Whole-body magnetic resonance imaging in children: state of the art

Whole-body imaging in children was classically performed with radiography, positron-emission tomography, either combined or not with computed tomography, the latter with the disadvantage of exposure to ionizing radiation. Whole-body magnetic resonance imaging (MRI), in association with the recently developed metabolic and functional techniques such as diffusion-weighted imaging, has brought the advantage of a comprehensive evaluation of pediatric patients without the risks inherent to ionizing radiation usually present in other conventional imaging methods. It is a rapid and sensitive method, particularly in pediatrics, for detecting and monitoring multifocal lesions in the body as a whole. In pediatrics, it is utilized for both oncologic and non-oncologic indications such as screening and diagnosis of tumors in patients with genetic syndromes, evaluation of disease extent and staging, evaluation of therapeutic response and post-therapy follow-up, evaluation of non neoplastic diseases such as multifocal osteomyelitis, vascular malformations and syndromes affecting multiple regions of the body. The present review was aimed at describing the major indications of whole-body MRI in pediatrics added of technical considerations.

Serological and virological surveys of the influenza A viruses in Antarctic and sub-Antarctic penguins

To evaluate the avian influenza virus (AIV) circulation in Antarctic and sub-Antarctic penguins we carried out a serosurvey on six species from Livingston, Marion and Gough islands. Seropositivity against AIV was performed on serum samples using a competitive enzyme-linked immunosorbent assay and haemagglutination and neuraminidase inhibition assays. Some oropharyngeal and cloacal swabs were also assayed to detect influenza virus genomes by real time reverse transcription-polymerase chain reaction. Overall, 12.1% (n = 140) penguins were seropositive to AIV. By species, we detected 5% (n = 19) and 11% (n = 18) seroprevalence in sub-Antarctic rockhopper penguins (Eudyptes spp.) from Gough and Marion islands, respectively, 42% (n = 33) seroprevalence in macaroni penguins (Eudyptes chysolophus Brandt), but no positives in the three other species, gentoo (Pygoscelis papua Forster; n = 25) and chinstrap penguins (P. antarctica Forster; n = 16), from Livingston Island and king penguins (Aptenodytes patagonicus Miller; n = 27) from Marion Island. While seropositivity reflected previous exposure to the AIV, the influenza genome was not detected. Our results indicate that AIV strains have circulated in penguin species in the sub-Antarctic region, but further studies are necessary to determine the precise role that such penguin species play in AIV epidemiology and if this circulation is species (or genus) specific.

Sexual foraging segregation in South American sea lions increases during the pre-breeding period in the La Plata River plume

Stable carbon and nitrogen isotopes in skin and bone of South American sea lions from Brazil and Uruguay were analysed to test the hypothesis that trophic overlap between the sexes is lower during the pre-breeding season than throughout the rest of the year. The isotopic values of skin and bone were used to infer the trophic relationships between the sexes during the pre-breeding period and year round, respectively. Prey species were also analysed to establish a baseline necessary for interpreting the stable isotope ratios of skin and bone. Standard ellipse areas, estimated using Bayesian inference in the SIBER routine of the SIAR package in R, suggested that males and females used a wide diversity of foraging strategies throughout the year and that no differences existed between the sexes. However, the diversity of foraging strategies was largely reduced during the pre-breeding period, with all the individuals of each sex adopting similar strategies, but with the two sexes differing considerably in stable isotope values and the ellipse areas of males and females not overlapping at all. Nevertheless, the results revealed a general increase in the consumption of pelagic prey by both sexes during the pre-breeding period. The progressive crowding of individuals in the areas surrounding the breeding rookeries during the pre-breeding period could lead to an increase in the local population density, which could explain the above reported changes.

Blocking and unblocking in a navigation task

Rodrigo, Chamizo, McLaren, & Mackintosh (1997) demonstrated the blocking effect in a navigational task using a swimming pool: rats initially trained to use three landmarks (ABC) to find an invisible platform learned less about a fourth landmark (X) added later than did rats trained from the outset with these four landmarks (ABCX). The aim of the experiment reported here was to demonstrate unblocking using a similar procedure as in the previous work. Three groups of rats were initially trained to find an invisible platfom in the presence of three landmarks: ABC for the Blocking and Unblocking groups and LMN for the Control group. Then, all animals were trained to find the platform in the presence of four landmarks, ABCX. In this second training, unlike animals in the Blocking group to which only a new landmark (X) was added in comparison to the first training, the animals in the Unblocking group also had a change in the platform position. In the Control group, both the four landmarks and the platform position were totally new at the beginning of this second training. As in Rodrigo et al. (1997) a blocking effect was found: rats in the Blocking group learned less with respect to the added landmark (X) than did animals in the Control group. However, rats in the Unblocking group learned about the added landmark (X) as well as did animals in the Control group. The results are interpreted as an unblocking effect due to a change in the platform position between the two phases of training, similarly to what is normal in classical conditioning experiments, in which a change in the conditions of reinforcement between the two training phases of a blocking design produce an attenuation or elimination of this effect. These results are explained within an error-correcting connectionist account of spatial navigation (McLaren, 2002).

Functional Study of Oncogenic Transcription Factor ERG and its Signaling in Prostate Cancer

TMPRSS2–ERG is the most frequent type of genomic rearrangement present in prostate tumors, in which the 5- prime region of the TMPRSS2 gene is fused to the ERG oncogene. TMPRSS2, containing androgen response elements (AREs), is regulated by androgens in the prostate. The truncated TMPRSS2-ERG fusion transcript is overexpressed in half of the prostate cancer patients. The formation of TMPRSS2-ERG transcript is an early event in prostate carcinogenesis and previous in vivo and in vitro studies have shown ectopic ERG expression to be associated with increased cell invasion. However, the molecular function of ERG and its role in cell signaling is poorly understood. In this study, genomic rearrangement of ERG with TMPRSS2 was studied by using comparative genomic hybridization (CGH) in prostate cancer samples. The biological processes associated with the ERG oncogene expression in prostate epithelial cells were studied, and the results were compared with findings observed in clinical prostate tumor samples. The gene expression data indicated that increased WNT signaling and loss of cell adhesion were a characteristic of TMPRSS2- ERG fusion positive prostate tumor samples. Up- regulation of WNT pathway genes were present in ERG positive prostate tumors, with frizzled receptor 4 (FZD4) presenting with the highest association with ERG overexpression, as verified by quantitative reverse transcription-PCR, immunostaining, and immunoblotting in TMPRSS2-ERG positive VCaP prostate cancer cells. Furthermore, ERG and FZD4 silencing increased cell adhesion by inducing active β1-integrin and E-cadherin expression in VCaP cells. Furthermore, we found a novel inhibitor, 4-(chloromethyl) benzoyl chloride which inhibited the WNT signaling and induced similar phenotypic effects as observed after ERG or FZD4 down regulation in VCaP cells. In conclusion, this work deepens our understanding on the complex oncogenic mechanisms of ERG in prostate cancer that may help in developing drugs against TMPRSS2-ERG positive tumors.

Behavior, performance and physiological parameters of pigs reared in deep bedding

An experiment was conducted to evaluate the behavior, performance and physiological parameters of pigs in different production systems. Twenty four animals in the growth phase were distributed in a randomized block design in three treatments: T1 - concrete floor, T2 - deep bedding with wood shaving, and T3 - deep bedding with coffee husks. The behavioral study was carried out by observing the animal behavior for an uninterrupted period of eight hours throughout seven weeks. The proportions of time spent in each behavior were characterized using the frequency histogram composition. Environmental (IBGTH), physiological (rectal and skin temperature and respiratory rate) and performance (weight gain, feed intake and feed conversion) parameters were measured in animals during the period. The production systems of deep bedding showed higher values of IBGTH. There was no effect of production systems evaluated on the performance parameters. Rectal temperature was higher in animals reared on deep bedding with coffee husks in relation to the concrete floor. The use of deep bedding benefited the behavior of piglets in the growth phase and it reduced the agonistic behavior among individuals.

Percutaneous core biopsy of palpable breast lesions: accuracy of frozen section histopathological exam in the diagnosis of breast cancer

OBJECTIVE: to evaluate the accuracy of frozen section histopathology from fragments of tissue obtained by percutaneous core needle biopsy of palpable tumors in the diagnosis of breast cancer. METHODS: a cohort study was performed on 57 patients with palpable tumors and suspected breast cancer undergoing percutaneous thick needle core biopsy. The fragments were analyzed by the same pathologist. RESULTS: frozen section diagnosed 16 benign cases (28.6%) and 40 malignant (71.4%), whereas paraffin showed that 15 were benign (26.8%) and 41 malignant (73.2%). Histopathological examinations were concordant in 55 cases and there was one false-negative (6.2%). Statistics rates were: negative predictive value of 93.8%, positive predictive value of 100%, no false-positive (0%), one false negative (6.2%), specificity of 100%, sensitivity of 97 6%; observed agreement = 98.2%; expected agreement = 59.9%, Kappa = 0.955 [ 95% CI = 0.925-0.974, p < 0.01 ]. CONCLUSIONS: frozen section histopathological findings showed excellent correlation with the findings by the technique in paraffin in the fragments of palpable breast tumors obtained by thick needle percutaneous core biopsy (98.2% accuracy). Therefore, in these patients, it was possible to anticipate the diagnosis, staging and the breast cancer treatment planning.

Toxoplasma gondii in semen of experimentally infected swine

Eight reproductive boars were divided into three groups and inoculated with Toxoplasma gondii [GI (n=3) 1.5x10(4) oocysts strain P; GII (n=3) 1.0x10(6) tachyzoites strain RH; and GIII (n=2) non-inoculated control]. Clinical, hematological, parasitemia and serological tests and studies of the parasite in the semen through bioassay and PCR, and in reproductive organs (Bioassay and immunohistochemical analyses) were conducted to evaluate the toxoplasmic infection. Blood and semen were collected on day -2, -1, 1, 3, 5, 7, 9, 11, 14 and weekly up to 84 days post-inoculation (DPI). No clinical or hematimetric alteration was observed in the boars. Parasitemia was detected in one boar inoculated with oocysts at the 7th DPI and in another boar infected with tachyzoites (GII) at the 3rd and 49th DPI. Serological tests revealed antibodies against T. gondii in animals inoculated with oocysts or tachyzoites at the 7th DPI with dilutions of 1:256 and 1:64, which reached peaks of 1:4096 at day 11 and 9, respectively. The bioassays revealed the presence of the parasite in semen samples of a boar inoculated with oocysts (GI) at 3, 49 and 56 DPI and from two boars infected with tachyzoites (GII), one animal at 5 and two animals at 49 days DPI. Mice inoculated with semen from the control group (GIII) remained serologically negative. PCR analysis showed T. gondii DNA in the semen of Boar 1 and Boar 3 inoculated with tachyzoites and oocysts, respectively. The immuno-histochemical tests showed T. gondii in the reproductive organs of Boar 1 and Boar 2, inoculated with tachyzoites and oocysts, respectively. These findings suggest the possible occurrence of venereal transmission of T. gondii in swine.

Immunohistochemical evaluation of e-cadherin, Ki-67 and PCNA in canine mammary neoplasias: correlation of prognostic factors and clinical outcome

E-cadherin is a cell-cell adhesion molecule and low e-cadherin expression is related to invasiveness and may indicate a bad prognosis in mammary neoplasms. The expression of cell proliferation markers PCNA and especially Ki-67, has also proved to have a strong prognostic value in this tumor class. The expression of these markers was related to the clinical-pathological characteristics of 73 surgically removed mammary tumors in female dogs by immunohistochemistry. There was no statistical correlation between these markers and death by neoplasm, survival time and disease-free interval. However, the loss of e-cadherin expression and marked Ki-67 expression (p=0.016) were considered statistically significant for the diagnosis (p=0.032). When evaluated as independent factors, there was evidence of the relationship between the loss of e-cadherin expression and high PCNA expression with changes in the body status (divided into obese, normal and cachectic) of female dogs (p=0.030); there was also evidence of the relationship between pseudopregnancy and e-cadherin alone (p=0.021) and for ulceration and PCNA alone (p=0.035). The significant correlation between the markers expression and these well known prognostic factors used individually or in combination suggests their prognostic value in canine mammary tumors.

Hematological profile of Chelonia mydas (Testudines, Cheloniidae) according to the severity of fibropapillomatosis or its absence

The green turtle Chelonia mydas feeds and nests in the Brazilian coastal area and is considered an endangered species by the World Conservation Union (IUCN 2009) and threatened by the Red List of Brazilian Fauna (Ministério do Meio Ambiente 2009). Fibropapillomatosis is a disease characterized by benign skin tumors (fibropapillomas), and it is one of the main threats to the survival of this species. Studies suggest the involvement of viruses as infectious agents associated with environmental and genetic factors. Blood samples were collected from 45 turtles captured in the coastal area of the state of Sao Paulo, Brazil. From these, 27 were affected by fibropapillomas and 18 were tumor free. Biometrical data on the turtles, size, location and quantity of tumors were recorded. The area occupied by fibropapillomas per animal was calculated and four groups were determined according to severity of the disease or its absence. The objective of the study was to compare hemogram results of the sea turtles classified in these four groups. The lowest hematocrit value was observed in severely affected animals. In the hemoglobin assay, the highest value was observed in the group of tumor free turtles and the lowest, in animals severely affected. Lymphocyte counts and curved carapace length were on the verge of statistical significance.

Clinical evaluation of enalapril maleate and furosemide usage in dogs with degenerative myxomatous mitral valve, CHF functional class Ib

Degenerative myxomatous mitral valve (DMMV) is a heart disease of high incidence in small animal clinical medicine, affecting mainly older dogs and small breeds. Thus, a scientific investigation was performed in order to evaluate the clinical use of the medicines furosemide and enalapril maleate in dogs with this disease in CHF functional class Ib before and after the treatment was established. For this purpose 16 dogs with the given valve disease were used, separated into two groups: the first received furosemide (n=8) and the second received enalapril maleate (n=8) throughout 56 days. The dogs were evaluated in four stages (T0, T14, T28 and T56 day) in relation to clinical signs, hematological, biochemical and serum assessment, which included serum angiotensin converting enzyme (ACE) and aldosterone, as well as radiography, electrocardiography, Doppler-echocardiography and blood pressure. The results regarding the clinical, hematological and serum chemistry evaluations revealed no significant changes in both groups, but significant reductions in the values of ACE and aldosterone in the group receiving enalapril maleate were verified. The radiographic examination revealed reductions of VHS values and variable Pms wave of the electrocardiogram in both groups, but no changes in blood pressure values were identified. The echocardiogram showed a significant decrease of the variables LVDd/s in the studied groups and the FS% in animals that received only enalapril. Therefore, analysis of results showed that monotherapy based on enalapril maleate showed better efficiency of symptoms control in patients with CHF functional class Ib.

Factors affecting immunoglobulin concentration in colostrum of healthy Holstein cows immediately after delivery

This study analyzed the influence of the number of milkings, number of births, and udder quarter in immunoglobulin (Ig) concentration in the colostrum of healthy Holstein cows. It was collected two samples of colostrum by manual milking, getting the first jets to completion of bacteriological examination and immunoglobulin levels by radial immunodiffusion test in agar gel. Positive samples for bacteriological examination were excluded from this investigation. Medians of immunoglobulin's G, A and M in the colostrum collected before the first and second milking were respectively 9,200 and 6,400mg/dL (p=0.0029); 400 and 200mg/dL (p=0.0018); 800 and 400mg/dL (p=0.0001). Median immunoglobulin concentration in animals that calved once, twice or three times or in cows that calved 4 to 6 times were 6,400; 6,400; 3,200 and 11,200mg/dL IgG; 100, 200, 100 and 800mg/dL IgA ; and 400, 400, 100 and 800mg/dL IgM, respectively. Concentrations of IgG, IgA and IgM were greater in animals that calved more than 4 times (p<0.05). Medians of IgG, IgA and IgM in the right fore quarter (RF), right hind quarter (RH), left fore quarter (LF) and left hind quarter (LH) were, respectively, 7,800; 6,400; 7,800 and 6,400mg/dL; 200, 200, 200 and 200mg/dL; and 400, 400, 400 and 400mg/dL. Ig concentrations in the colostrum of Holstein cows were influenced by the number of milkings after delivery and number of lactations. These variations may be considered risk factors to passive immunity transfer to newborn calves, predisposing them to diseases and causing economic losses to dairy production.

Cysticercosis in experimentally and naturally infected pigs: parasitological and immunological diagnosis

Our objective was to evaluate the diagnosis of swine cysticercosis by examining "ante mortem" (inspection of the tongue), "post mortem" (inspection and detailed necropsy) and ELISA for research in serum of antibodies (Ab-ELISA) and antigens (Ag-ELISA). Seven (7) pigs were experimentally infected orally with eggs of Taenia solium and another 10 were naturally infected. In the pigs experimentally infected, inspection of the tongue was negative in all animals, in the routine inspection detailed necropsy and cysticercis were identified in all of them. In pigs with heavy natural infection, inspection of the tongue identified cysticerci in two (20%), while at inspection with necropsy the parasites were identified in large quantities in all animals. In ELISA for antibody search (Ab-ELISA) TS-14 recombinant protein was used, and in search for antigen (Ag-ELISA) a monoclonal antibody against this protein. In animals experimentally infected, blood was collected weekly for 140 days. The Ab-ELISA identified an increase in titers of antibody to cysticerci 21 days after infection, and at the end of the experimental period six animals (86%) were positive to the test. The search for circulating antigens (Ag-ELISA) was positive in two pigs 28 to 91 days after infection. All naturally infected pigs were positive for Ag-ELISA and Ab-ELISA. The search for antibodies and antigens by ELISA in serum from 30 pigs of a local farm and without history of cysticercosis was negative. Thus, the use of TS-14 antigen in ELISA test (Ab-ELISA) can be useful for the diagnosis of cysticercosis in pigs with low infection.

Corrective shoeing in horses: analysis of the adaptation period to the new condition imposed

Corrective shoeing is a method commonly used to alter the locomotion pattern in animals or as therapy for various disorders of the locomotive system of horses. However, to date, there have been no scientific studies discussing the period during which animals adapt to this type of intervention. The goal of this study was to evaluate the horseshoe adaptation period with the toe or heel elevated by six degrees at 0, 48, and 96 hours after each type of shoeing. For this analysis, the horses were recorded while walking on a treadmill. Stride length and gait qualitative analyzes were performed using Dvideow software. The level of significance adopted was 5%. In the present study, there was no significant difference between the evaluation times; elevating the toe or heel by six degrees do not generates discomfort during locomotion, therefore, horses are able to return to a regular exercise or training routine immediately after shoeing.

Histopathological and immunohistochemical findings of swine with spontaneous influenza A infection in Brazil, 2009-2010

Swine influenza (SI) is caused by the type A swine influenza virus (SIV). It is a highly contagious disease with a rapid course and recovery. The major clinical signs and symptoms are cough, fever, anorexia and poor performance. The disease has been associated with other co-infections in many countries, but not in Brazil, where, however, the first outbreak has been reported in 2011. The main aim of this study was to characterize the histological features in association with the immunohistochemical (IHC) results for influenza A (IA), porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) in lung samples from 60 pigs submitted to Setor de Patologia Veterinária at the Universidade Federal do Rio Grande do Sul (SPV-UFRGS), Brazil, during 2009-2010. All of these lung samples had changes characterized by interstitial pneumonia with necrotizing bronchiolitis, never observed previously in the evaluation of swine lungs in our laboratory routine. Pigs in this study had showed clinical signs of a respiratory infection. Swine samples originated from Rio Grande do Sul 31 (52%), Santa Catarina 14 (23%), Paraná 11 (18%), and Mato Grosso do Sul 4 (7%). Positive anti-IA IHC labelling was observed in 45% of the cases, which were associated with necrotizing bronchiolitis, atelectasis, purulent bronchopneumonia and hyperemia. Moreover, type II pneumocyte hyperplasia, alveolar and bronchiolar polyp-like structures, bronchus-associated lymphoid tissue (BALT) hyperplasia and pleuritis were the significant features in negative anti-IA IHC, which were also associated with chronic lesions. There were only two cases with positive anti-PCV2 IHC and none to PRRSV. Therefore, SIV was the predominant infectious agent in the lung samples studied. The viral antigen is often absent due to the rapid progress of SI, which may explain the negative IHC results for IA (55%); therefore, IHC should be performed at the beginning of the disease. This study has shown how important a careful histological evaluation is for the diagnosis. Since 2009, a new histological feature of swine pneumonia in animals with respiratory clinical signs has been observed in samples from pigs with clinical respiratory disease submitted to SPV-UFRGS. In addition, the results proved the importance of histological evaluation for swine herd health management.