Activin is a dimeric protein of inhibin beta subunit, which is abundantly stored in normal bone matrix, presumably produced by osteoblasts in the process of normal bone formation. The expression of activins was examined in the wound healing of diabetic rats. In this study,insulin-dependent diabetes mellitus was induced in a group of mature Sprague-Dawley rats by injecting streptozotocin. Control animals were injected with citrate buffer only. After 3 weeks,all of rats underwent extraction of the right maxillary molars teeth after anesthesia. Rats were killed at varying intervals and the maxilla and calvaria were recovered in continuity. Tissue sections were stained with hematoxylin-eosin as well as immunohistochemical gent. Hematoxylin-eosin analyses showed that at 7 days after tooth extraction in the control and insulin-streptozotocin-treated rats there were, thick collagen fibers which formed a pretrabecular the scaffold dictated the direction of the forming trabeculae. However,the collagen fibers in the diabetic socket were thin and scanty, and only formed a narrow layer in the apical part of the socket. These histologic observations suggest that in uncontrolled, insulin-dependent diabetes, the formation of the collagenous framework in the tooth extraction socket is inhibited, resulting in delayed healing.The immunohistochemical analyses showed that at 7 days after tooth extraction in both control and insulin-streptozotocin-treated rats, osteoblasts were increased in extra-alveolar bone formation.Our findings also suggested that activin was actively involve in bone modeling during osteogenesis. These findings suggest that activin may play important role in the regulation of bone formation and it may be useful in the future for the wound healing in diabetic patients.

Orientador: Marcelo Macedo Crivelini / Resumo: Tem sido descrito que cerca de 30% do total leucoplasias possui tendência à malignização, a uma taxa de 2,9% ao ano. O envolvimento concomitante de leucoplasias com Candida albicans tem sido relacionado a possíveis processos de malignidade, tornando este questionamento uma fonte de debate. O presente trabalho avaliou a expressão qualitativa de p 53, Ki-67, PCNA e AgNOR em leucoplasias associadas à Candidose. Não foram observadas diferenças significativamente estatísticas (Tukey test, p<0,05) no grupo corado por AgNOR. Esses resultados discutem a taxa de proliferação celular epitelial e, talvez, indícios de alterações genéticas malignas presentes nas leucoplasias associadas à Candidose. / Abstract: It has been described that 30% of leukoplakia with tendences to malignization, in a rate of 2,9% per year. The envolvement of leukoplakia associated to Candida albicans has been related to possible process of malignity, witch makes this question a source of debate. The aim of this study was to evaluate the qualitative expression of p53, Ki-67, PCNA and AgNOR in leukoplakia related to Candidosis. It wasþt observated statistical diferences in the AgNOR group (F test, p<0,05-ANOVA one-way). This results discuss a rate of celular epitelial proliferation and possibly genetic alterations present in leukoplakia related to Candidosis. / Mestre

Made available in DSpace on 2014-06-11T19:25:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2005Bitstream added on 2014-06-13T19:11:57Z : No. of bitstreams: 1 baldan_rcf_me_araca.pdf: 521281 bytes, checksum: 0f50e815f21fa4a3959c51153cef58af (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Tem sido descrito que cerca de 30% do total leucoplasias possui tendência à malignização, a uma taxa de 2,9% ao ano. O envolvimento concomitante de leucoplasias com Candida albicans tem sido relacionado a possíveis processos de malignidade, tornando este questionamento uma fonte de debate. O presente trabalho avaliou a expressão qualitativa de p 53, Ki-67, PCNA e AgNOR em leucoplasias associadas à Candidose. Não foram observadas diferenças significativamente estatísticas (Tukey test, p<0,05) no grupo corado por AgNOR. Esses resultados discutem a taxa de proliferação celular epitelial e, talvez, indícios de alterações genéticas malignas presentes nas leucoplasias associadas à Candidose. / It has been described that 30% of leukoplakia with tendences to malignization, in a rate of 2,9% per year. The envolvement of leukoplakia associated to Candida albicans has been related to possible process of malignity, witch makes this question a source of debate. The aim of this study was to evaluate the qualitative expression of p53, Ki-67, PCNA and AgNOR in leukoplakia related to Candidosis. It wasþt observated statistical diferences in the AgNOR group (F test, p<0,05-ANOVA one-way). This results discuss a rate of celular epitelial proliferation and possibly genetic alterations present in leukoplakia related to Candidosis.

京都大学 / 0048 / 新制・課程博士 / 博士(人間健康科学) / 甲第20295号 / 人健博第43号 / 新制||人健||4(附属図書館) / 京都大学大学院医学研究科人間健康科学系専攻 / (主査)教授 高桑 徹也, 教授 藤井 康友, 教授 武藤 学 / 学位規則第4条第1項該当 / Doctor of Human Health Sciences / Kyoto University / DGAM

Granular cell tumors (GCTs) are rare neoplasms of neuroectodermal origin characterized by large polygonal cells with abundant eosinophilic and granular cytoplasm. GCTs rarely affect the lungs, with only a few cases reported in the literature. The pathophysiology of this Schwann cell-derived condition is not well understood but is thought to be due to recurring genetic mutations. GCTs have been linked with Noonan syndrome. Here, we report the case of a 17-year-old caucasian male who presented with partial upper airway obstruction due to a GCT. This case promotes awareness among pathologists and clinicians for this condition in the workup of patients presenting with upper airway obstruction.

In addition to the acute pathology produced by traumatic brain injury, there are chronic alterations that occur after the trauma, including a depressed state of neuronal activity (Feeney, 1991). This study included a preclinical testing of a novel treatment strategy focusing on increasing neuronal activity during the chronic hypofunctional posttraumatic stage. The present investigation tested the effects of repeated post-injury aniracetam administration on cognitive performance in the Morris water maze (MWM) and on the GluR2 - immunoreactivity and protein expression by Western blot analysis in the hippocampus. The first study examined the optimal dose of aniracetam in the MWM task. Animals received aniracetam (25 mg/kg, 50 mg/kg) or vehicle once daily for fifteen days and on days 11-15 were tested in the MWM. The results indicated that injured aniracetam-treated rats had a significant improvement in MWM performance compared to injured saline-treated animals. When the drug was delayed for 11 days post-injury in the second experiment, its beneficial effects were still present, as injured aniracetam-treated rats performed significantly better that injured saline treated rats on the MWM task. In the third experiment, chronic daily aniracetam administration was terminated after 15 days immediately before MWM testing on days 16-20. The results indicated that termination of aniracetam did not enhance MWM performance as injured terminated aniracetam-treated rats did not have significant improvement over injured saline-treated rats. In the fourth study we investigated the mechanism of aniracetam's effects by examining the expression of the AMPA receptor GluR2 subunit, the only AMPA receptor subunit that is Ca++ impermeable. Using a monoclonal antibody selective for the GluR2 subunit, immunohistochemical results indicated that injured rats treated with aniracetam (50mg/kg for 15 days post-injury) had a slight reduction in the GluR2- IR. The fifth study investigated a change in the GluR2 protein expression in the hippocampus with a Western blot analysis. The results were consistent with the immunohistochemical study outcome as the injured vehicle and injured aniracetam treated animals showed a reduced protein expression in the hippocampus. The changes were not significantly different from the controls. The results of these experiments suggested that chronic aniracetam treatment significantly attenuated injury induced spatial memory deficits when administered continually during the hypofunctional posttraumatic stage and when the treatment was delayed for 11 days, but not when the treatment was terminated before the MWM testing. These effects suggest that the compound does not induce chronic receptor changes and has to be biologically active in an organism for it to exert its beneficial properties. Results from the present studies suggest that aniracetam may become a potential treatment option for brain injury induced cognitive deficits.

Pólipos adenomatosos colorretais são conhecidos como lesões pré-malignas. Mutações germinativas nas enzimas de reparo (MMR) hMLH1, hMSH2 e hMSH6 são causas reconhecidas de câncer colorretal hereditário não polipóide, induzindo um fenótipo mutante caracterizado por instabilidade de microssatélite (MSI). A MSI também é detectada em cânceres colorretais esporádicos. O Cox-2 é uma enzima induzível que regula a síntese de prostaglandina, sendo fortemente manifestada em locais de inflamação, pólipos adenomatosos colorretais e câncer. Objetivos: Avaliar a imunoexpressão do hMLH1, hMSH2 e Cox-2 em pólipos ressecados através da colonoscopia e associar às características clínico-patológicas (idade, sexo, localização, tamanho, histologia e grau de displasia). Métodos: 138 pacientes com pólipos colônicos, 6 com mucosa colônica normal e 23 pacientes com adenocarcinoma colorretal foram incluídos no estudo. Nenhum paciente apresentava histórico familiar de câncer colorretal. Cento e sessenta e sete amostras foram coletadas e imunocoradas para hMLH1, hMSH2 e Cox-2, usando a técnica ABC-imunohistoquímica e amplificação por tiramida biotinilada. Resultados: A média de idade foi 60,2 + 13,8 (variando de 21 a 90 anos de idade) sendo 77 homens (55,8%) e 61 mulheres (44,2%). Adenomas tubulares estavam presentes em 81,4%, tubulo-viloso em 15,9%, serrilhados em 1,8% e vilosos em 0,9%. A maioria dos adenomas localizava-se na região retossigmoideana (63,5%), seguido pelo ascendente em 14,2%, descendente em 8,2%, ceco em 7,5% e o transverso em 6,7%. Displasia de alto grau foi detectada em 46 (40,4%) e de baixo grau em 68 (59,6%) dos adenomas. Perda de imunoexpressão hMLH1 e hMLH2 foi observada em 20% e 15,5% dos adenomas, respectivamente. O Cox-2 foi positivo em 9% dos adenomas e em 40% dos adenocarcinomas. Além disso, a imunoexpressão Cox-2 foi associada à multiplicidade de adenomas no mesmo paciente (p=0,001). Não houve associação entre a imunoexpressão de marcadores e o sexo, idade, localização, tamanho, histologia ou grau de displasia. Conclusões: 1. A perda de imunoexpressão hMLH1 e hMLH2 em adenomas é relativamente freqüente em pacientes sem histórico familiar de câncer colorretal; 2. O Cox-2 é fortemente manifestado em pólipos adenomatosos e adenocarcinomas colorrretais sendo que sua positividade em adenomas pode indicar um risco maior de lesões múltiplas. / Colorectal adenomatous polyps are known as premalignant lesions. Mutations in the mismatch repair (MMR) enzymes hMLH1, hMSH2 and hMSH6 are recognized causes of hereditary nonpolyposis colorectal cancer and act by inducing a mutator phenotype characterized by microsatellite instability (MSI). MSI is also detected in sporadic colorectal cancers. Cox-2 is an inducible enzyme that regulates prostaglandin synthesis and is overexpressed at sites of inflammation, in colorectal adenomatous polyps and cancer. Aims: To evaluate the immunoexpression of hMLH1, hMSH2 and Cox-2 in resected polyps through colonoscopy, and to associate to the clinicopathologic characteristics (age, gender, location, size, histology and grade of dysplasia). Methods: 138 patients with colonic polyps, 6 with normal colonic mucosa and 23 patients with colorectal adenocarcinoma were enrolled in this study. All patients had no familial history of colorectal cancer. The 167 samples were collected and immunostained for hMLH1, hMSH2 and Cox-2 using the ABC-immunohistochemistry technique and amplification by biotinylated tyramide. Results: The mean age was 60.2 + 13.8 (varying from 21 to 90 years-old) where 77 (55.8%) were men and 61 women (44.2%). Tubular adenomas were present in 81.4%, tubulous-villous in 15.9%, serrated in 1.8%, and villous in 0.9%. The majority of the adenomas were located in the retossigmoid region (63.5%), followed by ascendent in 14.2%, descendent in 8.2%, cecum in 7.5% and transverse in 6.7%. High-grade dysplasia was detected in 46 (40.4%) and low-grade dysplasia in 68 (59.6%) of the adenomas. Loss of hMLH1 and hMLH2 immunoexpression was observed in 20% and 15.5% of the adenomas, respectively. Cox-2 was positive in 9% of the adenomas, and in 40% of the adenocarcinomas. Moreover, Cox-2 immunoexpression was associated to the multiplicity of adenomas in the same patient, p=0.001. There was no association between marker immunoexpression and gender, age, location, size, histology or grade of dysplasia. Conclusions: 1. Loss of hMLH1 and hMLH2 immunoexpression in adenomas is relatively frequent in patients without colorectal cancer familial history; 2. Cox-2 is overexpressed in colorectal adenomatous polyps and adenocarcinomas, and its positivity in adenomas may indicate higher risk for multiple lesions.

No indivíduo adulto, a angiogênese ocorre particularmente em situações patológicas como nos tumores em crescimento, no desenvolvimento de metástases e no processo de cicatrização, sendo o fator de crescimento do endotélio vascular (VEGF) o principal fator envolvido na angiogênese tumoral. Por essa razão, o presente estudo teve como objetivo avaliar os níveis circulantes de VEGF no soro de cães com sarcoma de tecidos moles e sua relação com as células sanguineas, comparados com um grupo de animais sem câncer (controle), a expressão do VEGF e a densidade de microvasos nos espécimes tumorais dos cães com sarcoma de tecidos moles. O grupo controle foi composto de 30 cães machos e o grupo de animais com sarcoma de tecidos moles foi de 25 cães (18 machos e 7 fêmeas castradas) os quais foram avaliados prospectivamente. A coleta sangüínea foi realizada apenas uma vez no grupo controle e em três tempos nos animais com sarcoma (pré-operatório, duas semanas e três meses de pós-operatório) da mesma maneira. Após a colheita o sangue foi processado, para extração do soro e determinação dos níveis de VEGF a partir de um método quantitativo ELISA (enzime-linked immunosorbent assay). A expressão do VEGF e a densidade de microvasos foi investigada por meio da prova de imunoistoquiímica utilizando-se anticorpos anti-VEGF e anti-fator VIII respectivemente. Não houve diferença entre o nível sérico de VEGF dos animais controles e portadores de sarcoma de tecidos moles no tempo pré-operatório. O nível de VEGF sérico no pré-operatório mostrou-se discretamente aumentado em relação a duas semanas e três meses de pós-operatório. Houve correlação positiva entre VEGF sérico e contagem neutrófilos e correlação negativa entre o VEGF e quantidade de hemoglobina nos animais com sarcoma. Houve uma tendência dos animais com hemangiopericitoma apresentarem níveis maiores de VEGF sérico em relação aos portadores de tumor maligno da bainha neural periférica. Houve expressão do VEGF em 65% dos casos, sendo o hemangiopericitoma aquele que expressou maior quantidade de VEGF intratumoral. Não houve diferença na densidade de microvasos entre os tumores negativos e positivos ao VEGF. Os resultados encontrados sugerem contribuição das células do sangue circulante para os níveis de VEGF do soro de cães portadores de sarcomas de tecidos moles, células tumorais e outros tipos celulares parecem ser responsáveis pela angiogênese tumoral, mas não contribuem para elevação da concentração sérica desse fator. / In adult individual, angiogenesis occurs particularly in pathological situations as tumors growth, development of metastasis and in the wound healing process. The vascular endothelial growth factor (VEGF) is the main agent involved in tumor angiogenesis. Therefore, the aim of the present study was to evaluate the circulating levels of VEGF in the serum of dogs suffering from soft tissue sarcoma and its relation with the blood cells, and also the expression of VEGF and the micro vascular density in tumors specimens. A group of health animals was used as control. The control group and treatment group were composed of 30 male dogs 25 dogs (18 males and 7 castrated females) respectively. The blood collection was carried once in the control group and three times in the animals with sarcoma (timely, pre-surgery, two weeks and three months post-surgery) following the same protocol. The blood was processed and a quantitative method ELISA (enzime-linked immunosorbent assay) was used to determinate of the levels of VEGF. The expression of the VEGF and the microvascular density were investigated by means of the immunohistochemical test using anti-VEGF and anti-factor VIII antibodies respectively. There was no difference between serum level of VEGF of the controls animals and serum level of VEGF in the animal with soft tissue sarcoma in pre-surgical time. Serum level of VEGF in pre-surgical time revealed discrete increased in relation the two weeks and three months of post-surgery. There was a positive correlation between serum VEGF and neutrophils counting and negative correlation between the VEGF and amount of haemoglobin in the animals with sarcoma. The animals with hemangiopericytoma showed a trend to higher levels of VEGF in relation to the malignant peripheral nerve sheath tumor. The expression of the VEGF was detected in 65% of the cases; the hemangiopericytoma is the one that expressed greater intratumoral amount of VEGF. There was no difference in the microvascular density between the negative and positive tumors to the VEGF. The results suggest contribution of the circulating blood cells for the levels of serum VEGF of the of the dogs with of soft tissue sarcomas, tumors cells and other cells types seem to be responsible for tumor angiogenesis, but they don\'t contribute for rise serum level of VEGF.

INTRODUÇÃO: Acredita-se que os fatores de crescimento insulina símile 1 (IGF1) e IGF2 tenham um papel chave na progressão de tumores, resistência à apoptose e terapias. A resistência à insulina tem sido associada ao aumento do volume tireoidiano e aumento do risco de desenvolver nódulos e câncer de tireoide; no entanto, há poucos estudos que avaliaram o papel dos IGFs e seus receptores no carcinoma papilífero de tireoide (CPT) e, até o momento, nenhum estudo foi conclusivo sobre a relação entre a via insulina/IGF e o comportamento do CPT. OBJETIVOS: 1) Estudar a expressão do IGF1, IGF2 e o IGF1R no CPT, incluindo o microcarcinoma papilífero; 2) Correlacionar essa expressão com as características clínicas, variante histopatológica, estadiamento e estratificação de risco. MÉTODOS: Foram selecionados, retrospectivamente, 110 pacientes operados por CPT e atendidos no Ambulatório do Serviço de Endocrinologia do Hospital das Clínicas da FMUSP e separados em dois grupos: 62 microcarcinomas papilíferos (MCP) e 48 CPT > 1,0 cm. A presença e expressão do IGF1, IGF2 e IGF1R foi avaliada, através de exame imunohistoquímico, em 110 tecidos tumorais e 98 tecidos não tumorais (controle). Os casos positivos foram classificados, de acordo com a quantidade de células coradas, em: + (menos de 10% das células); ++ (em 10-50% das células) e +++ (mais de 50% das células). O grau da expressão foi classificada em leve, moderada e forte. A presença e intensidade desses marcadores foram correlacionados com as características clínicas, variante histopatológico, TNM e estratificação de risco. RESULTADOS: O IGF1 e o IGF1R estiveram presentes em 100% e 99% dos CPTs e mostraram-se significativamente hiperexpressos, tanto nos MCPs quanto nos CPTs > 1,0 cm, quando comparados ao tecido adjacente não tumoral (p < 0,001). O IGF2 esteve expresso em 46,7% dos CPTs e mostrou fraca expressão em apenas um tecido não tumoral (p < 0,001). O IGF1 apresentou expressão significativamente maior nos microcarcinomas nos estágios III e IVA quando comparados aos estágios I e II (p=0,022). Não houve diferença significativa na quantidade e intensidade de expressão do IGF1 e IGF1R nos MCT quando comparados aos CPTs > 1,0 cm. O IGF2 apresentou expressão significativamente maior nos MCTs e, nesse grupo, apresentou maior expressão nos tumores multicêntricos (p=0,017) e nos estágios III e IVA, quando comparados aos estagios I e II (p=0,041). CONCLUSÕES: No presente estudo, observamos que o IGF1 e IGF2 foram significativamente mais expressos nos microcarcinomas em estágios mais avançados. O IGF2 apresentou maior expressão nos microcarcinomas papilíferos e esta expressão foi significativamente maior nos tumores multicêntricos / INTRODUCTION: Insulin-like growth factor-1 and 2 (IGF-1 and IGF-2) are believed to play a key role in the progression of tumors, resistance to apoptosis and therapies. The insulin resistence has been associated with increased thyroid volume and increased risk in developing thyroid nodules and thyroid cancer. However, few studies have evaluated the role of IGFs and their receptors on papillary thyroid carcinomas (PTC), and there is no conclusive studies about the relationship between IGF axis and PTC behavior. OBJECTIVES: The aim of this study was to investigate the expression of IGF-1, IGF-2, and IGF-1R in PTC, including papillary microcarcinoma (PTMC), and correlate the expression data with clinical, histologic variants, TNM staging, and risk of recurrence. METHODS: We retrospectively selected 110 paraffin-embedded tumoral tissues from patients with PTC who underwent thyroidectomy at Hospital das Clínicas of FMUSP. These patients were divided into two groups: 62 microcarcinomas (PTMC) and 48 PTC > 1.0 cm. The presence and intensity of expression of IGF-1, IGF-2, and IGF-1R were evaluated through immunohistochemical staining in 110 tumoral tissues, and in 98 non-tumoral tissues (control group). Positive cases were classified according to the numbers of staining cells in: + less than 10% of staining cells; ++ in 10-50% of the staining cells, and +++ in more than 50% of staining cells. The degree of expression was classified as mild, moderate and strong. The presence and degree of IGF1, IGF2, and IGF1R staining were correlated with clinical features, histologic type, TNM staging, and risk stratification. RESULTS: IGF-1 and IGF-1R were expressed in 100% and 99% of PTC, and were significantly overexpressed in both PTMC and PTC > 1.0 cm, in comparison with non-tumoral tissues (control group) (p < 0.001). IGF-2 was expressed in 46.7% of PTC and had mild positivity expression in only one non-tumoral tissue (p < 0.001). IGF1 was significantly overexpressed in PTMC on stage III and IVa and was less expressed in stage I and II. There was no significant difference on IGF1 and IGF1R expression between PTMC and PTC >1.0 cm. IGF-2 presented greater expression in multicentric PTMC (p=0.017), specially in stage III and IVa. CONCLUSIONS: In our study, both IGF-1 and IGF2 were significantly overexpressed in PTMC group in advanced stages. IGF-2 was also significantly overexpressed in PTMC multicentric tumors

O estudo visou elucidar o desenvolvimento embrionário e fetal de pacas (Agouti paca) e demarcação dos sítios germinativos nos embriões em diferentes estágios. Foram utilizados sete espécimes de Agouti paca, sendo dois embriões e três fetos doados do pacário mantido pela UNESP - Jaboticabal e, dois doados do acervo da FMVZ-USP. Os fetos 1 e 2 apresentaram imaturidade facial acentuada, olhos recobertos por uma lente proeminente e lóbulos das orelhas; os fetos 3 e 4, mostravam-se com orelhas bem desenvolvidas, membros torácicos e pélvicos em grau equalitário de desenvolvimento, como vibrissas ao redor das bordas nasais e olhos também protegidos; no feto 5, haviam pêlos distribuídos por todo o corpo, membros torácicos e pélvicos com garras, vibrissas na face, olhos proeminentes e orelhas bem desenvolvidas. O embrião 1, apresentou a vesícula óptica com pigmentação da retina, o quarto ventrículo encefálico e curvatura cervical acentuada e broto dos membros em desenvolvimento; o embrião 2, possuiu divisão dos arcos branquiais e neuróporo cranial aberto; presença da área cardíaca e fígado; vesícula óptica sem pigmentação da retina, abertura do tubo neural na região do quarto ventrículo encefálico, rombencéfalo e mesencéfalo em desenvolvimento. Na microscopia de luz, visualizamos a medula espinhal, abertura do 4º ventrículo encefálico, presença das vesículas encefálicas (prosencéfalo, mesencéfalo e rombencéfalo), coluna vertebral, hipófise, cavidades oral e nasal, olho, átrio e ventrículo cardíacos, pulmão e diafragma, além das cristas metanéfrica e mesonéfrica, fígado, intestino e pedículo umbilical. Nas reações de imunohistoquímicas para OCT-4 não houve marcação expressiva em órgãos tais como pulmão, intestino e somitos, o coração apresentou uma leve positividade à reação, enquanto que nas cristas meso e metanéfrica e fígado obtiveram uma marcação expressiva, sendo mais acentuada no último. Nos testes com vimentina todos os órgãos mostraram-se imunopositivos em diferentes áreas; e em se tratando da reação a testes com actina apenas a região de somitos não obteve marcação positiva. Concluímos que o período embrionário/fetal da paca não pode ser comparado com o modelo clássico de roedor; sua embriogênese pode ser comparada à de ratos, Guinea pig, coelhos e humanos. A imunolocalização positiva de OCT-4 apresenta diferenças de acordo com a idade gestacional, devido às mudanças embriológicas dos tecidos. A imunolocalização positiva de OCT-4 apresenta diferenças de acordo com a idade gestacional, devido às mudanças embriológicas dos tecidos. A vimentina como marcador de mesênquima se expressou positivamente em todos os órgãos do embrião de paca. A actina como imunomarcador de músculo liso foi expressiva nas áreas contendo musculatura. / The study aimed elucidates the development of embryonic and fetal of pacas (Agouti paca) and demarcation of the germ sites in embryos at different stages. Seven specimens were used; two embryos and three fetuses from UNESP- Jaboticabal and other two fetuses were from FMVZ-USP collection. The fetuses 1 and 2 showed immaturity facial sharp, eyes covered by a lens and prominent lobes of the ears, the fetuses 3 and 4, showed up with well-developed ears, members thoracic and pelvic in equal level of development, vibrisses around the nasal edges and eye also protected;. The fetus 5 had hairs distributed throughout the body, members thoracic and pelvic with claws, vibrisses on the face, prominent eyes and ears well developed. The embryo 1, presented the optic vesicle with pigmentation of the retina, the fourth encephalic ventricle and cervical curvature and button members in development. The embryo 2, had split the branchial arches and open neuropore cranial; heart and liver were identified, optical vesicle without pigmentation of the retina, the neural tube was opening in the region of the fourth encephalic ventricle, rombencephalon and mesencephalon were in development. Light microscopy, shows the spinal cord, 4 th encephalic ventricle, resence of encephalic vesicles (prosencephalon, mesencephalon and rombencephalon), vertebral column, pituitary gland, oral and nasal cavities, eye, atrium and ventricle heart, lung and diaphragm, as well the metanephron and mesonephron, liver, intestine and mbilical pedicle. The immunohistochemical reactions for OCT-4 were non expressive in organs such as lung, intestine and somites; heart presented a discrete positive reaction, while kidneys and liver obtained an expressive expression, more pronounced in the last one. Vimentina\'s tests showed that all organs stained in different areas, and the reaction whit the actin was negative just in the region of somites. We conclude that the period embryonic/fetal of paca can not be compared with the classical model of rodents; its embryogenesis can be compared with the rats, Guinea pig, rabbits and humans ones. The positive immunolocalization of OCT-4 presents differences according to the gestational age, due to changes embryological tissue. The vimentine as a mesenchyme marker is expressed positively in all organs of the embryo of paca. The actin as immunomarker of smooth muscle was expressive in areas containing muscles.