Produção de novilhos castrados ou não castrados terminados em confinamento em idade jovem ou superjovem / Production of steers or bulls finished in feedlot at a young age or young steers

Avaliaram-se o desempenho produtivo e o rendimento de cortes comercias da carcaça de animais castrados ou não castrados terminados em confinamento e abatidos em idade jovem ou superjovem, alimentados com uma dieta contendo 11,2% de proteína bruta e 3,07Mcal de energia digestível/kg de matéria seca, composta de 50% de volumoso e 50% de concentrado. A idade no início do confinamento dos animais superjovens e jovens foi de nove e 22 meses, respectivamente. Maior PF foi observado para os animais jovens não castrados. O GMD foi 31% superior em favor dos novilhos jovens em relação aos superjovens. O CMS foi 27% superior para os novilhos jovens sobre os superjovens, e os novilhos não castrados consumiram 9% mais kg de matéria seca quando comparados aos castrados. A diferença de peso da meia carcaça entre animais não castrados e castrados foi de 43% para os jovens e de 18% para os superjovens. Maior percentual do corte serrote foi observado nos novilhos jovens castrados. Novilhos jovens apresentaram maior ganho de peso médio diário, bem como novilhos jovens não castrados apresentaram maior peso final. Animais não castrados apresentaram maiores pesos de meia carcaça fria, percentual de dianteiro e porção comestível do dianteiro em relação aos castrados.(AU)

The productive performance and yield of commercial cuts of the carcass of non-castrate or castrated males feedlot finished and slaughtered at a young age or young steers, fed a diet containing 11.2% crude protein and 3.07 Mcal of digestible energy / kg of dry matter, composed of 50% roughage and 50% concentrate were evaluated. The initial age at the beginning of confinement of young steers and steers were 9 and 22 months, respectively. Greater FW was observed for young non-castrate. The ADG was 31% higher for the steers in relation to young steers. The DMI was 27% higher for steers than young steers and non-castrated consumed 9% more dry matter kg compared to the castrated. The half-carcass weight difference between non-castrated and castrated animals was 43% for steers and 18% for young steers. Higher percentage hacksaw cut was observed in castrated steers. Steers showed higher average daily weight gain, as well as non-castrate steers showed higher final weight. Non-castrate animals have higher half cold carcass weights, front percentage, and of edible portion of the front in relation to castrated.(AU)

Terminação de novilhos em pastagem de aveia branca consorciada com leguminosa ou associada à suplementação energética / Finishing steers on oat pasture intercropped with legumes or receiving energetic supplementation

O objetivo do experimento foi avaliar a associação da ervilhaca (Vica sativa) ou da suplementação energética em pastagem de aveia branca (Avena sativa) sobre o desempenho de novilhos de corte na fase de terminação. Foram utilizados 18 novilhos castrados, 1/4 Marchegiana 1/4 Aberdeen Angus 2 / 4 Nelore, com peso vivo e idade média de 360kg e 19 meses, respectivamente, divididos em três tratamentos: pastagem de aveia branca, pastagem de aveia branca consorciada com ervilhaca e pastagem de aveia branca com suplementação energética (milho grão triturado, 1% do peso vivo por dia, na matéria seca)...

The aim of this experiment was to evaluate the association of vetch (Vica sativa) or energy supplementation in oat (Avena sativa) on the performance of steers in the finishing phase. The experiment was performed in 18 steers, quarter Marchegiana, quarter Aberdeen Angus and 2/4 Nellore genetic groups, with the live weight and age of 360kg and 19 months, respectively, divided into three treatments: pasture white oat, pasture white oat intercropped with vetch and oat pasture with energetic supplementation with the basis of ground corn (1% body weight per day in dry matter)...

Caracterização bromatológica e agronômica de genótipos de milho para produção de silagem / Chemical characterization and agronomic genotypes of maize for silage

O objetivo deste trabalho foi avaliar as características bromatológicas e agronômicas dos genótipos de milho para a produção de silagem dos cultivares do Ensaio Centro Superprecoce da Rede Nacional de Genótipos de Milho, bem como avaliar se a base genética (híbridos simples, duplos, tripos, intervarietais e variedades cultivadas) ou a dureza dos grãos (duro, semiduro e dentado mole) alteram a indicação de cultivares de milho para silagem. O experimento foi realizado na área experimental da Universidade Tecnológica Federal do Paraná (campus Dois Vizinhos). Os trinta e dois genótipos avaliados foram colhidos quando os grãos encontravam-se no estádio pastoso a farináceo, ensilados em microssilos de PVC e desensilados após 53 dias. Avaliou-se a relação entre as bases genéticas, a dureza do grão e as características individuais dos genótipos quanto à aptidão para a produção de silagem. Não se verificaram diferenças significativas entre os contrastes formados entre as bases genéticas, bem como a dureza dos grãos, para os caracteres estudados. Porém, foi possível identificar genótipos superiores para a produção de silagem pela produção de matéria seca pelos genótipos AS 1555 YG, AS 1572 YG, 30A37, 30A77, 20A78, Dx 908, Dx 603, 2A550, 2B433, AL2007A, Embrapa 1F640, PRE 22T10, PREXT0109, PRE 22D11, DKB330 YG (Test).

The aim of this study was to evaluate the nutritive value and agronomic characteristics of maize genotypes for the silage production cultivars test center network of Super Early National Corn Genotypes; and to assess whether the genetic background (hybrids simple, doubles, triples, intervarieties and cultivated varieties) or the hardness of the grains (hard, soft flint and dent) may change the indication of maize cultivars for silage. The experiment was conducted at the experimental Federal Technological University of Paraná (Campus Dois Vizinhos). Thirty-two genotypes were harvested when the grains were in the dough soft dough stage, micro-ensiled in PVC silos, silage cutters and after 53 days after silage cutters. We evaluated the characteristics and chemical plant parameters of each genotype. We evaluated the relationship between genetic bases, hardness of the grain and individual characteristics of genotypes related to the production of corn silage. There was no significant difference between the contrast formed between the genetic and hardness of the grains for the characteristics studied. However, it was possible to identify superior genotypes for the production of silage whit bases in dry matter production by genotype YG AS 1555, AS 1572 YG, 30A37, 30A77, 20A78, DX 908, DX 603, 2A550, 2B433, AL2007A, EMBRAPA 1F640, PRE 22T10, PREXT0109, PRE 22D11, DKB330 YG (Test).

Características da carcaça e do corpo vazio de bovinos Charolês de diferentes categorias abatidos com similar grau de acabamento / Carcass characteristics and empty body of Charolais cattle of different categories slaughtered at similar degree of fatness

Avaliaram-se as características de carcaça e do corpo vazio de novilhos (NO), novilhas (NA) e vacas de descarte (VA) Charolês n= 9, 10 e 10, respectivamente, terminados em confinamento e abatidos com similar grau de acabamento. O peso de abate e o peso de corpo vazio (PCVZ) foram similares entre NO, 480,2 e 417,4kg, e VA, 516,2 e 405,8kg, e maiores do que os das NA, 368,3 e 306,1kg. O rendimento de carcaça quente diferiu entre as categorias, sendo 57,2, 53,3 e 50,5%, respectivamente, para NO, NA e VA. Com o rendimento de carcaça quente expresso em relação ao PCVZ, as diferenças entre categorias diminuíram, sendo significativas apenas entre NO e NA. O conteúdo do trato digestivo das VA foi 34 e 45% maior que o dos NO e NA, respectivamente, sendo correlacionado (P<0,05) com peso de abate (r=0,66) e rendimento de carcaça quente (r=-0,41). O peso de carcaça quente foi similar entre NO, 274,9kg, e VA, 260,8kg, e maior que o NA, 196,4kg. O comprimento de carcaça foi maior nas VA, intermediário nos NO e menor nas NA. A área do músculo Longissimus dorsi foi menor nas NA. Novilhos apresentaram melhor conformação de carcaça que as fêmeas, as quais não diferiram entre si.

The carcass characteristics and empty body of Charolais steers n=9, cull heifers n= 10, and cull cows n=10, feedlot finished with similar subcutaneous fat thickness were evaluated. The slaughter weight and empty body weight (EBW) were similar between steers (480.2 and 417.4kg) and cows (516.2 and 405.8kg), which were higher than for heifers (368.3 and 306.1kg). Hot carcass dressing was significantly different among categories, being 57.2, 53.3 and 50.5%, respectively, for steers, heifers and cows. When carcass dressing was expressed in relation to EBW the differences became smaller among categories, being significant only between steers and heifers. The digestive tract content of cows was 34 and 45% higher than for steers and heifers, respectively, being correlated (P<0.05) with slaughter weight (r=0.66) and hot carcass dressing (r=-0.41). Hot carcass weight was similar for steers (274.9kg) and cows (260.8kg), both superior to heifers (196.4kg). Carcass length was higher for cows, intermediate for steers and lower for heifers. The Longissimus dorsi area was smaller for heifers. Steers showed better carcass conformation score than females, which did not differ between themselves.

Metabólitos sanguíneos de vacas de corte suplementadas ou não com sais de cálcio de ácidos graxos durante o período pré e/ou pós-parto / Blood metabolites from beef cows supplemented or not with calcium salts of fatty acids during pre and/or postpartum period

Avaliou-se a concentração de metabólitos sanguíneos de vacas de corte mantidas em pastagem natural recebendo suplementação com sais de cálcio de ácidos graxos (SCAG) durante 45 dias antes do parto (PRE), suplementação com SCAG durante 45 dias antes do parto e 63 dias pós-parto (PREPOS), suplementação com SCAG durante 63 dias pós-parto (POS) e de vacas não suplementadas (PN). As coletas de sangue foram realizadas em média 64 dias antes do parto, e aos 21, 42 e 63 dias pós-parto. Não ocorreu interação significativa entre tratamentos e períodos. As concentrações plasmáticas de β-hidroxibutirato (βHB), triglicerídeos (TRIG), colesterol, glicose e ureia não foram afetadas significativamente pela suplementação de gordura protegida. A análise de regressão mostrou queda linear significativa da concentração de TRIG no sangue com o aumento da produção de leite (PL) para as vacas do tratamento PN (TRIG = 23,10 - 2,18*PL, R² = 0,31) e efeito quadrático para as vacas do PRE (TRIG = 6,54 - 1,75*PL + 0,30*PL², R² = 0,62). Nos animais dos tratamentos POS e PREPOS, não houve efeito da produção de leite sobre a concentração de TRIG, indicando que a suplementação durante o período de produção de leite auxilia na manutenção de um balanço energético positivo. As concentrações de colesterol plasmático aumentaram, e as de triglicerídeos e ureia diminuíram linearmente até o final do experimento.

The study evaluated the blood metabolites of beef cows maintained on native pasture supplemented with calcium salts of fatty acids (CSFA) during 45 days pre-partum (PRE); supplemented with CSFA during 45 days pre-partum and 63 days post-partum (PREPOS); supplemented with CSFA during 63 days post-partum (POS) and cows not supplemented (PN): without supplementation. Blood samples were taken 64 days pre-partum, and at 21, 42 and 63 days post-partum. No significant interaction was observed between treatment and period. Plasma concentrations of β-hydroxybutyrate (βHB), triglycerides, cholesterol, glucose and urea were not affected by protected fat supplementation. The regression analysis showed significant linear decline of blood triglycerides (TRIG) concentration with the increase of milk production (PL) for PN cows (TRIG= 23.10 - 2.18*PL, R²= 0.31) and quadratic effect for PRE cows (TRIG= 6.54 - 1.75*PL + 0.30*PL², R²= 0.62). For cows submitted to the POS and PREPOS treatments there was no effect of milk production on blood triglycerides concentration, indicating that CSFA during milk production aids the maintenance of a positive energetic balance. The concentration of plasma cholesterol increased while the concentrations of triglycerides and urea decreased linearly until the end of the experiment.

Recria de bovinos de corte mantidos em pastagem de aveia preta com diferentes ofertas de forragem, com e sem suplementação / Rearing of beef cattle grazing oats with different forage allowances, with or without supplementation

O objetivo deste estudo foi avaliar o desempenho de bezerros recebendo ou não suplemento energético, mantidos em pastagem de aveia preta (Avena strigosa Schreb) manejada sob duas ofertas de forragem. Foram utilizados 16 animais do grupamento genético Composto Marchangus Z (1/4 Marchigiana 1/4 Angus 1/2 Nelore), com oito meses de idade, castrados, e com peso médio inicial de 200kg. O delineamento experimental utilizado foi o inteiramente ao acaso, em um fatorial 2x2 (duas ofertas de forragem x dois manejos alimentares - com e sem suplementação de milho moído). Não houve interação significativa entre oferta e suplementação para nenhuma das variáveis. A oferta de forragem real ficou próxima do estipulado para 6 e 10% (5,95% e 9,07%, respectivamente). A oferta de 6% apresentou maior porcentagem de folha (57,0 contra 30,4%), menor porcentagem de colmo (43,0 contra 69,6%) e, consequentemente, maior relação folha/colmo (1,45 contra 0,45), resultando em pastagens de melhor qualidade (PB = 20,0 contra 13,6%) na menor oferta. A taxa de acúmulo diária foi maior (P<0,05) para oferta de forragem de 6% (34,2kg de MS/ha/dia) em relação à oferta de 10% (28,1kg de MS/ha/dia). A suplementação proporcionou maior ganho de peso médio diário (0,749 contra 0,594kg/dia) na recria de bezerros em pastagem de aveia preta IPR-61.

The objective of this study was to evaluate the performance of calves fed supplemented energy or not maintained in oat (Avena strigosa Schreb) managed under two forage allowances. Sixteen Marchangus (1/4 Marchigiana 1/4 Angus 1/2 Nelore) animals were used at eight months old and average initial weight of 200kg. The experimental design utilized was completely randomized in a 2x2 factorial (two forage allowances x two feeding - with and without supplementation of corn). There was no significant interaction between supply and supplementation for the variables. The real forage allowance was close to the expected from 6 to 10% (5.95 and 9.07%, respectively). The offer of 6% shows higher percentage of leaf (57.0 versus 30.4%), lower percentage of stem (43.0 versus 69.6%) and, consequently, higher leaf/stem ratio (1.45 versus 0.45), resulting in better forage (PB=20.0 versus 13.6%), in lower offer. The accumulated rate was higher (P<.05) for forage allowance of 6% (34.2kg of MS/ha/day) in relation to the offer of 10% (28,1kg of MS/ha/day). Supplemented animals showed higher average dairy weight (.749 versus .549kg/day).

Características dos componentes não integrantes da carcaça de novilhos superjovens da raça Devon, terminados em diferentes sistemas de alimentação / Characteristics of non-integrant components of carcass of Devon young steers, finished in different feeding systems

O objetivo do estudo foi avaliar as características dos componentes não integrantes da carcaça de novilhos Devon terminados em confinamento (CONF), em pastagem de clima temperado (pastagem de azevém - Lolium multiflorum Lam - PTEM) ou em pastagem de clima tropical (associação de pastagem de milheto - Pennisetum americanum (L.) Leeke - e capim-papuã - Bracharia plantaginea - PTRO). Os novilhos, ao início da terminação, estavam com 320kg e 15 meses de idade. Os animais confinados foram alimentados com relação volumoso:concentrado de 60:40; o volumoso era constituído de silagem de milho, e o concentrado de farelo de trigo, milho e minerais. Os animais foram abatidos com pesos semelhantes de 388,3; 386,7 e 375,8kg no CONF, na PTEM e na PTRO, respectivamente. Os animais da PTRO apresentaram maior (P<0,10) rendimento de carcaça quente (RCQ) relativo a 100kg de peso corporal vazio (RCQPCV) do que os da PTEM, 64,6 versus 62,6 por cento, e os do CONF apresentaram RCQPCV intermediário, 63,7 por cento. Os pesos absolutos do fígado, 5,22; 4,43 e 3,87kg, do conjunto dos órgãos internos, 12,81; 11,37 e 10,83kg, do rúmen-retículo, 7,62; 6,54 e 6,06kg, da gordura do coração, 1,26; 0,65 e 0,30kg, e dos intestinos, 9,97; 7,13 e 7,49kg, foram mais altos (P<0,05) nos animais da PTEM, em relação aos do CONF e da PTRO, respectivamente. A mesma ordem de grandeza ocorreu com os pesos relativos desses órgãos. A PTRO e o CONF originaram animais com maior (P<0,05) peso de conteúdo gastrintestinal em relação à PTEM, respectivamente, 60,27; 55,32 e 41,21kg. O CONF proporcionou animais com pesos absolutos mais elevados (P<0,05) do omaso, 5,17kg, em relação aos da PTEM, 3,70kg, e este peso foi intermediário nos animais da PTRO, 4,77kg. A mesma ordem de grandeza ocorreu com os pesos relativos do omaso, 1,61; 1,12 e 1,54 por cento.

The non-integrant components of carcass of Devon steers were evaluated. Animals were finished in feedlot (CONF), winter pasture (pasture of ryegrass - Lolium multiflorum Lam -PTEM), or tropical pasture (association of millet pasture - Pennisetum americanum (L.) Leeke - and Alexander Grass - Brachiaria plantaginea - PTRO). At the beginning of finishing, the average weight of steers was 320kg and age was 15 months. The roughage:concentrate ratio of CONF was 60:40. The animals were slaughtered at similar weights of 388.3, 386,7, and 375.8 for CONF, PTEM, and PTRO, respectively. The PTRO animals showed higher hot carcass dressing (HCD) percentage relative to 100kg of empty body weight (HCDEBW) in comparison to PTEM (64.6 versus 62.6 percent), and CONF animals showed intermediary value for HCDEBW (63.7 percent). The absolute weights of liver, 5.22, 4.43, and 3.87kg; total weights of all internal organs, 12.81, 11.37, and 10.83kg; rumen-reticulum, 7.62, 6.54, and 6.06kg; heart fat, 1.26, 0.65, and 0.30kg; and intestines, 9.97, 7.13, and 7.49kg, were higher (P<0.05) in PTEM animals than in CONF and PTRO animals, respectively. The same differences were observed concerning relative weights of the same organs. PTRO and CONF animals showed higher (P<0.05) gastrointestinal content than PTEM animals, 60.27, 55.32, and 41.21kg, respectively. Feedlot finished animals exhibited higher absolute weight of omasum, 5.17kg, than PTEM animals, 3.70kg, and PTRO animals presented intermediary value, 4,77kg. The same order was observed concerning relative weigh of the omasum, 1.61, 1.12, and 1.54 percent.

Silagem de milho e grão de sorgo como suplementos para vacas de descarte terminadas em pastagem cultivada de estação fria / Corn silage and sorghum grain supplementation to cull cows finished on cultivated winter pasture

Avaliou-se o efeito da suplementação com silagem de milho ou grão de sorgo no desempenho e características da carcaça e da carne de vacas de descarte, submetidas ao pastejo restrito em pastagem de aveia (Avena strigosa) + azevém (Lolium multiflorum). Foram utilizadas 30 vacas mestiças Charolês-Nelore, com idade média de oito anos, distribuídas em igual número e ao acaso em três tratamentos: silagem de milho (TSI) ou grão de sorgo moído (TSO) como suplemento, e não suplementação (TPH). A suplementação com silagem de milho proporcionou aos animais maior escore corporal ao final do experimento (4,35 pontos contra 4,15 do TPH e 4,22 pontos para o TSO). Não houve efeito do volumoso ou concentrado suplementar sobre o peso corporal, ganho de peso diário e ganho em escore corporal. Não houve efeito de tratamento (P>0,05) sobre pesos e rendimentos quentes e frios da carcaça, espessura de gordura subcutânea, conformação, espessura de coxão, área de Longissimus dorsi e percentagem de cortes comerciais. A suplementação resultou em maior percentagem de gordura na carcaça e influenciou a cor e o marmoreio da carne. A silagem de milho e o grão de sorgo servem como alternativa para a suplementação de vacas de descarte em pastagem de aveia e azevém, uma vez que melhora as características da carcaça, embora sem efeito sobre o desempenho quando comparado à pastagem exclusiva.

The effect of supplementation with corn silage or sorghum grain on the performance and characteristics of carcass and meat of cull cows, under temporary grazing on oats (Avena strigosa) + ryegrass (Lolium multiflorum) pasture was evaluated. Thirty crossbred Charolais-Nellore cull cows, with averaging eight-yearold,were randomly distributed in three treatments. The animals received corn silage (TSI) or sorghum grain (TSO) as supplement, while another lot did not receive supplementation (TPH). Animals supplemented with corn silage showed higher final body condition score (4.35 points versus 4.15 for TPH and 4.22 for TSO). No effect of supplementation on body weight, average daily weight gain; and body condition score gain were verified. Differences were not observed concerning carcasses weight, hot and cold yield of carcasses, fat thickness, conformation, cushion thickness, Longissimus dorsi area, and commercial cuts percentages. Supplemented animals showed better color and higher marbling of meat. Corn silage and sorghum grain are alternative for the supplementation of cull cows in oats and ryegrass pasture, since they showed better carcass characteristics, although no effect on the performance in relation to exclusive pasture was detected.

Molecular and cellular pathogenesis of autosomal recessive polycystic kidney disease.

Autosomal recessive polycystic kidney disease (ARPKD) is an inherited disease characterized by a malformation complex which includes cystically dilated tubules in the kidneys and ductal plate malformation in the liver. The disorder is observed primarily in infancy and childhood, being responsible for significant pediatric morbidity and mortality. All typical forms of ARPKD are caused by mutations in a single gene, PKHD1 (polycystic kidney and hepatic disease 1). This gene has a minimum of 86 exons, assembled into multiple differentially spliced transcripts and has its highest level of expression in kidney, pancreas and liver. Mutational analyses revealed that all patients with both mutations associated with truncation of the longest open reading frame-encoded protein displayed the severe phenotype. This product, polyductin, is a 4,074-amino acid protein expressed in the cytoplasm, plasma membrane and primary apical cilia, a structure that has been implicated in the pathogenesis of different polycystic kidney diseases. In fact, cholangiocytes isolated from an ARPKD rat model develop shorter and dysmorphic cilia, suggesting polyductin to be important for normal ciliary morphology. Polyductin seems also to participate in tubule morphogenesis and cell mitotic orientation along the tubular axis. The recent advances in the understanding of in vitro and animal models of polycystic kidney diseases have shed light on the molecular and cellular mechanisms of cyst formation and progression, allowing the initiation of therapeutic strategy designing and promising perspectives for ARPKD patients. It is notable that vasopressin V2 receptor antagonists can inhibit/halt the renal cystic disease progression in an orthologous rat model of human ARPKD.

Molecular and cellular pathogenesis of autosomal recessive polycystic kidney disease

Autosomal recessive polycystic kidney disease (ARPKD) is an inherited disease characterized by a malformation complex which includes cystically dilated tubules in the kidneys and ductal plate malformation in the liver. The disorder is observed primarily in infancy and childhood, being responsible for significant pediatric morbidity and mortality. All typical forms of ARPKD are caused by mutations in a single gene, PKHD1 (polycystic kidney and hepatic disease 1). This gene has a minimum of 86 exons, assembled into multiple differentially spliced transcripts and has its highest level of expression in kidney, pancreas and liver. Mutational analyses revealed that all patients with both mutations associated with truncation of the longest open reading frame-encoded protein displayed the severe phenotype. This product, polyductin, is a 4,074-amino acid protein expressed in the cytoplasm, plasma membrane and primary apical cilia, a structure that has been implicated in the pathogenesis of different polycystic kidney diseases. In fact, cholangiocytes isolated from an ARPKD rat model develop shorter and dysmorphic cilia, suggesting polyductin to be important for normal ciliary morphology. Polyductin seems also to participate in tubule morphogenesis and cell mitotic orientation along the tubular axis. The recent advances in the understanding of in vitro and animal models of polycystic kidney diseases have shed light on the molecular and cellular mechanisms of cyst formation and progression, allowing the initiation of therapeutic strategy designing and promising perspectives for ARPKD patients. It is notable that vasopressin V2 receptor antagonists can inhibit/halt the renal cystic disease progression in an orthologous rat model of human ARPKD.

Immunohistochemical and in situ hybridization studies of the liver and kidney in human leptospirosis.

An in situ hybridization (ISH) assay for the detection of leptospiral DNA in tissues was described and its diagnostic and pathogenetic usefulness in combination with immunohistochemistry (IHC) was evaluated in formalin-fixed, paraffin-embedded liver and kidney samples from human fatal cases of leptospirosis. IHC assays with anti-E-cadherin antibodies assessed the liver-plate disarray frequently observed in leptospirosis. Immunohistochemistry detected leptospiral antigen (LAg) in macrophages, both in human liver and kidney. In guinea pigs, in addition to these findings, staining on cell membranes of hepatocytes and, occasionally, in apical membrane of kidney tubular cells was demonstrated. Positive ISH signal was observed chiefly in the nuclei of human hepatocytes and in the cytoplasm and nuclei of liver cells of experimentally infected guinea pigs. Loss of E-cadherin membrane expression is associated with liver-plate disarray. These findings were discussed in the contention that, in leptospirosis, cell membrane damage might be important for the pathogenesis of the disease. Finally, it was suggested that both IHC and/or ISH might be used for both diagnostic and research purposes.

Solitary fibrous tumour of the mouth: report of two cases involving the tongue and cheek.

We describe two additional cases of solitary fibrous tumour (SFT) affecting the mouth. SFT is very uncommon in the oral cavity and we found only 14 cases reported in the literature. Our two cases were well circumscribed, slow growing tumours that, after surgical removal, did not recur. Case 1 was a 3 cm nodule on the right cheek. Hypo and hypercellular adjacent areas were mainly patternless, and the stroma was formed by thin collagen fibrils. Case 2 was a 4.8 cm mass in the anterior portion of the tongue. Microscopically it was formed by spindle cells embedded in a vascularized sclerotic collagen matrix. Some areas were hypercellular with scarce collagen fibrils. The immunohistochemical findings were similar in both cases, with strong immunoreactivity for vimentin, CD34, bcl-2, focal positivity for Ki-67 and negativity for other immunomarkers. Based on these clinical, microscopical and immunohistochemical features the final diagnosis of these two cases was SFT. Diagnosis of SFT is difficult and, although uncommon, it should be considered in the differential diagnosis of oral soft tissue tumours.

[Variation of above-ground biomass of Allagoptera arenaria (Gomes) O. Kintze (Arecaceae) at a palm shrub community on the Marambaia beach ridge, Rio de Janeiro, Brazil]. / Variação da Biomassa Aérea de Allagoptera arenaria (Gomes) O. Kuntze (Arecaceae) em uma Comunidade Arbustiva de Palmae na Restinga de Marambaia, RJ.

Variation of above-ground biomass of Allagoptera arenaria (Gomes) O. Kuntze (Arecaceae) along five topographic profiles perpendicular to the ocean was examined in a palm scrub community on Marambaia beach ridge, Rio de Janeiro State, Brazil. Aerial biomass was positively correlated with distance from the sea (F = 39.57; R2 = 0.69; P < 0.01) as was detritus cover (F = 525.92; R2 = 0.92; P < 0.01). A. arenaria growth is closely related to the topography of the beach area. Dense populations of this palm enrich the soil by increasing organic matter under the plants through dead leaf material. This promotes the accumulation of nutrients and the creation of micro-climates that favor the establishment of other species.

Ectonucleotide diphosphohydrolase activities in Entamoeba histolytica.

In this work, we describe the ability of living cells of Entamoeba histolytica to hydrolyze extracellular ATP. In these intact parasites, whose viability was determined by motility and by the eosin method, ATP hydrolysis was low in the absence of any divalent metal (78 nmol P(i)/h/10(5) cells). Interestingly, in the presence of 5 mM MgCl(2) an ecto-ATPase activity of 300 nmol P(i)/h/10(5) cells was observed. The addition of MgCl(2) to the extracellular medium increased the ecto-ATPase activity in a dose-dependent manner. At 5 mM ATP, half-maximal stimulation of ATP hydrolysis was obtained with 1.23 mM MgCl(2). Both activities were linear with cell density and with time for at least 1 h. The ecto-ATPase activity was also stimulated by MnCl(2) and CaCl(2) but not by SrCl(2), ZnCl(2), or FeCl(3). In fact, FeCl(3) inhibited both Mg(2+)-dependent and Mg(2+)-independent ecto-ATPase activities. The Mg(2+)-independent ATPase activity was unaffected by pH in the range between 6.4 and 8. 4, in which the cells were viable. However, the Mg(2+)-dependent ATPase activity was enhanced concomitantly with the increase in pH. In order to discard the possibility that the ATP hydrolysis observed was due to phosphatase or 5'-nucleotidase activities, several inhibitors for these enzymes were tested. Sodium orthovanadate, sodium fluoride, levamizole, and ammonium molybdate had no effect on the ATPase activities. In the absence of Mg(2+) (basal activity), the apparent K(m) for ATP(4-) was 0.053 +/- 0.008 mM, whereas at saturating MgCl(2) concentrations, the corresponding apparent K(m) for Mg-ATP(2-) for Mg(2+)-dependent ecto-ATPase activity (difference between total and basal ecto-ATPase activity) was 0.503 mM +/- 0.062. Both ecto-ATPase activities were highly specific for ATP and were also able to hydrolyze ADP less efficiently. To identify the observed hydrolytic activities as those of an ecto-ATPase, we used suramin, a competitive antagonist of P(2) purinoreceptors and an inhibitor of some ecto-ATPases, as well as the impermeant agent 4'-4'-diisothiocyanostylbenzene-2'-2'-disulfonic acid. These two reagents inhibited the Mg(2+)-independent and the Mg(2+)-dependent ATPase activities to different extents, and the inhibition by both agents was prevented by ATP. A comparison among the ecto-ATPase activities of three amoeba species showed that the noninvasive E. histolytica and the free-living E. moshkovskii were less efficient than the pathogenic E. histolytica in hydrolyzing ATP. As E. histolytica is known to have a galactose-specific lectin on its surface, which is related to the pathogenesis of amebiasis, galactose was tested for an effect on ecto-ATPase activities. It stimulated the Mg(2+)-dependent ecto-ATPase but not the Mg(2+)-independent ATPase activity.

Effect of bacterial association on the phenotype and genotype of an Entamoeba histolytica clonal population.

A several-times-cloned population of Entamoeba histolytica trophozoites (clone MAVIII) was cultured under axenic (MAVIIIax), monoxenic (MAVIIImx) and polyxenic (MAVIIIpx) conditions. Clones MAVIIIax and MAVIIImx presented similar virulence in vitro, but differed in their virulence in vivo, whereas MAVIIIpx trophozoites were neither virulent in vitro or in vivo. The MAVIII clones maintained their zymodeme and exhibited three unusual glucose phosphate isomerase bands, absent in other E. histolytica strains studied. Similar patterns were shown by the three MAVIII clones in the signature of a 482-bp DNA fragment from the M17 gene (which encodes for a variable immunodominant antigen), obtained by low stringency single specific primer PCR technique. However, MAVIII clones displayed genotypic variability in the patterns obtained by the random amplified polymorphic DNA technique using total DNA as template. Results suggest that monomorphism is kept in certain regions of the genome, mainly in those carrying protein encoding genes, but a high polymorphism is present in total DNA of cloned trophozoites cultured under different conditions, confirming the plasticity of the E. histolytica genome.

Sealant and resin viscosity and their influence on the formation of resin tags.

The ability of resin to penetrate tooth enamel during orthodontic bonding may be affected by the viscosity of the resin and the presence of a sealant. Twenty-four extracted molars were randomly divided into six groups of four. Three resin viscosities were applied with and without sealant and resin tag formation was studied with a scanning electron microscope. Statistically larger resin tags resulted in the group using the more fluid composite resin (orthodontic Concise) in combination with the sealant, although the frequency, regularity and form of the tags did not differ significantly among the various viscosities.