Characterization of the cellular component of polymorphous low-grade adenocarcinoma by immunohistochemistry and electron microscopy

In order to characterize the cellular component of the polymorphous low-grade adenocarcinoma (PLGA) of the salivary gland, a morphological and immunohistochemical study was carried out. Thirty cases of PLGA were studied by light microscopy and immunohistochemistry and five cases by transmission electron microscopy (TEM). The expression of cytokeratins (CKs) 7,8,10,13,14,18,19, vimentin and muscle-specific actin (MSA) was investigated through the streptavidin-biotin method. The majority of tumor cells stained for vimentin, CKs 8,18 and 7. CK 14 was positive in most cells of the papillary and trabecular sub-types. Although the expression of CKs 8,18 and 14 varied among the tumors sub-types, a straight relationship between each histologic pattern and the CK expression could not be delineated. MSA was reactive in only three tumors while CKs 10 and 13 were not detected in any tumor studied. The absence of MSA and the expression of CKs 8,18 and 7, in most of the tumor cells, lead to the hypothesis that myoepithelial cells are not the major cellular component of the PLGA. TEM revealed cells exhibiting microvilli and variable amounts of secretory granules, some of them suggesting an excretory activity. The presence of CKs 8, 18 and 7, added to the secretory granules, indicates that PLGA originates from cells located at the acinar-intercalated duct junction. (C) 1999 Elsevier B.V. Ltd. All rights reserved.

EFFECT OF EXERCISE DURING PREGNANCY AND DAM AGE ON MATERNAL BLOOD-CHEMISTRY AND FETAL GROWTH

In order to determine the effect of maternal exercise on maternal nutritional status and fetal growth, young (Y = 45-50 days old) Wistar rats were divided into 4 groups of 5 to 8 animals: control pregnant (CP), control non-pregnant (CNP), exercise-trained (swimming 1 h/day, 5 days/week, for 19 days) pregnant (TP) and exercise-trained non-pregnant (TNP). Four equivalent groups of adult rats (A - 90-100 days old) were also formed. Serum glucose, total protein, albumin, hematocrit and liver glycogen were determined in female rats and pups. There were no statistical differences in serum glucose, total protein and albumin levels, litter size ot birth weight among exercise-trained animals, controls and their respective pups. Hematocrit was significantly lower in pups of exercise-trained young rats than in all other groups (YCP = 38.6 +/- 3.0; YTP = 32.6 +/- 2.1; ACP = 39.0 +/- 2.5; ATP = 39.2 +/- 2.9%). Liver glycogen levels were lower in pregnant than in non-pregnant rats but similar in exercise-trained and control rats of the same age and physiological status (YCNP = 4.1 +/- 0.2; YCP = 2.7 +/- 0.9; YTNP = 4.9 +/- 0.8; YTP = 2.7 +/-0.4; ACNP = 6.1 +/- 0.6; ACP = 3.1 +/- 0.8; ATNP = 6.6 +/- 0.8; ATP = 2.2 +/- 0.9 mg/100 mg). We conclude that pups of adult female rats are spared from the effects of this kind of exercise training during pregnancy. on the other hand, it appears that maternal adaptations to exercise training in young rats are able to preserve only some aspects of pup metabolism.

Complete staining of nerve fiber and myoneural junctions with acetylthiocholine and silver

We describe a combined stain for simultaneous demonstration of the preterminal axons and cholinesterase activity at myoneural junctions of mammalian muscles. This technique employs acetylthiocholine iodide as the substrate for cholinesterase activity and silver nitrate impregnation of preterminal axons. The procedure is rapid, simple and uses fresh muscles. Intramuscular nerves, preterminal axons and myoneural junctions are stained simultaneously brown or black with minimal background staining of connective tissue and muscle fibers.

Neo-clerodane diterpenoid, a new metalloprotease snake venom inhibitor from Baccharis trimera (Asteraceae): anti-proteolytic and anti-hemorrhagic properties

Many plants are used in traditional medicine as active agents against various effects induced by snakebite. Few attempts have been made however to identify the nature of plain natural products with anti-ophidian properties. Baccharis trimera (Less) DC (Asteraceae), known in Brazil as carqueja. has been popularly used to treat liver diseases. rheumatism. diabetes, as well as digestive, hepatic and renal disorders. The active component was identified as 7alpha-hydroxy-3,13-clerodadiene-16,15:18,19-diolide, C20H28O5, (clerodane diterpenoid, Bt-CD). We report now the anti-proteolytic and anti-hemorrhagic propenies against snake venoms of a Bt-CD inhibitor from B. trimera. Bt-CD exhibited full inhibition of hemorrhage and proteolytic activity caused by Bothrops snake venoms. The inhibitor was able to neutralize the hemorrhagic, fibrinogenolytic and caseinolytic activities of class P-I and III metalloproteases isolated from B. neuwiedi and B. jararacussu venoms. No inhibition of the coagulant activity was observed. Bt-CD also partially inhibited the edema induced by other crude venoms, metallopronteases, basic and acidic phospholipases A(2). To further elucidate the inhibitory specificity of Bt-CD against metalloproteases isolated from snake venoms, a deeper understanding of its Structure and function is necessary. Furthermore, the potential use of these inhibitors to complement anti-venom as an alternative treatment of snakebite envenomations needs to be evaluated in future Studies. (C) 2004 Elsevier B.V.. All rights reserved.

Influence of diet on assimilation and turnover of C-13 in the tissues of broiler chickens

1. The C-13 turnover rates of the liver and thoracic pectoral muscle of growing broilers were determined by feeding diets with varying C-13 content.2. Male chicks ( 1- d- old) were subjected to treatments based on free choice of 5 different mixes of energy and protein sources from plants with C-3 and C-4 photosynthetic pathways that had differing C-13 content. Rice bran ( R) and soybean meal ( S) were the C-3 sources, while maize ( C) and maize gluten meal ( G) were the C-4 sources. Choices were R + S, C + G, R + G, C + S or R + C +G + S. The 6th treatment was a complete feed ( CF) that was similar to a commercial broiler feed.3. The isotopic composition of the birds' tissues was representative of the isotopic composition of the diets. The assimilation was faster for C-3, in both liver and muscle, than for C-4 diets, and give the delta per mil difference between the diet and tissues.4. The liver is the most active metabolic tissue and gave more rapid isotope turnover than in muscle.

SUPEROXIDE RADICAL AND TOXICITY OF ENVIRONMENTAL NICKEL EXPOSURE

Three nickel compounds were tested for pancreatic, hepatic and osteogenic damage in rats by a single i.m. injection Ni++ (7 mg kg(-1)). The nickel induced biochemical alterations included significantly increased levels of serum alkaline phosphatase in rats with NiS (75%) and NiO (50%). Amylase and aspartate transaminase were also increased, and lipoperoxide was increased in rats with NiO (5.6-fold) and NiS (3.4-fold). No serum changes were observed with NiCl2. Daily injection of Cu-Zn superoxide dismutase (SOD) conjugated with polyethylene glycol prevented the serum level changes, indicating that superoxide radical is an important intermediate in toxicity of nickel insoluble compounds.

Protein malnutrition does not impair glucose metabolism adaptations to exercise-training

Malnutrition is a common health problem in developing countries and is associated with alterations in glucose metabolism. In the present study we examine the effects of chronic aerobic exercise on some aspects of glucose metabolism in protein-deficient rats. Two groups of adult rats (90 days old) were used: Normal protein group (17%P)- kept on a normal protein diet during intra-uterine and postnatal life and Low protein group (6%P)- kept on a low protein diet during intrauterine and post natal life. After weaning (21 days old), half of the 17%P and 6%P rats were assigned to a Sedentary (Sed) or an Exercise-trained (Exerc = swimming, 1 hr/day, 5 days/week, supporting an overload of 5% of body weight) subgroup. The area under blood glucose concentration curve (Delta G) after an oral glucose load was higher in 17%P Sed rats (20%) than in other rats and lower in 6%P Exerc (11%) in relation to 6% Sed rats. The post-glucose increase in blood insulin (Delta I) was also higher in 17%P Sed (9%) than in other rats. on the other hand, the glucose disappearance rate after exogenous subcutaneous insulin administration (Kitt) was lower in 17%P Sed rats (66%) than in other rats. Glucose uptake by soleus muscle was higher in Exerc rats (30%) than in Sed rats. Soleus muscle glycogen synthesis was reduced in 6%P Sed rats (41%) compared to 17%P Sed rats but was restored in 6%P Exerc rats. Glycogen concentration was elevated in Exerc (32%) rats in comparison to Sed rats. The present results indicate that glucose-induced insulin release is reduced in rats fed low protein diet. This defect is counteracted by an increase in the sensitivity of the target tissues to insulin and glucose homeostasis is maintained. This adaptation allows protein deficient rats to preserve the ability to appropriately adapt to aerobic physical exercise training. (C) 2000 Elsevier B.V.

Dietary macronutrients and performance and plasma hormone and metabolite levels of broiler chickens fat by carbohydrate substitution

The present experiment was aimed to study the effects of an isocaloric substitution of fat by carbohydrate calories while maintaining the same CP content - on some endocrine parameters and key metabolites of the lipid (L), protein (CP) and carbohydrate (CHO) metabolism and muscle cell membrane integrity of broiler chickens. Ninety male broiler chicks (Cobb) were obtained at 1-day old and raised in an environmentally controlled room. Food and water was provided ad libitum. At day 7, the chicks were provided with the experimental diets: Control diet (CON: 20% CP; 9.1% L; 39.6% CHO), Low lipid diet (LowL: 22% CP; 3.36% L; 59.7% CHO), and low carbohydrate diet (LowCHO: 22% CP; 8.09% L; 46.7% CHO). T e chickens fed the CON manifested the best growth rate feed conversion compared to both other groups. The CO chickens showed the highest plasma T-3 Concentrations at 14 days of age as compared to both LowL and LowCHO chickens. At 35 days of age however, LowL chickens were characterized by the highest plasma T-3 levels. Overall, CON birds had the highest plasma T-4 levels (P < 0.0001) compared to LowL and LowCHO chickens. Plasma corticosterone levels were not affected by diet composition. Glucose levels increased towards the end of the experimental period, but there was no overall effect of diet composition on plasma glucose levels. Chickens fed the CON diet were consistently characterized by the highest plasma uric acid levels compared to LowL and LowCHO chickens. Irrespectively of diet, plasma triglyceride levels were high at 14 days of age, then decreased and finally increased again during the last week. This latter increase was most pronounced for the CON chickens and is congruous with their high fat deposition. At 28 days of age, a significant effect of diet was observed, as CON birds had lower plasma free fatty acid (FFA) levels compared to LowL but not to LowCHO chickens. However there was no overall effect of diet composition on plasma FFA levels. Creatine kinase (CK) activities increased significantly with age and were consistently higher in CON chickens. In conclusion, fast growth in broiler chickens is positively correlated with catabolism of protein from dietary or endogenous origin and (muscle) cell membrane disruption as reflected in high plasma uric acid levels and CK activity, respectively. The currently investigated substitution of fat by CHO had no marked effects on endocrine functioning and intermediary metabolism, but this does not exclude that larger substitutions between both nutrients can have an effect.

Influência do banho de aspersão ante-mortem na eficiência da sangria e em parâmetros bioquímicos da carne bovina

To determine the effects of the pre-slaughter showering on some meat quality parameters, the biochemical changes in the Longus colli muscle and the bleeding efficiency were studied. Thirty-six Nelore steers were slaughtered in a commercial slaughterhouse. Eighteen animals were submitted to pre-slaughter showering; a control group of eighteen animals were slaughtered without showering. Samples were collected for evaluations in the muscle depth, in the anterior portion of longus colli muscle,just before chilling. Bleeding efficiency was evaluated through the ratio of muscle haemoglobin/blood haemoglobin using blood samples taken five seconds after bleeding, and muscle sample taken before chilling. Longus colli muscle samples were also used to determine glycogen, glucose, pH and acidity, 5, 24 and 48 hours after slaughtering. Multivariate methods were used to evaluate biochemical data and the bleeding efficiency data analysis followed the randomized block design. Haemoglobin retained in the muscle and bleeding efficiency were not affected (P > .05) by pre-slaughter showering. The pre-slaughter showering did not affect (P > .05) the glycolysis. There was a significant effect of time in glycogen, glucose, pH and acidity, in the first 24 hours.

Analysis of various conditions in order to measure electromyography of isometric contractions in water and on air

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Additive genetic relationship of longevity with fertility and production traits in Nellore cattle based on bivariate models

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Expressed sequence tags from Atta laevigata and identification of candidate genes for the control of pest leaf-cutting ants.

Leafcutters are the highest evolved within Neotropical ants in the tribe Attini and model systems for studying caste formation, labor division and symbiosis with microorganisms. Some species of leafcutters are agricultural pests controlled by chemicals which affect other animals and accumulate in the environment. Aiming to provide genetic basis for the study of leafcutters and for the development of more specific and environmentally friendly methods for the control of pest leafcutters, we generated expressed sequence tag data from Atta laevigata, one of the pest ants with broad geographic distribution in South America. Results: The analysis of the expressed sequence tags allowed us to characterize 2,006 unique sequences in Atta laevigata. Sixteen of these genes had a high number of transcripts and are likely positively selected for high level of gene expression, being responsible for three basic biological functions: energy conservation through redox reactions in mitochondria; cytoskeleton and muscle structuring; regulation of gene expression and metabolism. Based on leafcutters lifestyle and reports of genes involved in key processes of other social insects, we identified 146 sequences potential targets for controlling pest leafcutters. The targets are responsible for antixenobiosis, development and longevity, immunity, resistance to pathogens, pheromone function, cell signaling, behavior, polysaccharide metabolism and arginine kynase activity. Conclusion: The generation and analysis of expressed sequence tags from Atta laevigata have provided important genetic basis for future studies on the biology of leaf-cutting ants and may contribute to the development of a more specific and environmentally friendly method for the control of agricultural pest leafcutters.

Peripheral giant cell granuloma. An immunohistochemical and ultrastructural study.

OBJECTIVE: To study the nature of multinucleated and mononuclear cells from peripheral giant cell granuloma (PGCG). MATERIALS AND METHODS: Formalin-fixed, paraffin-embedded sections of 40 cases of PGCG were immunohistochemically stained for vimentin, alpha I-antichymotrypsin, CD68, S-100 protein, lysozyme, leucocyte common antigen (LCA), factor VIII-related antigen and muscle cell actin. Six cases of PGCG were also studied by transmission electron microscopy. RESULTS: Vimentin, alpha I-antichymotrypsin and CD68 were expressed in both the mononuclear and multinucleated giant cells. Dendritic mononuclear cells, positive for S-100 protein, were noted in 67.5% of the lesions, whereas lysozyme and leucocyte common antigen were detected in occasional mononuclear cells. Ultrastructural examination showed mononuclear cells with signs of phagocytosis and sometimes interdigitations with similar cells. Others presented non-specific characteristics and the third type exhibited cytoplasmic processes and occasional Birbeck granules. Some multinucleated giant cells showed oval nuclei, abundant mitochondria and granular endoplasmic reticulum whereas others presented with irregular nuclei and a great number of cytoplasmic vacuoles. CONCLUSIONS: Immunohistochemical and ultrastructural results suggest that PGCGs of the jaws are composed mainly of cells of the mononuclear phagocyte system and that Langerhans cells are present in two thirds of the lesions.

Long-term toxicity following acute administration of nickel

Nickel compounds have high potential risk for the health of populations and for this reason their toxic effects should be urgently established. To determine the effect of nickel monosulfide in the muscle at the injection site on pancreatic, hepatic, and osteogenic lesions and the potential therapeutic effect of Cu-Zn superoxide dismutase (SOD), male Wistar rats received single intramuscular injections of nickel monosulfide (NiS - 7 mg Ni2+/Kg). A group of these experimental rats were injected intraperitoneally, with a single weekly dose of SOD covalently linked to polyethylene glycol (SOD-PEG). Rats were sacrificed at 2, 4, 6, and 8 months after Ni2+ injection. Nickel monosulfide produced tumors at the injection site. The increased phospholipid, alanine transaminase (ALT), alkaline phosphatase (ALP), and amylase levels in serum, in absence of SOD-PEG, reflected the toxic effects on pancreatic, hepatic, and osteogenic tissues of rats. SOD activity was increased in serum of rats receiving SOD-PEG throughout the experiment, and no significant difference was observed in biochemical parameters of control and experimental rats in presence of SOD- PEG. Superoxide radical generated by Ni2+ is of primary importance in the development of tumors at the injection site. Superoxide anion (O2 -) is also an important toxic intermediate with respect to hepatic, pancreatic, and osteogenic injury, since SOD-PEG has a potential therapeutic effect.

Immunohistochemical aspects of basal cell adenoma and canalicular adenoma of salivary glands

Basal cell adenoma is a benign epithelial neoplasm with a uniform histologic appearance dominated by basaloid cells. Those cells may be distributed in various arrangements as solid, trabecular, tubular and membranous. Canalicular adenoma is also a benign neoplasm composed by columnar cells arranged in branching and interconnecting cords of single or double cell thick rows. There is some disagreement among investigators about whether canalicular adenoma should be included within the basal cell adenoma histologic spectrum. In the present study we compared the expression of cytokeratins (CK), vimentin and muscle-specific actin, utilizing immunohistochemical technique, in three cases diagnosed as basal cell adenomas predominantly of the solid type, and three cases of canalicular adenomas. The results obtained showed a distinct immunoprofile for both neoplasms. Solid areas of basal cell adenomas did not stain for any of the tested antibodies; only when there was tubular differentiation, those structures expressed CKs 7, 8, 14, and 19 in luminal cells and vimentin in non-luminal cells. On the other hand, canalicular adenomas strongly expressed CKs 7 and 13. The panel of antibodies utilized supports the separation of the two entities. © 2001 Elsevier Science Ltd.