Down-regulation of the cardiac sarcoplasmic reticulum ryanodine channel in severely food-restricted rats

We have shown that myocardial dysfunction induced by food restriction is related to calcium handling. Although cardiac function is depressed in food-restricted animals, there is limited information about the molecular mechanisms that lead to this abnormality. The present study evaluated the effects of food restriction on calcium cycling, focusing on sarcoplasmic Ca2+-ATPase (SERCA2), phospholamban (PLB), and ryanodine channel (RYR2) mRNA expressions in rat myocardium. Male Wistar-Kyoto rats, 60 days old, were submitted to ad libitum feeding (control rats) or 50% diet restriction for 90 days. The levels of left ventricle SERCA2, PLB, and RYR2 were measured using semi-quantitative RT-PCR. Body and ventricular weights were reduced in 50% food-restricted animals. RYR2 mRNA was significantly decreased in the left ventricle of the food-restricted group (control = 5.92 +/- 0.48 vs food-restricted group = 4.84 +/- 0.33, P < 0.01). The levels of SERCA2 and PLB mRNA were similar between groups (control = 8.38 +/- 0.44 vs food-restricted group = 7.96 +/- 0.45, and control = 1.52 +/- 0.06 vs food-restricted group = 1.53 +/- 0.10, respectively). Down-regulation of RYR2 mRNA expressions suggests that chronic food restriction promotes abnormalities in sarcoplasmic reticulum Ca2+ release.

O exercício físico potencializa ou compromete o crescimento longitudinal de crianças e adolescentes? Mito ou verdade?

A sociedade atual tem valorizado de forma significativa a aparência alta e esbelta. Essa constituição física tem sido reforçada desde a infância e atinge a população adolescente, que deseja enquadrar-se nos estereótipos, particularmente aqueles veiculados pela mídia. Nesse sentido, profissionais de saúde são questionados rotineiramente sobre os efeitos positivos que o exercício físico exerce sobre o crescimento longitudinal de crianças e adolescentes. Procurou-se revisar a literatura especializada a respeito dos principais efeitos que o exercício físico exerceria sobre a secreção e atuação do hormônio de crescimento (GH) nos diversos tecidos corporais, durante a infância e adolescência. Através dessa revisão, foi possível verificar que o exercício físico induz a estimulação do eixo GH/IGF-1. Embora muito se especule quanto ao crescimento ósseo ser potencializado pela prática de exercícios físicos, não foram encontrados na literatura científica específica estudos bem desenvolvidos que forneçam sustentação a essa afirmação. No tocante aos efeitos adversos advindos do treinamento físico durante a infância e adolescência, aparentemente, esses foram independentes do tipo de esporte praticado, porém resultantes da intensidade do treinamento. A alta intensidade do treinamento parece ocasionar uma modulação metabólica importante, com a elevação de marcadores inflamatórios e a supressão do eixo GH/IGF-1. Entretanto, é importante ressaltar que a própria seleção esportiva, em algumas modalidades, recruta crianças e/ou adolescentes com perfis de menor estatura, como estratégia para obtenção de melhores resultados, em função da facilidade mecânica dos movimentos. Através dessa revisão, fica evidente a necessidade de realização de estudos longitudinais, nos quais os sujeitos sejam acompanhados antes, durante e após sua inserção nas atividades esportivas, com determinação do volume e da intensidade dos treinamentos, para que conclusões definitivas relativas aos efeitos sobre a estatura final possam ser emanadas.

Effect of maternal hydration on the increase of amniotic fluid index

The objective of this study was to determine the effect of maternal hydration with oral isotonic solution and water on the amniotic fluid (AF) index of women with normohydramnios. Women with a normal AF index and gestational age between 33 and 36 weeks without maternal complications were randomized into three groups [isotonic solution (Gatorade (R)), water, control]. The isotonic solution and water groups were instructed to drink 1.5 L of the respective solution and the control group was instructed to drink 200 mL water over a period of 2 to 4 h. AF index was measured before and after hydration by Doppler ultrasonography. The investigator performing the AF index measurement was blind to the subject's group. Ninety-nine women completed the study without any adverse maternal effects. The median increase in AF index after hydration was significantly greater for the isotonic solution and water groups than for the control group. There was no significant difference between the isotonic solution and water groups. Hydration with isotonic solution and water caused a 10-fold (95% CI: 2.09-49.89) and 6-fold (95% CI: 1.16-30.95) increase in the chance of a 20% increase of AF index, respectively. Maternal hydration with isotonic solution or water increased the AF index in women with normohydramnios.

Effect of obesity on rat reproduction and on the development of their adult offspring

The aim of the present study was to assess the reproductive parameters of obese Wistar rats and to determine the frequency of their obese adult offspring. Neonatal rats were divided into two groups: F-1 generation, induced to obesity by monosodium glutamate (MSG; F(1)MSG, N = 30), and rats given saline (F1CON, N = 13). At 90 days of age all animals were mated, producing the F-2 offspring (F2CON, N = 28; F(2)MSG, N = 15). Reproductive parameters (fertility, pregnancy, and delivery indexes) were evaluated in F-1 rats. F-2 newborns were weighed, and the obesity parameter for F-1 and F-2 generations was determined from months 5 to 7 of life. At month 7, periovarian fat was weighed and no differences were found. Mean newborn weight also did not differ. The F-1 and F(2)MSG groups presented approximately 90% of obese rats since month 5 of life, whereas F-1 and F2CON groups presented only 33%. There was no difference in periovarian weight among groups. Although obesity did not affect reproductive parameters, obese dams (F(1)MSG) were responsible for the appearance of obesity in the subsequent generation. Thus, obesity induced by neonatal MSG administration did not interfere with reproduction, but did provide a viable model for obesity in second-generation adult Wistar rats. This model might contribute to a better understanding of the pathophysiological mechanisms involved in transgenerational obesity.

Relationship of IL-1 and TNF-alpha polymorphisms with Helicobacter pylori in gastric diseases in a Brazilian population

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

Follicular Development in Ewes During Natural and Prostaglandins Induced Estrous Cycle

The follicular development was evaluated in ovine females during natural and prostaglandin-F(2 alpha) (PG) induced estrous cycle. Ewes were randomly divided in two treatments (n=7/treatment): T1 with natural cycle and T2 synchronized with two injections of PG. From one day before PG injection until next ovulation, daily transrectal ultrasonography was done. All follicles >= 2 mm were assessed. During the interovulatory intervals, follicular growth and regression occurred in a wave like pattern (2-3 waves). The maximum diameter of the largest follicle of the first wave was greater in T1 (5.83 +/- 0.31 mm) compared with T2 (5.0 +/- 0.1 mm; P<0.01), but there was no significant difference among the emergency day of largest follicle, during the growth phase of the follicular waves. The duration of the plateau phase in wave 2 differed between the two treatments (P<0.05) showing 0.83 +/- 0.31 and 1.83 +/- 0.17 d, for natural and synchronized treatment, respectively. Growth rate did not differ between treatments. Presence of new luteal tissue was detected on day 3 after ovulation. In conclusion, the follicular development was similar in female ovine during natural and PG induced estrous cycle.

Genetic diversity in Egeria densa and E. najas in Jupia Reservoir, Brazil

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

Permian bivalves of the Taciba Formation, Itarare group, Parana basin, and their biostratigraphic significance

A small and poorly diversified bivalve fauna from Taciba Formation, Itarare Group, Parana Basin (State of Santa Catarina, Mafra Municipality), is described in this paper for the first time, based on new findings. The fauna is recorded in a 30 cm thick interval of fine sandstone locally at the top of Taciba Formation, in the Butia quarry. The studied fossil-bearing sand-stone bed is a marine intercalation recording a brief eustatic rise in sea-level, probably following glacier retreat and climate amelioration at the end of a broad glacial scenario. The fauna is mainly dominated by productid brachiopods, which are not described here, and rare mollusk shells (bivalves and gastropods). Two bivalve species were identified: Myonia argentinensis (Harrington, 1955), and Aviculopecten multiscalptus (Thomas, 1928). The presence of Myonia argentinensis is note-worthy since this species is also present in the Baitaca assemblage found in marine siltstones (Baitaca assemblage) of the Rio do Sul Formation, cropping out at the Teixeira Soares region, Parana State. This species is also recorded in the bivalve fauna from the Bonete Formation, Pillahinco Group, Sauce Grande Basin, Buenos Aires Province, in Argentina. Hence, the marine bivalves of the Taciba Formation are associated with the transgressive event that characterizes the Eurydesma fauna, indicating a Late Asselian-Sakmarian age for the bivalve fauna. Presence of the Myonia argentinensis megadesmid species reinforces the Gondwanic nature of the studied fauna.

Viés Analítico em Estudos Tafonômicos com Macroinvertebrados: Implicações (Paleo)Ambientais e (Paleo)Ecológicas

A review of recent literature shows that most taphonomic studies of Holocene and fossil macrovertebrates are not methodologically standardized. Hence, results from distinct studies are not comparable, even among researches sharing virtually identical goals, targeting the same biological group of similar age and depositional environment. The effects of the shell size in the taphonomic analysis are still poorly understood. In order to study this issue, the taphonomic signatures (articulation, valve type, fragmentation, abrasion, corrosion, edge modification, color alteration, bioerosion and encrustation) of brachiopod shells (Bouchardia rosea (Mawe)), from Ubatuba Bay in the northern coast of São Paulo State, were investigated according to the sieve sizes. In the study area, 14 collecting stations were sampled via Van Veen grab sampler, along a bathymetric gradient, ranging from 0 to 35 m of depth. Bulk samples were sieved through 8 mm, 6 mm, and 2 mm mesh sizes, yielding a total of 5.204 shells. The results indicate that, when taphonomic signatures were independently analyzed per size classes (8 mm, 6 mm, and 2 mm), the taphonomic signatures are recorded in a complex and random way. Additionally, cluster analysis showed that the similarity among the clusters vary according to the considered sieve size. Thus, the sieve size plays an important role in the distribution of taphonomic signatures in shells of distinct sizes. These results suggest that the concentration of the taphonomic analysis on one class (e.g., the largest sieve size, 8 mm) is not always the best method. Rather, the total data (all sieves included) seems more accurate in recording the whole spectrum of taphonomic processes recorded in shells of a given assemblage.

Tafonomia de tempestitos conchíferos amalgamados da formação Teresina em Rio Preto (Estado do Paraná, permiano médio, bacia do Paraná) e suas implicações paleoambientais

The deposits of the Permian Teresina Formation are mainly characterized by fi ne-grained siliciclastic rocks and centimetric intercalations of tempestites (bioclastic sandstones and coquinas). Despite the relevance of the bivalve-rich carbonate beds of the Teresina Formation to paleoenvironmental studies, their taphonomy is still poorly studied. The fossil concentration studied in this work was found in a quarry in the city of Irati, Rio Preto district, Parana State. The fossil concentration is located in the middle/upper portion of the unit, far from the top. The studied bed is a bioclastic, intraclastic, peloidal, grainstone/ packstone, with abundant bivalve shell fragments, pelitic and micritic intraclasts, peloids, rare ooids and oncoids, as well as permineralized of Lycophyta microphylles and fish scales. The grains of this carbonate concentration show: high degree of time-averaging, variable degree of packing (dense to disperse), no sorting and chaotic orientation. Notably, the concentration includes a mixture of elements which are indicative of: a) restrictive, low energy, carbonate environment (peloids, ooids and oncoids); b) subaerial environment surrounding the main body of water (Lycophyta microphylles) and c) quiet-water environment punctuated by storm events, where the suspension-feeding bivalves thrived. At least four depositional events caused by storm fl ows were recorded. The amalgamated nature of the bed is a result of storm events in an intracratonic basin with very low seafl oor slope and low rates of sedimentation and subsidence.

Tafonomia de biválvios em calcários oolíticos da formação Teresina (Bacia do Paraná, Permiano Médio, Prudentópolis, PR)

Herein, it is presented the first detailed taphonomic study on bivalve mollusk shells preserved in the oolitic limestones of the Teresina Formation (probably Kungurian-Roadian, Lower-Middle Permian) in the eastern margin of the Parana basin. The selected beds are located in two quarries (informally named PRU 1 and PRU 2) in Prudentopolis municipality (Center-South Parana State), and positioned approximately in the middle of the formation and probably in the Pinzonella illusa Zone. The PRU 1 limestone ([approximately]30 cm thick), which is partially silicified and intercalated with predominantly pelitic rocks, is classified as a bivalve oolitic grainstone. The basal contact is erosive and the top shows symmetrical ripple marks, which are draped by shale with mud cracks. There are two fining-upwards successions characterized by dense to dispersed packing of the shells, which are usually disarticulated, randomly oriented (many nested/stacked) and mixed with some Formapelitic intraclasts. Microhummocky cross-stratification occurs a little below the top of the bed. The PRU2 bed is classified as ooidbivalve rudstone[approximately] (~5 cm thick), where all shells are disarticulated and fragmented, showing dense packing. The bivalves probably inhabited a muddy substrate and were mixed (as parautochtonous and allochthonous bioclasts) with ooids during high-energy storm events, including posterior shell displacement as a result of bioturbation. Thus, the calcareous beds represent amalgamated proximal tempestites with a complex taphonomic history, strong temporal/spatial mixing of bioclasts and limited paleoecological resolution. They are a typical example of shell beds generated in a huge epeiric sea, which was not necessarily connected to the ocean and where very low depositional-slope gradient, very slow subsidence and minimum sediment accommodation space caused frequent sediment reworking by storm related processes.

Semiótica peirceana e produção poética

Entre as diversas semióticas e semiologias atualmente existentes, devem-se distinguir dois projetos gerais: o de origem saussureana e o de origem peirceana. O primeiro recolhe da ciência lingüística seu modo de proceder e as características gerais do signo. O segundo pertence à tradição crítica filosófica. Para a inteligência capaz de aprender com a experiência, a dimensão temporal e histórica é essencial. O signo peirceano implica as relações de um tempo irreversível. À produção presente do signo cabe a função poética, a qual é essencial à vida de toda inteligência. A hipótese cientifica, as revoluções sociais em seu momento originário e a produção artística produzem novos signos, recortam novos objetos e abrem feixes de possibilidades para a conduta futura.