Northwest African Neolithic initiated by migrants from Iberia and Levant.

In northwestern Africa, lifestyle transitioned from foraging to food production around 7,400 years ago but what sparked that change remains unclear. Archaeological data support conflicting views: (1) that migrant European Neolithic farmers brought the new way of life to North Africa1-3 or (2) that local hunter-gatherers adopted technological innovations4,5. The latter view is also supported by archaeogenetic data6. Here we fill key chronological and archaeogenetic gaps for the Maghreb, from Epipalaeolithic to Middle Neolithic, by sequencing the genomes of nine individuals (to between 45.8- and 0.2-fold genome coverage). Notably, we trace 8,000 years of population continuity and isolation from the Upper Palaeolithic, via the Epipaleolithic, to some Maghrebi Neolithic farming groups. However, remains from the earliest Neolithic contexts showed mostly European Neolithic ancestry. We suggest that farming was introduced by European migrants and was then rapidly adopted by local groups. During the Middle Neolithic a new ancestry from the Levant appears in the Maghreb, coinciding with the arrival of pastoralism in the region, and all three ancestries blend together during the Late Neolithic. Our results show ancestry shifts in the Neolithization of northwestern Africa that probably mirrored a heterogeneous economic and cultural landscape, in a more multifaceted process than observed in other regions.

Genomic ancestry and social dynamics of the last hunter-gatherers of Atlantic France.

Since the early Holocene, western and central Europe was inhabited by a genetically distinct group of Western Hunter-Gatherers (WHGs). This group was eventually replaced and assimilated by the incoming Neolithic farmers. The western Atlantic façade was home to some of the last Mesolithic sites of mainland Europe, represented by the iconic open-air sites at Hoedic and Téviec in southern Brittany, France. These sites are known for the unusually well-preserved and rich burials. Genomic studies of Mesolithic European hunter-gatherers have been limited to single or a few individuals per site and our understanding of the social dynamics of the last Mesolithic hunter-gatherers of Europe and their interactions with incoming farmers is limited. We sequenced and analyzed the complete genomes of 10 individuals from the Late Mesolithic sites of Hoedic, Téviec, and Champigny, in France, four of which sequenced to between 23- and 8-times genome coverage. The analysis of genomic, chronological and dietary data revealed that the Late Mesolithic populations in Brittany maintained distinct social units within a network of exchanging mates. This resulted in low intra-group biological relatedness that prevented consanguineous mating, despite the small population size of the Late Mesolithic groups. We found no genetic ancestry from Neolithic farmers in the analyzed hunter-gatherers, even though some of them may have coexisted with the first farming groups in neighboring regions. Hence, contrary to previous conclusions based on stable isotope data from the same sites, the Late Mesolithic forager community was limited in mate-exchange to neighboring hunter-gatherer groups, to the exclusion of Neolithic farmers.

Recombinant guanosine-5'-triphosphate (GTP)-binding protein associated with Poloxamer 407-based polymeric micelles protects against Leishmania infantum infection.

Leishmania virulence proteins should be considered as vaccine candidates against disease, since they are involved in developing infection in mammalian hosts. In a previous study, a Leishmania guanosine-5'-triphosphate (GTP)-binding protein was identified as a potential parasite virulence factor. In the present work, the gene encoding GTP was cloned and the recombinant protein (rGTP) was evaluated as a vaccine candidate against Leishmania infantum infection. The protein was associated with saponin (rGTP/Sap) or Poloxamer 407-based micelles (rGTP/Mic) as adjuvants, and protective efficacy was investigated in BALB/c mice after parasite challenge. Both rGTP/Sap and rGTP/Mic compositions induced a Th1-type immune response in vaccinated animals, with significantly higher levels of IFN-γ, IL-12, IL-2, TNF-α, GM-CSF, nitrite, specific IgG2a isotype antibody and positive lymphoproliferation, when compared to the control groups. This response was accompanied by significantly lower parasite load in the spleens, livers, bone marrows and draining lymph nodes of the animals. Immunological and parasitological evaluations indicated that rGTP/Mic induced a more polarized Th1-type response and higher reduction in the organ parasitism, and with lower hepatotoxicity, when compared to the use of rGTP/Sap. In conclusion, our preliminary data suggest that rGTP could be considered for further development as a vaccine candidate to protect against VL.

Megalithic tombs in western and northern Neolithic Europe were linked to a kindred society.

Paleogenomic and archaeological studies show that Neolithic lifeways spread from the Fertile Crescent into Europe around 9000 BCE, reaching northwestern Europe by 4000 BCE. Starting around 4500 BCE, a new phenomenon of constructing megalithic monuments, particularly for funerary practices, emerged along the Atlantic façade. While it has been suggested that the emergence of megaliths was associated with the territories of farming communities, the origin and social structure of the groups that erected them has remained largely unknown. We generated genome sequence data from human remains, corresponding to 24 individuals from five megalithic burial sites, encompassing the widespread tradition of megalithic construction in northern and western Europe, and analyzed our results in relation to the existing European paleogenomic data. The various individuals buried in megaliths show genetic affinities with local farming groups within their different chronological contexts. Individuals buried in megaliths display (past) admixture with local hunter-gatherers, similar to that seen in other Neolithic individuals in Europe. In relation to the tomb populations, we find significantly more males than females buried in the megaliths of the British Isles. The genetic data show close kin relationships among the individuals buried within the megaliths, and for the Irish megaliths, we found a kin relation between individuals buried in different megaliths. We also see paternal continuity through time, including the same Y-chromosome haplotypes reoccurring. These observations suggest that the investigated funerary monuments were associated with patrilineal kindred groups. Our genomic investigation provides insight into the people associated with this long-standing megalith funerary tradition, including their social dynamics.

Population genomics of Mesolithic Scandinavia: Investigating early postglacial migration routes and high-latitude adaptation.

Scandinavia was one of the last geographic areas in Europe to become habitable for humans after the Last Glacial Maximum (LGM). However, the routes and genetic composition of these postglacial migrants remain unclear. We sequenced the genomes, up to 57× coverage, of seven hunter-gatherers excavated across Scandinavia and dated from 9,500-6,000 years before present (BP). Surprisingly, among the Scandinavian Mesolithic individuals, the genetic data display an east-west genetic gradient that opposes the pattern seen in other parts of Mesolithic Europe. Our results suggest two different early postglacial migrations into Scandinavia: initially from the south, and later, from the northeast. The latter followed the ice-free Norwegian north Atlantic coast, along which novel and advanced pressure-blade stone-tool techniques may have spread. These two groups met and mixed in Scandinavia, creating a genetically diverse population, which shows patterns of genetic adaptation to high latitude environments. These potential adaptations include high frequencies of low pigmentation variants and a gene region associated with physical performance, which shows strong continuity into modern-day northern Europeans.

Four millennia of Iberian biomolecular prehistory illustrate the impact of prehistoric migrations at the far end of Eurasia.

Population genomic studies of ancient human remains have shown how modern-day European population structure has been shaped by a number of prehistoric migrations. The Neolithization of Europe has been associated with large-scale migrations from Anatolia, which was followed by migrations of herders from the Pontic steppe at the onset of the Bronze Age. Southwestern Europe was one of the last parts of the continent reached by these migrations, and modern-day populations from this region show intriguing similarities to the initial Neolithic migrants. Partly due to climatic conditions that are unfavorable for DNA preservation, regional studies on the Mediterranean remain challenging. Here, we present genome-wide sequence data from 13 individuals combined with stable isotope analysis from the north and south of Iberia covering a four-millennial temporal transect (7,500-3,500 BP). Early Iberian farmers and Early Central European farmers exhibit significant genetic differences, suggesting two independent fronts of the Neolithic expansion. The first Neolithic migrants that arrived in Iberia had low levels of genetic diversity, potentially reflecting a small number of individuals; this diversity gradually increased over time from mixing with local hunter-gatherers and potential population expansion. The impact of post-Neolithic migrations on Iberia was much smaller than for the rest of the continent, showing little external influence from the Neolithic to the Bronze Age. Paleodietary reconstruction shows that these populations have a remarkable degree of dietary homogeneity across space and time, suggesting a strong reliance on terrestrial food resources despite changing culture and genetic make-up.

Stereological analysis of the New Zealand rabbits (Oryctolagus cuniculus) placenta.

The onset of gestation is characterized by growth, morphological and functional changes of the placenta. We aim to evaluate the placental compartments in New Zealand rabbits by means of stereological methods. The fetal and maternal portion of placenta (12, 14, 18 and 20 gestational days) was randomly sampled for the stereological analysis. Histological sections were scanned to estimate fetal (labyrinth and junctional) and maternal (decidua) compartment volumes. The total volume of the placenta for the ages of 12, 14, 18 and 20 days was, respectively, 320 mm3, 340 mm3, 940 mm3 and 1300 mm3. The volume of the labyrinth was 56 mm3, 119 mm3, 231 mm3 and 481 mm3, respectively. The volume of junctional zone was 75 mm3, 76 cm3, 238 mm3 and 314 mm3, respectively. The volume of decidua was 174 mm3, 143 mm3, 469 mm3 and 504 mm3, respectively. We concluded that the rabbit´s placenta compartments varied according to the gestational period, increasing continuously over the 20 gestational days. However, on the onset of the development of the placenta the decidua presented faster growth, whereas after the 20 days of development, the labyrinth developed more quickly. This study represents an aid to the understanding of placentation in humans.

Incidence of Central Venous Catheter-Related Bloodstream Infections: Evaluation of Bundle Prevention in Two Intensive Care Units in Central Brazil.

BACKGROUND: Central venous catheter-associated bloodstream infections (CVC-BSIs) have been associated with increased length of hospital stay, mortality, and healthcare costs, especially in intensive care units (ICUs). The aim of this study was to evaluate the incidence density of CVC-BSIs before and after implementation of the bundle in a hospital of infectious and dermatological diseases in Central Brazil. METHODS: A retrospective cohort study was conducted in two ICUs (adult and pediatric) between 2012 and 2015. Two periods were compared to assess the effect of the intervention in incidence density of CVC-BSIs: before and after intervention, related to the stages before and after the implementation of the bundle, respectively. RESULTS: No significant reduction was observed in the incidence density of CVC-BSIs in adult ICU (incidence rate ratio [IRR]: 0.754; 95.0% CI: 0.349 to 1.621; p-value = 0.469), despite the high bundle application rate in the postintervention period. Similarly, significant reduction in the incidence density in pediatric ICU has not been verified after implementation of the bundle (IRR: 1.148; 95.0% CI: 0.314 to 4.193; p-value = 0.834). CONCLUSION: Not significant reduction in the incidence density of CVC-BSIs was observed after bundle implementation in ICUs, suggesting the need to review the use of process, as well as continuing education for staffs in compliance and correct application of the bundle. Further studies are needed to evaluate the effect of bundle in the reduction of incidence density of CVC-BSIs in Brazil.

The quantification of testicular cells during the postnatal development in two Caviomorph rodents: the guinea pig (Cavia porcellus) and the cutia (Dasyprocta agouti).

The germinative, Sertoli and Leydig cells of two caviomorph rodents (Cavia porcellus and Dasyprocta agouti) were counted as well as the estimation of the total volume of the testis and the total volume of seminiferous tubules and interstitium in prepubertal, pubertal and adult animals. The number of spermatogonia, spermatocytes and spermatids cells increased during the pubertal phase in both rodents, notably the spermatid cells. The spermatocyte and spermatid slightly decreased in the adult of both rodents, but the increment in spermatogonia cells number was seen, mainly in cutias. The number of Sertoli cells increased in pubertal rodents, but in the adult the number reduced. Substantial number of Leydig cells was counted in pubertal and adult guinea pigs. In cutias, the number of Leydig cells increased in pubertal phase and decline in adults. The design-based stereological method has proven to be unbiased and reliable to be applied in reproduction studies.

Iron age genomic data from Althiburos - Tunisia renew the debate on the origins of African taurine cattle.

The Maghreb is a key region for understanding the dynamics of cattle dispersal and admixture with local aurochs following their earliest domestication in the Fertile Crescent more than 10,000 years ago. Here, we present data on autosomal genomes and mitogenomes obtained for four archaeological specimens of Iron Age (∼2,800 cal BP-2,000 cal BP) domestic cattle from the Eastern Maghreb, i.e. Althiburos (El Kef, Tunisia). D-loop sequences were obtained for an additional eight cattle specimens from this site. Maternal lineages were assigned to the elusive R and ubiquitous African-T1 haplogroups found in two and ten Althiburos specimens, respectively. Our results can be explained by post-domestication hybridization of Althiburos cattle with local aurochs. However, we cannot rule out an independent domestication in North Africa considering the shared ancestry of Althiburos cattle with the pre-domestic Moroccan aurochs and present-day African taurine cattle.

Assessing Genetic Structure in Common but Ecologically Distinct Carnivores: The Stone Marten and Red Fox.

The identification of populations and spatial genetic patterns is important for ecological and conservation research, and spatially explicit individual-based methods have been recognised as powerful tools in this context. Mammalian carnivores are intrinsically vulnerable to habitat fragmentation but not much is known about the genetic consequences of fragmentation in common species. Stone martens (Martes foina) and red foxes (Vulpes vulpes) share a widespread Palearctic distribution and are considered habitat generalists, but in the Iberian Peninsula stone martens tend to occur in higher quality habitats. We compared their genetic structure in Portugal to see if they are consistent with their differences in ecological plasticity, and also to illustrate an approach to explicitly delineate the spatial boundaries of consistently identified genetic units. We analysed microsatellite data using spatial Bayesian clustering methods (implemented in the software BAPS, GENELAND and TESS), a progressive partitioning approach and a multivariate technique (Spatial Principal Components Analysis-sPCA). Three consensus Bayesian clusters were identified for the stone marten. No consensus was achieved for the red fox, but one cluster was the most probable clustering solution. Progressive partitioning and sPCA suggested additional clusters in the stone marten but they were not consistent among methods and were geographically incoherent. The contrasting results between the two species are consistent with the literature reporting stricter ecological requirements of the stone marten in the Iberian Peninsula. The observed genetic structure in the stone marten may have been influenced by landscape features, particularly rivers, and fragmentation. We suggest that an approach based on a consensus clustering solution of multiple different algorithms may provide an objective and effective means to delineate potential boundaries of inferred subpopulations. sPCA and progressive partitioning offer further verification of possible population structure and may be useful for revealing cryptic spatial genetic patterns worth further investigation.

The morphology of paca (Cuniculus paca) testis with high dose of letrozole an aromatase inhibitor / La morfología del testículo de paca (Cuniculus paca) con altas dosis de letrozol, un inhibidor de la aromatasa

SUMMARY: The study reported the influence of the high and acute dose of Letrozole on the testis morphology in paca (Cuniculus paca), an aromatase inhibitor that reduces the endogenous estrogen, the essential hormone for spermatogenesis. Morphological changes were observed in seminiferous epithelium with germ cells with apoptotic characteristics and presence of vacuoles and nuclei in pycnose.

RESUMEN: El objetivo de este estudio fue analizar la influencia de una dosis alta de Letrozol en la morfología de los testículos de la paca (Cuniculus paca), un inhibidor de la aromatasa que reduce el estrógeno endógeno, la hormona esencial para la espermatogénesis. Se observaron cambios morfológicos en el epitelio seminífero con células germinales con características apoptóticas y la presencia de vacuolas y núcleos en picnosis.

[Impact of Haemophilus influenzae b (Hib) vaccination on meningitis in Central Brazil]. / Impacto da vacinação contra o Haemophilus influenzae b na redução de meningites, Goiás.

OBJECTIVE: To assess the impact of the Haemophilus influenzae b (Hib) conjugate vaccine in reducing the incidence of meningitis among children under five years old. METHODS: A 'before-after' design was used to compare Hib meningitis incidence rates in the pre-vaccine (July 1995 - June 1999) and post-vaccine (July 1999 - June 2001) periods in the state of Goias, central Brazil. Bacterial meningitis case definition was based on World Health Organization criteria. Incidence rates of S. pneumoniae and N. meningitidis were used for comparison purposes. Chi-squared and Student's t tests were used for statistical analysis. P-values below 0.05 were considered as statistically significant. RESULTS: 979 children with acute bacterial meningitis were detected throughout the entire period. The incidence rate of Hib meningitis decreased from 10.8 (x10(5)) in the pre-vaccine period to 2.3 (x10(5)) in the 2nd year post vaccination, leading to a risk reduction of 78%, targeted to the 7-23 months age group (p<0.05). A total of 65 cases of Hib meningitis were prevented. An increase in S. pneumoniae meningitis was observed. Vaccine failure was detected in one child. CONCLUSIONS: This study showed that mass immunization with Hib conjugate vaccine brought about an expressive decline in childhood Hib meningitis in Goias soon after the first year. Notwithstanding, an enhancement of surveillance using high-accuracy tools is essential to: (i) detect a possible reemergence of Hib; (ii) identify vaccine failure, and (iii) monitor changes in the H. influenzae serotype profile over time.

Digital stethoscope as an innovative tool on the teaching of auscultatory skills.

Physical cardiovascular examination, particularly cardiac auscultation, is one of the most difficult clinical skills for students during their medical training. Studies suggest that the use of technologies such as digital stethoscope increase the accuracy of clinical examination, however, its impact on the teaching of cardiac auscultation for undergraduate students of medicine is not known. The objective is to demonstrate the usefulness of the digital stethoscope compared to traditional methods as a tool in the teaching of auscultatory skills. nterventional, longitudinal, controlled, unicenter and randomized study. Thirty-eight medicine students were enrolled for a cardiovascular semiology course lasting eight weeks. The course program included lectures and bedside practice in Cardiology wards. In the practical lessons, the students were randomized into two groups: 1) (n = 21) digital stethoscope (Littmann® Model 3200, 3M); and 2) (n = 17) conventional stethoscopes. A pre-training evaluation was conducted through a test using the software Heart Sounds®, which was repeated after the course. The average scores were compared by paired T test and unpaired T test. It is observed that, at the end of the course, there was a significantly greater improvement in the group that used the digital stethoscope (51.9%) compared to the group using the conventional stethoscope (29.5%). Short-term interventions for cardiac semiology teaching are able to contribute significantly to improving proficiency in the identification of heart sounds. The use of digital stethoscope proved to be a positive factor in teaching these skills.

Susceptibility of Argentinean Biomphalaria tenagophila and Biomphalaria straminea to infection by Schistosoma mansoni and the possibility of geographic expansion of mansoni schistosomiasis.

INTRODUCTION: Human migration and the presence of natural vectors (mollusks) of Schistosoma mansoni are the primary causes of the expansion of mansoni schistosomiasis into southern areas of South America. Water conditions are favorable for the expansion of this disease because of the extensive hydrographic network, which includes the basins of the Paraná and Uruguay rivers and favors mollusk reproduction. These rivers also aid agriculture and tourism in the area. Despite these favorable conditions, natural infection by S. mansoni has not yet been reported in Argentina, Uruguay, or Paraguay. METHODS: Two species of planorbid from Argentina, Biomphalaria straminea and B. tenagophila, were exposed to the miracidia of five Brazilian strains of S. mansoni. RESULTS: Biomphalaria tenagophila (Atalaya, Buenos Aires province) was infected with the SJS strain (infection rate 3.3%), confirming the experimental susceptibility of this Argentinian species. Biomphalaria straminea (Rio Santa Lucía, Corrientes province) was susceptible to two Brazilian strains: SJS (infection rate 6.7%) and Sergipe (infection rate 6.7%). CONCLUSIONS: These results demonstrate that species from Argentina have the potential to be natural hosts of S. mansoni and that the appearance of foci of mansoni schistosomiasis in Argentina is possible.

Correlation between myocardial scintigraphy and CT angiography in the evaluation of coronary disease.

BACKGROUND: Coronary multidetector CT angiography (CTA) has shown good accuracy for detection of coronary stenosis. Although this is a promising technique for the evaluation of CAD, its correlation with the functional expression of the disease is not yet well established. OBJECTIVE: To evaluate whether the presence of CAD and the degree of coronary stenosis assessed by CT angiography are associated with changes in the Myocardial Perfusion Scintigraphy (MPS). METHODS: This is a retrospective observational study, which included 99 consecutive patients with known or suspected CAD. MPS and CTA were conducted. We compared the presence of perfusion defects by MPS with the presence of CAD and the degree of luminal obstruction by CTA. For statistical analysis, Student's t-test, ANOVA, and Chi-square (or Fisher's exact test for n <5) tests were used. Multivariate analysis was performed using logistic regression: the level of significance was 5%. RESULTS: Mean age was 62 ± 11.4 years, with 46 (71.7%) men. The variable analysis was performed per patient (n = 99) and per coronary irrigation territory (n = 297). Of the 67 territories that had significant CAD by CTA, 44.8% had abnormal MPS. Considering the degree of stenosis, abnormal MPS was present in 18.7% of the territories with no significant stenosis, 45.28% of the territories with moderate stenosis, and 42.8% of the territories with severe injuries. CONCLUSIONS: CTA is a good method for exclusion of CAD. However, its use to evaluate the severity of stenosis and its functional impact has not shown good correlation.

Imunidade para Hepatite B entre Trabalhadores de um Hospital de Referência em Doenças Infectocontagiosas, vítimas de acidente com material biológico / Immunity for Hepatitis B among Workers of a Reference Hospital in Infectious Diseases, victims of an accident with biological material

Introdução: O Ministério da Saúde define Acidente de Trabalho com Exposição a Material Biológico, aquele envolvendo sangue e outros fluidos orgânicos ocorridos com os trabalhadores durante o desenvolvimento de suas atividades laborais. O risco de infecção pelo vírus da imunodeficiência humana (HIV) pós-exposição ocupacional percutânea é de aproximadamente 0,3%, pelo vírus da hepatite C (HCV) é de 1,8% a 10% e pelo vírus da hepatite B (HBV) pode atingir até 40%. Objetivo: descrever o perfil epidemiológico situação vacinal e a imunidade para hepatite B dos profissionais da área da saúde que sofreram acidentes com exposição a material biológico no período de janeiro de 2006 a junho de 2015, evidenciando a realidade de um hospital público de alta complexidade e referência em doenças infectocontagiosas do Centro-Oeste. Métodos: Trata-se de um estudo epidemiológico retrospectivo, descritivo, com abordagem quantitativa. Resultados: Este estudo constatou que, entre os profissionais da área da saúde expostos a material biológico a maioria era da equipe de enfermagem e do sexo feminino. Houve mais casos por exposição percutânea, por agulha com lúmen envolvendo sangue. Verificou-se que 76,9% eram vacinados e 57% possuíam anti-HBs maior ou igual a 10UI/L. Conclusão: o estudo permitiu conhecer o perfil epidemiológico dos trabalhadores acidentados; os resultados mostraram indicadores importantes sobre exposição ocupacional a material biológico e o potencial risco de soroconversões para hepatite B. (AU)

Introduction: The Brazilian Ministry of Health defines Work Accident with Exposure to Biological Material that involves blood and other organic fluids which occur with workers during the development of their work activities. The risk for human immunodeficiency virus (HIV) infection after percutaneous occupational exposure is approximately 0.3%; the hepatitis C virus (HCV) is 1.8% to 10% and the hepatitis B virus (HBV) can reach up to 40%. Objective: to describe the epidemiological profile and vaccination status for hepatitis B among health professionals who have suffered an accident with exposure to biological material from January 2006 to June 2015, evidencing the reality of a public hospital of high complexity and reference regarding infectious diseases in the Midwest. Methods: This is a descriptive retrospective epidemiological study with a quantitative approach. Results: This study has found that among the health professionals exposed to biological material, most were from the nursing team and from the female sex. There were more cases on percutaneous exposure, by needle with lumen involving blood. It was found that 76.9% were vaccinated and 57% had anti-HBs greater than or equal to 10 IU / L. Conclusion: the study showed the epidemiological profile of injured workers; the results showed important indicators on occupational exposure to biological material and the potential risk of seroconversion for hepatitis B. (AU)

Acute schistosomiasis in brazilian traveler: the importance of tourism in the epidemiology of neglected parasitic diseases.

Parasitic infectious diseases acquired in tourist areas may pose a challenge to physicians and to travel medicine practitioners. Acute schistosomiasis may be seen in returning travelers and migrants after primary infection. This form of schistosomiasis is frequently misdiagnosed due to its temporal delay and its nonspecific presentation and might occur even in countries where the disease is endemic, such as in Brazil. The patient developed the acute phase of schistosomiasis with severe clinical manifestations. The quantitative analysis revealed the presence of 240 eggs per gram of stool. The treatment was administered with oxamniquine, and the control of cure of the patient was monitored and was favorable. The present paper aims to emphasize the importance of a detailed clinical history including information regarding travel history.

Morfologia e topografia do baço da paca ( Cuniculus paca Linnaeus, 1766) / Morphology and topography of the spleen of paca ( Cuniculus paca )

A paca é um grande roedor, presente em parte do território brasileiro e na América Latina, cuja importância está na crescente produção comercial de carne exótica e na pesquisa científica como um promissor modelo experimental. Assim, este trabalho objetivou-se descrever a morfologia e a topografia do baço da paca (Cuniculus paca). Foram utilizadas cinco pacas adultas, machos e fêmeas, fixadas em formaldeído a 10% e armazenados em solução salina a 30% para sua conservação. Na paca, o baço tem sua localização relacionada ao estômago, ao fígado, ao rim esquerdo, ao pâncreas e ao omento maior. Possui forma irregular, sendo mais longo do que largo, possui coloração avermelhada-escura e textura lisa. Quanto à descrição histológica, apresenta cápsula de tecido conjuntivo denso que emitiu trabéculas que se projetam no parênquima. A cápsula e as trabéculas apresentam fibras musculares lisas. O parênquima è composto pela polpa branca e polpa vermelha, esta última formada por seios e cordões esplênicos.(AU)

Paca is a large rodent, distributed in part of the Brazilian territory and in Latin America, whose importance is related to the crescent commercial production of exotic meat and in scientific research as a promising experimental model. The morphology and topography of the spleen of paca (Cuniculus paca) is described. Five adult pacas, male and female, were fixed with formaldehyde 10% and stored in 30% saline solution for preservation. The spleen of paca has the anatomical position related to stomach, liver, left kidney, pancreas and greater omentum. The spleenis irregular, longer than larger, with reddish-dark color and smooth texture. Related to the histological description, the spleen has capsule of dense connective tissue that emitted trabeculae projecting into the parenchyma. The capsule and trabeculae has smooth muscle fibers. The parenchyma is composed by the white and red pulp, the latter composed with sinusoids and splenic cords.(AU)

The quantification of testicular cells during the postnatal development in two Caviomorph rodents: the guinea pig (Cavia porcellus) and the cutia (Dasyprocta agouti)

ABSTRACT The germinative, Sertoli and Leydig cells of two caviomorph rodents (Cavia porcellus and Dasyprocta agouti) were counted as well as the estimation of the total volume of the testis and the total volume of seminiferous tubules and interstitium in prepubertal, pubertal and adult animals. The number of spermatogonia, spermatocytes and spermatids cells increased during the pubertal phase in both rodents, notably the spermatid cells. The spermatocyte and spermatid slightly decreased in the adult of both rodents, but the increment in spermatogonia cells number was seen, mainly in cutias. The number of Sertoli cells increased in pubertal rodents, but in the adult the number reduced. Substantial number of Leydig cells was counted in pubertal and adult guinea pigs. In cutias, the number of Leydig cells increased in pubertal phase and decline in adults. The design-based stereological method has proven to be unbiased and reliable to be applied in reproduction studies.