Fast and Simultaneous Growth of Multiple Melanocytic Nevi Associated with Seminoma

Os potenciais efeitos em nevos melanocíticos, de hormonas associadas à gravidez, assim como de outras hormonas endógenas ou exógenas, são conhecidos desde há anos. Os autores descrevem o caso de um doente do sexo masculino, 35 anos, observado pelo crescimento rápido e simultâneo, num período de 6 meses, de múltiplos nevos melanocíticos, previamente existentes, localizados no tronco, associado à elevação da gonadotrofina coriónica humana subunidade beta (β-HCG) produzida por seminoma testicular. Após orquidectomia radical e radioterapia adjuvante, verificou-se indetecção desse marcador tumoral. Sem evidência de recidiva ou de crescimento adicional dos nevos após 3 anos. Foi possível estabelecer uma relação, raramente descrita, entre β-HCG derivada do seminoma e o crescimento de nevos melanocíticos.info:eu-repo/semantics/publishedVersio

Detection of virulence-associated genes in pathogenic and commensal avian Escherichia coli isolates

Poultry colibacillosis due to Avian Pathogenic Escherichia coli (APEC) is responsible for several extra-intestinal pathological conditions, leading to serious economic damage in poultry production. The most commonly associated pathologies are airsacculitis, colisepticemia, and cellulitis in broiler chickens, and salpingitis and peritonitis in broiler breeders. In this work a total of 66 strains isolated from dead broiler breeders affected with colibacillosis and 61 strains from healthy broilers were studied. Strains from broiler breeders were typified with serogroups O2, O18, and O78, which are mainly associated with disease. The serogroup O78 was the most prevalent (58%). All the strains were checked for the presence of 11 virulence genes: 1) arginine succinyltransferase A (astA); ii) E. coli hemeutilization protein A (chuA); iii) colicin V A/B (cvaA/B); iv) fimbriae mannose-binding type 1 (fimC); v) ferric yersiniabactin uptake A (fyuA); vi) iron-repressible high-molecular-weight proteins 2 (irp2); vii) increased serum survival (iss); viii) iron-uptake systems of E. coli D (iucD); ix) pielonefritis associated to pili C (papC); x) temperature sensitive haemaglutinin (tsh), and xi) vacuolating autotransporter toxin (vat), by Multiplex-PCR. The results showed that all genes are present in both commensal and pathogenic E. coli strains. The iron uptake-related genes and the serum survival gene were more prevalent among APEC. The adhesin genes, except tsh, and the toxin genes, except astA, were also more prevalent among APEC isolates. Except for astA and tsh, APEC strains harbored the majority of the virulence-associated genes studied and fimC was the most prevalent gene, detected in 96.97 and 88.52% of APEC and AFEC strains, respectively. Possession of more than one iron transport system seems to play an important role on APEC survival

Theoretical prediction of 'optimal' freezing programmes

We have developed a quantitative description of the osmotic behaviour of cells during freezing without a presupposed value of the cooling rate. Instead, at all times the intracellular supercooling is maximised provided that it does not exceed a predetermined value 'p' (e.g., 2°C). This should preclude intracellular ice formation, but also ensures that the osmotic gradient and the CPA concentration gradient are limited, as well as the gradient driven transmembrane fluxes of water and CPA. Using the condition of a constant level of supercooling of p°C, equations can be derived to generate non-linear cooling curves in which at all times the cooling rate is maximised (to minimise slow cooling damage), while preventing conditions that could lead to fast cooling damage. Simulations of the osmotic events during freezing, and prediction of the 'optimal' freezing curve can be performed provided that values are available for the membrane permeability coefficients for water (L p) and cryoprotectant (Ps), and their respective activation energies, the initial intracellular osmotically active aqueous volume, and the membrane surface area. Simulations are shown, both with and without permeant solute, to demonstrate how the predicted 'optimal' freezing curve is affected by medium composition, and by membrane permeability and osmotic cell characteristics

Cryopreservation of boar semen: equilibrium freezing in the cryomicroscope and in straws

Supercooling causes very abrupt temperature and osmotic changes and can thus lead to freezing damage. Supercooling can be prevented by seeding, using a sample volume and geometry that allows rapid spreading of the ice throughout the sample. In a split-sample comparison of such samples on the cooling stage of a cryomicroscope and seeded at ¿5 and ¿15 °C, respectively, the percentages of membrane-intact sperm and sperm with acrosomes with a `normal apical ridge¿ (NAR) were 72.5 ± 3.8 and 75.8 ± 2.0 versus 46.3 ± 4.8 and 36.0 ± 3.7 (means ± S.E.M., n = 4). In ejaculates of 15 unselected AI boars, after seeding at ¿5 °C, the post-thaw % live and % NAR were 66.3 ± 10.4 and 74.8 ± 7.5, respectively. Our present research is aimed at translating these findings to freezing in straws and at a high sperm concentration. We have designed a novel type of freezing apparatus for controlled-rate freezing of straws, in which supercooling can be effectively prevented in the entire straw. In a split-sample comparison of semen frozen in straws at a sperm concentration of 1.5 × 109 cells/ml with nine ejaculates from eight unselected AI boars, we found 54.8 ± 1.9% versus 40.7 ± 1.7% (means ± S.E.M.) membrane-intact sperm for the new apparatus and a conventional freezing apparatus, respectively. With bull semen (eight ejaculates from six bulls), we obtained 67.3 ± 3.0% versus 59.3 ± 2.9% (means ± S.E.M.) membrane-intact sperm for the new apparatus and conventional freezing, respectively. Additionally, the temperature curve after ice nucleation is of great importance. We have developed a model that allows us to predict that optimal cryopreservation requires a non-linear cooling curve in which the cooling rate varies as a function of subzero temperatur

The effects of three extenders on refrigerated boar semen

This study aims to evaluate the quality of boar sperm that was refrigerated for 14 days at 17 ºC with three extenders. For this study, samples from four boars were collected twice a week using the gloved-hand technique. After collection, only ejaculates showing total motility of 75% or greater were submitted to the refrigeration process. Ejaculates were diluted in Androhep, MR-A® or Reading. Each portion was kept for two hours at 22 ºC, then sperm motility was assessed through contrast microscopy. Sperm mitochondrial activity, viability and acrosome integrity were measured by the flow cytometric technique. The remaining diluted semen was maintained at 17 ºC for 336 h, and the same analysis being repeated every 48 h. Semen diluted in Androhep revealed no significant quality deterioration in percentage of live spermatozoa during refrigeration. However, after 144 h, viability decreased significantly for MR-A® and Reading (63.3% ± 7.0 and 66.4% ± 6.2, respectively), and after 336 h, this decrease was accentuated (56.3% ± 3.9 and 18.4% ± 6.2, respectively, for MR-A® and Reading). On average, for all three extenders, acrosome integrity values did not differ statistically up to 144 h, ranging from 48.3 ± 2.3 for MR-A® to 62.4 ± 3.2 for Androhep. Then values decreased towards the end of the experiment, with Androhep always presented the higher values, while Reading resulted in the lowest values (46.3 ± 3.2 and 5.6 ± 1.4, respectively). No significant changes in mitochondrial membrane potential were observed during the refrigeration period. Results of this study indicate that Androhep achieves the best results for the various parameters studied over time.Keywords: Boar, flow cytometry, long-term extenders, refrigeration, seme

Cutaneous Larva Migrans - a Case Report

A larva migrans cutânea representa uma das dermatoses mais frequentes nos turistas que regressam de países tropicais e sub-tropicais. O agente mais frequente é a larva Ancylostoma brasiliensis que habita no intestino de cães e gatos. Os humanos são afetados quando contatam com solo contaminado com os excrementos de animais infetados. Apresentamos o caso de uma professora, 39 anos de idade, natural e residente em Portugal que, após regressar de férias no Nordeste do Brasil, refere dermatose localizada à 4ª prega interdigital e porção adjacente do dorso dos pés, constituída por várias lesões eritematosas, pruriginosas, de trajecto serpiginoso, compatíveis com larva migrans cutânea. O quadro regrediu após terapêutica com Albendazol. Devido à maior frequência de fluxos migratórios na atualidade, as dermatoses tropicais podem tornar-se mais frequentes nos países de clima temperado. Salienta-se a importância do aconselhamento dos turistas para a prevenção desta dermatose, nomeadamente através do uso de calçado protetor