NtWBC1, an ABC transporter gene specifically expressed in tobacco reproductive organs

To identify genes specifically or predominantly expressed in the stigmas/styles and to establish their possible function in the reproductive process of plants, a tobacco stigma/style cDNA library was constructed and differentially screened, resulting in the isolation of several cDNA clones. The molecular characterization of one of these clones is described here. After sequencing the cDNA and the isolated genomic clone, it was determined that the corresponding gene encodes a protein containing an ATP-binding cassette, characteristic of ABC transporters. This gene, designated as NtWBC1 (Nicotiana tabacum ABC transporter of the White-Brown Complex subfamily), encodes a protein that contains the typical structure of the 'half-transporters' of the White subfamily. To establish the spatial expression pattern of the NtWBC1 gene, northern blot and real-time RT-PCR analyses with total RNA from roots, stems, leaves, sepals, petals, stamens, stigmas/styles, ovaries, and seeds were performed. The result revealed a transcript of 2.5 kb present at high levels in stigmas and styles and a smaller transcript (2.3 kb) present at a lower level in stamens. NtWBC1 expression is developmentally regulated in stigmas/styles, with mRNA accumulation increasing toward anthesis. In situ hybridization experiments demonstrated that NtWBC1 is expressed in the stigmatic secretory zone and in anthers, at the stomium region and at the vascular bundle. NtWBC1 is the first ABC transporter gene with specific expression in plant reproductive organs to be identified and its expression pattern suggests important role(s) in the reproductive process.

Calorimetry, Morphometry, Oxidative Stress, and Cardiac Metabolic Response to Growth Hormone Treatment in Obese and Aged Rats

This study investigated the effects of growth hormone therapy on energy expenditure, lipid profile, oxidative stress and cardiac energy metabolism in aging and obesity conditions. Life expectancy is increasing in world population and with it, the incidence of public health problems such as obesity and cardiac alterations. Because growth hormone (GH) concentration is referred to be decreased in aging conditions, a question must be addressed: what is the effect of GH on aging related adverse changes? To investigate the effects of GH on cardiac energy metabolism and its association with calorimetric parameters, lipid profile and oxidative stress in aged and obese rats, initially 32 male Wistar rats were divided into 2 groups (n = 16), C: given standard-chow and water; H: given hypercaloric-chow and receiving 30 % sucrose in its drinking water. After 45 days, both C and H groups were divided into 2 subgroups (n = 8), C + PL: standard-chow, water, and receiving saline subcutaneously; C + GH: standard-chow, water, and receiving 2 mg/kg/day rhGH subcutaneously; H + PL: hypercaloric-chow, 30 % sucrose, receiving saline subcutaneously; H + GH: hypercaloric-chow, 30 % sucrose, receiving rhGH subcutaneously. After 30 days, C + GH and H + PL rats had higher body mass index, Lee-index, body fat content, percent-adiposity, serum triacylglycerol, cardiac lipid-hydroperoxide, and triacylglycerol than C + PL. Energy-expenditure (RMR)/body weight, oxygen consumption and fat-oxidation were higher in H + GH than in H + PL. LDL-cholesterol was highest in H + GH rats, whereas cardiac pyruvate-dehydrogenase and phosphofrutokinase were higher in H + GH and H + PL rats than in C + PL. In conclusion, the present study brought new insights on aging and obesity, demonstrating for the first time that GH therapy was harmful in aged and obesity conditions, impairing calorimetric parameters and lipid profile. GH was disadvantageous in control old rats, having undesirable effects on triacylglycerol accumulation and cardiac oxidative stress.

Solid-state reactions of mercury with pure noble metals - Part 2. Mercury-iridium system

Thermogravimetry, cyclic voltammetry and other analytical techniques were used to study the reactions of mercury with pure iridium. The results allowed to suggest when subjected to heat or anodic stripping voltammetry an electrodeposited mercury film reacts with Ir substrate and at least three mass loss steps and three peaks appear in the mercury desorption process. The first two were attributed to Hg(0) species removal like a mercury bulk and a mercury monolayer. The last can be ascribed to the mercury removal from a solid solution with iridium.

5-HT1A, but not 5-HT2 and 5-HT7, receptors in the nucleus raphe magnus modulate hypoxia-induced hyperpnoea

Aim: In the present study, we assessed the role of 5-hydroxytryptamine (5-HT) receptors (5-HT1A, 5-HT2 and 5-HT7) in the nucleus raphe magnus (NRM) on the ventilatory and thermoregulatory responses to hypoxia.Methods: To this end, pulmonary ventilation (V-E) and body temperature (T-b) of male Wistar rats were measured in conscious rats, before and after a 0.1 mu L microinjection of WAY-100635 (5-HT1A receptor antagonist, 3 mu g 0.1 mu L-1, 56 mM), ketanserin (5-HT2 receptor antagonist, 2 mu g 0.1 mu L-1, 36 mM) and SB269970 (5-HT7 receptor antagonist, 4 mu g 0.1 mu L-1, 103 mM) into the NRM, followed by 60 min of severe hypoxia exposure (7% O-2).Results: Intra-NMR microinjection of vehicle (control rats) or 5-HT antagonists did not affect V-E or T-b during normoxic conditions. Exposure of rats to 7% O-2 evoked a typical hypoxia-induced anapyrexia after vehicle microinjections, which was not affected by microinjection of WAY-100635, SB269970 or ketanserin. The hypoxia-induced hyperpnoea was not affected by SB269970 and ketanserin intra-NMR. However, the treatment with WAY-100635 intra-NRM attenuated the hypoxia-induced hyperpnoea.Conclusion: These data suggest that 5-HT acting on 5-HT1A receptors in the NRM increases the hypoxic ventilatory response.

Obesity and Physical Activity in the Daily Life of Patients with COPD

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Apatite coatings onto titanium surfaces submitted to laser ablation with different energy densities

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Tensoes Residuais na Soldagem, Aspectos Basicos

The purpose of this paper is to analyze the basic aspects of the residual stresses in welding. Concepts about macro and micro residual stresses in metals are considered in welding. In a simple welding model is shown how shrinkage macro stress results and how this can contribute to understand the distribution of residual stresses in common type of welded joint. Further, comments are made concerning the effects of additional mechanical and metallurgical phenomena, distortion in weldments and dimensional discrepancies.

Glucose-induced insulin secretion is impaired and insulin-induced phosphorylation of the insulin receptor and insulin receptor substrate-1 are increased in protein-deficient rats

Malnutrition is related to diabetes in tropical countries. In experimental animals, protein deficiency may affect insulin secretion. However, the effect of malnutrition on insulin receptor phosphorylation and further intracellular signaling events is not known. Therefore, we decided to evaluate the rate of insulin secretion and the early molecular steps of insulin action in insulin-sensitive tissues of an animal model of protein deficiency. Pancreatic islets isolated from rats fed a standard (17%) or a low (6%) protein diet were studied for their secretory response to increasing concentrations of glucose in the culture medium. Basal as well as maximal rates of insulin secretion were significantly lower in the islets isolated from rats fed a low protein diet. Moreover, the dose-response curve to glucose was significantly shifted to the right in the islets from malnourished rats compared with islets from control rats. During an oral glucose tolerance test, there were significantly lower circulating concentrations of insulin in the serum of rats fed a low protein diet in spite of no difference in serum glucose concentration between the groups, suggesting an increased peripheral insulin sensitivity. Immunoblotting and immunoprecipitation were used to study the phosphorylation of the insulin receptor and the insulin receptor substrate-1 as well as the insulin receptor substrate-1-p85 subunit of phosphatidylinositol 3-kinase association in response to insulin. Values were greater in hind-limb muscle from rats fed a low protein diet compared with controls. No differences were detected in the total amount of protein corresponding to the insulin receptor or insulin receptor substrate-1 between muscle from rats fed the two diets. Therefore, we conclude that a decreased glucose-induced insulin secretion in pancreatic islets from protein-malnourished rats is responsible, at least in part, for an increased phosphorylation of the insulin receptor, insulin receptor substrate-1 and its association with phosphatidylinositol 3-kinase. These might represent some of the factors influencing the equilibrium in glucose concentrations observed in animal models of malnutrition and undernourished subjects.

Batch and filter approaches to spacecraft sensor alignment estimation

Two Kalman-filter formulations are presented for the estimation of spacecraft sensor misalignments from inflight data. In the first the sensor misalignments are part of the filter state variable; in the second the state vector contains only dynamical variables, but the sensitivities of the filter innovations to the misalignments are calculated within the Kalman filter. This procedure permits the misalignments to be estimated in batch mode as well as a much smaller dimension for the Kalman filter state vector. This results not only in a significantly smaller computational burden but also in a smaller sensitivity of the misalignment estimates to outliers in the data. Numerical simulations of the filter performance are presented.

Efeitos da Seleção para Peso Pós-desmame sobre Medidas Corporais e Perímetro Escrotal de Machos Nelore de Sertãozinho (SP)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Hemoglobinas anormais e dificuldade diagnóstica

The human hemoglobins, with genetically defined inheritance patterns, have shown characteristic polymorphic variation within the Brazilian population, depending on the racial groups of each region. They have appeared under the form of hemoglobin variants or thalassemias, the variant types S and C and the alpha and beta thalassemias being more common, all of them in heterozygote form. During the year of 1999, blood samples from 506 individuals, with suspected anemia or that had already passed through hemoglobinopathies screening, were sent to the Hemoglobin Reference Center - UNESP for diagnostic confirmation and submitted to electrophoresis proceedings, biochemical and cytological analyses in order to characterize the type of abnormal hemoglobins. The goal of the present study was to verify which abnormal hemoglobin types show greater diagnostic difficulty. The samples came from 24 cities in twelve states. The results showed that 354 (69.96%) individuals presented abnormal hemoglobins, 30 (5.93%) being Hb AS, 5 (0.98%) being Hb AC, 76 (15.02%) suggestive of heterozygote alpha thalassemia, 134 (26.48%) suggestive of heterozygote beta thalassemia and 109 (21.54%) with other forms of abnormal hemoglobin, including rare variants and different forms of thalassemias and variant hemoglobin interactions. It has been concluded that, despite the improved techniques currently available and a constant influx of capacitated personnel, the heterozygote form of thalassemias (210 individuals -41.50%) is challenging to diagnose, followed in difficulty by rare variant characterization and interactive forms of hemoglobinopathies (109 individuals-21,54%), suggesting that the capacity for production of qualified professionals and information about these genetic changes in our population should be increased.

Enzymatic activity of hypopharyngeal gland extracts from workers of Apis mellifera (Hymenoptera, Apidae, Apinae)

This research presents a comparative study of enzymatic activity of the hypopharyngeal gland extracts from workers of Apis mellifera in three physiologic stages: newly emerged, nurse and forager workers, with the objective of contributing to the comprehension of the gland function. In order to determinate the enzymes present in the extracts, the Api Zym kit (Bio Mérieux) was used to test the activity of 19 different enzymes. The enzymes found in larger amounts only in the hypopharyngeal glands from certain individuals were the following: in newly emerged workers, the N-acetyl-down double arrow sign-glucosaminidase that may be digesting the chitin of some food ingested by the bee; in forager workers, the acid phosphatase that is likely acting in authophagic processes, the a-glucosidase, in the processing of nectar into honey, and the down double arrow sign-glucosidases, in the pollen digestion.

Electromyographic validation of the trapezius and serratus anterior muscles in rowing exercises with middle grip

Because the lack of textbooks based on electromyographic studies in the area of exercises for physical conditioning, the authors proposed to study the trapezius (upper portion) (TS) and the serratus anterior (lower portion) (SI) muscles during the execution of four different modalities of rowing exercises with middle grip in 24 male volunteers, 18 to 25 years old. For the recordings, it was used a two-channel TECA TE 4 electromyograph and Hewlett Packard surface electrodes. For the movements, a supine bench and a 120 cm-long bar made of low weight wood were used. The results showed that TS acted significantly in upright, sitting and inclined rowing, justifying its inclusion in physical conditioning programmes, while SI, in spite of acting preferentially in upright and sitting rowing, presented activity levels which do not justify its inclusion.

Integrability and conformal symmetry in higher dimensions: A model with exact hopfion solutions

We use ideas on integrability in higher dimensions to define Lorentz invariant field theories with an infinite number of local conserved currents. The models considered have a two-dimensional target space. Requiring the existence of lagrangean and the stability of static solutions singles out a class of models which have an additional conformal symmetry. That is used to explain the existence of an ansatz leading to solutions with non-trivial Hopf charges. © SISSA/ISAS 2002.