredes de oleodutos, através de ultrassom. O algoritmo desenvolvido será implementado em um circuito digital, fazendo parte de um sistema que poderá ser embarcado em pigs ultrassônicos para inspeção de dutos à procura de corrosão. O modelo matemático conhecido como filtro casado é usado como base do algoritmo, além de um método de detecção de picos para localização dos sinais de eco de ultrassom, provenientes das reflexões do sinal nas paredes dos dutos. Um dos problemas é a definição do sinal (e do filtro) que será utilizado, mas por meio de sinais sintetizados (signal design) uma grande gama de alternativas foi analisada e apenas algumas foram selecionadas para testes em experimentos. Por último os melhores sinais foram utilizados na inspeção de um corpo de prova feito à partir de um duto corroído, e os resultados são analisados. A detecção da primeira parede do oleoduto apresenta resultados promissores em comparação com a medição tridimensional das mesmas paredes. O sistema foi capaz de reconstruir o perfil da parede interna do duto com elevada verossimilhança, mesmo em regiões severamente corroídas. A detecção da segunda parede apresenta resultados satisfatórios para baixos níveis de corrosão, porém alguns problemas foram encontrados para níveis mais altos de corrosão, prejudicando a medição direta da espessura da parede nestas condições. / This work describes the development of an algorithm to evaluate the degree of corrosion in pipeline walls, using ultrasound. The developed algorithm will be implemented in a dedicated digital circuit that can be embedded in ultrasonic pigs for pipeline corrosion inspection. The algorithm is based on the mathematic model known as matched filter, besides a peak detection method for the location of ultrasound echoes, originated from the signal reflections in the pipeline walls. One problem is the determination of the signal (and filter) that should be used, but using a signal design approach a large number of possibilities could be analyzed and only a few was tested in experiments. Finally, the best signals were used to inspect a test specimen made of a corroded pipeline section, and the results were analyzed. The first wall detection shows promising results when compared to the results of a three-dimensional inspection of the same walls. It was possible to reconstruct the profile of the internal wall with good likelihood, even at badly corroded areas. The second wall detection shows some satisfactory results on low corrosion levels, but show some problems with high corrosion levels, compromising the direct measurement of the wall of the pipeline.